Dynamic Channel Allocation for Real-Time Connections in Highway Macrocellular Networks

Abstract

The wide deployment of multimedia services in third generation wireless networks will require handoff designs that can simultaneously reduce the blocking probability of handoff requests and decrease the handoff delay. Reducing the handoff blocking probability is needed to prevent frequent call dropping of real-time VBR/VCR connections and decreasing the delay associated with handoff is needed to prevent QoS degradation for multimedia traffic. In this paper, we present a channel assignment/reassignment scheme for highway cellular networks that achieves both requirements. The scheme can be used to deliver real-time data to a large segment of global highways, namely, highways in which the radio channels used in a given cell cannot be simultaneously used in the two neighboring cells to its left and to its right. The scheme possesses the desirable features of real-time algorithms: the execution time per handoff request has a constant time complexity, the number of transmitted messages per request is small, and the space overhead is also O(1). The scheme uses a non-compact initial assignment of nominal channels to neighboring cells and utilizes a set of pointers in each base station to implement an efficient channel assignment and reassignment strategy. The resulting approach greatly simplifies the selection process and avoids the expensive computation and message exchanges typically needed by dynamic channel allocation schemes. The low communication overhead of the scheme can be further reduced via control thresholds. Performance simulation results show that the scheme achieves low blocking probability and is therefore suitable for handling handoffs of real-time connections in highway cellular networks.