QoS in Routing Enabled Bandwidth Estimation Techniques for MANETS – A Survey

Now-a-days, Quality of Service (QoS) is the most important factor for Mobile Adhoc Networks (MANets). Various protocols were developed with metrics such as delay, bandwidth,jitter, energy, number of hops etc., to find the best route from source to destination. But few protocols are available to estimate the residual bandwidth along the path. Estimating the residual bandwidth at a given period of time is a difficult task in MANets. To solve this problem, intrusive and nonintrusive techniques are used. These techniques are better at sensing the channel when the carrier sensing mechanism blocks channel access. Intrusive technique uses probe packets whereas nonintrusive technique uses hello messages to know about channel utilization. These techniques perform QoS aware routing which discover the route satisfying the bandwidth requirements. In this paper, survey of these two techniques are presented.