With radio access systems, the objective is usually to provide connection to as many customers as possible, and offer each the highest possible data rates. In the first half of this article, a new fixed radio technology, known as mesh or multipoint-to-multipoint, is presented. This is shown to offer the potential to overcome many of the coverage and capacity, limitations of existing networks, most of which use point-to-multipoint architectures. The second half of the article goes on to describe opportunity driven multiple access (ODMA), a technique which can be applied to mobile networks. Simulation results are presented which indicate the capacity increases that can be achieved. Both of these technologies use the same basic idea to achieve coverage and capacity increases-user equipment within the network can operate as relay stations for other users' traffic. However, both systems are immature and tack extensive deployments. If proven in practice they will offer a significant contribution to the next generation of radio access networks, be they fixed or mobile.
