ABSTRACT
Provision of Quality of Service (QoS) in wireless ad hoc networks depends upon the accurate quantification of available resources in the network. One of the most fundamental and widely requested resources is the available bandwidth (ABW). In the present literature a lot of work has been done in the area of estimating the ABW but still no promising solution is achieved till date. In this paper, we are presenting a modified approach of “ABE” given by Sarr et al.(2008) for estimating the ABW on a link in terms of collision probability and average backoff. Lagrange Interpolating polynomial used by “ABE” does not exhibit permanence property and is restricted to a fixed range of data points. Thus, we are using a better polynomial known as Newton Divided Difference interpolating polynomial for calculating the collision probability which is much simpler and equally applicable to the outside range of data points. Further, according to IEEE 802.11 standard a station must wait for an EIFS (Extended Inter frame space) time rather than DIFS (Distributed Inter frame space) time in case the last transmission is unsuccessful during the calculation of average backoff. Incorporating these changes improves the overall accuracy of bandwidth estimation technique.
