New Location Management for Reducing HLR Overhead Traffic in Mobile Networks

abstract

IS-41 and GSM have a structural drawback : as the number of users increase, home location register(HLR) becomes the bottleneck problem. We propose a newmobilit y management method, Leaving Trace (LT) scheme, which effectively reduces mobility management cost in mobile network. The basic idea is that putting the VLR ID of the registration area where the terminal currently resides into the registration-cancellation message, the trace of terminals is left in the VLRs visited so that querying to the VLRs rather than to the HLR when the terminal-terminated-call occurs may connect a call. The LT scheme distributes messages to VLRs. The location registration process is performed as follows: 1. The terminal stores the ID of the new VLR into the tail of its queue. If the number of IDs stored in the queue exceeds the terminal K, the terminal deletes the VLR ID stored in the head of the queue in order to keep the trace length of the terminal K and generates a pointer cancellation (POCANC) message which will be sent to the VLR whose ID is just deleted from the queue. 2. The routing request (REGREQ) message and the POCANC message (if exists) are sent to the newVLR. 3. The newVLR checks whether the terminal is already registered. If not, it sends the registration notification message to the HLR and the POCANC message to the newVLR to the old VLR. 4. The HLR sends a registration cancellation message including the ID of the newVLR to the old VLR. 5. The old VLR generates a pointer composed of the terminal