Shared Infrastructure Power Saving for Solar Powered IEEE 802.11 WLAN Mesh Networks

Solar powered WLAN infrastructure is a cost effective option in outdoor deployments where continuous power sources are not practical. In these nodes the cost of the solar panel and battery can be a significant fraction of the total, and therefore reducing access point power consumption is very important. In this type of network, peak bandwidth requirements may not be satisfied by a single access point radio, even though long term average bandwidth requirements may be very low. In this case multiple radio APs or overlapped AP coverage deployment is required to meet this peak demand. When this happens the long term power consumption of the nodes can be reduced by implementing shared dynamic power saving between the WLAN mesh nodes. In this paper we propose and evaluate two algorithms for efficiently activating the solar powered infrastructure when additional bandwidth is needed. The algorithms are designed to be compatible with the existing IEEE 802.11 standard and include conventional load balancing when more than one AP is active in a given coverage area. We demonstrate that the proposed algorithms can significantly reduce the power consumption of the shared solar powered infrastructure.