A multiple-beam antenna protocol at a wireless access point for exploiting spatial parallelism

We propose a protocol for use at a wireless access point (AP) that uses multiple beam smart antennas. Such APs can be deployed in traffic hotspots to overcome bottlenecks by enhancing capacity significantly. Our protocol is fully compatible with IEEE 802.11 in its current form, and can function with omnidirectional devices. The protocol seeks to exploit parallel packet transmission of downstream data (from the AP to the nodes), while reverting to normal 802.11 for upstream data (from a node to the AP). The performance gain expected from our protocol is proportional to the spatial resolution (number of beams) and the amount of downstream data. Typically, mobile terminals running applications download data from other servers, and hence the volume of downstream data far exceeds the upstream data. In such conditions, our protocol provides substantial gain.