NXDN NXDN is a trademark of Icom Incorporated and Kenwood Corporation
IDAS in General Icom Digital Advance System Pronounced eye-duss System name given to Icom products that are compatible with the NXDN protocol Kenwood goes by NEXEDGE Robust Analog Feature Set Not to be forgotten in the IDAS discussions today Digital Feature Set Finalized Over 2 years on the market
NXDN Development Overview Regulatory History Re-farming in 1995 March 2007 Report and Order Icom s Role in 6.25 khz Development February 2005 Joint Development Agreement with Kenwood $10M US Stock Swap Product History March 2005: First NXDN Compatible Portable Radio March 2006: First NXDN Compatible Mobile Radio January 2008: 2 nd Generation IDAS Portable February 2008: FR5000 Series IDAS Repeaters
NXDN Overview Continued Partner Expansion Icom Japan and Kenwood Japan initial partners This has now expanded to include not only Icom America and Kenwood USA, but Daniels, Ritron, Trident Micro Systems and Aeroflex as well
FCC Report And Order - 3/22/07 "FCC...strongly urges licensees to consider migrating directly to 6.25 khz technology rather than first adopting 12.5 khz technology and later migrating to 6.25 khz technology." "The FCC reiterated, however, that it will expeditiously establish a schedule for transition to 6.25 khz narrowband technology once the technology matures to the point that sufficient equipment is available for testing." "Deferring the implementation date permits manufacturers to develop and test equipment after the expected finalization of 6.25 khz standards in the near future."
FCC Report And Order - 5/12/08 We are aware that many licensees.. have already commenced the transition to 12.5 khz technology in order to comply with the 2013 deadline. We applaud these efforts, and do not believe that they should be suspended or abandoned. Third Report and Order urging licensees to consider migrating directly to 6.25 khz technology was not intended to dissuade migration to 12.5 khz technology by licensees that have already begun the process.
FCC Report And Order - 5/12/08 We reiterate, however, that 12.5 khz technology is a transitional step in the eventual migration of PLMR systems to 6.25 khz technology. As the demand for scarce PLMR spectrum continues to grow, the Commission will closely monitor the progress made by standards-setting
4 Main Benefits using 6.25 NXDN Technology Regulatory Improved voice information transfer at range Demonstrated better performance in multi-path conditions Lack of white noise and static reduces operator fatigue Digital features Digital provides better integration of signaling features than analog Digital provides new features not available in analog 800-950 BPS control data NEMA GPS compatibility Transport latitude, longitude etc. Limited telemetry
Benefits - Continued Digital features Continued Use entire 6.25 for data Significantly better spectrum efficiency On VHF, 6.25kHz eliminates geographic separation on 7.5kHz channel centers Space every 7.5 khz On UHF, space every 6.25 khz
IDAS Highlights IDAS uses existing one signal/one voice path paradigm No repeater-less complications Site failure only brings down one channel Full backward analog compatibility and mix-mode makes transition to digital an orderly event Uses existing FM hardware Simple to use Easy to repair More affordable components Backwards compatible Easily merges into existing fleets
IDAS Transition Challenges - General DTMF Tones will pass through 6.25 NXDN in limited testing In voting systems, comparators need to work on BER rather than SINAD. This should also be studied. Tonal quality of voice is slightly altered This can be worked with through operator training Agreement about how to handle answer back in Mixed Mode
Band Plan Ready for 6.25 khz in VHF
Band Plan Ready for 6.25 khz in UHF
Choosing the Right Platform When considering a radio platform, you need to consider both current and future needs: Robust, feature rich analog radios Narrow band digital radios with enhanced feature sets
Digital Features PTT ID Alias Table Call Log Call Alert Radio Check Stun Kill Revive Remote Monitor Select Call Group Call Man Down (F3161 Series) Emergency Call Status Message Short (fixed) Message PC remote control Mixed Mode Encryption (15 bit) GPS
6.25 NXDN Next Generation Digital Narrowband
How 6.25 NXDN Works
6.25kHz NXDN Emission Designator 4K00F1E, Voice (for when the use is primarily for voice information) 4K00F1D, Digital (for when the use is primarily for data information)
AMBE+2 versus IMBE Half-rate of IMBE Superior Voice Quality/Performance
Basic Technology (FDMA): Transmitter Circuit Digital signal processing is carried from the microphone voice signal to the modulation input signal to the VCO/PLL. MIC A/D Vocoder processing Frame Sync FEC coding & Frame structure 2-level 4-level Bandwidth limiting filter D/A VCO PLL 4-level FSK Signal Control data 4,800bps 2,400sps A/D: Analog to Digital Converter D/A: Digital to Analog Converter FEC: Forward Error Correction
Symbol Mapping Transfer Rate: 4,800 bps (2,400 symbol per sec.)
Basic Technology (FDMA): Receiver Circuit Digital signal processing is carried from the FM detector output signal to the speaker voice signal Sync Processing Bandwidth limiting filter A/D FM detection 4-level FSK Signal SP D/A Vocoder processing Control data FEC coding& Frame Breakdown 4-level 2-level 4-level judgment 4,800bps 2,400sps
Conventional System 16 bit Unit ID, uniquely definable for each system Identifiable approx. 65,000 units per 1 system 16 bit Group ID, uniquely definable for each system Identifiable approx. 65,000 groups per 1 system 6 bit Radio Access Number (RAN) CTCSS/CDCSS like operation Similar operation to an analog system possible Group call using only RAN (CTCSS/CDCSS like) Selective call using RAN and Unit/Group ID (CTCSS + DTMF like) Even if in Selective Call, Late Entry function works
Channel Parameters Single Data Rate and Single Channel Bandwidth 4800bps, 6.25kHz BW Parameters for 6.25kHz Channel (Mask E) Channel Access FDMA/SCPC Vocoder AMBE+2tm Modulation 4 Level FSK TX BB Filter Root Raised Cosine + sinc RX BB Filter Root Raised Cosine + 1/sinc Data Rate 4800bps Frame Length 80ms Deviation ±1050Hz@±3symbol ±350Hz@±1symbol
Common Air Interface (CAI) Made up from Frame Sync, Control data and Voice data User data can be included Transfer data together with voice data The diagram below shows the basic frame structure of the CAI. Frame Sync Area Control Data Area Voice Data Area
Basic Technology (FDMA): Emission Mask The bandwidth measurements below show the 6.25kHz FDMA signal meets the FCC designated emission mask requirements. 6.25 khz channel
2 6,25 NXDN Signals at 7.5 khz Separation
2 6,25 NXDN Signals at 6.25 khz Separation
Icom IDAS Capable Products, Specifications and Features
Features IDAS F3161 portable and IDAS F5061 mobile are cousins 3-in-1 Platforms - Analog, Digital, Trunking in the same radio 512 Channel Capacity Uses same programming (cloning) software 2.5kHz, 3.125kHz PLL channel steps -22F to +140F Usable temperature range
F3161 Portable one radio, many applications 14 Hour Battery Life @5/5/90 duty cycle 2000 mah Li-Ion Industry Standard low battery alert tones Durability Aluminum die-cast frame and polycarbonate casing Mil-Std 810E IP54/55 dust, splash, and water jet resistance Rugged dual-rail guide securely locks the battery to the radio Full Dot-Matrix Display Selectable from 1 line, 12 character; or 2 line, 24 character Bottom row shows assigned functions [P0] to [P3] Enhanced Audio BTL Amplifier increases audio output Built-in compander provides clear, low noise communications
F3161 Portable one radio, many applications Specifications Transmitter: +/-1ppm stability 75dB Spurious Emissions 80dB Adjacent channel power (25kHz) 46dB FM Hum and Noise (25kHz) Receiver: 75dB Adjacent Channel (25kHz) 70dB Spurious Response 74dB Inter-modulation
F5061 Mobile one radio, many applications 5-50W adjustable power output Excellent Receiver Specifications 85dB Adjacent Channel (25kHz) 90dB Spurious Response 77dB Inter-modulation Front Firing Speaker = Loud Audio, may not require external speaker Splash and Dust Resistant IP54/55 Compliant Ingress Protection rated as resistant to dust and low pressure water jet +/-1ppm stability - Use as inexpensive base station/repeater
F5061 Mobile one radio, many applications 25 Pin Connector and coffee beans Too detailed for this discussion Specific information available on KB
FR5000 Base Station/Repeater Designed from scratch as a base/repeater, not based on mobiles Available mid 2008, samples well before then Supports 25kHz and 12.5kHz Analog, and 6.25kHz NXDN 50 watts, 25 watt continuous duty 19 rack mount 220/110VAC, 12VDC, Battery Back Up Ready Slide in networking card for IP expansion
IDAS LTR-like digital trunking system in summer 08 Both 3161 and 5061 can be upgraded to digital trunking by upgrading firmware
Future System Possibilities
NXDN in the real world
Basic Technology: Analog vs Digital Coverage FDMA achieves the same or better audio coverage than analog FM at distance. Similar performance is stated for MOTOTRBO (TDMA) products. Audio Quality Analog 4L FSK/ FDMA Distance
Coordinating NXDN Icom s Findings
The Coordinating Process As we understand it
Exclusive Channels Much of the discussion here will revolve around exclusive channel coordination
Service Area For the purposes of coordination three different factors are considered HAAT (Height Above Average Terrain) ERP (Effective Radiated Power) Contour
HAAT Way of determining about how high your antenna is ON AVERAGE, in any direction by averaging the terrain to one height Take at least 50 samples along each radial (commonly 72) extending from 2 to 10 miles from site ComStudy does every 1/10 kilometer
ERP Effective Radiated Power The amount of RF power coming from the actual antenna of the transmitter toward the horizon
R-6602(Carey) Contours Based on averaged (flat) terrain Service Contour: Approximate area of service for incumbent Interference Contour: Area where proposed station might interfere with an incumbent. An interference contour is always be larger than a service contour. Currently, coordinators only check to make sure that a proposed licensee s Interference Contour will NOT overlap an incumbent s service contour.
Contours - Continued Field strength values for defining a contour are in dbµ (decibels above 1 µv/meter) In UHF, for example, the service contour is 39 dbµ. VHF is 37 dbµ. Also in UHF, for example, the interference contour is 21 dbµ. VHF is 19 dbµ.
Co-Channel & Adjacent The previous examples were for the purposes of Co-Channel coordination A co-channel signal is any signal at the same frequency. Coordinators often considered frequency separations 6.25 khz (or less) to be the same as co-channel for UHF (7.5 khz for VHF). Adjacent channel signals are considered for coordination also An adjacent channel signal is any signal within 12.5 khz of channel center for UHF and 15 khz for VHF Adjacent channel signals are currently de-rated 12.5 db when being considered
Co-Channel & Adjacent Proposed for 6.25 VHF systems will use a 13 db derating of the interference contour for systems spaced at 7.5 khz. The service contour is the 37 dbu f(50,50) contour and the interference contour is the 32 dbu f(50,10) contour. UHF systems will use an 8 db derating of the interference contour for systems spaced at 6.25 khz. The service contour is the 39 dbu f(50,50) contour and the interference contour is the 29 dbu f(50,10) contour. The derating factors will be reviewed in 2 years and increased by 3 db unless interference cases are documented during the review period. The criteria is used in both directions; i.e. the interference contour of the proposed system may not overlap the service contour of the incumbent system and the interference contour of the incumbent system may not overlap the service contour of the proposed systems.
Adjacent Channel Example With a proposed site, coordinators look at surrounding incumbents up and down from the Proposed Site s center frequency. If their de-rated service contour does not intersect incumbent site service contour, then coordination can proceed.
Tying HAAT, ERP and Contours Together ERP and HAAT both affect the service area radius. If either increases, the radius will increase 50, 50 means that 50 percent of receivers will receive the signal 50% of the time based on above ERP/HAAT. It takes more signal for that. 50, 10 means that 50 percent of receivers will receive the signal 10% of the time based on above ERP/HAAT. It takes less signal for that. Currently, service contours use 50, 50. Interference contours use 50, 10.
Coordination If the proposed stations co-channel or adjacent channel interfering contours cross the incumbents service contour, the proposed stations application cannot go forward. If they do not, then the proposed station can be coordinated.