Impact of routing protocols on packet retransmission over wireless networks

TCP is known to exhibit poor performance in Over wireless networks. Various parameters may be considered to configure the network functioning with multi-hop wireless connectivity. Many routing protocols could be used over WSN. In this paper, we show that the choice of the routing protocol (and its parameters) will surely have an impact on the whole network functioning. We focus, in particular, on packet retransmission process which is an usual process used by a node when the network is disturbed (traffic jam, non connected nodes, ...) However, multi-hop end-to-end transmissions require cooperation of several layers of the communication protocol stack. At each layer different mechanisms and protocols are used, each of them are set default values. In this paper, we investigate how these layers are designed and we consider taking a look at default configurations of the layers parameters/mechanisms and comparing them to alternative possibilities. We also explore cross-layer effects between layers and how they affect the performance. We analyze the impact of usual routing protocols such as Direct Diffusion, AODV, AOMDV, DSDV and DSR on the packet retransmission used by the transport layer. These analysis are conducted through the NS-2 simulator to enhance two relevant indicators: the CWL value and the MAC retries ratio.