A.T.E.T. Azienda Torinese Elettronica Telecomunicazioni S.r.l.

Transcription

1 ETELM 9, avenue des Deux Lacs P.A de Villejust Courtaboeuf cedex Tel : Fax : Web site : RC : Evry TETRA SYSTEM DESCRIPTION TETRA SYSTEM DESCRIPTION 1/97

2 TABLE OF CONTENT 1. GENERAL OVERVIEW PURPOSE GLOSSARY NETWORK ARCHITECTURE OVERVIEW LINK ARCHITECTURE Link based up on E1 G Link based on IP EXPANSION CAPABILITY TETRA RADIO EQUIPMENT TETRA IP@NODE Overview Base Station Interface Network Management Console Interface Dispatching System Interface PABX/ PSTN Interface TBS11 TETRA BASE STATION Overview Tetra Features Equipment Modules Site Configurations System Parameters Fall back Mode Technical Specifications FREQUENCIES AND COMBINERS Cavity combiner Hybrid combiner Antennas and diversity GPS synchronisation TSC10 NETWORK MANAGEMENT TERMINAL Overview Configuration of Technical Parameters Administrative Database DISPATCHER STATION AUTOMATIC VEHICLE LOCATION (AVL) IP RECORDER SERVER AUDIO MAILBOX GATEWAY ANALOG GATEWAY FLIGHT MANAGEMENT TERMINAL SERVER GATEWAY TETRA IP ROUTER SYSTEM FEATURES MULTI ORGANISATION TETRA SYSTEM DESCRIPTION 2/97

3 4.1.1 General organisation Numbering plan Routing Plan for radio terminals Routing Plan for Telephone Groups Short Numbering Assignment SPEECH SERVICES Individual call establishment Group call establishment SUPPLEMENTARY SERVICES Broadcast Communication Over The LAN Group Communication Types Talking Party Identification Discreet Listening Conference Call Between Dispatcher Push to Talk (PTT) Management - Priority Hand over during Group Communication Individual communication release Group communication release Data Transmission during Communication Call Forwarding Baring of Calls Ambience Listening Call Completion Call Queuing Management DATA TRANSMISSION Circuit mode data call Predefined message (Status) and SDS IP Packet Data Transfer SECURITY AND ENCRYPTION Overview Security Classes Authentication Class 2 Ciphering Class 3 Ciphering End to End Encryption INTER SYSTEM INTERFACE SERVICES (ISI) LIST OF TETRA SERVICES NETWORK MANAGEMENT FEATURES REAL TIME MONITORING & SUPERVISION Frequency disturbance monitoring SNMP SYSTEM MANAGEMENT DATA BASE & USER S MANAGEMENT Mobiles data base Groups database EVENTS & LOG FILES MANAGEMENT Statistics / billing EXTERNAL SYSTEM INTERFACE TETRA SYSTEM DESCRIPTION 3/97

4 6. INTEROPERABILITY TESTS TETRA INTEROPERABILITY WITH ETELM INFRASTRUCTURE STANDARD CABINET CONFIGURATION TETRA SYSTEM DESCRIPTION 4/97

5 TABLE OF FIGURES Figure 2-1 : Multi IP@node TETRA radio network configuration Figure 2-2 : Sub network IP meshed architecture Figure 2-3 : Sub network using star architecture Figure 2-4 : Redundancy Failure scenarios at sub network level Figure 2-5 : Multi IP@node with dynamic RBS attachment Figure 2-6 : Multi IP@node configuration independent networks Figure 2-7 : Ring & Star architecture Figure 2-8 : Typical communication scheme for TETRA Figure 3-1 : ETELM IP@node Figure 3-2 : TETRA Base Station Figure 3-3 : Block diagram Cavity Combiner Figure 3-4 : Block diagram Hybrid Combiner Figure 3-5 : Network Management Terminal Figure 3-6 : Dispatcher WorkStation Figure 3-7 : Block Diagram Dispatcher station Figure 3-8 : AVL WorkStation Figure 3-9 : IP Recorder server Figure 3-10 : Audio Mail Box Gateway Figure 3-11 : Analog Gateway Figure 3-12 : Flight Management console Figure 3-13 : server device Figure 3-14 : Front panel IP Router Figure 3-15 : Back panel IP Router Figure 4-1 : TETRA Networks and sub networks numbering plan Figure 4-2 : Numbering Plan Editor Figure 4-3 : Numbering Plan Status Figure 4-4 : IP Packet Data - Functional Schematic Figure 4-5 : Transparent IP connection for embedded application Figure 4-6 : TETRA Networks with visitor subscribers Figure 5-1 : Hierarchical view of radio network components Figure 5-2 : Link configuration Network Management Terminal Figure 5-3 : Base Station parameters Network Management Terminal Figure 5-4 : Call Data Records Events Log Figure 5-5 : Network Traffic Load graphical reports per hour Figure 5-6 : Radio site Traffic Load graphical reports per Day Figure 7-1 : 4 Tetra carriers cabinets with IP@node Figure 7-2 : 2 Tetra carriers cabinets with Backup power supply TETRA SYSTEM DESCRIPTION 5/97

6 1. GENERAL OVERVIEW TETRA SYSTEM DESCRIPTION 6/97

7 1.1 PURPOSE The aim of this document is to describe the main system features proposed by the Digital Trunking Radio Network manufactured by ETELM in compliance with the TETRA standard defined by the ETSI organisation. ETELM is also a member of the TETRAMoU organisation in charge of assuring the Interoperability between TETRA infrastructure equipment and terminals proposed by several different manufacturers. ETELM is a French company well known on the TETRA market for its capability to supply digital radio network systems using multi vendor terminal manufacturer according to the user requirements and to field constraints. ETELM is an independent company which is not manufacturing terminal. ETELM has the capability to propose the most efficient technology according to the customer constraints. Most part of the TETRA radio network supplied by ETELM are using different terminal manufacturer like AIR FRANCE, SNCF, TOTAL. For those customers, it is essential to mix terminal manufacturer according to the huge quantity of terminals used on the same radio network and diversity of user constraints even in real difficult environment. More than 52 customer networks up and running, from the single site configuration to the multi site configuration, ETELM manufactures several product family which are fully compatible. The compatibility assures to implement a TETRA radio network from a single site configuration to a multisite configuration by addition of components. ETELM infrastructure ensures also interoperability of terminal operating simultaneously on the same network with main terminal manufacturer. TETRA SYSTEM DESCRIPTION 7/97

8 1.2 GLOSSARY AI AIE AKD AKMT API ASCCH AVL CA CB C2 CDR CLIP CLIR DGNA DHCP DMO DMR DNS E2EE EMI ETSI FSSN FTP GPRS GPS GSM GTSI GUI IP IPSec ISDN ISI ISP IT ITSI ITU-T K LAN LAPD LLC LNA MCCH Description Air Interface Air interface encryption Authentication and Key Distribution system Authentication Key Management Tool Application Programming Interface Assigned Secondary Control Channel Automatic Vehicle Location Certification Authority Combiner Command and Control Call Data Record Calling Line Identification Presentation Calling Line Identification Restriction Dynamic Group Number Assignment Dynamic Host Configuration Protocol Direct Mode Operation Digital microwave radio unit Domain Name System End-To-End Encryption Electromagnetic Interference European Telecommunications Standards Institute Fleet Specific Short Number File Transfer Protocol General Packet Radio Service Global Positioning System Global System for Mobile Communications Group TETRA Subscriber Identity Graphical User Interface Internet Protocol Internet Security Protocols Integrated Services Digital Network Inter System Interface Internet Service Provider Information Technology Individual TETRA Subscriber Identity G.703/G.704-compliant line) Radio terminal authentication key Local Area Network Link access procedure on the D-channel Logical link control Low-noise amplifier Main Control Channel TETRA SYSTEM DESCRIPTION 8/97

9 MGT MMI MS NMT NMEA OSI PABX PC PCI PDCH PDCU PDP PDU PIN PMR PSTN PTT QoS RAM RF RTC RX SDS SDS-TL SwMI TRBS TCH TCP/IP TDMA TETRA TX VLAN VLR VPN WAN WAP Management Man Machine Interface Mobile Station Network Management Terminal National Marine Electronics Association Open Systems Interconnect Private Automatic Branch Exchange Personal Computer Peripheral Component Interface Packet Data Channel Packet Data Communications Unit Packet Data Protocol Packet Data Unit Personal Identity Number Professional Mobile Radio Public Switched Telephone Network Push-to-talk Quality of Service Random Access Memory Radio Frequency Real-Time Clock Receiver Status and short data message SDS Transport Layer Switching and Management Infrastructure TETRA Radio Base Station Traffic Channel Transmission Control Protocol/Internet Protocol Time-division Multiple Access TErestrial Trunked RAdio Transmitter Virtual LAN Visitor Location Register Virtual Private Network Wide Area Network Wireless Access Protocol TETRA SYSTEM DESCRIPTION 9/97

10 2. NETWORK ARCHITECTURE TETRA SYSTEM DESCRIPTION 10/97

11 2.1 Overview The network architecture of the TETRA radio network proposed by ETELM is based upon configurations interconnected to a Wide Area Network using IP standard protocols. The multi IP@node configuration provides the most efficient architecture in terms of performances, robustness against multiple failures on the transmission network, easy integration within an existing IT networks and capability to interface external software applications to the radio network, quality of service and availability of the radio network required for professional mobile radio users. IP@node manages a radio sub network as if it is an independent radio network with the capability to be interconnected to another IP@node for permitting inter-networks communications. Each sub networks can be configured to operate as a local radio network and all traffic are managed through the local IP@node. This architecture optimises the dataflow required for local communication area and improves inter-networking communications between IP@nodes. This configuration also authorises the usage of several radio sub networks dedicated to specific organisation and upon demand organisation can share a part or their overall network. Figure 2-1 : Multi IP@node TETRA radio network configuration TETRA SYSTEM DESCRIPTION 11/97

12 Figure 2-2 : Sub network IP meshed architecture The sub-network configuration can be composed of direct IP Ethernet connection from the base station or from the IP@node so as to integrate a TETRA radio network within an existing IP backbone. In that case, each component requires an access to the IP network in order to communicate with other infrastructure equipment. Operator s consoles like dispatcher, NMT or AVL can operate directly through the existing Local Area Network and communicate with Ip@nodes (dual redundancy capability) and PABX/PSTN gateways connected to telephone lines. The main interface with external IP backbone is based upon a router device. Furthermore, the ETELM infrastructure is also able to support standard star architecture configuration using E1 links, V11 or V35 wherever existing transmission networks using multiplexers / demultiplexer devices will be used for integration of the TETRA radio network.. TETRA SYSTEM DESCRIPTION 12/97

13 Figure 2-3 : Sub network using star architecture The resilience of the radio network is dependent upon the sub network architecture (star, ring or meshed) and also upon the capability of the system to provide the service after multiple random failures occurring at different level of the network. The diagram attached below describes the different levels of failures. Green links shows parts of the system in operation Red links shows parts of the system not in operation TETRA SYSTEM DESCRIPTION 13/97

14 Figure 2-4 : Redundancy Failure scenarios at sub network level The network architecture is fully transparent for terminal users. Terminal users can be authorised, by the network administrator, to migrate to another sub network or several others sub networks. A full redundancy of the equipment can be proposed to secure sub networks with mechanisms of dynamic attachment for radio base stations to other sub networks in case of disconnection with the preferred IP@node equipment. TETRA SYSTEM DESCRIPTION 14/97

15 Radio site Radio site Radio site Radio site Radio site Radio site IP network link IP network / NMS / NMS Figure 2-5 : Multi IP@node with dynamic RBS attachment This architecture offers following advantages: Geographic security: in case of a disaster in an area, others area are not affected: there are no common central equipments (SW, data base,...) for the whole network that is there are no sensitive location where a destruction may affect the whole network. Functional security: each sub network can be equipped with a full duplicated IP@node. P@node duplication is independent from one sub network to the other. Extension capacity: the capacity of each sub network is larger than required and each sub network may be easily extended. In another hand, one may add others sub networks. TETRA SYSTEM DESCRIPTION 15/97

16 Radio site Radio site Radio site Radio site Radio site Radio site IP network Link failure IP network SW / NMS SW / NMS Figure 2-6 : Multi IP@node configuration independent networks Each sub network can be completely independent from the other one and reliability is assured thanks to the stand alone mode with full features provided for each sub networks. 2.2 Link Architecture Link based up on E1 G703 Several types of link architecture can be supported by the TETRA network like the star architecture or ring architecture which is mainly based upon E1 G703, V11 or V35 links available from the transmission network equipment (microwaves). Figure 2-7 : Ring & Star architecture TETRA SYSTEM DESCRIPTION 16/97

17 The ETELM solution is perfectly adapted to be interfaced to those types of networks by optimising the data bandwidth required for each radio site and providing the synchronisation service directly through the E1 protocol. G703 2Mbit/s interfaces support the implementation of the internal drop and insert multiplex service to fit with the exact number of slots required for each radio site connected to equipment. As example, a G703 link is configured to operate with a single slot from the 30 slots available on a 2 Mbit/s links. The band width required is only 64 Kbit/s per base station (frequency carrier) Link based on IP Depending on the transmission network architecture or existing telecommunication networks to be used, the links of the TETRA system proposed by ETELM can support direct LAN connections through the IP protocols. In that case, mainly two protocols are used: TCP/IP for signalling transmissions UDP for audio transmission TETRA radio communication networks design is not similar to the well known GSM networks. Indeed, a TETRA network must handle a lot of multipoint communications, while GSM communication scheme is only point to point. Typically, in a Professional Mobile Radio communications (PMR) most part of the communication are group calls in comparison with individual calls mainly used when interconnection with an external system shall be realised like PSTN access. Furthermore, even in case of individual calls, any communication must be monitored by third parties like dispatcher consoles and/or recorded by a specific equipment device. Typical communications involve simultaneously several radio sites, several dispatchers and at least a recorder. The main objective on a TETRA network is to establish communications as fast as possible and to optimise the audio path by reducing the number of radio resources involve within the call. TETRA SYSTEM DESCRIPTION 17/97

18 Dispatcher 1 Monitoring the communication Dispatcher 2 Monitoring the communication Network Radio site 1 Radio site 2 Group of hand portables Communication recorder Figure 2-8 : Typical communication scheme for TETRA If the audio is carried by point to point messages, the IP traffic drastically increases and data bandwidth required at the IP backbone level also increase. In order to prevent it, the data packets including audio are broadcasted inside a sub network. Each component of the TETRA system having been previously authenticated may listen to a communication by selecting the right communication number. Any other components which are not authorised by the system and are connected to this sub network can not get access to the audio message. Communication numbers are managed by the system and all on going communication signalling is also broadcasted. Such broadcasted method is very efficient; it uses UDP messages with restricted domain. The implementation of TETRA IP Router within the IP backbone ensure the full broadcast management of the audio and permit optimisation of data bandwidth required at node levels. 2.3 Expansion Capability Each sub-network may be easily extended to increase traffic capacity and also the radio coverage. By addition of TETRA radio base station to the sub network, the global communication network can be expanded. Base stations may be added anywhere on the LAN or WAN and also base station equipment may be added on a radio site, without any change to existing equipments. Each sub-network may handle up to 128 TETRA carriers. TETRA SYSTEM DESCRIPTION 18/97

19 3. TETRA RADIO EQUIPMENT TETRA SYSTEM DESCRIPTION 19/97

20 3.1 TETRA Overview Figure 3-1 : ETELM IP@node The TETRA IP@node is a full IP product being capability to interface many types of equipment for the TETRA infrastructure and also any external networks. The IP@node allows a flexible and a resilient architecture specially designed to fit with the customer constraints applying to a professional mobile radio network. Using an IP grape philosophy for radio sites and a direct IP Ethernet connection from the base station to the IP@node, the digital TETRA radio network proposed by ETELM is the most convenient for assuring communications in any situations. Those grapes can be interconnected to any type of network like star architecture, rings or meshed IP networks. The multi IP@node facility ensure highest performances for communications, robustness against failures and adaptability to customer existing networks. The multi IP@node architecture ensures reliability of the radio network because there is no single point of failure. Upon failure detection of an IP@node, base stations are automatically reconnected to the most appropriate neighbour IP@node equipment. Each IP@node can ensure redundancy for the neighbour equipment. The TETRA IP@node is responsible for all the Level 3 and higher tasks of the ETSI TETRA standard which includes communications management and mobility management. The TETRA SYSTEM DESCRIPTION 20/97

21 operation of an can be monitored via the Network Administration Console, and it can be accessible to external application by the dispatching network via TCP/IP. The is a modular chassis which can be easily integrated within a standard 19 inches cabinet and composed of dedicated boards for each interfaces. Any expansion requirements are easily fulfilled by addition of another chassis.this component of the network contains a part of the intelligence of the system which is also shared with CPU units integrated within each base station at the radio site level. The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment Base Station Interface Several types of Base station interfaces are available like IP Ethernet 100Mbit/s port or G703, V11 or V35 depending on field configuration, bandwidth and transmission network. Ethernet port interfaces can be plugged directly to Ethernet Switch equipment or any Commercial on the Shelf (COTS) router devices. The data bandwidth offered is 10 or 100 Mbit/s. Other Interface are either G703 or V11 or V35 In case of using standard 2Mb/s G703 access, a base station uses one standard time slot of the link. Internal drop and insert multiplex integrated in any base station offers the possibility to connect radio sites in a daisy chain way on the same 2Mb/s link. (the physical architecture is a daisy chain but the functional architecture remains a star one). As soon as a base station is connected to its own IP@node, configuration parameters are automatically transmitted including carrier frequencies, power settings and access mode. Base stations needs to be accurately synchronised, mainly for mobile roaming performances. This synchronisation is achieved (low and high level) either through the G703 2Mb/s links, without additional equipments, or with GPS, by adding external antenna at each radio site location. Audio Signalling& Data Transmission Data to be broadcasted to all subscriber radios within local site covered by each base station Subscriber radio s registration and assignment data Audio signalling data Audio blocks TETRA SYSTEM DESCRIPTION 21/97

22 Control Signalling data SDS messages Bearer data packets Operating Modes The manages the operating mode for each base station with Assignment of channels (MCCH, SCCH, etc.), power modes and others Network Management Console Interface A local or remote Network Management Console can be connected to the IP@node through a direct IP Ethernet port. The network management interface manages features as detailed below: Technical Database Manage the configuration files of all base stations of the network Manage the configuration files of subsets constituting the IP@node Routing table for flows between various network equipment Maintain the operating parameters of the network Administrative Database Visiting mobile acceptance criteria Declaration of resident mobiles System Monitoring Allows permanent control of the network by sending all summary information pertinent to the states and statuses of various network equipment and communication links to the Administration Console. Event Logging Alarms and acknowledgement Registration and De-registration of mobiles Call requests from subscriber radios Call setup and call release User group assignments Dispatching System Interface A local or remote dispatcher console can be connected to the IP@node through a direct IP Ethernet port. TETRA SYSTEM DESCRIPTION 22/97

23 Furthermore, the Dispatcher system interface is also able to interconnect Computer-based Dispatching System through IP Ethernets ports. The dispatcher interface manages features as detailed below: Signalling 1 UDP channel for the broadcasting of network communications and data transmission such as SDS and Status messages 1 TCP/CP channel Audio 1 UDP channel for voice PABX/ PSTN Interface The IP@node equipment is able to support dedicated interface in order to interconnect the TETRA radio Network to a private PABX or to the Public Network (PSTN). Several type of interfaces are available like S0/T0 interfaces permitting to establish one simultaneous communication between the TETRA network and telephone through the PABX. Another card is a T2 interface permitting up to 30 simultaneous communications between the radio network and the telephony world. The same type of interface can also be plugged at the radio site level to interface local PABX, if required. TETRA SYSTEM DESCRIPTION 23/97

24 3.2 TBS11 Tetra Base Station Overview Figure 3-2 : TETRA Base Station The TBS11 manages a single carrier of a TETRA site. It is responsible for the routing of the following traffic via the IP@node: Writing In of the Mobile Stations (according to a programmed table) Selective mobile/mobile or mobile/base call (half or full-duplex) Group call from a mobile or from a base Open Channel call Mobile / Telephone interconnect call Mobile / Dispatching Network communications in both directions SDS - Mobile / Dispatching Network, Dispatching Network / Mobile, Mobile / Mobile SDS to user groups Broadcast of network information User Data transmission by IP packet The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment Tetra Features TBS11 integrates and complies to all level 1 and 2 functionalities provided for in the ETST TETRA V+D standard. TETRA SYSTEM DESCRIPTION 24/97

25 Level 1 includes compliance transmission and reception on 25 khz channels, modulation/demodulation, coding and error correction. Level 2 includes MAC and LCC (basic and advanced links) All these features allow the using of the base station to route 4 voice and/or data calls in circuit mode, protected circuit mode or packet mode. Each base station is controlled by the IP@node to carry the MCCH and SCCH channels. It is assumed that at least one base station from a radio site manage to broadcast signalling information through the air interface using the first slot for signalling purpose. As a basic feature supported within each base station, a set of 8 external alarms (inputs per carrier) and 7 remote control (outputs per carrier) can be programmed in order to transmit those alarms to the network management terminal. Telemetry actions can be proposed easily from any network management terminals connected to the TEP radio network. Those Inputs/Outputs support direct dry contacts Equipment Modules TBS11 base station can be directly interconnected through IP Ethernet Ports to a standard IP backbone so as to be interconnected to its preferred IP@node. TBS11 base station can also accommodate to interconnect through a G703 interface with a second communication board allowing a daisy chain multiplexing on the 2Mbps channel. TBS11 base station can accommodate up to 2 additional demodulators for receiver diversity operation, i.e. a total of 3 reception channels Site Configurations Single Base Station Several configurations are available for site installation of a single frequency carrier depending on field requirements (radio coverage expected, site constraints, ). With Diversity 1 omni directional RX/TX with one or two auxiliary RX antennas (Yagi panels omni) Without Diversity 2 antennas (1 for Tx and 1 for Rx respectively), Without Diversity - 1 antenna using duplexer equipment With Diversity 2 or 3 directional Rx antennas with 1 omni-directional Tx antenna, TETRA SYSTEM DESCRIPTION 25/97

26 Alternatively, 2 or 3 duplexed directional antennas Special combining systems can be designed to cover indoor areas like underground or overhead coverage, for example, by RF distribution network or by Fibre Optical links Multi Base Station Radio sites can be configured to support up to 8 base stations per site. Each base station is fully independent and can manage the air interface. Several RF configurations are available as described below: Same as above RX combiner by pre-amp distribution (4 channels: 3 diversity channels) Hybrid or cavity combiner, Special combining system for underground and overhead coverage, for example, by RF distribution network or by Fibre Optical links System Parameters The TBS11 parameters are provided entirely from the IP@node except for the link configuration. As soon as the base station is connected to a IP@node, the latter will automatically send its configuration file. A file reload can also be initiated upon TBS11 requests or when the IP@node detects a fault with a base station. If the IP@node is re-initialized or the configuration file undergoes a general reload, the configuration files of all base stations of the network are systematically retransmitted Fall back Mode When a TETRA radio site is disconnected from the IP@node (ie: link failure), each base station of the affected site will operate in fall back mode. Then base stations transmit to all users under its coverage a broadcast message informing the fall back operation mode. According to the TETRA standard, terminals shall request registration to a neighbour radio site assuring radio coverage in this area, on which intersite calls services are still available. If there is no overlap coverage between radio sites, then terminals still operate through the same radio site, even if the site is isolated. The System is also able to be configured in order to remove the capability for the radio site to operate when the radio site is isolated. TETRA SYSTEM DESCRIPTION 26/97

27 A base station in fall back mode is able to manage local traffic (mobile to mobile) according to the latest list of authorised mobiles known and recorded into the base station before the link failure. All types of calls like individual calls (half duplex, full duplex), group calls and SDS services are available limited to local traffic. An authorisation list is pertinent to each TBS11 of the network and may be different from the network s list of general authorizations. This feature also can be configured to restrict access to the TBS11 to a fleet of terminals getting higher priority than some other user. The encryption Class 2 mechanisms are still in operation using authentication process for each registration. The air interface is still encrypted using latest encrypted keys uploaded by the system. The TBS11 can be interfaced to the radio network by using direct IP connection. This configuration allows implementing standard IP protocols like OSPF to dynamically reroute and recover the link to the preferred IP@node or to any other neighbour IP@node connected to the IP backbone Technical Specifications 1 frequency carrier (TX frequency and RX frequency) support up to 4 TETRA channels Frequency Band The TETRA Base Station proposed by ETELM is available in the most common frequency band used. Those bands are detailed below: MHz, MHz, MHz MHz The Duplex spacing, as standard is 10MHz for frequency range MHz and 14 MHz for MHz. On specific demand the duplex spacing can be configured. The frequency offset is also configurable (6,25kHz step) Output Power 10 or 25 Watts available Integrated circulator for safety TETRA SYSTEM DESCRIPTION 27/97

28 Receiver Diversity ( 1 to 3 receivers diversity) Static sensitivity: < -118 dbm excluding diversity gain TETRA Class A with multipropagation equaliser Connectivity Ethernet RJ45 100Mbit/s 64kbps link V.24, V.11, G703 (one time slot used only) at TETRA TLX-SAP 2Mbps multiplex integrated Configuration TETRA base station configuration is made automatically by remote downloading from the IP@node through the Management Console Operation & Maintenance The maintenance procedures are operated directly from PC computer connected to the IP@node or at any point of the IP network. Access to base station parameter Link and radio technical monitoring Mechanical 19 rack mount 6U Dimension (Length x Heigth x Depth) : 600 x 300 x 600 mm 220V AC or 48V DC Main Power Supply TETRA SYSTEM DESCRIPTION 28/97

29 3.3 Frequencies and combiners Cavity combiner It is always better to use cavity Tx combiner than hybrid, not only for lower loss but also for cavities reject any spurious and wide band noise, that reduce interference probability with others radio surrounding equipments. Cavities may be used only if frequencies are spaced with minimum 500 KHz. It is possible to down to 300 KHz but losses increase. Below 300 KHz, hybrid must be used. Fixed cavities are proposed while frequencies are fixed allocated in one area and can t be changed. Auto tune cavities present a little lower performance level compared to laboratory tuned cavities and are not as reliable as a blocked tune. Those types of cavities may vary and a shift of frequency can be observed after a period of usage. Rx combiner offers 3 channels with 4 outputs per channel, in order to be used with 3 ways diversity. Expansion up to 8 Radio channels is achieved with a second Rx combiner and only by adding cavities (they are linked in a daisy chain mode). The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment. TETRA SYSTEM DESCRIPTION 29/97

30 Duplexer Ant RX Pre-amp distribution TX Cavity Combiner BS 1 BS 2 BS 3 BS 4 IP WAN Figure 3-3 : Block diagram Cavity Combiner Hybrid combiner Hybrid combiner can be proposed within the ETELM TETRA system in case of the frequency plan does not permit to use collocated TETRA frequency channels separated of at least 300 KHz. TETRA SYSTEM DESCRIPTION 30/97

31 In that case, the internal architecture for each combiner is as follows depending on quantity of base station required at the site level: hybrid Combiner 4 ways Ant 1 Ant 2 Duplexer Duplexer RX pre-ampli distribution TX Combiner BS 1 BS 2 BS 3 BS 4 IP WAN Figure 3-4 : Block diagram Hybrid Combiner TETRA SYSTEM DESCRIPTION 31/97

32 3.3.3 Antennas and diversity The TETRA radio communication system proposed by ETELM is compliant to the most efficient technology for diversity by using up to three ways diversity which improves the uplink performance. On a TETRA radio network, the usage of hand portable limits the radio coverage by the link between terminals to the base station. The hand portable has a limited output power in comparison with the base station. In order to improve the budget link the implementation of receiver diversity increase the minimum signal strength level received by the base station against fading effect. For outdoor coverage, two ways or three ways diversity can be proposed depending on budget links requirement. Furthermore, many type of antenna configuration can also be proposed as standard as detailed below: Two antennas configuration: One omnidirectional antenna for Rx1 & Tx One omnidirectional antenna for Rx2 only Thee antennas configuration: One omnidirectional antenna for Rx1 & Tx One omnidirectional antenna for Rx2 only One omnidirectional antenna for Rx3 only Four antennas configuration: One omnidirectional antenna for Tx One directive antenna for Rx1 One directive antenna for Rx2 One directive antenna for Rx3 Aerial and Combining systems can be designed according to the radio coverage required, the environment topography, the area (urban, large city, rural) or the wind load. More and more, outdoor radio coverage has to be assured with capability to ensure in-building coverage close to the site location. For those configurations, it is important to use one of the diversity receivers for connecting coaxial cables. Other types of configuration can be proposed also using specific antennas so as to improve the uplink radio communication path according to the field topography and installation constraints. TETRA SYSTEM DESCRIPTION 32/97

33 3.3.4 GPS synchronisation TETRA radio site must be synchronised for perfect hand over operation (all other features may be performed without such synchronisation). This synchronisation is either provided by the E1 G703 links from the equipment or by proposing GPS receiver located at each radio site posi As IP links can t carry synchronisation signal with the required accuracy (about 10 microseconds), on use GPS synchronisation: A small standard GPS antenna is installed and the received signal is split to any carrier equipment. In case of long GPS antenna cables (more than 30 meters), it is always possible to insert small amplifier which are directly powered through the cable from the GPS receiver or splitter. GPS cable could be difficult to install for indoor base station. TETRA SYSTEM DESCRIPTION 33/97

34 3.4 Tsc10 Network Management Terminal Figure 3-5 : Network Management Terminal Overview The TSC10 Network Management terminal is based on a standard PC computer running through the operating system Microsoft Windows XP or Microsoft Vista edition. The Management console is connected to the TETRA Radio Network through an Ethernet IP connection. The Network Management terminal allows the complete control and monitoring of the TETRA network including IP@nodes, TBS11 base stations, PABX interfaces, dispatcher network and all gateways available for being connected to the TETRA world. In a grape architecture network using multi-ip@node equipments, at least one network management terminal shall manage each IP@node. Network administration tasks include: Technical monitoring & supervision of the network (e.g. alarms, busy status etc.) and present graphically in a mimic diagram (depends on specific project requirements) Technical parameter settings of the network Administrative parameters settings include management of subscriber records and their rights Record and retrieval of network events TETRA SYSTEM DESCRIPTION 34/97

35 The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment Configuration of Technical Parameters A valid technical password is required to access the technical parameters of the network. The technical administrator can access: Synoptic Parameter Settings Configuration of any network elements (incl. IP@node, Dispatcher Network, Base Stations, Telephone Interconnect) and the communication links Loading of background screen for mimic display Network Parameter Settings Site Configuration Site neighbourhood declaration General Service Parameters Telephony setting Data parameter setting Level 2 and 3 timers Numbering plan (call routing, message routing etc.) Administrative Database The administrative database is located at each IP@node level and contains all pertinent information concerning Individual TETRA subscribers, mobiles and Group TETRA Subscribers within the TETRA radio network Mobile Declaration and Management The declaration of mobile within the infrastructure is a mandatory procedure in order to permit dedicated terminals to be able to use the radio resources of the TETRA network. The information contains within components of the infrastructure are as follows: Static Data Identity of each mobile and descriptive information (ITSI) Mnemonics name of each mobile TETRA SYSTEM DESCRIPTION 35/97

36 User groups (GTSI) Key technical characteristics of mobiles Static Data on the Capabilities Granted to Each Mobile List of throughout the traffic is authorised (region coverage areas) List of base stations throughout the traffic is authorised (local coverage areas) List of call authorised entities (mobiles, user groups, telephones) List of possible calling parties Call types authorised, priority level, preemption level Call restrictions Dynamic Data (Real Time Status of Each Mobile) Registration location information with date & time stamped Standby status, pending call, call in progress information User Group Declaration and Management Declaration of resident user groups User groups characteristics Call restrictions User group priority User group pre-emption Historic Files Management The sends all events recorded to the network management terminal. The organises events and allows printing out the global list. Each event are time and date stamped. The system can indicates also the location for each event and origin). All events are colour-coded to denote the type of events and also the priority depending on the severity Additional Features The network management terminal may be configured to broadcast SNMP messages each an event is detected and reported to the NMT so as to report technical alarms to a higher level console (e.g. SNMP manager console). At any time, the manager console may request the status of one or more alarms. Statistics and Call Data Records Two types of statistics can be compiled from the event data: Technical statistics allows observation of network loading User statistics allows analysis of traffic flow and pattern TETRA SYSTEM DESCRIPTION 36/97

37 Call data records can also be recorded within an Excel format files in order to export it to an external system for statistic purpose. Remote Administration In a network with multiple IP@node, there is a dedicated management terminal per IP@node. A number of administrative features may be remotely controlled via a LAN. The TETRA network administration instructions are routed to the corresponding IP@node via its management terminal to prevent any inconsistency between the multiple databases. The remote features include: Technical monitoring of the network Declaration related to the mobiles authorized in the network TETRA SYSTEM DESCRIPTION 37/97

38 3.5 Dispatcher Station Figure 3-6 : Dispatcher WorkStation Dispatcher stations are made from a standard multimedia PC with 2 loudspeakers and microphone. Dispatch stations are connected to the IP@node through the LAN which carries Voice over IP. The 2 loudspeakers organisation (primarily used for stereo in standard use) allows offering functions for specific purpose as public safety: one way (right loudspeaker) is used as a normal one for selective or group communication; the second (left loudspeaker) is used for discrete listening of selected groups or mobiles. Main functions available from dispatch stations are: selective call transmission to mobile (dialed or selected from an agenda) selective call to another dispatch station group call transmission (dialed or selected from an agenda) selective call receives from a mobile or another dispatch station (call to a dispatch station) with calling party identification when the dispatch station is affected to this group group call receive from a mobile or another dispatch station (call to a dispatching) with calling party identification TETRA SYSTEM DESCRIPTION 38/97

39 send predefined status to mobile or group send SDS (typed or predefined) to mobile or group receive and display status and SDS with sending party identification display on going communication on the network discrete listening of a communication selected from the ongoing communication list selection of the mobiles and or groups to be listened on the second loudspeaker short term recorder: this function allow the operator to listen back, as many time as wanted, the 4 last minutes of communications broadcasted from its loudspeaker this is achieved in an ergonomic way with a programmable bargraph. Interrogate the data base for a mobile or a group edit and change information Set up and delete dynamic groups from selected mobiles Several different ergonomics software are available for dispatch: ergonomic standard dispatch ergonomic software applications dedicated to transport ergonomic features optimised for repetitive calls, with touch screen ergonomic operation for simultaneous multiple communications... Any Man machine interface may be developed by IT software engineer who has not previous experience in radio communication or TETRA specialized, thanks to DLL which are delivered for interfacing to the system. The dispatcher console has a specific field on display where any types of calls received are displayed and an audio signal is transmitted to the user to alert on a call received. The dispatcher is able to put on hold a terminal in order to proceed to another call. Factory training can also give support and help to software developer for DLL use. In that way, Air France developed its own software. TETRA SYSTEM DESCRIPTION 39/97

40 LAN Standard Communication DLL DLL for Signalling Standard sound card Ergonomic software Application Keyboard mouse Figure 3-7 : Block Diagram Dispatcher station The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment. TETRA SYSTEM DESCRIPTION 40/97

41 3.6 Automatic Vehicle Location (AVL) Figure 3-8 : AVL WorkStation AVL workstations are designed from a standard multimedia PC with Large Flat screen and graphical capabilities to support any types of digital maps like satellite images, city maps. AVL workstations are connected to the IP@node through the LAN which transmit the GPS positions and Identities of terminal managed by the authorised user of the console. Main features available for AVL workstations are as follows: Security and protection for accessing to the application (Login & password) Remote control of mobiles for the configuration of the polling periodicity display the location on a map (map license not included) Display of terminal status by changing icons colours on the map (Switched off, normal, emergency) Immediate localisation request from AVL user decision for a dedicated terminal Administration and configuration of maps Zoom in and out, list of terminal fleet to be displayed The AVL workstation is able to support multi language capability. TETRA SYSTEM DESCRIPTION 41/97

42 The AVL workstation is supplied with the dispatcher capability in order to perform easy operation like call set up directly from the map (Individual call, group call, conference call, ) The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment. TETRA SYSTEM DESCRIPTION 42/97

43 3.7 IP Recorder Server Figure 3-9 : IP Recorder server The IP recorder device is based upon standard COTS equipment designed to provide the best performances in accordance with the minimum customer requirements. The recorder is fully compatible with latest IP technologies and can be interconnected in any area where the TETRA IP radio network can be accessed. All communications can be recorded on the IP recorder including the signalling information relating to the call like identity of the calling party, called party and speaker identity. The IP recorder includes RAID 5 controllers for hard Disks management and redundant hot swap power supply in order to secure audio information and to recover data upon potential hard disk failures. The main features supported by the IP recorder are as follows: TETRA ACELP audio packet recorded through an IP standard format, Large capacity for archiving TETRA records on Hard Disks, Capacity to archive tetra records on DVD-ROM support, Capability to replay tetra records on real time basis, An automatic clean up service to prevent failures caused by full hard disks, A SNMP management from the network management terminal. The Recorder Replay software can be installed within any consoles connected to the IP radio network and provides all services to select and listen to the corresponding communication. Rapid selection can be made by terminal identity, radio site location or date & time period to replay each communications. The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment. TETRA SYSTEM DESCRIPTION 43/97

44 3.8 Audio Mailbox Gateway Figure 3-10 : Audio Mail Box Gateway The audio mail box gateway is based upon standard PC equipment that can be interconnected to the TETRA radio network infrastructure and which provides automatic answering services and record voice message when the called party is not available. This feature is comparable to the service implemented within all GSM mobile telephony networks and used on a day to day basis by all mobile phone s users. It is very useful and appreciated for PMR networks connected to PABX and PSTN. The unit is also used to perform audio automatic responses while, any non established call is routed to the mailbox. Messages indicate the reason of the failure and, according to case, asks if the calling party want to record a message. Example: This number do not exist The called party is busy, if you want to record a message, please press * Such messages may be generalized for some groups, especially for flight number groups, as: This flight does not exist This flight is not opened TETRA SYSTEM DESCRIPTION 44/97

45 3.9 Analog Gateway Figure 3-11 : Analog Gateway The gateway to VHF or UHF analog channels is performed using a standard PC connected to the LAN. This gateway can also be remote connected using any WAN devices which ensures the link between the Gateway and its own IP@node. This unit is able to control up to 4 analog radio equipment using a basic interface involving audio Tx, audio Rx, PTT and carrier detection signalling. Specific analog audio signalling like 5 tones, TCS or equivalent are ensured by the Analog radio equipment. Two main features are provided: Access to selected channel from TETRA terminal (or dispatch): each VHF channel is registered with a special number in the numbering plan (mnemotechnic if possible) and, by selecting this number, the calling party can join the analog open channel: The user is able to listen to every received VHF signal and may talk only by pressing the TETRA PTT. This is achieved by declaring an open TETRA group associated for any VHF channel with no TETRA terminal belonging to this group. Monitoring an analog channel from a TETRA terminal (or dispatch) is the second feature; it is achieved by opening a TETRA group call as soon as a carrier detection signal is transmitted from the analog system within the ongoing communication. The group(s) may be programmed as scanned group or not inside TETRA terminals. Those two features are separated in order not to disturb any TETRA terminal by the external analog communication if not required. Some dedicated TETRA terminals can be programmed to monitor analog channels. The equipment is designed to support normal vibrations, bumps and knocks incurring during transportation. The equipment does not cause any electrostatic discharges to he environment. TETRA SYSTEM DESCRIPTION 45/97

46 3.10 Flight Management Terminal Figure 3-12 : Flight Management console The flight management unit is able to create, delete and/or register directly terminals to flights. The user operational mode can be split in two parts: A standard operation mode consisting in usage of a stand alone console. In that particular case, flights can be created and/or deleted by authorised user only, from a dedicated console connected to the TETRA radio network. A specific operation mode consisting in the capability to the system to be interconnected with an external system like passengers information (example to the panels inside airports which display departure and arrival flights) Any type of external interface can be specifically developed according to the requirement. As extension, pre-defined message (status) may be managed by this unit when the TETRA radio network is connected to another external system: As the flight management unit knows exactly the flight registered for any terminal at any moment, the system is able to map status received from a terminal to the registered flight and transmit both to the external software application. This ensures that a terminal may directly send a status only by pressing minimum keys and without flight dialling. The use of Status message is very efficient for airport software application as soon as flash messages are used intensively as real time feedback to TETRA terminals. Flash messages are fully supported by the ETELM TETRA radio infrastructure.. TETRA SYSTEM DESCRIPTION 46/97

47 3.11 Server Gateway Figure 3-13 : server device The server equipment is based upon standard COTS equipment running through a Red Hat Linux or Microsoft Windows operating system. The Server Gateway provides automatic message services from an external server application like Lotus Notes or Microsoft Exchange interconnected through the LAN and the TETRA radio infrastructure proposed by ETELM. The Tetra infrastructure is in charge of transmitting messages to the TETRA terminal through an SDS format. In this case, terminal users can operate with standard terminal on the field and received short message within the message box of the terminal. The service is independent of the availability of the user thanks to the simultaneous voice and data feature provided by the ETELM TETRA infrastructure. The server is also able to transfer a SDS message sent from a TETRA terminal to the external server application through an format. The main features supported by the server Gateway are as follows: Automatic POP3 service from standard software application, Automatic SMTP service to standard software application, Management and configuration of the equipment from NMT, Capability to use SDS acknowledged service to ensure that are received, Any types of TETRA terminals can support the service. TETRA SYSTEM DESCRIPTION 47/97

48 3.12 TETRA IP Router Figure 3-14 : Front panel IP Router The technology designed by ETELM is based upon latest routing device equipment permitting to improve links communication on an IP backbone dedicated to a TETRA radio network. IP routers proposed by ETELM allow optimising the IP traffic management through the network by transmitting only the traffic required to each components of the radio network. A specific technology developed for TETRA services upon a standard COTS routing device for layer 2 protocols with the ability to be integrated within an existing IP backbone provided by any customers. Principle of it is as follow: Audio data communications are broadcasted in order to avoid multiple point to point transmissions An equipment aware of the on going communication and want to listen and/or to talk with this communication send a request to open the channel from the source to him TETRA routers open a link only when the communication request is received Figure 3-15 : Back panel IP Router TETRA SYSTEM DESCRIPTION 48/97

49 When a TETRA IP router receives a request from authorised infrastructure equipment to access to a communication, it routes the audio data packet from the originating site to the destination site. As result: Audio data packets are broadcasted, that avoids multiple point to point transmissions IP network links carry broadcasted audio packets only if necessary. TETRA routers may be used at any node of the IP network. TETRA IP Router can support up to 4 routing Ethernet ports or 8 routing Ethernet ports. The TETRA IP Router can be directly interconnected on an IP backbone without routing protocol constraints requested to the existing backbone. A quality of service is to be implemented on the backbone to ensure the minimum data bandwidth required for the normal operation of the TETRA network. Upon requirements a few other interfaces can be proposed. TETRA SYSTEM DESCRIPTION 49/97

50 4. SYSTEM FEATURES TETRA SYSTEM DESCRIPTION 50/97

51 4.1 Multi Organisation Multi organisation TETRA feature is fully supported within the ETELM TETRA radio network. Multi organisation is based upon the capability for each organisation to use its own network code with the same Country Code for all organisations. The multi organisation service integrated within the ETELM TETRA network allows a real sub division for each organisation and a full independency. Each organisation can be linked to another network by easy interconnection through IP between IP@nodes General organisation There are two methods to interconnect sub networks: The sub networks have a different network code: they manage their own numbering plan and each communication between these networks will be with a prefix to designate the called network. (refer to ISI chapter) The sub networks share the same network code but they must use a harmonized numbering plan in general, each sub network manages a subset of the general numbering plan. ETELM offers both solutions, it is a basic choice to be made with a lot of functional consequences. TETRA SYSTEM DESCRIPTION 51/97

52 subnetwork 1 Visitors subrange ITSI range 0 to subnetwork 2 Visitors subrange subnetwork n Visitors subrange Each sub network manages a slide of the general database and owns a specific part for visitors from another network or sub network. Figure 4-1 : TETRA Networks and sub networks numbering plan In case when sub networks share the same numbering plan (same network code), following method is generally implemented: Each sub network may manage its own subset of numbers; it may declare or delete any group, terminal, dispatch station, application inside this range. Each sub network may read any database element in the whole range but may write only inside its own range. TETRA SYSTEM DESCRIPTION 52/97

53 4.1.2 Numbering plan A Numbering plan has to be defined to give an utilization easier for the users. Requirements are: Integration of telephone numbers, mobiles numbers, group numbers and dispatch stations number, in the same numbering plan. Mnemotechnic use of the numbering plan Minimum key depress (dialling) to reach a neighbour terminal Technical limitations are: TETRA numbering is seven digits with automatic 0 insertion on the left when less than seven digits are dialled. TETRA numbering only uses 0 to 9 digits and can t use standard * and # keys. A common solution may be done to preserve a range for the telephone numbers into the TETRA full address range that allows reaching mobiles as telephone sets. There are a lot of other solutions, according to specifics requirements (and existing user rules). These possibilities only apply if there are no technical limitations in the system (limitation example: any group must be numbered with a specific first number). In order to offer the maximum flexibility for the numbering plan, the proposed system integrates routing tables covering the whole TETRA address range (ten millions numbers) Routing Plan for radio terminals The routing table allows declaring types of users for any sub range of the full range. Types can be: Mobiles Telephone set Static group Dynamic group as flight number Dispatch station Dispatch group TETRA SYSTEM DESCRIPTION 53/97

54 Visitor mobile Data servers Gateways Figure 4-2 : Numbering Plan Editor For airports, it is important to reach a large group capacity address range: while a flight number is made from a prefix (company) followed by 4 digit, a minimum of groups may be declared for transparent operation. Thanks to the group number capacity offered by the proposed system, it is easy to introduce flight numbers A second routing table is implemented for status routing. This table must optimise data transmission when several data applications use the same network and the same mobiles. Figure 4-3 : Numbering Plan Status The management of status message is directly made within the infrastructure level. For each status, a free text is associated and saved at the infrastructure level. TETRA SYSTEM DESCRIPTION 54/97

55 Status are routed to the called party (data server or dispatcher) depending on its own content and authorise the system to reuse the called number dialled on terminal as data information transmitted by the user itself. i.e: If a user wants to indicate that an aircraft is full filled and the quantity of gas supplied is 3000 l then he can select on his handheld the status named aircraft full of gas and dialled on his terminal 3000 for the destination party. The system itself will automatically route the status to the correct data server and the called party field is used by the data application to record the quantity of gas filled in Routing Plan for Telephone An incoming call from telephone may reach a mobile, a group, a dispatch or a dispatch group. Routing process is declared with: A window to select the only useful digit (that rubout non significant digits - as prefix - transmitted over the Euro ISDN signalling) A predefined prefix to be added to any number By this way, it is very easy to interconnect incoming telephone numbers and mobile numbers with transparency operation for the user Groups Any resident mobile is programmed with static groups. It also may be included in dynamic groups declared on infrastructure and downloaded. This allows the group to change without laboratory return. Groups are of the most importance for professional networks. A lot of functions are available: Affected group: a radio terminal or a dispatch station can be affected at the same time to several groups (static or dynamic). Attached group: a radio terminal is, at any moment, attached to one and only one of its affected groups. The choice of the attached group can be made by the operator (by knob or menu) by selecting one of the affected groups. Infrastructure knows at any moment, the group attached to any terminal (the last affected group selected by the operator) Static group: group programmed into the terminal and declared into the network. Dynamic group: group declared by any application on the infrastructure and automatically downloaded to the radio terminal. Improves group: special dynamic group declared by a dispatch station. TETRA SYSTEM DESCRIPTION 55/97

56 Open group/close group: a close group can be called only by a group member; an open group may be called by anybody. The radio user does not need to know all these differences; he only has to know how it works: When a radio terminal is affected to one group, any incoming call to this group opens the radio terminal and the user listens to this communication and, if allowed, he can transmit only by depressing the PTT command. When a radio terminal is not involved in a communication (selective or group) and when the operator depresses its PTT command, a group communication to the attached group is opened. This is like a predefined open channel. For airport application, flight numbers are used as dynamic groups which are created and deleted by the airport flight management application Short Numbering Assignment The SNA TETRA feature is implemented within the ETELM infrastructure and can be used by user or by external data applications. The usage of SNA is potentially well appropriated for data applications because SNA can optimise the data flow through the air interface by reducing the address field and increasing the remaining data field. Furthermore, the SNA is also efficient on specific radio networks supporting a lots of SDS messages and using polling mechanisms to optimise performances of the system. The combination of SNA and GPS compact positions improves the overall amount of traffic being supported by the infrastructure. TETRA SYSTEM DESCRIPTION 56/97

57 4.2 Speech Services Individual call establishment MOBILE TO MOBILE CALL Such calls are transmitted after dialing. The allows or not the call according to the mobile and group data base. Selective calls are with duplex or half duplex mode (according to the type of the request from the calling party), and involve one or two radio sites. The call is performed either in direct mode or with hook. Establishment time is < 500 milliseconds. Incoming call to a radio terminal displays the calling party identity. An incoming selective call to a radio terminal involved in a group call is or not serviced according to declared priority in the data base. If the group has been declared with lower priority than selective, the called terminal is automatically extracted from the group communication and selectively called. At the end of the selective call, the called terminal will join again automatically the group call (if still existing) by the late entry supplementary service MOBILE TO DISPATCHER STATION CALL Mobile may perform selective call to a dispatch station as a mobile one. The request may be with direct mode or hook, duplex or half duplex MOBILE TO DISPATCHING CALL As a dispatching is a group of dispatch station, the call is performed by ringing any of the dispatch stations of the selected dispatching. With hook method, the first dispatch station which hang up takes the communication and other dispatch stations stop ringing. The calling party is displayed on any ringing dispatch station TELEPHONE TO MOBILE CALL The call may be restricted according to the mobile data base content. The call is performed with hook and duplex mode. If the PABX transmits the calling phone number, it is displayed on the radio terminal; if not only the indication telephone is displayed. If the called radio terminal is busy a busy indication is transmitted to the telephone. TETRA SYSTEM DESCRIPTION 57/97

58 INDIVIDUAL CALL DISPATCH STATION TO MOBILE Operator selects selective call function and enters the correct identity (or selects it in a agenda). The call can be transmitted with direct hook mode (no hook). The calling party can be displayed on the radio terminal. If the called mobile is busy, an indication is displayed; if the called mobile is not reachable, another indication is displayed CALL BACK REQUEST TO DISPATCHER A call back request is a specific predefined message (status message), defined by the standard, which can bear three priority levels (normal, urgent and emergency). Those messages are transmitted to a dispatcher console. The dispatcher console receives the message within a list displaying the priority of message. The Call back messages are managed specifically by the infrastructure. An automatic mechanism of transmission retry, made by the infrastructure to the dispatcher console, operates until the message is received and acknowledged MOBILE TO TELEPHONE CALL Any mobile is declared in the mobile data base with specific indications about its possibilities to perform tel. call. This is declared according to the following: A list of telephone numbers is established which correspond to authorized telephone call. A telephone number may be shortened in this case, any phone number beginning by this number is allowed. Example the list : Only allow performing a specific call to a German tel user and allow performing call to any French mobile EMERGENCY PREMPTIVE CALL TETRA SYSTEM DESCRIPTION 58/97

59 This pre-emptive call is programmed directly into radio mobile with the red button function declaration including the fixed address to be called (mobile or group or telephone or dispatch station or dispatching) and the duplex mode request. This call is with the highest priority. In case when infrastructure have no more radio capacity it automatically suppress the oldest on going communication with the lowest priority in order to transmit the pre-emptive call DISPATCH STATION TO DISPATCH STATION CALL These communications are directly managed by dispatch stations, without any action from the The calling party is displayed on the called dispatch station HANDOVER DURING SELECTIVE CALL The Handover feature can be set up within the TETRA radio network in order to apply to every selective call. Selective calls can be half duplex mode or full duplex mode. Handover feature implement many TETRA supplementary services simultaneously in order to permits to migrate the communications from one site to another site during an ongoing call without audio disruption. Those TETRA supplementary services are listed below: Neighbour cell information Undeclared cell reselection type 1 Unannounced cell reselection type 2 Announced cell reselection type 3 Call restoration Each of those services operates simultaneously in order to permit the terminal and the infrastructure to automatically authorise the migration to another neighbour radio site. The decision to select another site can be taken by the mobile itself or by the infrastructure according to information shared between the received signal strength levels. Neighbour cell information permit to broadcast to terminals information corresponding to potential existing neighbour radio site. If the user is already engaged within an ongoing call and the environment disconnect the link with the last registration site (i.e : vehicle going under a tunnel) then as soon as an authorised TETRA SYSTEM DESCRIPTION 59/97

60 radio site signal is received, the terminal request for a call restoration and the call is reestablished on the other radio site. If the user is already engaged within a call and the received signal strength level decrease under a configurable level then a mutual procedure between the infrastructure and the terminal is engaged in order to transfer the communication from the originating site to the destination site. Those processes are implemented according to the situation and does not required any operation from the user Group call establishment For the following, there are no distinctions between static or dynamic group GROUP CALL AUTHORISATION Any group is declared in the mobile and group data base with indications about possible calling party. Restriction possibilities are: Group only reachable from dispatch station. Group not reachable from mobiles not affected to the group (closed group). Group not reachable from telephone GROUP CALL FROM A MOBILE The group number is selected by the operator; the infrastructure recognize the group number according to the routing table and modify the call type if necessary (forces half duplex and direct mode). The infrastructure performs the call on any radio site where a group member is registered, in order to use the minimum radio channels GROUP CALL FROM TELEPHONE The beginning of the procedure is the same as for telephone to mobile call; but the infrastructure recognizes the group number according to the routing table and performs a group call as for a group call from mobile. The only difference is with the PTT management which is critical in this case while the telephone set has no PTT command. TETRA SYSTEM DESCRIPTION 60/97

61 GROUP CALL FROM DISPATCH STATION This chapter is the same as the one concerning group call from a mobile station but with higher priority level ACKNOWLEDGED GROUP CALL This group call may be requested from a dispatch station: first it is a normal group call but, at the beginning of the communication, the system automatically checks the mobiles which have been reached. This is achieved thanks to discrete data exchange during the communication. A report is send to the calling dispatch station. This type of group call is a parameter attached to the group; it is stored in the data base GROUP CALL IN A DYNAMIC PREDEFINED AREA A generic group call can be configured in each terminal. This group call can be configured to operate within a selected coverage area of the radio network. From the selected coverage area, the terminal who will initiate the group call is located by the infrastructure. The infrastructure determines the originating site and will only establish the group call in a predefined restricted area of the selected coverage area. i.e: A group call can be configured to be common to all fire brigades in a city. In that case, the group call will be established only within a predefined sector of the city, where the call had been initiated PRIORITY GROUP SCANNING A radio terminal may be affected to several groups. In case when one of these group is opened for communication and there is a call to another of these groups the radio terminal may: Either stay in the first communication and ignores the second one Or live the first communication and join the second one This choice is made according to priority parameters affected to any group and programmed inside the radio terminal LATE ENTRY A radio terminal affected to a group may not be involved in a communication for this group for several reasons: TETRA SYSTEM DESCRIPTION 61/97

62 Switched off during the call Out of coverage during the call Busy during the call When the late entry function is activated, the periodically transmits the group call during all the time the communication is ongoing. That offers the possibility to some non reachable radio terminal to join the communication. Late entry is programmed individually for each group in the mobile data base IMMEDIATE ENTRY A radio terminal affected to a group may not be involved in the ongoing group communication for several reasons like busy subscriber during a call, out of coverage, Nevertheless, the immediate entry service allows a terminal subscriber which is not within an ongoing group call, to join immediately the group after having dialled or requested to open this group. TETRA SYSTEM DESCRIPTION 62/97

63 4.3 Supplementary services Broadcast Communication Over The LAN Any communication is broadcasted over the LAN using VoIP technology. This allow any authorized dispatch station to listen a selected communication (discrete listening) and, if authorized to enter into this communication and to release it Group Communication Types There are three types of group communications: Broadcast communication: only the calling party may transmit to the group and other group members can t respond. Half broadcast communication: the calling party may transmit to the group, other group members may respond but the response is only listening by the calling party, not by other group members. Open communication: any member of the called group may transmit. The group communication type is a parameter of the group which is included in the data base Talking Party Identification The calling party can be identified on terminals. In some case, it is interesting to know, at any time who is speaking during a group communication this information is transmitted to mobiles and to dispatchers at any time, all along the communication and displayed to radio terminals and dispatcher stations. This information is also recorded by digital VoIP recorder. When the play back session is requested by authorised user for an old communication from such recorder, the system is able to identify exactly the called party, the calling party and the speaker at any moment during a group call. TETRA SYSTEM DESCRIPTION 63/97

64 4.3.4 Discreet Listening An authorised dispatcher may listen any communication upon request on the dispatcher console (mobile, group, telephone..). Authorisations are programmed for each mobile from the administration console (a mobile may or may not be listened by dispatcher). An Authorised dispatcher during the monitoring session of a specific call may enter within the communication with both parties and may clear down this communication if considered as useless Conference Call Between Dispatcher Several dispatchers, simultaneously, may listen to the same communication when one of them is talking, other dispatchers listen to it. This feature is interesting while with other systems, dispatchers involved in the same individual or group communication listen only radio terminals and not other speaking dispatcher Push to Talk (PTT) Management - Priority Only one mobile may transmit at any time during a group call. This is achieved with special procedure with request to talk (very short exchange when depressing the PTT command) and talking authorisation from the infrastructure. The infrastructure gives only one authorisation at any moment and, thanks to duplex mode, this authorisation may be suppressed for a mobile, even if it is transmitting. In general, talking authorization is allocated to the requesting mobile if and only if there no activity. If another mobile is transmitting the permission is either refused, or put in a waiting list according to if the queuing function is or not activated (general parameter of the data base). However, some mobiles may be with highest priority in this case, a PTT command from such mobile stops transmitting of lower priority mobile and allows the higher priority mobile to transmit. Dispatcher stations have the highest priority. TETRA SYSTEM DESCRIPTION 64/97

65 4.3.7 Hand over during Group Communication In a group communication, mobiles are individually checked by infrastructure and the communication involves only radio sites where mobiles are registered; this ensures the optimisation of radio resources in use. Such arrangement is provided all along the communication; that is when a mobile of the group roams from one site to another, the infrastructure automatically adapts channel assignments. As result, a roaming mobile in a group communication does not lose the communication, an automatic hand over mechanism apply during the ongoing call Individual communication release A duplex selective mobile to mobile communication may be released: by one of the mobiles or, by the timeout for selective communications A half duplex selective mobile to mobile communication may be released by one of the mobiles or, by the timeout for selective communications or by a non activity timeout A duplex mobile / telephone communication may be released by the mobile by the telephone when hook off by the timeout for telephone communication all these communications may also be released by an authorized dispatch station with discrete listening function. A dispatch station / mobile communication may be released by the mobile by the dispatch station by a general timeout TETRA SYSTEM DESCRIPTION 65/97

66 4.3.9 Group communication release A mobile to group communication may be released by the calling party by a non activity timeout by the timeout for group calls Telephone to group communication may be released by the telephone by the telephone communication timeout A dispatch station to group call may be released by the calling dispatch station by a general timeout Data Transmission during Communication SDS and status transmission, point to point or points to multipoint are achieved even during a communication and even if one of the called mobiles is transmitting. This feature is extended up to SDS type Call Forwarding Any terminal user can be forwarded to another terminal user, to a telephone connected to the PABX or to the voice mailbox (if required). Several type of call forwarding are available and detailed as follows; Call forwarding unconditional Call forwarding on busy subscriber Call forwarding on no reply This operation is controlled from the infrastructure and also multiple call forward are supported with protection against creation of a loop. TETRA SYSTEM DESCRIPTION 66/97

67 Baring of Calls The ETELM infrastructure is able to support the baring calls features to restrict rights of users against access to external networks like PABX/PSTN interface. Two types of service are available: Baring of Incoming calls Baring of Outgoing calls According to the terminal rights defined within the Network Management terminal, a user is authorised or not to get access to external calls or are restricted to dial only a list of telephone numbers. In the same way, external telephone lines can not access to a TETRA terminal user if the terminal enabled the baring of Incoming calls. It is the responsibility of the user administrator to define those access parameters Ambience Listening Upon request from an authorised dispatcher operator, a dedicated TETRA terminal can be remotely monitored (remote control of the terminal microphone) in order to listen to the environmental audio within the close area of the called party terminal. At the terminal level, depending on terminal manufacturers, there is no indication on display, no indication on transmitting LED. The terminal is supposed to be as standby. Even if the terminal is switched off, the ambience listening service is still in operation. Those types of operation mode can be configured at the terminal level. The ambience listening service can be stopped upon request of the authorised dispatcher. The ambience listening can be remotely convert to a normal individual call from the authorised dispatcher for a while and convert back to an ambience listening operation mode upon request of the dispatcher. i.e: On public transportation, a dispatcher can request an ambience listening call after a driver was attacked to ear the environment, to convert the ongoing call to an individual call for negotiating and convert back the call to an ambience listening mode to ensure the follow up of the intervention. i.e: On fire intervention, if a fireman having a terminal has an accident during intervention, the terminal and the owner can be searched by audio signalling transmitted to the terminal under heavy smoke. TETRA SYSTEM DESCRIPTION 67/97

68 Call Completion Any types of call within the TETRA radio network infrastructure can be setup even if the called party is busy or is not replying. If the called party is busy a specific audio tones from the infrastructure is return to the called party to indicate the status of the call. A parameter can be configured from the network management terminal to setup the maximum duration timer for which the call is considered as completed. Two main services apply: Call completion on busy subscriber Call completion on no reply Call Queuing Management Call queuing management only apply when radio resources are not available to permit the normal call process. Upon request of the user to set up a call, the infrastructure is in charge of establishing the communication. If radio resources are not available, the call is placed within a queue according to its priority level and pre emption rights. The highest priority level terminal shall be given a priority within the queuing list of calls and the call will be established as soon as radio resources shall be available. The size of the queuing list for each site can be configured from the network management terminal. If the list of waiting calls increase above the maximum size of the queuing list then oldest calls or lowest priority calls will be released. After having over passed a maximum duration waiting timer, the call is also released and a message to the user is given as network busy. If the called party is not reachable (ie: called user under a tunnel) then the system released the call and display a party not reachable message. When the call set up is under process the system informs that the call is in progress. The queuing management service applies to all users on the TETRA network like terminal users, dispatcher operators, telephone users. TETRA SYSTEM DESCRIPTION 68/97

69 4.4 Data Transmission Data transmissions are performed from a data dispatch (specific application) running on standard PC directly connected to the IP@node via a standard LAN (10Mb/s or 100Mb/s) to mobiles equipments which includes a radio unit and a data unit connected together via the standard PEI junction Circuit mode data call Circuit mode data call can be setup between two terminals using point to point communication through the IP@node. Circuit mode is available up to 7,2 Kb/s duplex transmission. For such transmissions, the infrastructure opens an end to end link witch uses a radio channel all along the communication. Available rates: Non protected mode: 7.2 Kbit/s, Low protection mode: 4.8 Kbit/s, High protection mode: 2.4 Kbit/s Predefined message (Status) and SDS The ETELM infrastructure is able to support any type of pre defined message or free message according to the TETRA standard. 4 types of free message can be used by the infrastructure depending on the size of the data to be transmitted. All types of data message are supported like status and SDS type 1, 2, 3 or 4. Status and SDS messages can be transmitted from mobile to mobile or from mobile to a group of mobiles. Status and SDS messages are transmitted even during ongoing communications. The ETELM infrastructure supports simultaneous voice and data communications. SDS messages offer following services: Short individual messages transmission and reception Short group messages transmission and reception Predefined short messages individual transmission and reception, Predefined short messages group transmission and reception TETRA SYSTEM DESCRIPTION 69/97

70 SDS may be transmitted and received by mobiles, dispatching stations and data servers; they are not transmitted by phone. Some type 1 SDS are reserved for special normalized purpose; most of them are supported by the infrastructure. The infrastructure supports the flash message service. The 4 SDS messages classes are supported Type 1: fixed length 16 bit Type 2: fixed length 32 bit Type 3: fixed length 64 bit Type 4: variable length 0 to 2047 bit A maximum of 256 characters can be sent within the same message using the SDS type 4 mechanisms. SDS messages are transmitted by infrastructure on the air interface by using any signalling channels. (MCCH, SCCH, FSCCH,..) That permits transmission during ongoing communications. In most cases, data are exchanged between a fixed equipment and mobile(s) equipment(s). In this case, the most interesting way is to directly connect the fixed equipment to the IP@node, using the LAN (and avoid exchanging data between two radio units, witch is less efficient) such data server, directly connected to IP@node looks like a data dispatching. Protocol over the LAN is standard TCP/IP and UDP IP Packet Data Transfer This service is available on the infrastructure; it offers exchanges of standard IP or UDP packets between a data server connected to the IP@node via the LAN and a mobile equipment using the standard PEI junction. This service uses traffic channel, dynamically allocated by the infrastructure according to data traffic requirements. TETRA SYSTEM DESCRIPTION 70/97

71 LAN ETHERNET Radio network Base station PEI PC MOBILE Figure 4-4 : IP Packet Data - Functional Schematic The connection between the LAN and a PC connected to the mobile is IP transparent. PC LAN Mobile = PCM Transfert application IP (LAN) TETRA Gateway IP (PEI) Transfert application Figure 4-5 : Transparent IP connection for embedded application The IP packet data TETRA service authorise a terminal within an ongoing data transfer to delay the data transmission when an audio call is received from another party (terminal, dispatcher, pabx, ). The data transmission is restored as soon as the audio call is released. Terminal user can received audio calls even if the data IP packet service is processed Individual data transfer Software applications used for transferring data to individual mobile are standard software (ftp, telnet, etc.). The dialog between terminals is managed by the TETRA Gateway which is fully transparent for IP protocols. TETRA SYSTEM DESCRIPTION 71/97

72 Any type of software application using those standard tools for data transfer like Microsoft outlook, Microsoft Internet explorer can be supported from any computers connected to the TETRA terminal Broadcast data transfer IP packets received by PCM are without the individual IP address of the PCM, they are referenced to an IP group address. Standard software can t be used as they do not support the multi address process specifics software must be used. In order to use group addresses, one must define static IP addresses. Correspondence between ITSI/GSSI and IP addresses must be declared as parameters in the infrastructure (by using administration console). Available address in the usual class C domain is restricted to 255. Class B is preferred; it uses 4 bytes (2 bytes for the domain and 2 variable bytes). As defined in IP norm, class B domain lies between and and the sub network mask is In order to avoid address problems, the data servers connected to the LAN must not be tied to Internet; if necessary, a domain reservation must be provided from the National Regulation Authority. Addressing examples : From to From to Mobiles 2048 Mobiles groups Multi-slot packet data The ETELM infrastructure is designed to support multi slot packet data permitting to allocate up to 4 slots simultaneously. Upon request from the user, radio resources can be allocated to expand the data bandwidth at the air interface level. In order to prevent any limitation for the usage of this service, a second base station in each radio site is at least proposed in order to support the maximum data bandwidth offered by the system allocating up to 4 slots. In that typical case, one full base station is used to provide the bandwidth required for the on going communication. The data channel opened for data transmission is as follows: Single slot Packet data service up to 7,2 Kbit/s Two slots Packet Data service up to 14,4 Kbit/s TETRA SYSTEM DESCRIPTION 72/97

73 Three slots Packet Data service up to 21,6 Kbit/s Four slots Packet Data service up to 28,8 Kbit/s It is strongly recommended not to use the four slots configuration due to the use of a full base station resource on the same radio site for only a data transmission call and also because duplex protocols for the data transmission can not be enabled when four slots are in-use. It is often more efficient in terms of performances to transfer data using two slots on full duplex operation mode rather than 4 slots in half duplex mode. TETRA SYSTEM DESCRIPTION 73/97

74 4.5 Security and Encryption Overview The TETRA radio network proposed by ETELM is fully compliant with the TETRA standard defined by the ETSI. The TETRA standard defined also the security level for a radio network depending on minimum mechanisms required to implement the security. Main features are detailed below and also encryption algorithm supported by the infrastructure according to final destination of the system. Any type of radio network implementing security services and encryption algorithms are subject to export licence prior to any delivery of equipment outside of the European Union (EU). The main objectives of the security within a radio communication system are to unable any external devices or users to communicate, capture information from a part or the overall system. The security gives a reply to preserve confidentiality by avoiding interception of confidential data within the network, traffic analysis so as to locate or prepare any actins against the efficiency of the system. The security also must ensure the availability of the system by preventing any external actions permitting to insert and overload the radio network or occupied radio resources to minimise the efficiency of user on field. The security must also preserve the integrity of the system by avoiding any change of the information transmitted along the network and detect if information had been opened by an unauthorised party Security Classes TETRA networks are mainly divided within three security levels having different characteristics and classified according to their level of protection against external threatened. Those security classes applied only to the air interface level between terminals to the base station. The three levels are defined as follows: Class 1 network: Those networks do not apply any specific security services. Those networks are commonly named clear networks or can implement minimum service like authentication only. TETRA SYSTEM DESCRIPTION 74/97

75 Class 2 network: Those networks implement a good level of security in order to preserve integrity, confidentiality and availability of the system. This level is commonly named Static encrypted network. The efficiency of the system depends on the update cycle of encrypted keys. Class 3 network: Those networks implement the highest innovative and efficient protocols to dynamically distribute encrypted keys within the infrastructure network and also dynamically upload terminals over the air interface. This level is commonly named Dynamic encrypted networks. The following table details the different capabilities of the network: Security Class Authentication OTAR* Encryption End To End Encryption Results 1 Optional - - Optional No encryption 2 Optional Optional Mandatory Optional Static encryption 3 Mandatory Mandatory Mandatory Optional Dynamic encryption * OTAR : Over The Air Rekeying TETRA radio networks Class 2 or Class 3 are using different algorithm in charge of calculating processing to the encryption of information for the signalling channel and also the traffic channel. Each algorithms governed by Security and Fraud Protection Group (SFPG), which is the security group of the ETSI, can be proposed to end user dependent to the type of final user and country location restricted TEA1: This algorithm is suitable for any final users and no export restriction TEA2: This algorithm is suitable only for public safety and Europe restricted area TEA3: This algorithm is suitable only for public safety and no export restriction TEA4: This algorithm is suitable for any final users and no export restriction Authentication The authentication procedure is launched in order to identify either terminal access permission or infrastructure authorised access. Authentication can be requested from a mobile only, from the infrastructure only or through a mutual authentication requested. This procedure is prior to any registration acknowledgment on the TETRA radio network. If authentication procedure failed, terminals are rejected from the network. A specific algorithm named TETRA Authentication Algorythm (TAA1) is used to calculate the authentication results. TETRA SYSTEM DESCRIPTION 75/97

76 The terminal can not be registered and will not affect any radio resources because any other attempt will not be considered. The authentication process is based upon the introduction of a common key K shared at the terminal level and also within the infrastructure. The calculation of a derived key from key K using TAA1 algorithm determines the access authorisation or not. The main elements involved within the authentication process are listed below: Authentication Key, Random Seed, Random challenge value, Response value, Expected response value Class 2 Ciphering The Class 2 mechanisms are based upon a usage of a Static Cipher Key called (SCK) permitting to calculate a derived sequence named Key stream segment (KSS) in order to encrypt or decrypt the TETRA signalling and traffic segment. The system proposed by ETELM is able to support up to 32 SCK on the same network. It is mandatory to use only one SCK at a time on the same network. The security manager has the rights to operate and choose one of the other 32 keys within the system. Base station shall then upload again the new SCK in use. Thus, TETRA signalling channel and also the data transmitted within the air interface on the traffic channel are fully protected through the calculation process derived by the SCK. The IP@node is responsible to manage the transfer to each base station of the corresponding keys in order to be compatible with key directly programmed within terminals. The Key management is made from the Network management console for the infrastructure part and from a dedicated tool to insert keys within terminals. The access rights for performing this procedure are protected by password and specific profile. The network management console and also base station are supposed to be located at a secure location. The dedicated application in charge of administration of the keys associates the Identities of terminals (ITSI, GTSI) with the key inserted. Those operations are organised during the manufacture of terminals and infrastructure to ensure a sufficient level of security when the system is ready to be delivered. TETRA SYSTEM DESCRIPTION 76/97

77 The SCK are delivered to the key management tool according to a special format defined by the SFPG. Specific End user Algorithms can be proposed under prior authorisation of the French regulation authorities. Some specific parameters can also be configured to propose dedicated algorithms calculations to specific end user Class 3 Ciphering The class 3 networks are based upon a usage of a common cipher key (CCK) and a derived cipher key (DCK) that are calculated by the system and terminals according to random parameters and derived keys provided by the OTAR mechanisms. The Class 3 networks are commonly named Dynamic encrypted network because of the automatic process for uploading new derived ciphered keys over the air and without having to reprogram the network by man operation. All information transmitted through the air interface is fully secured and protected themselves by a specific algorithm. No information is transmitted in clear mode under this class level End to End Encryption The TETRA radio network proposed by ETELM is fully compliant with the End to End encryption (E2E) service implemented at terminals levels. The infrastructure authorise usage of a E2E encryption and becomes transparent to any information transmitted by terminals within the traffic channel. Encrypted keys are directly saved at the terminal level. A set of at least 10 encrypted keys are saved at the terminal level with three sub keys for the current key, the previous key and the future key. In that particular case, the traffic channel containing audio tetra packet are fully encrypted before the information is sent through the air interface. Nevertheless, the signalling channel is not protected against monitoring because the signalling channel must be in clear mode to operate on any type of infrastructure Class 1, Class 2 and Class 3 networks. Mainly End to End encryption algorithms used are IDEA, AES 256 or AES 128 using encrypted keys in which the length is 128 bytes or 256 bytes. Some other algorithm can also be proposed according to specific demand. TETRA SYSTEM DESCRIPTION 77/97

78 4.6 Inter System Interface services (ISI) A specific range of individual subscribers identities are reserved within the TETRA infrastructure dedicated to subscribers visitor identities which are authorised to migrate within the destination tetra network. Using the Network Management Terminal, the user administrator can declare a list of country code and network code that are considered as valid to operate within the TETRA network. All TETRA terminals requesting registration on the destination TETRA network and using a different MCC or MNC, are authorised by the system after a complete check on the list of authorised terminal subscribers. NETWORKS WITH DIFFERENT NETWORK CODES (MCC/MNC) Mobiles and groups data base range ITSI 0 to Sub-range visitors Each network owns its data base over the full ITSI range (10 millions of numbers) a part of this range must be preserved for visitors. Figure 4-6 : TETRA Networks with visitor subscribers Upon validation of the system, the Tetra terminal is affected with a new SSI chosen within the list of visitors and all services attached to this terminal can operate. All communication are supported using the temporary SSI and a translation of addresses are also made when external communications are requested (PABX, PSTN, ). TETRA SYSTEM DESCRIPTION 78/97

79 The list of services below is supported by subscriber visitor terminals: Individual calls (half and full duplex, Group calls, SDS messages, Mobility management, Priority calls, Emergency calls, Dynamic group numbering assignment (DGNA). IP packet data calls. The ISI interface is working of an IP linked protocol sharing database information between each sub networks. TETRA SYSTEM DESCRIPTION 79/97

80 4.7 List of TETRA services services authorized beneficiary affected Ambiance listening administration Dispatch stations Radio teminals Discrete listening administration Dispatch stations Radio teminals Radio group Acknowledge group call administration Dispatch stations Radio group Call forward administration Radio terminals Telephone, dispatch Radio terminals Telephone, dispatch Call baring administration Radio terminals Telephone, dispatch Include call administration Radio terminals Telephone, dispatch Radio terminals Telephone, Dispatch Radio group List call Dispatch station Dispatch, telephone Radio terminals Radio terminals Short number addressing administration Dispatch Radio terminals Radio terminals dispatch Talking party identification administration Radio group dispatch Radio terminals Dispatch Late entry administration Radio group dispatch Radio terminals Dynamic group assignement Administration Dispatch stations Dispatch stations Radio terminals Radio terminals Dipatch stations TETRA SYSTEM DESCRIPTION 80/97

81 5. NETWORK MANAGEMENT FEATURES TETRA SYSTEM DESCRIPTION 81/97

82 5.1 Real Time Monitoring & Supervision A schematic of the TETRA radio network is displayed with icons representative any equipment (base station, IP@node, dispatching, PABX,..). Those icons are using different colors according to the equipment status. The graphical Man Machine Interface provided by the ETELM radio network emphasises the importance of having, on a real time basis, a clear view of the network stats and the system proves is ability to provide efficient information to assist maintenance operations. Upon a simple click on a component the supervision system is able to propose more real time information s, by performing a zoom. As example, zooming on a base station displays radio level signal strength received for each of the 4 time slots and for each of the diversity inputs. Figure 5-1 : Hierarchical view of radio network components TETRA SYSTEM DESCRIPTION 82/97

83 5.1.1 Frequency disturbance monitoring The TETRA radio network proposed by ETELM, for all frequency bands available, is able to provide extended features relating to frequency disturbance. Diagnostic of interference is difficult with radio digital technologies while the only sensitive effect is to reduce coverage, without any audio indication. The proposed system automatically detects interference signals received by the base stations and display the level of the interferer with red color for alarm. This feature is mainly important for assisting maintenance team operations and optimisation of the radio frequency use. This is really efficient to monitor any external influence of the TETRA system produced by a collocated radio network or any radio transmission equipment degrading the service level SNMP The Network Management Terminal includes a SNMP agent which is able to redirect any Detected alarms to an external supervision Workstation. From the LAN, it is possible to get a SNMP report and alarms automatically sent by the NMT as standard SNMP message. TETRA SYSTEM DESCRIPTION 83/97

84 5.2 System Management A lot of technical parameters, stored in standard PC file, describe the full hardware and service configuration of the system. Main parameters to enter are: Radio site parameters: these parameters are common for any base station on the site Base station parameters Link description and parameters PABX/PSTN parameters Dispatching parameters Administration console hardware parameters Addressing plan Routing tables Time out timers.. From this file, the system automatically compiles parameters to be downloaded to any of the involved equipment. Links parameters describe the complete double ring link architecture. From these parameters, the system automatically elaborates routing tables for any equipment of the system and sends it Figure 5-2 : Link configuration Network Management Terminal TETRA SYSTEM DESCRIPTION 84/97

85 Base station parameters remote access Figure 5-3 : Base Station parameters Network Management Terminal TETRA SYSTEM DESCRIPTION 85/97

86 5.3 Data Base & User s Management Mobiles data base Any resident mobile is described with four types of information s: Identity Complete ITSI Mobile mnemotechnic name Attached group Technical characteristic of the mobile Traffic rights of the mobile: Radio site where the mobile is accepted Called parties allowed list Authorised calling parties priority. Current state of the mobile Last registration Call forward State: idle, on communication, forwarding, Groups database Any groups information required is described with following information s: Identity Static or dynamic Open or close group Only reachable from dispatcher Reachable by telephone Priority over selective communications Priority under selective communications Type (broadcast, half broadcast or open) Acknowledge group call Restricted area TETRA SYSTEM DESCRIPTION 86/97

87 5.4 Events & Log Files Management Any event in the network is dated and recorded: Events are stored in files one file for one day, automatically opened by the system. In case of disc overflow, oldest files are automatically rubbed out. These file may be either locally edited or exported through the IP network with Excel format in order to be externally processed by standard software for any statistic purpose. Recorded events are: Mobile registrations (with registration radio site indication) Call from mobile, dispatcher or phone (with radio site indication and communication type) Begin and end of any communication. Group attachment Alarms That information s are recorded at the same time from both IP@node with full redundant organisation. Figure 5-4 : Call Data Records Events Log TETRA SYSTEM DESCRIPTION 87/97

88 5.4.1 Statistics / billing A lot of data are recorded in the event files, which may be used for any statistic purpose. These files are available through the LAN from any standard PC and may be used by EXCEL specific programs. Main statistics generally needed are: Technical statistics of the network traffic (and overload detection), area by area. Billing Two typical software are provided with the system: Printing out of the traffic load for any area This software gives histogram of the load for any selected radio site, with peak detect as short as 1 second, according to the date. A zoom is provided for any selected time window. A complementary histogram is available with the sum of all traffics on the network. RESEAU AIR France 6.COM ROISSY - Traitement du fichier : C:\DONNEES\Air France\Roissy\dossier de travail\technique\statistique\histo\histo juillet 06\ his Tous Les Sites H 1H 2H 3H 4H 5H 6H 7H 8H 9H 10H 11H 12H 13H 14H 15H 16H 17H 18H 19H 20H 21H 22H 23H Figure 5-5 : Network Traffic Load graphical reports per hour TETRA SYSTEM DESCRIPTION 88/97

89 Figure 5-6 : Radio site Traffic Load graphical reports per Day TETRA SYSTEM DESCRIPTION 89/97

90 5.5 External System Interface The TETRA radio network proposed by ETELM is an opened system getting ability to be easily interfaced to any types of external IT system connected to the LAN of the equipment. A set of Application Protocol Interface (API) can be provided in order to interface existing external software applications to control audio and data transmission through the TETRA network. Those API can permit to interconnect Command and Control system (C2) for the dispatching part. Also External Webmail servers can be interconnected to the TETRA network in order to transmit standard mail message to an embedded data terminal connected via TETRA terminal. TETRA SYSTEM DESCRIPTION 90/97

91 6. INTEROPERABILITY TESTS TETRA SYSTEM DESCRIPTION 91/97

92 6.1 TETRA Interoperability with ETELM infrastructure ETELM Networks EADS MOTOROLA TELTRONIC SEPURA Bus for Marseille city Bus & Metro for Rennes city Public transportation for Fribourg (Switzerland) Public transportation for Bordeaux Public transportation for Valenciennes Public transportation for Nice Public transportation for Grenoble Roissy - Charles de Gaulle - Air France Airport Municipal Police City of Roubaix Public transportation for Lausanne (Switzerland) Regional Hospital Complex of city of Lille SNCF Train station for Tours SNCF Train station for Ourq SNCF Train station for PARIS Est SNCF Train station for Bordeaux SNCF Train station for Strasbourg SNCF Train station for Marseille SNCF Train station for Lyon SNCF Train station for PARIS Saint Lazare SNCF Train station for PARIS D Austerlitz SNCF Train station for Landy SNCF Train station for Hendaye SNCF Train station for PARIS Montparnasse Electricity central EDF of Bugey TETRA SYSTEM DESCRIPTION 92/97

93 ETELM Networks EADS MOTOROLA TELTRONIC SEPURA Electricity central EDF of Paluel Electricity central EDF of Golfech Electricity central EDF of Flamanville Electricity central EDF of Nogent Electricity central EDF of Tricastin Electricity central EDF of Saint Alban Electricity central EDF of Chinon Electricity central EDF of Cruas Electricity central EDF of Saint Laurent Electricity central EDF of Civaux Electricity central EDF of Cattenom Electricity central EDF of Creys Electricity central EDF of Dampierre Electricity central EDF of Belleville Electricity central EDF of Chooz Electricity central EDF of Penly Public transportation for Geneva (Switzerland) Public transportation for Strasbourg Shopping Centre (UK) City council of Sète Public transportation for Clermont Ferrand City council of Mulhouse Global tracking network Roissy/Orly airport City council of le Mans Security network Elf Pétroleum Nigeria TETRA SYSTEM DESCRIPTION 93/97

94 Beijing Police (Chine) Prison centre of Vaud (Switzerland) Public transportation for Neuchâtel (Switzerland) ETELM Networks EADS MOTOROLA TELTRONIC SEPURA City council of Saint Quentin City council of Strasbourg Bus for Rouen Charleroi Airport (Belgium) Total Congo Record of Worldwide speed train championship (France) Harbour of Hambourg (Germany) Heathrow airport (UK) TETRA SYSTEM DESCRIPTION 94/97

95 7. STANDARD CABINET CONFIGURATION TETRA SYSTEM DESCRIPTION 95/97

96 Figure 7-1 : 4 Tetra carriers cabinets with IP@node TETRA SYSTEM DESCRIPTION 96/97

97 Figure 7-2 : 2 Tetra carriers cabinets with Backup power supply End of Document TETRA SYSTEM DESCRIPTION 97/97