VoIP over Wi-Fi Networks: Performance Analysis and Acceleration Algorithms

Experimental evaluation of asymmetric QoS in IEEE 802.11g wireless networks

“…(1) layer 2 contributes the most overhead to the overall frame transmission time. Jeong et al [1] proposed an algorithm to implement MAC-layer frame aggregation, which improved the VoIP call capacity by 300%. Because of high WLAN overhead, it is obviously necessary to implement QoS on WLAN to support efficient traffic delivery for converged networks.…”

“…If the channel is busy during the backoff period, the wireless device pauses the backoff counter and resumes it DIFS after the end of frame again. Following the i th ( 1) i ≥ unsuccessful transmission attempt, the random backoff number n is selected from a uniform distribution in the range [ …”

“…With 802.11 DCF, all stations associated with the same Access Point (AP) operate independently and share the channel bandwidth. Therefore, it is difficult to satisfy the low delay and jitter requirements of VoIP traffic over WLANs [1].…”

Measuring VoIP Performance in IEEE 802.11P Vehicular Networks

“…There are some papers in which the capacity (namely, the number of concurrent voice calls supported) of VoIP over IEEE 802.11 is considered by means of analysis and/or simulation [7], [8], [9], [10]. In [8], two problems are addressed: increasing the VoIP capacity in a WLAN environment, and improving the VoIP performance in presence of TCP traffic, for different codecs, considering both CBR and VBR voice streams, and different 802.11 standards (a/b/g/e).…”

“…Similarly, in [7], a comparison among IEEE 802.11a/b/g technologies is presented, with both CBR and VBR. In [9] and [10], the voice capacity limit is studied considering both IEEE 802.11e and 802.11b WLAN environments.…”