International Journal of Modern Engineering Research (IJMER)
Transmitting voice through IP data network can provide significant cost savings. However if not managed properly, voice quality can degrade due to data network congestion. VoIP is Voice over an Internet Protocol (IP) based network. In this paper, the authors will investigate QoS indications (for voice packets), Improvement of NS2 network simulator in order to simulate statistical QoS in 802.11 MAC (Medium Access Control). The IEEE 802.11e Standard has been introduced recently for providing Quality-of-Service (QoS) capabilities in the emerging wireless local area networks. This 802.11e introduces a contention window based that is Enhanced Distribution Channel Access (EDCA) technique that provides a prioritized traffic to guarantee minimum bandwidth needed for time critical applications.