This paper proposes a channel allocation scheme for multimedia wireless networks,in which a twolayer macro-cell or micro-cell architecture is considered.Macro-cells are used to access high-mobility services;while micro-cells,which are overlaid by the macro-cells,are used to cater low-mobility services.To analyze the scheme,a multidimensional Markov traffic model is firstly developed,in which traffic characteristic of two special periods of time is considered.And then,a pre-emptive channel-borrowing scheme combined with trafficoverflowing strategy for multimedia(voice,video or data) networks is proposed,in which handoff requests can not only borrow channels from adjacent homogenous cells,but also be overflowed to heterogeneous cells.Priority strategies are also dedicated to high-mobility services for they can pre-empt channels being used by low-mobility services in macro-cells.To meet the high quality of service(QoS) requirements of video services and increase the channel utilization ratio,video services can be transformed between real-time services and non-real-time services as necessary.Simulation results show that our schemes can decrease the blocking probabilities and improve the channel utilization. This paper proposes a channel allocation scheme for multimedia wireless networks, where a two layer macro-cell or micro-cell architecture is considered. Macro-cells are used to access high-mobility services; while micro-cells, which are overlaid by the macro -cells, are used to cater low-mobility services. To analyze the scheme, a multidimensional Markov traffic model is developed, in which traffic characteristic two special periods of time is considered. And then then, a pre-emptive channel-borrowing scheme combined with traffic overflowing strategy for multimedia (voice, video or data) networks is proposed, in which handoff requests can not only borrow channels from adjacent homogenous cells, but also be overflowed to heterogeneous cells. Priority strategies are also dedicated to high-mobility services for they can pre-empt channels being used by low-mobility services in macro-cells. To meet the high quality of service (QoS) requirements of video services and increase the channel utilization ra tio, video services can be transformed between real-time services and non-real-time services as necessary. Simulation results show that our schemes can decrease the blocking probabilities and improve the channel utilization.