**Abstract:**

Multimedia applications such as digital audio and video have much more stringent QoS requirements than traditional datagram applications. For a network to deliver QoS guarantees, it must reserve and control resources. A major challenge in multihop, multimedia networks is the ability to account for resources so that bandwidth reservations (in a deterministic or statistical sense) can be placed on them. We note that in cellular (single hop) networks, such accountability is made easily by the fact that all stations learn of each other’s requirements, either directly or through a control station (e.g., the base station in cellular systems).

However, this solution cannot be extended to the multihop environment. To support QoS for real-time applications, we need to know not only the minimal delay path to the destination, but also the available bandwidth on it. A VC should be accepted only if there is enough available bandwidth. Otherwise, it would disrupt the existing VC’s.

We only consider “bandwidth” as the QoS (thus omitting signal-to-interference ratio (SIR), packet loss rate, etc.). This is because bandwidth guarantee is one of the most critical requirements for real-time applications. “Bandwidth” in timeslotted network systems is measured in terms of the amount of “free” slots. The goal of the QoS routing algorithm is to find a shortest path such that the available bandwidth on the path is above the minimal requirement.

To compute the “bandwidth”-constrained shortest path, we not only have to know the available bandwidth on each link along the path, but we also have to determine the scheduling of free slots. Though some algorithms were proposed to solve this QoS routing problem, they unfortunately may only work in some special environments.

For Explanation/Installation of above project by our expert faculty please register here