Title
Fine-Grained Channel Access in Wireless LAN
Abstract
With the increasing of physical-layer (PHY) data rate in modern wireless local area networks (WLANs) (e.g., 802.11n), the overhead of media access control (MAC) progressively degrades data throughput efficiency. This trend reflects a fundamental aspect of the current MAC protocol, which allocates the channel as a single resource at a time. This paper argues that, in a high data rate WLAN, the channel should be divided into separate subchannels whose width is commensurate with the PHY data rate and typical frame size. Multiple stations can then contend for and use subchannels simultaneously according to their traffic demands, thereby increasing overall efficiency. We introduce FICA, a fine-grained channel access method that embodies this approach to media access using two novel techniques. First, it proposes a new PHY architecture based on orthogonal frequency division multiplexing (OFDM) that retains orthogonality among subchannels while relying solely on the coordination mechanisms in existing WLAN, carrier sensing and broadcasting. Second, FICA employs a frequency-domain contention method that uses physical-layer Request to Send/Clear to Send (RTS/CTS) signaling and frequency domain backoff to efficiently coordinate subchannel access. We have implemented FICA, both MAC and PHY layers, using a software radio platform, and our experiments demonstrate the feasibility of the FICA design. Furthermore, our simulation results show FICA can improve the efficiency of WLANs from a few percent to 600% compared to existing 802.11.
Year
DOI
Venue
2013
10.1109/TNET.2012.2212207
IEEE/ACM Transactions on Networking (TON)
Keywords
DocType
Volume
OFDM,Wireless LAN,Sensors,IEEE 802.11 Standards,Media Access Protocol,Synchronization
Journal
21
Issue
ISSN
Citations 
3
1063-6692
20
PageRank 
References 
Authors
0.83
22
8
Name
Order
Citations
PageRank
Ji Fang153538.62
Kun Tan2135098.64
Yuanyang Zhang322010.19
Shouyuan Chen41869.98
Lixin Shi530120.26
Jiansong Zhang659648.98
Yongguang Zhang73461248.65
Zhenhui Tan847038.24