Performance evaluation of a mobile QoS adaptation strategy for wireless ATM networks

We introduce an end-to-end QoS adaptation framework to resolve QoS inconsistencies as a result of mobile handoffs in wireless ATM (WATM) networks. We define mobile QoS (M-QoS) to comprise of wired, wireless and handoff QoS parameters. We introduce two forms of adaptation, namely: (a) application and (b) network QoS adaptation. The former is concerned with bandwidth, delay variation and packet loss adaptation by the mobile application while the latter refers to M-QoS fulfilment, upgrade and downgrade. New procedures are defined for M-QoS upgrade and downgrade, so that QoS 'refresh' traffic is controlled and the overall time required to perform a handoff remains largely unaffected. Results obtained from a call-level mobile network simulator further confirms the advantages of the proposed QoS adaptation scheme.