Date Added: Jul 2012
Voice over Internet Protocol (VoIP) is one of the most important technologies in the world of communication. Around 20 years of research on VoIP, some Quality of Service (QoS) problems of VoIP are still remaining. During the past decade and with growing of wireless technologies, the authors have seen that many papers turn their concentration from Wired-LAN to Wireless-LAN. VoIP over Wireless LAN (WLAN) faces many challenges, due to the loose nature of wireless network. Issues like providing QoS at a good level, dedicating capacity for calls and having secure calls is more difficult rather than wired LAN.