Supporting quality of service in multiple heterogeneous wireless networks

As users become mobile across multiple heterogeneous wireless networks, supporting quality of service across such networks becomes an important issue. In this paper, we present several different QoS schemes designed for allowing QoS support among multiple heterogeneous wireless networks. Fault-tolerant architectures are also introduced to provide continued QoS support in the case of network failures. In addition to an overlay or hierarchical wireless architecture, we believe that it may be possible to achieve a certain level of fault tolerance by allowing users to access one of several wireless networks. Such a level of fault tolerance is likely to be time and location-dependent. A simulation model has been developed to evaluate the effectiveness of various fault-tolerant architectures and schemes in terms of QoS improvement. The simulation model will be extended to grow into a network simulator for designing wireless networks with a certain QoS guarantees.