Collision-aware channel monitoring at the link layer of a wireless network

In this paper, we investigate and propose a method to address the problem of estimating channel quality at the medium access control (MAC) layer for a CSMA/CA type of wireless LAN that is subject to time-varying impairments. A key step in solving this problem is to distinguish the packet loss caused by channel impairments from that caused by collisions. Our proposed method estimates packet loss due to the channel impairments alone from the overall packet loss statistics at the MAC layer of a transmitter by exploiting the benefits of the bandwidth manager in such a wireless LAN. The state of each wireless channel can be estimated by deriving a channel quality factor from the estimated packet loss probability due to channel impairments.