METHOD OF SELECTIVELY DIRECTING A MOBILE STATION TO RETRY SYSTEM ACCESS IN A RADIO TELECOMMUNICATION SYSTEM

A method of reducing co-channel interference in a cellular telecommunication system having a congested serving cell, a plurality of neighbor cells controlled by a mobile switching center (MSC), and an accessing mobile stati on attempting to access the cellular system in the serving cell. The MSC fetche s (16) signal strength information from mobile stations camped on the serving cell's digital control channel (DCCH). The signal strength information includes received signal strengths at the camped mobile stations from the serving cell and the neighbor cells. The MSC then fetches (27) signal streng th information from busy mobile stations involved in on-going calls in the serving cell. For each busy and camped mobile station, the expected downlink signal strength from each neighbor cell is subtracted from the maximum downlink signal strength from the serving cell (28). The mobile station/neighbor cell combination with the numerically least difference caus es the least co-channel interference when the identified mobile station is move d into the identified neighbor cell. If the identified mobile station is the accessing mobile station (34), the MSC redirects the accessing mobile statio n to access the cellular system in the identified neighbor cell. If the identified mobile station is a busy mobilestation involved in a call, the MS C forces a handoff of the identified mobile station to the identified neighbor cell.