3-level database hierarchy for location management in PCS networks

A 3-level hierarchical database architecture is proposed for location management in PCS networks. It adds a regional location register (RLR) for roamers between the home location register (HLR) and the visitor location register (VLR) of the current 2-level database hierarchy in GSM or IS-41. The strategy for location registration and call delivery is described. Calculations show that the signaling cost is reduced significantly. Functions of existing network elements such as the HLR and VLR remain unchanged. This greatly facilitates the deployment of this scheme in the evolution of current cellular mobile communication networks.