WIDENS

- user's perspective

- technologies

Most of the present standards and products in the telecommunications field are targeting the commercial mass market. This provides cost-effective solutions and markets with sufficient size. On the other side, the public safety market is small and relies on public funding and citizen support, thus competing with other social or political priorities. There is therefore a strong incentive to use commercial mass market communications products and standards in the public safety domain. R. Knopp, presenting the WIDENS prototype and demonstrator, provided a detailed argument for the need to develop new technology for public safety communications systems, showing why the existing air interface standards (UMTS, 802.11a in particular) do not match the needs of broadband ad hoc networks. It was thus clear from the workshop that more research and developments are required, including PHY, MAC and NETwork layers, to provide public safety users with communications systems that meet their needs.

The approach exemplified by the WIDENS project (or in the past by standard TETRA) is to reuse the work done for mass market communications standards and adapt them to the needs of public safety users. This minimises the cost of research and manufacturing, but this will necessarily lead to a different specification.

One of the key aspects that has been addressed is the support of Quality of Service in the network. This is a challenge in ad hoc networks (whether based on UWB as discussed by G. Guibé, or on adapted wifi as in WIDENS). QoS classes have to be derived from user's application requirements.

- architectures and standards