The article compares the quality of service for packet telephony and mobile ad hoc networks. In case of mobile ad hoc networks, multiple mobile stations communicate without the support of a centralized coordination station for the scheduling of transmissions. The most widely adopted network architecture for ad hoc wireless networks is based on the IEEE 802.11 standard, which was initially designed for data services. IEEE 802.11 standard is compatible with the needs of data transmission and it is now widely applied for the implementation of wireless local area networks and wireless access to the Internet by telecommunication operators. Currently, the combination of voice over Internet Protocol with both cellular and wireless ad hoc connectivity is under the area of research to provide users with sophisticated voice services. A wide variety of MAC protocols for ad hoc wireless networks have been proposed and most of them use the distributed coordination function of the IEEE 802.11 MAC with several types of enhancements