Enhancement and Performance Analysis of VoIP Algorithms in Wireless Networks

Voice over Internet Protocol (VoIP) is currently one of the fastest spreading telephone technologies. In recent years, VoIP has been widely used in wired and wireless networks because of its compatibility with and adoption in IEEE 802.11 devices. This technology works in the second layer of data link layer, and thus, is compatible with the carrier-sense multiple access with collision avoidance protocol (CSMA/CA), which works in IEEE 802.11 networks. The operation of this protocol depends on various algorithms, including the distributed coordination function (DCF) algorithm. This algorithm is governed by the transmission of packets at any time without considering the priorities of other stations. A collision of packets may occur when transmitting simultaneously with the rest of the stations. Another algorithm is the enhanced distributed channel access (EDCA), which sets a priority when sending packets between stations. Thus, if more than one station is transmitting simultaneously, then one of the stations will have higher priority and the remaining stations in the transmitter will have to wait depending on the order of priority. Consequently, collisions do not occur. In this regard, EDCA is better than DCF. The parameters of these algorithms are modified to produce a new algorithm, called M_EDCA. The three algorithms are applied using a simulation program, i.e. OPNET. The final results are obtained, and the results of the new algorithm are compared with those of the existing algorithms. The best results are achieved using the new algorithm, and consequently, the best voice quality in transmission and reception, and the best performance and service in VoIP applications.