VoIP traffic support in mobile ad hoc networks

Mobile ad hoc networks (MANETs) are temporary networks which are formed for a specific purpose. They are infrastructureless, autonomous and entirely distributed systems where different wireless mobile nodes are capable of arbitrary movement and power switching without breaking the network connectivity since it is physically possible. In these networks, nodes must operate both as hosts and as routers. Their use is suited when it is impossible or undesirable to use fixed infrastructures. The flexibility offered by ad hoc mobile networks drive researchers to investigate the possibilities of allowing real-time multimedia applications on such networks. However, support for such demanding applications requires quality of service (QoS) guarantees especially regarding latency and losses while those networks are very constrained and poor comparing to conventional networks. Accordingly, this work aims at investigating MANETs performance with VoIP applications through simulation (ns2) in an IEEE 802.11/802.11b based network. We also show through it the important optimization that can be obtained from early dropping of expiring packets in the network. We choose VoIP for our tests as a real-time multimedia application which is having a big growth these last years.