Extending the QoS paradigm of wireless ATM to mobile broadband applications and to the user

ATM enforces traffic contracts-applications agree to send not more data then negotiated and the network tries to provide predictable service. Thus ATM based applications should be easy to develop. For wireless ATM the situation remains not the same. Hand-off to new a access point may result in invalidating the old contract and dropping connections. Applications have to cope with the new situation by e.g. adapting their bandwidth needs. In the context of this paper, we propose to shift the burden of adaptation from the application to a middleware layer, which also acts as a central co-ordinator for requesting and reserving local resources. Media adaptation is performed by using media filters which are controlled by the QoS-providing middleware. A distributed resource negotiation protocol negotiates end-to-end application QoS parameters and uses QoS mappers to derive the necessary filter settings