Design, Implementation and Measurements of a Transport Protocol for Ad Hoc Networks

Many previous papers have pointed out that TCP performance in multi-hop ad hoc networks is not optimal. This is due to several TCP design principles that reflect the characteristics of wired networks dominant at the time when TCP was designed, that are not adequate for multi-hop ad hoc networks. For example, congestion phenomena in multi-hop networks are very different than in traditional wired networks, and route failures and route changes may be frequent events. To overcome these problems, in a previous work we presented a novel transport protocol – named TPA – specifically tailored to multi-hop ad hoc networks. In this chapter we present the implementation in a GNU/Linux environment of a TPA prototype. This prototype has been implemented at the user level to make the debugging process easier and to do not affect the system stability. This chapter also reports some results of the experimental evaluation of TPA in a static multi-hop scenario. Specifically, we used our prototype to compare TCP and TPA performance in a chain topology network. Our experimental results show that, in the analyzed scenarios, TPA always outperforms TCP in a significant way both in terms of throughput and energy consumption.