A time-splitting solution
Published: 01 April, 2009
Motorola’s medium range, non-TETRA solution, the MOTOTRBO digital mobile radio (DMR), is proving extremely popular in the professional market. So why is the DMR option proving so popular? Tim Clark, PCR Product Director (EMEA), Motorola, explains.
Firstly, the audio quality is better, and the speech synthesiser (vocoder) of DMRs eliminates any background noise on the transmitting radio. “But what is most impressive for digital customers is the improved audio at the fringes of radio coverage - as opposed to analogue audio quality which gradually tails off over distance.”
What makes the MOTOTRBO special in the market, however, is its built-in TDMA (time division multiple access) technology. MOTOTRBO is compliant with the open ETSI DMR standard which uses TDMA technology to deliver two voice or data channels in one RF channel - increasing spectrum efficiency and doubling traffic capacity when using a repeater in the network. In effect, TDMA splits an existing radio channel into two time slots. A user who is holding the terminal and speaking is therefore not transmitting the entire time - but only half the time. This results, says Clark, in average power savings and an impressive battery life of 16 hours. The TDMA also means that other users can interrupt transmissions to request priority usage.
One of the first emergency services to have taken up the MOTOTRBO is the Tbilisi Medical Emergency Response Service Centre in the capital of Georgia, which provides 24/7 emergency medical care for 1.3 million people.
The Centre’s ambulance service has replaced its analogue system with 200 fixed mobiles, 60 portable radios and two repeaters in the MOTOTRBO range, while at the same time making the new system compatible with the analogue radios used by the doctors.
Tbilsi’s ambulance service solution also combines voice, text and position location services in a single device.
What is also interesting, however, is the additional applications that are open to users, points out Clark. MOTOTRBO enables simple integration of voice and data communications. The MOTOTRBO radios have built-in IP data modems, enabling cost-effective connectivity with IT systems and the Internet. “MOTOTRBO has recently been enhanced with the launch of IP-Site Connect, a standard feature which enables users to communicate via voice and data over a much wider coverage area and allowing organisations to interconnect sites using the Internet Protocol (IP). So it is now possible to scale up city-wide using up to 15 repeaters, using IP between sites.”
And the fact that the units have an impressive water/dust rating of IP 67 means they could just as easily be used in demanding environments such as USAR and UN disaster relief areas.
MOTOTRBO also operates in digital and analogue mode - providing customers with a cost-effective phased upgrade path, rather than expensive “forklist” replacements of entire systems.
