Mobile Phone Subscribers World-wide. 4. Wireless Telecommunication Systems. Mobile Subscribers by Continent. Development of Mobile Telecom Systems

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1 Mobile Phone Subscribers World-wide Wireless Telecommunication Systems Market GSM DECT TETRA UMTS Subscriber [Million] [Year] GSM total TDMA total CDMA total PDC total Analog total Total wireless Prediction (1998) 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 2 Mobile Subscribers by Continent Development of Mobile Telecom Systems Subscriber [Million] 1, Rest of the world Latin America Asia Pacific (excl. Japan) Western Europe Japan (excl. AP) North America [Year] Courtesy of L.-F. Pau, Ericsson CDMA TDMA FDMA CT0/1 AMPS NMT CT2 IS-136 TDMA D-AMPS GSM PDC IS-95 cdmaone GPRS cdma EDGE 1G 2G 2.5G 3G IMT-FT DECT IMT-SC IS-136HS UWC-136 IMT-DS UTRA FDD / W-CDMA IMT-TC UTRA TDD / TD-CDMA IMT-TC TD-SCDMA IMT-MC cdma EV-DO 1 EV-DV (3) 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 4 GSM: Overview Performance Characteristics of GSM GSM: Formerly: Groupe Spéciale Mobile (founded in 1982) Now: Global System for Mobile Communication Pan-European standard: ETSI: European Telecommunications Standardization Institute Simultaneous introduction of essential services in three phases (1991, 1994, 1996) by the European telecommunication administrations Germany: D1 and D2) Seamless roaming within Europe possible Today many providers all over the world use GSM: More than 184 countries in Asia, Africa, Europe, Australia, the Americas More than 1 billion subscribers More than 70% of all digital mobile phones use GSM Applications in GSM besides telephony: Short Message Service (S): Over 10 billion S per month in Germany, > 360 billion/year worldwide 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 5 Analog systems view point: Communication: Mobile, wireless communication; support for voice and data services Total mobility: International access Chip-card enables use of access points of different providers World-wide connectivity: One number, the network handles localization High capacity: Better frequency efficiency, smaller cells, more customers per cell High transmission quality: High audio quality and reliability for wireless Uninterrupted phone calls at higher speeds (e.g., from cars, trains) Security functions: Access control Authentication via chip-card and PIN 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 6 1

2 There is no perfect system! Drawbacks of GSM Technology-wise: No end-to-end encryption of user data No full ISDN bandwidth of 64 kbit/s to the user No transparent B-channel Environment-wise: Reduced concentration while driving Electromagnetic radiation Security-wise: Abuse of private data possible Roaming profiles accessible Organizational: High complexity of the system Several incompatibilities within the GSM standards 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 7 GSM Mobile Services GSM offers: Several types of connections: Voice connections Data connections Short Message Service (S) Multi-service options (combination of basic services) Three service domains: Bearer Services (Trägerdienste) require layers 1-3 Telematic Services require layers 1-7 Supplementary Services Bearer services TE MT GSM-PLMN Transit Source/ Destination TE R, S U m (, ISDN) (U, S, R) Tele services 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 8 : Mobile Station TE: Terminal Equipment MT: Mobile Terminal PLMN: Public Land Mobile : Public Switched Telephone ISDN: Integrated Services Digital GSM Bearer Services GSM Tele Services (1) Telecommunication services to transfer data between any two access points Specification of services up to the terminal interface: L1-3 Different data rates for voice and data (original standard): Data service (circuit switched): Synchronous: 2.4, 4.8, or 9.6 kbit/s Asynchronous: bit/s Data service (packet switched): Synchronous: 2.4, 4.8, or 9.6 kbit/s Asynchronous: bit/s Transparent bearer services require layer 1 only: May include FEC, but no error correction within GSM Non-transparent bearer services require layer 1-3: Radio Link Protocol (RLP) with retransmission, achieving 10-7 error rates Today: Data rates of approx. 50 kbit/s possible later! 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 9 Telecommunication services enabling voice communication via mobile phones All basic services have to obey: Cellular functions Security measurements Offered services: Mobile telephony: Primary goal of GSM was to enable mobile telephony offering the traditional bandwidth of 3.1 khz Emergency number: Common number throughout Europe (112) Mandatory for all service providers; free of charge; connection with the highest priority (preemption of other connections possible) Multi-numbering: Several ISDN phone numbers per user possible 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 10 Additional services: Non-Voice-Tele-services: GSM Tele Services (2) Group 3 fax Voice mailbox Implemented in the fixed network supporting mobile terminals Electronic mail: MHS (Message Handling System) implemented in the fixed network... Short Message Service (S): Alphanumeric data transmission to/from the mobile terminal Limited to 160 Byte message length Uses the signaling channel Allowing simultaneous use of basic services and S GSM Supplementary Services Services in addition to basic services: Cannot be offered stand-alone Similar to ISDN services: Besides lower bandwidth due to the radio link May differ between different service providers, countries, and protocol versions Important services: Identification: forwarding of caller number Suppression of number forwarding Automatic call-back Conferencing with up to 7 participants Locking of the mobile terminal (incoming or outgoing calls) Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 12 2

3 Architecture of the GSM System GSM System Overview GSM is a PLMN (Public Land Mobile ): Several providers setup mobile networks following the GSM standard within each country separately Components required: (Mobile Station) BS (Base Station): Coding/Decoding of voice: 13 kbit/s<-> 64 kbit/s (Mobile Switching Center): Connection set-up to s/s LR (Location Register) Subsystems: RSS (Radio Subsystem): Covers all radio aspects NSS ( and Switching Subsystem): Call forwarding, handover, switching OSS (Operation Subsystem): Management of the network 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 13 NSS with OSS RSS OMC, EIR, AUC HLR 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 14 G Fixed : Base Transceiver Station G: GSM : Visiting LR HLR: Home LR OMC: Operations and Maintenance Center : Base Station Controller EIR: Equipment Identity Register AUC: Authorization Center : Mobile Switching Center GSM System Elements and Interfaces GSM System Architecture Radio Cell RSS NSS Fixed Partner s RSS U m Radio Cell U m ISDN NSS OSS A bis A EIR HLR O AUC OMC G IWF Signaling ISDN, PDN : Base Transceiver Station : Base Station Controller IWF: Inter-working Functions PDN: Public Data : Public Switched Telephone A bis A SS7 IWF EIR HLR CSPDN: Circuit Switched PDN PSPDN: Packet Switched PDN ISDN PSPDN CSPDN 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 16 System Architecture Radio Subsystem RSS U m A bis A NSS 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 17 Components (Mobile Station) (Base Station Subsystem): consisting of: (Base Transceiver Station): sender and receiver (Base Station Controller): controlling several transceivers Interfaces U m : radio interface A bis : standardized, open interface with 16 kbit/s user channels A: standardized, open interface with 64 kbit/s user channels SS7 IWF System Architecture and Switching Subsystem NSS EIR HLR Fixed Partner s ISDN ISDN PSPDN CSPDN 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 18 Components: (Mobile Services Switching Center): IWF (Inter-working Functions) ISDN (Integrated Services Digital ) (Public Switched Telephone ) PSPDN (Packet Switched Public Data ) CSPDN (Circuit Switched Public Data ) Data-bases: HLR (Home Location Register) (Visitor Location Register) EIR (Equipment Identity Register) 3

4 Radio Subsystem The Radio Subsystem (RSS) comprises: Cellular mobile network up to Switching centers Components: Base Station Subsystem (): Base Transceiver Station (): Radio components including sender Receiver Antenna - if directed antennas are used one can cover several cells Base Station Controller (): Switching between s Controlling s Managing of network resources Mapping of radio channels (U m ) onto terrestrial channels (A interface) = + sum() + interconnection Mobile Stations () GSM Cellular Use of several carrier frequencies: Not the same frequency in adjoining cells Cell sizes vary from some 100 m up to 35 km: Depending on user density, geography, transceiver power etc. Hexagonal shape of cells is idealized: Cells overlap, shapes depend on geography If a mobile user changes cells Hand-over of the connection to the neighboring cell Segmentation of the area into cells cell Possible radio coverage of the cell Idealized shape of the cell 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 20 Example Coverage of GSM s Example Coverage of GSM s Orange (GSM-1800) TDC Sunrise (GSM-900/1800) T-Mobile (GSM-900/1800) Berlin Vodafone (GSM-900/1800) Swisscom (GSM-900/1800) e-plus (GSM-1800) O 2 (GSM-1800) Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 22 Base Transceiver Station/Base Station Controller Tasks of a are distributed over and comprises radio specific functions is the switching center for radio channels Functions Management of radio channels Frequency hopping (FH) Management of terrestrial channels Mapping of terrestrial onto radio channels Channel coding and decoding Rate adaptation Encryption and decryption Paging Uplink signal measurements Traffic measurement Authentication Location registry, location update Handover management 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 23 : Base Transceiver Station : Base Station Controller : Base Station Subsystem Mobile Station Terminal for the use of GSM services A mobile station () comprises several functional groups: MT (Mobile Terminal): Offers common functions used by all services the offers Corresponds to the network termination (NT) of an ISDN access End-point of the radio interface (U m ) TA (Terminal Adapter): Terminal adaptation, hides radio specific characteristics TE (Terminal Equipment): Peripheral device of the, offers services to a user Does not contain GSM specific functions SIM (Subscriber Identity Module): Personalization of the mobile terminal, stores user parameters TE TA MT R S 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 24 U m 4

5 and Switching Subsystem Mobile Services Switching Center NSS is the main component of the public mobile network GSM: Switching Mobility management Interconnection to other networks System control Components: Mobile Switching Center (): Controls all connections via a separated network to/from a mobile terminal within the domain of the - several can belong to a Databases (important with respect to scalability, high capacity, low delay): Home Location Register (HLR): Central master database containing user data, permanent and semi-permanent data of all subscribers assigned to the HLR (one provider can have several HLRs) Visitor Location Register (): Local database for a subset of user data, including data about all user currently in the domain of the 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 25 The (Mobile Switching Center) plays a central role in GSM: Switching functions Additional functions for mobility support Management of network resources Inter-working functions via Gateway (G) Integration of several databases Functions of a : Specific functions for paging and call forwarding Termination of SS7 (Signaling System No. 7) Mobility specific signaling Location registration and forwarding of location information Provision of new services (fax, data calls) Support of short message service (S) Generation and forwarding of accounting and billing information 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 26 Operation Subsystem The OSS (Operation Subsystem) enables: Centralized operation Management Maintenance of all GSM subsystems Components: Authentication Center (AUC): Generates user specific authentication parameters on request of a Authentication parameters used for authentication of mobile terminals and encryption of user data on the air interface within the GSM system Equipment Identity Register (EIR): Registers GSM mobile stations and user rights Stolen or malfunctioning mobile stations can be locked and sometimes even localized Operation and Maintenance Center (OMC): Different control capabilities for the radio subsystem and the network subsystem 2005 Burkhard Stiller and Jochen Schiller FU Berlin M f in 900 MHz 374 f in 1800 MHz GSM TDMA/FDMA (Air Interface: U m ) Frequency GSM TDMA Frame GSM Time-slot (Normal Burst) 2005 Burkhard Stiller and Jochen Schiller FU Berlin M MHz 124 Channels (200 khz) Downlink MHz 124 Channels (200 khz) Uplink Higher GSM Frame Structures time Up-link and down-link are sent 3 slots later ms Guard Space Tail User Data S Training S User Data Tail Guard Space 3 bit 57 bit 1 26 bit 1 57 bit 3 bit 148 bit: 33,8 kbit/s S bit: Control or Signaling µs 577 µs GSM Hierarchy of Frames GSM Protocol Layers for Signaling Hyper-frame h 28 min s U m A bis A Super-frame Multi-frame s 120 ms CM MM RR LAPD m Radio RR LAPD m Radio M LAPD PCM RR M LAPD PCM AP SS7 PCM CM MM AP SS7 PCM Frame slot burst 2005 Burkhard Stiller and Jochen Schiller FU Berlin M ms ms 577 µs : Mobile Switching Center : Mobile System : Base Transceiver Station : Base Station Controller LAPD: Link Access Protocol type D 16/64 kbit/s 2005 Burkhard Stiller and Jochen Schiller FU Berlin M kbit/s / Mbit/s AP: Base Station System Application Part M: Base Transceiver Station Management RR: Radio Resource Management MM: Mobility Management CM: Communication Management 5

6 Mobile Station Terminated Call (MTC) Mobile Station Originated Call (MOC) 1: Calling a GSM subscriber Calling 2: Forwarding call to G Station 1 3: Signal call setup to HLR 4, 5: Request RN from 6: Forward responsible to G 7: Forward call to current 8, 9: Get current status of 10, 11: Paging of 12, 13: answers 4 HLR G , 2: Connection request 3, 4: Security check 5-8: Check resources (free circuit) 9-10: Set up call 6 5 G , 15: Security checks 16, 17: Set up connection G: Gateway Mobile Switching Center RN: Mobile Station Roaming Number 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 32 MTC/MOC 4 Types of Hand-over MTC paging request channel request immediate assignment paging response authentication request authentication response ciphering command ciphering complete setup call confirmed assignment command assignment complete alerting connect connect acknowledge data/speech exchange channel request immediate assignment service request authentication request authentication response ciphering command ciphering complete setup call confirmed assignment command assignment complete alerting connect MOC connect acknowledge data/speech exchange MTC: Mobile Terminated Call MOC: Mobile Originated Call : Mobile System : Base Transceiver Station 1. Intra-cell hand-over: within a single range (different freq.) 2. Inter-cell hand-over: between 2 and one 3./4. Inter- or intra-technology hand-over: between s/s Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 34 Hand-over Decision Hand-over Procedure Receive Level old HO_MARGIN Receive Level new Measurement Report old old Measurement Result HO Decision HO Required new new HO Request Resource Allocation Change Activation HO Command HO Command Change Activation HO command HO Request ACK ACK HO Access Link Establishment HO Complete HO Complete Clear CommandClear Command Clear Complete Clear Complete old new 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 36 6

7 Security services: Access control/authentication: Security in GSM User SIM (Subscriber Identity Module): Secret PIN (personal identification number) SIM : challenge response method Confidentiality: Voice & signaling encrypted on wireless link (after successful authentication) Anonymity: Temporary identity TI (Temporary Mobile Subscriber Identity) Newly assigned at each new location update (LUP) Encrypted transmission 3 algorithms specified in GSM: A3 for authentication ( secret, open interface) A5 for encryption (standardized) A8 for key generation ( secret, open interface) 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 37 Definition of secret : A5 published A3 and A8 available via the Internet providers can use stronger mechanisms K i : Individual Subscriber Authentication Key RAND: Random SRES: Signed Mobile Response K i RAND AC (Access Control) 2a. GSM Authentication 128 bit 128 bit A3 SRES* 32 bit SRES* =? SRES RAND SRES 32 bit 2005 Burkhard Stiller and Jochen Schiller FU Berlin M b. RAND A3 K i 128 bit 128 bit SRES SIM SRES 32 bit AuC calculates, transfer to HLR (Ki, SRES, RAND), asks for those for a new. sent RAND to (SIM), returns SRES, compares. SIM GSM Key Generation and Encryption AC Cipher Key Mobile K i A8 RAND 128 bit 128 bit K c 64 bit A5 2a. Data 1. RAND 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 39 2b. 3. Encrypted Data with SIM RAND A8 K i 128 bit 128 bit K c 64 bit Data SRES A5 K i : Individual Subscriber Authentication Key RAND: Random K c : Cipher Key SIM GSM System Parameter Overview Multiple Access Method: TDMA / FDMA Up-link frequencies: MHz (basic GSM) Down-link frequencies: MHz (basic GSM) Multiplexing: FDD: Channel spacing: 200 khz Modulation: GK Portable T power, maximum/average: 1000 mw/125 mw Power control, handset and : Yes Speech coding and rate: RPE-LTP with 13 kbit/s Speech Channels per RF channel: 8 Channel rate: kbit/s Channel coding: Rate 1/2 convolutional Frame duration: ms 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 40 GSM Interfaces Overview (1) Um: The air interface is used for exchanges between a and a. LAPDm, a modified version of the ISDN LAPD, is used for signaling. Abis: This is a internal interface linking the and a, and it has not been standardized. The Abis interface allows control of the radio equipment and radio frequency allocation in the. A: The A interface is between the and the. The A interface manages the allocation of suitable radio resources to the s and mobility management. B: The B interface between the and the uses the MAP/B protocol. Most s are associated with a, making the B interface "internal". Whenever the needs access to data regarding a located in its area, it interrogates the using the MAP/B protocol over the B interface. GSM Interfaces Overview (2) C: The C interface is between the HLR and a G or a S-G. Each call originating outside of GSM (i.e., a terminating call from the ) has to go through a Gateway to obtain the routing information required to complete the call, and the MAP/C protocol over the C interface is used for this purpose. Also, the may optionally forward billing information to the HLR after call clearing. D: The D interface is between the and HLR, and uses the MAP/D protocol to exchange the data related to the location of the and to the management of the subscriber. E: The E interface interconnects two s. The E interface exchanges data related to hand-over between the anchor and relay s using the MAP/E protocol Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 42 7

8 GSM Interfaces Overview (3) F: The F interface connects the to the EIR, and uses the MAP/F protocol to verify the status of the IMEI that the has retrieved from the. G: The G interface interconnects two s of different s and uses the MAP/G protocol to transfer subscriber information, during, e.g., a location update procedure. H: The H interface is between the and the S-G, and uses the MAP/H protocol to support the transfer of short messages. I: The I interface is the interface between the and the. Messages exchanged over the I interface are relayed transparently through the Burkhard Stiller and Jochen Schiller FU Berlin M4 43 Data Services in GSM (1) Data transmission standardized with only 9.6 kbit/s: Advanced coding allows 14,4 kbit/s Not enough for Internet and multimedia applications HSCSD (High-speed Circuit Switched Data): Mainly software update Bundling of several time-slots to get higher AIUR (Air Interface User Rate) (e.g., 57.6 kbit/s using 4 slots, 14.4 each) Advantage: ready to use, constant quality, simple Drawback: channels blocked for voice transmission AIUR [kbit/s] TCH/F4.8 TCH/F9.6 TCH/F Burkhard Stiller and Jochen Schiller FU Berlin M4 44 TCH: Traffic Channel TCH/F: TCH Full Rate Data Services in GSM (2) GPRS Architecture and Interfaces GPRS (General Packet Radio Service): Packet switching Using free slots only if data packets ready to send (e.g., 115 kbit/s using 8 slots temporarily) Standardization 1998, introduction 2001 Advantage: one step towards UMTS, more flexible Drawback: more investment needed (new hardware) GPRS network elements: GSN (GPRS Support Nodes): GGSN and SGSN GGSN (Gateway GSN) Inter-working unit between GPRS and PDN (Packet Data ) SGSN (Serving GSN) Supports the (location, billing, security) GR (GPRS Register) User addresses 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 45 SGSN GGSN U m SGSN EIR 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 46 G n G b G n G i HLR/ GR PDN GSN: GPRS Support Nodes ( Router ) GGSN: Gateway GSN (Address Translation) SGSN: Serving GSN (Accounting and Access Control) GR: GPRS Register GPRS Quality-of-Service (QoS) GPRS Protocol Architecture Reliability class Lost SDU probability Duplicate SDU probability Out of sequence SDU probability Corrupt SDU probability ETSI Standard Delay SDU size 128 byte SDU size 1024 byte class mean 95 percentile mean 95 percentile 1 < 0.5 s < 1.5 s < 2 s < 7 s 2 < 5 s < 25 s < 15 s < 75 s 3 < 50 s < 250 s < 75 s < 375 s 4 unspecified ETSI Standard U m G SGSN b G GGSN n apps. IP/.25 SNDCP LLC SNDCP GTP LLC UDP/TCP IP/.25 GTP UDP/TCP RLC RLC GP GP IP IP MAC MAC FR FR L1/L2 L1/L2 radio radio SNDCP: Sub-network Dependent Convergence Protocol GP: Base Station Subsystem GPRS Protocol GTP: GPRS Tunneling Protocol G i 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 48 8

9 DECT DECT System Architecture Reference Model DECT (Digital European Cordless Telephone): Standardized by ETSI (ETS x) for cordless telephones Standard describes: Air interface between base station and mobile phone DECT has been renamed for international marketing reasons into Digital Enhanced Cordless Telecommunication Characteristics: Frequency: MHz Channels: 120 full duplex Duplex mechanism: TDD (Time Division Duplex) with 10 ms frame length Multiplexing scheme: FDMA with 10 carrier frequencies, TDMA with 2x 12 slots Modulation: digital, Gaussian Minimum Shift Key (GK) Power: 10 mw average (max. 250 mw) Range: approximately 50 m in buildings, m open space (LoS) 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 49 PA PA D 4 PT PT D 3 FT FT Local D 1 Local 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 50 D 2 VDB Simple services behind D 2 D 4, (DECT-internal). Value-added services available from local or global network. HDB Global PA: Point of Attachment PT: Portable Radio Termination FT: Fixed Radio Termination VDB: Visitor Data Base HDB: Home Data Base MT: Mobile Terminal DECT Reference Model DECT Layers (1) C-Plane Signaling, Inter-working Layer Data Link Control Management Medium Access Control Physical Layer U-Plane Application Processes Data Link Control OSI Layer 3 OSI Layer 2 OSI Layer 1 Close to the OSI reference model Management plane over all layers Several services in C(ontrol)- and U(ser)- plane Physical layer: Modulation/demodulation Generation of the physical channel structure with a guaranteed throughput Controlling of radio transmission Channel assignment on request of the MAC layer Detection of incoming signals Sender/receiver synchronization Collecting status information for the management plane MAC layer: Maintaining basic services, activating/deactivating physical channels Multiplexing of logical channels E.g., C: signaling, I: user data, P: paging, Q: broadcast Segmentation/reassembly Error control/error correction 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 52 Basic Connection Mode: Send in s Receive in s+12 A: Control (6.4 kbit/s) B: User Data : Transmission Quality C: 16 bit Checksum 25.6 kbit/s Simplex Bearer 32 kbit/s DECT Time Multiplex Frame 1 Frame = 10 ms 12 Down Slots 12 Up Slots Slot Guard bit + 52 µs Guard Time ( 60 bit ) in ms Sync D Field Burkhard Stiller and Jochen Schiller FU Berlin M4 53 A Field B Field Field Protected Mode Unprotected Mode DATA 64 C 16 DATA 64 C 16 DATA DATA 64 C 16 DATA 64 C 16 DECT Layers (2) Data link control layer: Creation and keeping up reliable connections between the MT and BS Two DLC protocols for the control plane (C-Plane) Connectionless broadcast service: Paging functionality (Lb) Lc+LAPC protocol: In-call signaling (similar to LAPD within ISDN) Adapted to the underlying MAC service Several services specified for the user plane (U-Plane) Null-service: offers unmodified MAC services Frame relay: simple packet transmission Frame switching: Time-bounded packet transmission Error correcting transmission: Uses FEC, for delay critical, time-bounded services Bandwidth adaptive transmission Escape service: For further enhancements of the standard 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 54 9

10 DECT Layers (3) layer: Similar to ISDN (Q.931) and GSM (04.08) Offers services to request, check, reserve, control, and release resources at the base station and mobile terminal Resources: Necessary for a wireless connection Necessary for the connection of the DECT system to the fixed network Main tasks: Call control: Setup, release, negotiation, control Call independent services: Call forwarding, accounting, call redirecting Mobility management: Identity management, authentication, management of the location register 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 55 Enhancements of the Standard Several DECT Application Profiles in addition to the DECT specification: GAP (Generic Access Profile) standardized by ETSI in 1997: Assures interoperability between DECT equipment of different manufacturers (minimal requirements for voice communication) Enhanced management capabilities through the fixed network: Cordless Terminal Mobility (CTM) Fixed DECT Base Station DECT/GSM Inter-working Profile (GIP): Connection to GSM ISDN Inter-working Profiles (IAP, IIP): Connection to ISDN Radio Local Loop Access Profile (RAP): Public telephone service CTM Access Profile (CAP): Support for user mobility 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 56 DECT Common Air Interface GAP DECT Portable Part TETRA Terrestrial Trunked Radio Trunked radio systems (Bündelfunksysteme): Many different radio carriers Assign single carrier for a short period to one user/group of users Applications: Taxi service, fleet management, rescue teams Traditional systems with separate frequencies, TETRA with application of FDM/TDM on a single carrier (sharing of frequencies) Interfaces to public networks, voice, and data services Very reliable, fast call setup, local operation, less complex architecture TETRA: ETSI standard (1991), formerly: Trans European Trunked Radio Offers Voice+Data (V+D) and Packet Data Optimized (PDO) service Point-to-point and point-to-multipoint: 128 Byte message with < 100 ms delay Ad-hoc and infrastructure networks for kbit/s Several frequencies: MHz, MHz with FDD, DQPSK Channel with 25 khz, 36 kbit/s raw data rate Group call, broadcast, sub-second group-call setup 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 57 DQPSK. Differential Quatrature Phase Shift Keying UMTS and IMT-2000 Proposals for IMT-2000 (International Mobile Telecommunications): UWC-136, cdma2000, WP-CDMA UMTS (Universal Mobile Telecommunications System) from ETSI UMTS: UTRA (was: UMTS, now: Universal Terrestrial Radio Access) Enhancements of GSM: EDGE (Enhanced Data rates for GSM Evolution): GSM up to 384 kbit/s CAMEL (Customized Application for Mobile Enhanced Logic) VHE (Virtual Home Environment) Fits into GMM (Global Multimedia Mobility) initiative from ETSI Requirements Minimum of 144 kbit/s rural (goal: 384 kbit/s) Minimum of 384 kbit/s suburban (goal: 512 kbit/s) Up to 2 Mbit/s urban 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 58 Frequencies for IMT-2000 IMT-2000 Family ITU allocation (WRC 1992) Europe China Japan North America MHz GSM 1800 GSM 1800 T DE D CT D IMT-2000 UTRA FDD IMT-2000 S S S cdma2000s PHS W-CDMA PCS T D D S IMT-2000 S UTRA FDD S IMT-2000 S cdma2000s W-CDMA S MHz rsv. IMT-2000 Core ITU-T Initial UMTS (R99 w/ FDD) IMT-2000 Radio Access ITU-R IMT-DS (Direct Spread) UTRA FDD (W-CDMA) 3GPP GSM (MAP) IMT-TC (Time Code) UTRA TDD (TD-CDMA); TD-SCDMA 3GPP Interface for Internetworking ANSI-41 (IS-634) Flexible assignment of Core and Radio Access IMT-MC (Multi Carrier) cdma2000 3GPP2 IP- IMT-SC (Single Carrier) UWC-136 (EDGE) UWCC/3GPP IMT-FT (Freq. Time) DECT ETSI 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M

11 Licensing Example: UMTS in D; August 18, 2000 UTRA-FDD: Uplink MHz Downlink MHz duplex spacing 190 MHz 12 channels, each 5 MHz UTRA-TDD: MHz, MHz; 5 MHz channels Coverage: 25% of the population until 12/2003, 50% until 12/2005 Sum: billion Multiple Access Methods European Telecommunication Standards Institute (ETSI): SMG2 committee compared five alternative proposal for the multiple access scheme to be employed on the air interface in ETSI UTRA air interface technology process Concept group Alpha Beta Multiple access scheme Wideband code division multiple access (W-CDMA) Orthogonal frequency division multiple access (OFDM) Gamma Wideband time division multiple access (Wideband-TDMA ) Delta Time division/code division multiple access (TD-CDMA ) Epsilon Opportunity driven multiple access (ODMA) Selection: W-CDMA -> used sometimes as a synonym for UMTS Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 62 UMTS Architecture (Release 99 used here!) UTRAN (UTRA ) Cell level mobility Radio Subsystem (RNS) Encapsulation of all radio specific tasks UE (User Equipment) CN (Core ) Inter system hand-over Location management, if there is no dedicated connection between UE and UTRAN UE U u UTRAN I u CN USIM Domain UMTS Domains and Interfaces (1) C u Mobile U u Access I u Equipment Domain Domain User Equipment Domain Home Domain Z u Serving Domain Infrastructure Domain User Equipment Domain Assigned to a single user in order to access UMTS services Infrastructure Domain Shared among all users Offers UMTS services to all accepted users Y u Core Domain Transit Domain 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 64 UMTS Domains and Interfaces (2) Universal Subscriber Identity Module (USIM) Functions for encryption and authentication of users Located on a SIM inserted into a mobile device Mobile Equipment Domain Functions for radio transmission User interface for establishing/maintaining end-to-end connections Access Domain Access network dependent functions Core Domain Access network independent functions Serving Domain currently responsible for communication Home Domain Location and access network independent functions 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 65 Standards of Radio Access Harmonization of the FDD and TDD modes resulted in the UTRA (UMTS Terrestrial Radio Access): Chip rate Modulation UTRA parameters (at time of submission of rtt to ITU) Multiple access scheme Carrier spacing (bandwidth) Pulse shaping Frame length Timeslots per frame 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 66 FDD TDD W-CDMA TD-CDMA MHz 5 MHz Mchip/s (Mcps); now 3.84 Mcps QPSK Root raise cosine, roll-off = ms 16; now 15 FDD: Frequency Division Duplex TDD: Time Division Duplex 11

12 UMTS FDD Frame Structure UMTS TDD Frame Structure (Burst Type 2) 10 ms µs µs Radio frame Time slot Pilot TFCI FBI TPC 2560 chips, 10 bits Data 2560 chips, 10*2 k bits (k = 0...6) µs Data 1 TPC TFCI Data 2 Pilot DPDCH DPCCHDPDCHDPCCH 2560 chips, 10*2 k bits (k = 0...7) 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 67 uplink DPCCH 15 kbit/s min CH, 256 S uplink DPDCH Slot structure NOT for user separation, but synchronization for periodic functions! downlink DPCH 6 kbit/s 512 S 1872 kbit/s 4 S W-CDMA MHz uplink MHz downlink Chipping rate: Mchip/s Soft hand-over QPSK Complex power control (1500 power control cycles/s) Spreading: Up-link: 4-256; Down-link: FBI: Feedback Information TPC: Transmit Power Control TFCI: Transport Format Combination Indicator DPCCH: Dedicated Physical Control Channel DPDCH: Dedicated Physical Data Channel DPCH: Dedicated Physical Channel 10 ms Radio frame Time slot µs Data Mid sample Data GP 1104 chips 256 chips 1104 chips 2560 chips TD-CDMA: 2560 chips per slot, 10 ms frame duration Spreading: 1-16 Symmetric or asymmetric slot assignment to UL/DL (min. 1 per direction) Tight synchronization needed due to a similar chips sequence in all BS/MT Simpler power control ( power control cycles/s) due to synchronization and orthogonal codes 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 68 Traffic burst GP: guard period 96 chips UTRAN Architecture UTRAN Functions RNS UE 1 I ub RNC UE 2 UE 3 I ur I ub RNC RNS 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 69 I u RNC: Radio Controller RNS: Radio Subsystem CN UTRAN comprises several RNSs can support FDD or TDD or both RNC is responsible for handover decisions requiring signaling to the UE Cell offers FDD or TDD Admission control Congestion control System information broadcasting Radio channel encryption Hand-over SRNS moving Radio network configuration Channel quality measurements Macro diversity Radio carrier control Radio resource control Data transmission over the radio interface Outer loop power control (FDD and TDD) Channel coding Access control 2005 Burkhard Stiller and Jochen Schiller FU Berlin M4 70 Core : Protocols Core : Architecture RNS GSM-CS backbone G / ISDN GSM A bis RSS I u G CS Domain HLR PDN (.25), Internet (IP) Node B I u CS AuC RNS Layer 3: IP Layer 2: ATM Layer 1: PDH, SDH, SONET UTRAN SGSN GPRS backbone (IP) SS 7 CN GGSN RNC: Radio Controller RNS: Radio Subsystem CN: Core GSN: GPRS Support Nodes GGSN: Gateway GSN SGSN: Serving GSN UTRAN RNS I ub RNC RNS EIR SGSN I u PS HLR GR PS Domain G n GGSN G i CN 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M

13 Core UMTS Protocol Stacks (User Plane) The Core (CN) and thus the Interface I u, too, are separated into two logical domains Circuit Switched Domain (CSD): Circuit switched service incl. signaling Resource reservation at connection setup GSM components (, G, ) I u CS Packet Switched Domain (PSD): GPRS components (SGSN, GGSN) I u PS Release 99 uses the GSM/GPRS network and adds a new radio access! Helps to save a lot of money Much faster deployment Not as flexible as newer releases Circuit switched Packet switched UE U u UTRAN I u CS 3G apps. & protocols RLC MAC radio RLC MAC radio SAR AAL2 ATM SAR AAL2 ATM UE U u UTRAN I u PS 3G G n apps. & protocols SGSN IP, PPP, IP tunnel PDCP PDCP GTP GTP GTP RLC RLC UDP/IP UDP/IP UDP/IP MAC radio MAC radio AAL5 ATM AAL5 ATM L2 L1 3G GGSN IP, PPP, GTP UDP/IP L2 L Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 74 Support of Mobility: Macro Diversity Example Hand-over Types in UMTS/GSM Soft hand-over UE UE: User Equipment CN: Core RNC: Radio Control RNC CN Multicasting of data via several physical channels: Enables soft handover FDD mode only Up-link: Simultaneous reception of UE data at several s Reconstruction of data at, SRNC (serving) or DRNC (drift) Down-link: Simultaneous transmission of data via different cells Different spreading codes in different cells Intra-node B, intra-rnc Inter-node B, intra-rnc Inter-RNC or Inter- Inter-System UE 1 UE 2 UE 3 UE 4 1 RNC 1 3G 1 I u 2 I ub I ur 3 RNC 2 3G 2 2G 3 A bis A 2005 Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M4 77 Voice UMTS Services (Originally) Data transmission service profiles: Service Profile High Interactive MM High MM Medium MM Switched Data Simple Messaging Bandwidth Transport Mode 128 kbit/s Circuit switched 2 Mbit/s Packet switched 384 kbit/s Circuit switched 14.4 kbit/s Circuit switched 14.4 kbit/s Packet switched 16 kbit/s Circuit switched Bidirectional, video telephone Low coverage, max. 6 km/h Asymmetrical, MM, downloads S successor, Virtual Home Environment (VHE): Enables access to personalized data independent of location, access network, and device operators may offer new services without changing the network Service providers may offer services based on components which allow the automatic adaptation to new networks and devices Integration of existing IN services Global UMTS-related Harmonization 3GPP Third Generation Partnership Project: Aim: Harmonization of various proposals on W-CDMA in 1998 Merger of ETSI and Japanese proposals into a single common standard was achieved by 3GPP! 3GPP2 Third Generation Partnership Project 2: Aim: Harmonization of various proposals on cdma2000 in 1999 OHG Operator Harmonization Group: Aim: Harmonization of 3GPP and 3GPP2 concepts! Resulted in Global Third Generation (G3G) project: Inter-working between UTRA and cdma Burkhard Stiller and Jochen Schiller FU Berlin M Burkhard Stiller and Jochen Schiller FU Berlin M