Performance of Header Compression for VoIP in Wireless LANs

The increasing number of Voice over IP (VoIP) phones in wired and wireless technologies leads us to the performance discussion of VoIP traffic in IEEE 802.11 WLAN environments. Originally designed to transport best effort data traffic, WLANs may experience some problems with delay-sensitive and low-rate voice traffic. This paper investigates the Voice over WLAN (VoWLAN) capacity for different WLAN standards. Our simulations show that the IEEE 802.11e Quality-of-Service (QoS) extension does not increase the system performance in terms of maximum number of supported VoWLAN users. Therefore, we try to improve the capacity by using a header compression mechanism which reduces the upper layer headers to around 10 percent of its original size.

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