Method of controlling paging in a plurality of mobile switching centers

Abstract

A method of paging for a mobile station operating in a radio telecommunications network having a serving mobile switching center (MSC), a home location register (HLR), and a plurality of border MSCs. The method comprises the steps of paging for the mobile station in the serving MSC, and sending an intersystem paging message from the serving MSC to each of the plurality of border MSCs. The intersystem paging message includes an instruction to page the mobile station, an indication of a number of page attempts to perform, and an indication of a page response time for each page attempt. A total page response time is calculated in the serving MSC by taking into account the entry time of a Routing Request Invoke message, the signaling delay in the border system, the average time for designation of a voice channel, and an additional average time for transferring the call to voice mail in the event of a no page response condition. If a page response is received in one of the border MSCs prior to expiration of the maximum time period for completion of the page attempts, the method stops internal paging in the serving MSC and may send a release message from the serving MSC to the non-responding border MSCs from which no response was received, to release paging resources in the non-responding border MSCs. If no page response is received within the maximum time period allowed, the HLR may initiate transfer of the call to voice mail.