Adaptive Channel Borrowing Algorithm for Multimedia Wireless/Mobile Networks

Abstract

In a cellular-based wireless/mobile network that adopts an adaptive multimedia environment, each of the multimedia substreams (i.e. video, audio and data) has its own distinct quality of service (QoS) requirements (e.g. cell loss rate, delay, jitter, etc.). These requirements constitute a certain QoS level. In contrast to the static approach, we propose an adaptive QoS platform where each substream declares a preset range of acceptable QoS levels (e.g., high, medium, low) instead of just a single one. This range of QoS levels is defined in a user-defined profile (UDP). In this paper, we suggest a channel borrowing algorithm based on such adaptive QoS platform. In our suggested algorithm, an acceptor cell that has used all its nominal cell can borrow from any neighboring (donor) cell as long as this donor cell has some channels available after satisfying a minimum QoS (minQ) level defined in the UDP. A donor cell assigning QoS levels (to calls under its coverage) higher than the minQ levels will declare those channels as available for borrowing by other acceptor cells. The criteria for choosing the free channel include not only the number of free channels but also the QoS levels in the donor cell. The criteria is also extended to include the effect of channel locking on the number of free channels and the QoS levels on the locked cells. Simulation results indicate that call blocking rate is significantly decreased while offered load increases.