Adaptive QoS Platform in Multimedia Networks

Abstract

In an adaptive multimedia environment, each of the multimedia sub-streams (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, each substream declares 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 an adaptive QoS platform. In a channel borrowing algorithm, an acceptor cell that has used all its nominal channels can borrow free channels from its neighboring cells (candidate donors) to accommodate new calls. In our suggested algorithm, an acceptor 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 defined in the UDP will declare those channels as available for borrowing by other acceptor cells. When a channel is borrowed, several other cells are prohibited from using it due to channel locking. The proposed channel borrowing algorithm differs in the way a free channel is selected from a donor cell to be borrowed by an acceptor cell. 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.