We present a new scheme that addresses the call handoff problem in mobile cellular networks. Efficiently solving the handoff problem is important for guaranteeing Quality of Service (QoS) to already admitted calls in the network. Our scheme is based on a new concept called channel car,rying: when a mobile user moves from one cell to another, under certain mobility conditions, .the user is allowed to carry its current channel into the new cell. We propose a new channel assignment scheme to ensure that this movement of channels will not lead to any extra co-channel interference or channel locking. In our scheme, the mobility of channels relies entirely on localized information, and no global coordination is required. Therefore, this new handofl' scheme is simple and can be easily implemented. We further develop a hybrid channel carrying scheme that allows us to maximize performance under various constraints. We provide numerical results comparing our scheme with the traditional channel reservation types of techniques. We find that our scheme outperforms the reservation scheme over a broad range of traffic parameters.

Date of this Version

July 1996