Efficient rate based transport protocols for multihop ad hoc wireless network

Abstract

Estimating the end-to-end bandwidth (rate) of the link in multihop ad hoc wireless network is important for rate based transport protocol to prevent congestion and to allow the source node to control and regulate its rate of data transmission so that the throughput increases. However, due to the dynamic topology of ad hoc network, rate estimation becomes a challenging task. The aim of this research is to improve the performance of rate estimation mechanism followed in rate based transport protocol such as ad hoc transport protocol (ATP). Firstly, the energy loss due to memory usage and central processing unit (CPU) usage is to be explored as opposed to the previous work on radio related energy loss, to increase the life time of ad hoc network nodes. Secondly, the fairness related issue of rate based transport protocol over IEEE 802.11 based ad hoc network is investigated. Thirdly, the performance problem such as high energy consumption associated with piggybacking the delay (rate/available bandwidth) along with transport layer acknowledgement based on expiry of epoch timer is to be studied. Finally, the pros and cons associated with the effect of transmitting, the delay along with data link acknowledgement in addition to transmitting, the delay along with transport layer acknowledgement are expected to be analyzed. In this thesis, the following four new efficient rate estimation techniques which are derivatives of ATP are proposed and evaluated. Processor power aware transport protocol for ad hoc network (PPATPAN) is designed to minimize the protocol processing power. Per flow rate based transport protocol (PFRTP) is aimed to achieve a good fairness ratio. Thus, in this thesis, it is shown that the techniques PPATPAN, PFRTP, DRF and a node-to-node rate based transport protocol achieves improvement in terms of processing power based on CPU and memory usage, fairness ratio, energy consumption and throughput respectively. newline newline newline