I. Field
The present disclosure relates generally to communication, and more specifically to techniques for transmitting data in a wireless communication network.
II. Background
Wireless networks are widely deployed to provide various communication services such as voice, video, packet data, and so on. These networks may be capable of supporting communication for multiple users by sharing the available network resources. Examples of such networks include wireless local area networks (WLANs), wireless wide area networks (WWANs), wireless metropolitan area networks (WMANs), and wireless personal area networks (WPANs). The terms “network” and “system” are often used interchangeably.
A wireless network may include any number of access points (APs) and any number of stations (STAs). An access point may act as a coordinator for communication with the stations. A station may actively communicate with an access point, may be idle, or may be powered down at any given moment depending on the data requirements of the station.
The access points and stations may operate in an unscheduled mode. In this mode, transmissions for different stations are not scheduled and hence may collide with one another when sent at the same time via a wireless channel. A collision typically results in transmission failures for all affected stations, which may then require retransmissions from these stations. The retransmissions consume air time (which is a valuable network resource), consumes battery power at the stations, cause additional delays in traffic data, and may result in other deleterious effects.
There is therefore a need in the art for techniques to avoid collision in unscheduled operation.