Patent attributes
Multi-pattern transmission of wireless frames. A digital device contains a transmitter feeding an electronically steerable antenna system where the radiation pattern produced by the antenna system may be selected. Different antenna radiation patterns are used in transmitting a first portion of a wireless frame and a second portion of a wireless frame in a wireless digital network. In one embodiment, a first portion of a wireless frame is transmitted using a wide radiation pattern while the second portion of the frame is transmitted using a second radiation pattern. Switching among radiation patterns in the electronically steerable antenna system may be accomplished by switching between antenna types, such as an omnidirectional antenna for the wide pattern, and beam-steered or sectorized antennas for the second radiation pattern. Beam-forming and/or phasing approaches may also be used. The first and second portions of the frame may be transmitted at different power levels. For high throughput (HT) frames such as IEEE 802.11n frames, the non-HT preamble and L-Sig are taken as the first portion of the frame, with the HT-Sig, HT-training and HT-data portions of the frame taken as the second portion of the frame, transmitted using a narrower radiation pattern.
