The DMR Trunk– BS mainly works as interface between two communication networks either wired or wireless. This works for trunking feature between different users. The Trunk has IP connectivity providing flexibility to connect to different network users / services via IP. The different modules involved in Base station with trunk are Antenna System comprises of three antennas each of 10 dBi gain covering full 360 deg HPBW, Channel Unit with RF Booster, Switches to route RF to and from different Antennae, filters, Diversity selection switches, controls redundancy switches, Transceiver Section, Baseband Processing and Interfaces Section built around FPGA SoC and interfaces to various devices through the designated interfaces, Other Interfaces: USB interface, GPS interface, Wi-Fi interface, Bluetooth Interface, Ethernet interface and Power Supply Section accepts input from 230 V AC mains provides DC 24 V. Alternately, 24 V DC is also accepted for the operation in case of no AC power availability. Auto changeover provision is built -in.
| Frequency Band | VHF, UHF |
| Frequency Range | VHF 136-174 MHz , UHF 400-470 MHz , 800-890 MHz |
| Frequency increment/channel step | VHF: 2.5 kHz /3.125 kHz , UHF: 5 kHz /6.25 kHz |
| External frequency reference | 10 MHz /12.8 MHz (auto detect) |
| Packet data DMR | ½Rate, ¾Rate, Full rate, SingleSlot |
| Air interface standard DMR | ETSI TS 102 361-1,-2,-3,-4 |
| General design standard | ETSI TR 102 398 V1.4.1 |
| Technology | TDMA-two slot DMR Tier- III Radio trunking Protocol, ETSI standard |
| Frequency Stability | +0.5 ppm or better |
| Channel Spacing | 12.5 kHz , 25 kHz |
| Channel Capacity | 1000 |
| Emission marks | Analog – 11K0F3E(for 12.5 kHz modulation), Digital – 7k60FXD(data), 7K60FXE(voice), 7K60F1W (voice and data) for 4FSK digital modulation |
| Power Supply | Vendor to indicate |
| Digital Vocoder | AMBE+2 |
| Antenna System | Separate antenna system for Tx and Rx which shall include high gain antenna system. Minimum 10dBi or better for Tx (1+1) and Rx ,2 Surge protecting device in RF cables |
| Channel Unit | Shall be modular/Expandable , 2 Each channel should be configurable to traffic and control unit and vice-versa |
| Air Interface Standards | Shall be open standards DMR Tier-Ⅲ |
| Base Station to Base Station and Mater Station Control Interface | For inter cell traffic communication with microwave, optical fibre or PSTN leased line independently |
| RF Output Power | 1 to 50 W (Programmable) |
| FM Hum& Noise | -40 db or better |
| Adjacent channel power | -60 dBc or better |
| Conducted Spurious Emissions | <-36 dBm 30 MHz to1 GHz and <-30 dBm 1 GHz to 4 GHz /12.75 GHz |
| Audio Distortion | 3% |
| Audio Response | +1, -3 dB |
| Modulation | 4FSK |
| Modulation Limiting | +/-2.5 at 12.5 kHz , +/-5.0 kHz at 25 kHz |
| Sensitivity (Analog) | 0.30 µV at 12 dbSINAD |
| Sensitivity (Digital) | 0.30 µV at 5% BER |
| Inter-modulation rejection | 70 dB |
| Adjacent Channel selectivity | >65 db at 12.5 kHz |
| Spurious Rejection | 70 db |
| Hum and Noise | -40 dB |
| Audio Response | +1/-2 db(0.3-2.55 kHz ) |
| Audio Distortion | 3% at 4 W |
| Blocking rejection >1 MHz | 100 db at 1% BER |
| Operating Temperature | -30˚C to +60˚C |
| Storage Temperature | -40°C to +70°C |
| Humidity | 95% Max at +40˚C non-condensing |
| Lowpressure(Altitude15,000ft (4572m)) | MIL STD 810G |
| Vibration | MIL STD 810G |
| Shock | MIL STD 810G |