Method and apparatus for paging and responding to pages in a mobile radio communications system

Abstract

A paging origination identifier associated with an origination of a page to a mobile radio terminal is included with a mobile terminal's response to the page. For example, assuming that the page to the mobile terminal is in a first area, the mobile terminal responds to the page from a second area and includes the identifier in that response. The second area may be a cell controlled by another radio network control node, another radio network operator, or even another type of cellular system. The identifier is used to route the page response through the radio network ultimately to the paging originator. The identifier may be, for example, a paging area identifier, a registration area identifier, or a network exchange identifier. Another example identifier is the cell where the mobile terminal received the page. Cell evaluation and selection processes need only be performed while the mobile terminal is listening to the paging channel, for example, thereby saving mobile terminal battery life. Since the mobile terminal checks for an optimum cell just before it transmits a paging response, it ensures that the optimum cell is used, thereby improving the quality of the communication. As a result, there is less chance of increased interference caused by the uplink transmission, of a lost connection, or of an error in the message.