Performance of Tcp/Ip Model In Multihop Adhoc Networks |

ABSTRACT:

Incorporating the concept of TCP end-to-end congestion  control  for  wireless networks  is  one  of  the primary concerns in designing ad hoc networks since TCP was primarily designed  and  optimized based on  the assumptions  for  wired networks. In this study, our interest lies on tackling  the  TCP instability and in particular intra-flow  instability problem since due to the nature of  applications in multihop ad hoc networks, connection instability or starvation even for a shortperiod of time can have a negative impact on the Quality of Service and may not be acceptable for the end user. Through a detailed analysis, it will be shown that the main causes of TCP intra-flow instabilitylies in overloading the network by  sending more packets thanthe capacity of the channel. Based on this, the paper proposes a novel cross  layer solution called “TCP Contention Control” that dynamically adjusts the amount of outstanding data in the network based on the level of contention experienced by packets as well as the throughput achieved by connections. The simulation results show TCP  Contention  Control can drastically improve TCP stability over 802.11 multihop ad hoc networks.