Taking TETRA indoors – provision of in-building coverage for public safety and private networks
Date: Thu, 05/26/2011 - 18:47 Source: Axell Wireless press department
Outdoor networks have been configured to provide a robust and resilient wireless coverage system for the emergency services and other public safety organisations. On the flipside, in-building and ‘confined area’ coverage still requires ‘fine tuning’ before the networks are completed.
The outdoor network can extend coverage to buildings that are positioned close to the site of a base station. However, this doesn’t apply to buildings outside of the range of base station sites, the greater the distance the less sufficient the coverage. The construction and layout of a building can also lead to signal interference, particularly structures with thick walls and sections below ground-level.
It is critical that the emergency services, and internal public safety teams, can use their handsets and communication equipment confidently when entering a building. One solution would be to install a dedicated base station for each building, but this would be a time consuming and costly process, particularly for buildings with low capacity requirements. Another solution is DMO (Direct Mode Operation), which allows direct communication between two handsets without the support of a base station. Despite this DMO can be limited, as it does not support all aspects of the TETRA standard.
This is the view of Håkan Samuelsson, the CTO of Axell Wireless a provider of wireless coverage solutions. He believes that in-building or confined area projects require careful planning. High security applications for TETRA such as metro (underground) networks, airport terminals or road tunnels require a combination of different solutions to provide resilient coverage for a public safety network. According to Samuelsson multi-band repeaters provide operators, and public safety providers, with a cost-effective method of delivering TETRA indoors. The digital repeaters use a software-defined-radio (SDR) approach, and they are able to accommodate future developments, and enhancements, in network functionality without the need to replace older equipment.