Method of supporting functionality for roamer port calls in a radio telecomminications network in which number portability is implemented

Abstract

A method of supporting functionality for roamer port calls in a radio telecommunications network in which Number Portability (NP) is implemented, the network having a plurality of mobile switching centers (MSCs) and home location registers (HLRs). The network includes a roamer port MSC having a roamer port which is shared with at least one neighboring MSC. A number portability database (NPDB) associates a location routing number (LRN) with each distinct MSC/HLR pair in the network. When a roamer port call, which includes the mobile directory number (MDN) of the called mobile station, is received in the roamer port MSC, the roamer port MSC determines whether the MDN falls within a ported range. If so, a request is sent to the NPDB to retrieve a LRN for the called mobile station. From the LRN, a HLR associated with the mobile station is identified. The roamer port MSC then sends a location request to the identified HLR which returns a routing number for the called mobile station, or indicates that a call-diversion type service is active. If no call-diversion type service is active, the roamer port MSC determines whether the called mobile station is located in a neighboring MSC to which the roamer port MSC allows routing of calls. If so, the call is routed locally to the neighboring MSC.