Handoff control in the PNNI hierarchy of mobile ATM networks

This paper studies handoff control mechanisms for mobile ATM networks with private network-network interface (PNNI) hierarchical structure. In this paper, we propose a hierarchical rerouting (HRR) scheme for handoff control which utilizes the PNNI routing information during the path rerouting procedures. The scheme can identify the crossover switch (COS discovery) in a hierarchical fashion, so that the additional signaling delay for the handoff control becomes scalable to the size of the network. Compared with previously available flat rerouting (FRR) schemes, the HRR scheme can effectively reduce the processing time for COS discovery in a PNNI network and, therefore, reduce the handoff latency. Experimental results are obtained using a PNNI network simulator and the performance of typical path rerouting algorithms is evaluated.