Janus : media access in full-duplex wireless networks
Abstract/Contents
- Abstract
- Single-channel full-duplex wireless is a radio technology that transmits and receives at the same time and on the same frequency band. It is a nascent and exciting field of research that provides new opportunities to greatly improve wireless networks. Traditional wireless systems isolate transmission and reception in time, such as in timedivision duplex (TDD), or in frequency, as in frequency-division duplex (FDD). This is necessary because huge self-interference from the transmitting antenna is usually millions of times stronger than the signal at the receiving antenna and it saturates the receiver analog-to-digital converter (ADC). However, feasibility of full-duplex radios has been recently demonstrated at the physical layer with off-the-shelf components. Since then, there has been a lot of progress towards the goal of suppressing the huge self-interference signal with clever multi-stage cancellation schemes. Existing full-duplex work focuses on the physical layer and has not yet deeply studied its impact on the the MAC layer. There are several proposals that provide simple extensions from CSMA/CA popularly used in WiFi networks, but experiments show that these extensions poorly utilize the full-duplex channel, falling far short of the projected theoretical 2x throughput increase. In order to make the most out of the unique characteristics of a full-duplex physical layer, it is important to design a clean-slate MAC layer. This dissertation presents Janus, a media access protocol for full-duplex wireless local area networks. By allowing nodes to simultaneously transmit and receive on the same band, full-duplex by itself provides at most a 100% throughput improvement over half-duplex networks. Janus demonstrates that a media access control protocol designed especially for full-duplex can allow a network to achieve even greater gains: experimental results with WARP software radios show improvements of 150%. Janus achieves these gains through three mechanisms: inexpensively maintaining real-time interference topology information, centralizing scheduling at access points to use this information while reducing control overhead, and an intelligent scheduling algorithm that maximizes full-duplex cooperations while simultaneously minimizing bitrate reductions from inter-client interference. The effectiveness of such a centralized media access protocol design suggests that full-duplex may benefit from revisiting and rethinking many long-held assumptions about wireless protocol design.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2013 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Kim, Jae Young |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Levis, Philip |
| Thesis advisor | Levis, Philip |
| Thesis advisor | Gill, John T III |
| Thesis advisor | Poon, Ada Shuk Yan |
| Advisor | Gill, John T III |
| Advisor | Poon, Ada Shuk Yan |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Jae Young Kim. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2013. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2013 by Jae Young Kim
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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