China’s largest two-way radio manufacturer Hytera is undertaking an ambitious programme of launches in Europe, where it is concentrating on pushing its DMR product range.
Kok Gee Siong, VP for RND Center, Hytera, explained to UK dealers in September that it was highly unlikely that countries which had invested heavily in TETRA, P25 or APCO would switch to another system for public safety communications.
‘The UK Government, for example, will not invest in a new structure. DMR may be cheaper, but the government does not have the cash at the moment,’ he said. ‘UK police forces have been using TETRA for 10 years, there is no point trying to push DMR into public safety organisations here, or in other parts of Europe using TETRA.’
So, while Hytera continues to manufacture TETRA, dPMR and PDT (China’s police communications standard) products, it is concentrating on selling its DMR products in other market segments in countries with strongly embedded public safety communications systems.
Hytera believes there are major opportunities for DMR to penetrate commercial markets, along with the utilities, public services, education and construction sectors.
The company argues that DMR will appeal to users looking for a cheaper system than TETRA. For a start DMR’s longer range means fewer base stations need to be deployed, and Hytera claims the overall cost is three times less than a TETRA system.
Hytera’s latest products are designed to meet the ETSI DMR Tier 2 standard for conventional licensed radio systems. This uses a two-slot TDMA (time division multiple access) structure in the 12.5kHz band and supports voice and IP data services.
The company’s current product range comprises two robust terminals, the PD786 and PD706, the in-vehicle MD785 digital mobile radio and the RD985 digital repeater. Everything is designed to be able to switch between existing analogue equipment and newer digital products.
In the next phase of its roadmap, Hytera will be launching more applications for its systems, while coming down the road in a third phase will be the PD796Ex explosion proof terminal and the SD906 covert radio. It will also launch a DMR trunking system designed to meet the DMR Tier 3 standard for trunked systems, and a DMR simulcast system in 2011.
Kok Gee Siong explained that the unique feature of Hytera’s system is its use of time division multiple access (TDMA). This retains the 12.5kHz channel width and divides it into two alternating timeslots, thereby doubling voice capacity. Each time slot acts as a separate communication channel with an equivalent bandwidth of 6.25kHz, but the channel as a whole maintains the same profile as an analogue 12.5kHz signal. This means that DMR will fit into existing licensed PMR bands, so no re-branding or re-licensing is required, but capacity is doubled. The alternating slot can also be used for data transmissions if necessary.
Kok Gee Siong added that Hytera’s Release 2 software upgrade will allow ‘pseudo-trunking’, whereby the second time slot can be used as a separate speech channel. Hytera also offers various levels of encryption, from basic to full advanced, and a stand encryption board interface for customers who want to add their own encryption system.
The great advantage of DMR TDMA is that it uses two channels with one repeater, one antenna and a simple duplexer. A two-channel analogue or digital FDMA system requires a dedicated repeater for each channel plus expensive combining equipment to enable multiple frequencies to share a single base station antenna.
Kok Gee Siong admitted that such a set up has its disadvantages. ‘It’s a good entry-level system, but it is dangerous in that if the repeater goes down you have no voice channel. But if you buy a two-frequency license and add another repeater and a combiner you will have the necessary back up.’
The TDMA two-slot system also prolongs the battery life of the equipment. ‘Some 80% of the battery life is used on transmission,’ said Kok Gee Siong. ‘With the two-slot TDMA each call requires only half the transmitter’s capacity. You can get a 40% battery life improvement with TDMA.’
Because the DMR system can co-exist with existing analogue systems, Kok Gee Siong sees it as an ideal solution for those customers migrating from analogue to digital.
‘Customers can add a digital site and remove some of their analogue repeaters, but the DMR repeaters will talk to the analogue group. Customers can migrate slowly to suit their needs and available funding until they have a fully digital system,’ he said.
Hytera is looking to roll out further products next year and in particular is looking to increase the amount and type of data that can be transmitted. Its data services so far include: location service; text messaging; call control; telemetry; data transfer; and radio registration.
The company is now in the process of setting up its European distribution system.
PD786 and PD706 terminals
The robust PD786 and PD706 terminals are designed to provide a louder and clearer audio output (1.5W) and range and can operate for 14 hours. The PD786 has a 1.8-inch TFD colour display and full keypad. Among their innovative features is an antenna in the middle, separating the volume and channel knobs, which doubles as an integrated GPS antenna.
MD785 digital mobile radio
The in-vehicle MD785 digital mobile radio features a 2.0 TFT colour LCD display and a louder audio output (6W). The high power model has an output power of 45W and the low power model of 25W. A GPS version is also available.
RD985 digital repeater
The RD985 digital repeater can be used as a base station. It features 16 channels and can auto detect between analogue and digital modes. It has a two-inch 262K TFT LCD screen.