Power Saving Gateways for Real-Time Voice Handset Support in IEEE 802.11 Wireless LANs

In the past decade there has been a huge proliferation of wireless local area networks (WLANs) based on the IEEE 802.11 WLAN standard. Unfortunately, there is currently a large variety of commercial installations already deployed using APs with poor capabilities for supporting real-time QoS and power saving. This presents a problem for voice handset manufacturers and network operators. In this paper we consider the use of a power saving real-time gateway (i.e., POWSAR gateway). The gateway is installed on the wired infrastructure and filters all traffic towards a set of existing APs. A single gateway can support a large number of APs since infrastructure data rates are typically much higher than those of the air interface. We first consider the worse-case situation where the APs involved support neither station power saving nor packet QoS. Following this, performance comparisons are presented for a WiFi-compatible power saving solution and the POWSAR gateway approach. Results are presented which suggest that a POWSAR gateway has the potential for greatly improving power saving and real-time performance in certain legacy WLAN situations.