Fine-grained Spectrum Adaptation in WiFi Networks
Explosive growth of WiFi traffic calls for new technologies to dramatically improve spectrum efficiency. In this paper, we propose an approach to adapt the spectrum on a per-frame basis. It consists of three major components: (i) a fine-grained spectrum access design that allows a sender and receiver to change their transmission and reception spectrum on demand, (ii) fast and accurate spectrum detection that allows a receiver to determine which spectrum is used by its sender on a per-frame basis by exploiting the IEEE 802.11 preamble structure, and (iii) an efficient spectrum allocation algorithm that determines which spectrum to use for each transmission by taking into account frequency diversity and interference. It can further be adapted to perform a joint assignment of spectrum, schedule, and access point (AP) for each frame. Using a SORA implementation and trace-driven simulation, we demonstrate the feasibility of per-frame spectrum adaptation and its sig- nificant benefit over existing channel assignment approaches. To our knowledge, this is the first per-frame spectrum adaptation prototype for WiFi networks.