Improved Grade-of-Service in Random Access Schemes with Frequency Binning

In random access schemes with no power control, such as the RTS/CTS method used in IEEE 802.11 for channel reservation, users with better channels have an advantage over those with bad channels. We propose the use of frequency binning in which a user randomly chooses one of M frequency bins to transmit the RTS. Such frequency binning has two competing effects: a) it reduces the chances of collision for the RTS, which increases the cell radius, b) it increases the signal power required for successful RTS reception due to higher spectral efficiency, which decreases the cell radius. We show that a) dominates in cases of interest and this leads to several advantages: i) it tends to provide equal grade-of-service to competing users in the presence of fading, shadowing, and propagation loss, which increases the cell radius, ii) it reduces access latency, and iii) it enables reception of multiple RTSs (with hardly any increase in transceiver complexity), which can be utilized for further improving the grade-of-service.