Mobile Location Management in ATM Networks

This paper presents two mobile location management algorithms for ATM (asynchronous transfer mode) networks based on the PNNI (private network-to-network interface) standard. The first solution is called the mobile PNNI scheme because it builds on the PNNI routing protocol. It uses limited-scope (characterized by a parameter S) reachability updates, forwarding pointers, and a route optimization procedure. The second solution is called the LR (location registers) scheme because it introduces location registers (such as the cellular home and visitor location registers) into the PNNI standards-based hierarchical networks. This scheme uses a hierarchical arrangement of location registers with the hierarchy limited to a certain level S. Analytical models are set up to compare the average move, search, and total costs per move of these two schemes for different values of the CMR (call-to-mobility ratio), and to provide guidelines for selecting parameters of the algorithms. Results show that at low CMRs (CMR<0.025), the LR scheme performs better than the mobile PNNI scheme. We also observe that the two schemes show a contrasting behavior in terms of the value to be used for the parameter S to achieve the least average total cost. At low CMRs, the parameter S should be high for the mobile PNNI scheme, but low for the LR scheme, and vice versa for high CMRs.