A distributed dynamic channel assignment method for a mixture of narrowband and broadband traffic in a cellular system

This paper proposes an autonomous distributed dynamic channel assignment me thod, considering a mixture of narrowband and broadband traffic processing in a multicarrier TDMA mobile communication system. As the first step, narr owband and broadband calls are considered, and the system in which the call s share the carrier [carrier-sharing (CS) method], and the system in which the calls use separate carriers [carrier partitioning (CP) method], are com pared. For each method, a mathematical model is proposed for the blocking p robability analysis in the dynamic channel assignment, based on the steady- state probability. Using the models, the range for which the CS method exhi bits a better performance than the CP method is specified. A problem in the dynamic channel assignment in the CS method is that the transmission quali ty of the broadband call may be degraded by interference from a narrowband call. In order to overcome such a problem, a method is proposed where the s uppression of the leftovers of nonavailable channels for assignment, the mu lticarrier modulation using frequency hopping, the reallocation connection of calls, the variable-rate transmission connection, and the retry-type han d-off are combined. It is verified by computer simulation that the proposed method exhibits a performance which is better than that of the conventiona l method. (C) 2000 Scripta Technica.