On the impact of Wi-Fi multimedia power save mode on the VoIP capacity of WLANs

VoIP capacity is an important metric as it determines the maximum number of calls that can be supported by a Wireless Local Area Network (WLAN) before call quality degrades. To this end, researchers have conducted extensive simulation and analytical studies to determine the VoIP capacity of different WLANs. These previous works, however, assume stations are always awake during a call. In 2005, the Wi-Fi Alliance proposed a power saving mode extension that allows stations to retrieve packets from the Access Point (AP) at any time. In light of this development, this paper derives the VoIP capacity of a IEEE 802.11a WLAN where stations sleep for different time intervals. Moreover, it proposes a novel opportunistic scheduler that addresses a critical problem that arises when the power save extension is used in conjunction with a solution that improves the VoIP capacity of a WLAN by aggregating packets

Evaluating the Performance of VoIP Over Different Wireless Environment

WiFi and WiMAX are the most technologies for broadband wireless access are used nowadays. The excessive demand for providing mobile users with broadband wireless access has attracted tremendous investment from the telecommunications industry in the development and deployment of WiMAX and WiFi networks. Voice over IP (VoIP) over these technologies will be one of the killer applications for rapid deployment of WiMAX and WiFi networks. The legal desire for bundling voice and data will increase the portion of voice traffic in these networks. Therefore, VoIP, as the current technology for making voice calls through packet switch networks, will be a key application in WiMAX and WiFi networks. The increase of Voice over IP (VoIP) applications such as Skype, Google Talk, and MSN Messenger along with emerging deployment of WiMAX networks is making VoIP over WiMAX an attractive market and a driving force for both carriers and equipment suppliers in capturing and spurring the next wave of telecommunications innovation, though challenges remain. However, the enhancement on the hardware and application sides only seems inadequate. The chosen of proper network environment is also crucial in order to deliver the voice communication and multimedia session over the Internet. Optimization of the VoIP call capacity over WiMAX and WiFi networks is one such crucial challenge and remains an open research issue. Hence, in this project, we present the performance evaluation of VoIP in two wireless network protocols, WiMAX and WiFi as a baseline to evaluate the VoIP performance