 a wireless switch will be able to monitor the total number of voice sessions being routed at any moment and intelligently manage capacity by handing off VoWLAN traffic where possible to alternative access points. RF Coverage Voice services put greater demands on wireless coverage, SO that roaming users do not encounter coverage gaps in corridors or stair wells while talking on their VoWLAN phones. If the WLAN has been designed to provide coverage of work areas and meeting rooms, a more focussed propagation and signal strength survey will be required when planning for VoWLAN service. Quality of service to voice clients will be improved if only the maximum supported data rate is enabled on all access points. This ensures that overall network throughput is not slowed when a client moves away from the access point, but also means that a higher density of access points will be necessary to give adequate RF coverage to support voice traffic. Implementing Wireless LANs Quality of Service VoWLAN requires guaranteed quality of service in order to minimise packet loss, delay and jitter that cause degradation of voice quality. As described in the Section "Quality of Service (802.11e specification), p. 157", the 802.11e standard has been developed to address the lack of QoS in the original 802.11 specification, and the Wi-Fi Alliance has also released wireless multimedia (WMM) as an interim subset of the 802.11e specification. WMM and 802.11e prioritise voice traffic over video, best effort and background traffic categories, and 802.11e or WMM compliance will be an essential technical requirement for WLAN hardware in all but the least demanding VoWLAN applications. However, 802.11e and WMM define traffic categories by device and not by application, SO that frames transmitted by a laptop user running a software phone will be queued according to the device priority, which will typically be best effort. Future enhancements of QoS standards are likely to provide for prioritisation by application. Seamless Roaming Complete RF co