Cassidian has supplied a customer with the world’s first prototype of a mobile TETRA LTE radio system, which will allow voice and broadband data services to be used in parallel. As part of the German Armed Forces’ highly mobile cellular networks study, HochZeN (Hochmobile Zellulare Netzwerke), the system passed its first functional test when it was accepted by the Armed Forces’ Technical Centre for Information Technology and Electronics (WTD 81) in November. 

The radio range used for the voice transmission is 400 MHz, which is assigned, in particular, to the military, German security authorities and organisations (BOS), as well as providers and companies in the public transport sector. Enhancing the TETRA radio system with broadband LTE system technology now enables larger volumes of data to be transferred alongside voice services, for example images or videos. 
As part of the study, two radio cells combining TETRA (terrestrial trunked radio) and LTE (Long Term Evolution) were successfully tested, over a period of two weeks, in two of the Armed Forces’ EAGLE IV armoured vehicles. The result was the first test demonstration of the next generation of secure PMR (Professional Mobile Radio) systems. 

Thanks to this highly mobile cell, radio communications are now possible for the first time using a moving base station in a vehicle. Using these highly mobile cells allows between 100 and 1000 users to communicate in all mobile use cases with voice and data services.

During the two-week functional test, more than 100 assessment cases were used to test aspects such as radio range, data transfer rate, performance while moving and interfaces to other systems. The scenarios involved the connection of vehicle and hand-held radios to stationary and moving radio cells. The results achieved for radio coverage were above expectations. Initial evaluation of the results shows that similar ranges were attained for LTE data transfer as for TETRA. In the case of stationary cells, this was, in ideal conditions, up to 19 km. Data rates were dependent on the distance and antenna used and lay between 100 Kbps and 2 Mbps (kilobits/megabits per second). 

The systems delivered by Cassidian will be further developed over the next 12 months and will be subjected to further field tests by the Bundeswehr in 2015.