Two connection re-routing schemes for wireless ATM environment

To support mobile multimedia computing, one interesting approach is to extend ATM technology to wireless networks. This extension, termed "wireless ATM", presents several interesting challenges such as managing an end-to-end ATM connection (using connection re-routing) and location management, handling high error rate performance of wireless links, maintaining the ATM cell sequence, and supporting quality of service (QoS) requirements. In this environment, since the access point for a mobile user is not fixed, a technique/scheme is required to maintain the end-to-end ATM connection with user mobility. Previously, the design of such rerouting schemes has received some consideration in the literature. This paper presents two such schemes, termed RAC (rearrange ATM connection) and EAC (extend ATM connection), which can be used in isolation or in conjunction to support connection management in wireless ATM networks. The choice to use one or both schemes could be based on desired level of bandwidth utilization, level of implementation complexity, and the acceptable level of connection processing load. When used in conjunction, these schemes place the handoff processing in the ATM network first provided that NCP (network call processor) is not overloaded. However, if NCP is overloaded or if NCP is unable to process the (RAC) request due to insufficient bandwidth between switches in the new path, then the connection extension (EAC) is performed in wireless network. EAC includes detection and removal of any possible triangular or circular path that may be caused due to connection extension.