Methods and apparatus for clear channel assessment

摘要

Methods and systems disclosed provide for clear channel assessment of first and second communication channels. In one aspect, a first primary channel has a first frequency spectrum bandwidth and a second primary channel has a second frequency spectrum bandwidth including the first frequency spectrum bandwidth. A method may include performing a first back-off procedure based on whether the first primary channel is idle if a transmission bandwidth for a wireless message is the first frequency spectrum bandwidth, performing a second back-off procedure based on whether the second primary channel is idle if the transmission bandwidth for the wireless message is greater than the first frequency spectrum bandwidth, and transmitting the wireless message based on a completion of the performed back off procedure.

主权项

1. A method in a wireless communications system including a first primary channel having a first frequency spectrum and a second primary channel having a second frequency spectrum, wherein the second frequency spectrum includes the first frequency spectrum, and secondary channels are associated with the second primary channel but not with the first primary channel, comprising:
determining whether to transmit a wireless message over the first primary channel based on a property of the wireless message; in response to determining the wireless message is to be transmitted over the first primary channel:
determining whether the first primary channel is idle based, at least in part, on whether a preamble is detected on the second primary channel;performing a first back-off procedure based on the determination andtransmitting the wireless message over the first primary channel when the first back-off procedure completes, wherein the transmission is restricted to the first frequency spectrum, and in response to determining the wireless message is to be transmitted over a channel different than the first primary channel;
second determining whether the second primary channel is idle based, at least in part, on whether a preamble is detected on the first primary channel,performing a second back-off procedure based on the second determination,
determining whether one or more of the secondary channels associated with the second primary channel are idle for a PCT Inter-frame Space (PIFS) time period before a transmission of the wireless message, andtransmitting the wireless message over the second primary channel and the determined idle secondary channels based on a completion of the second back-off procedure.