Jim Snow - Wireless research
I'm currently working on two projects:
Employing a time-division multiple access scheme to save power in an 802.11 network:
- With 802.11 networking hardware, significant energy savings can be had by turning the receiver off when not in use
- If latency is not an issue, an adaptive TDMA protocol could be implemented with the following characteristics:
- Stations may turn their radios off entirely when it isn't their turn to transmit
- Overall throughput is no worse than standard 802.11
Evaluating the negative effects of, and possible solutions to, propogation delay on long distance 802.11 networks, including:
- Delay of acknowledgement
- Immediate acknowledgement causes 1 round-trip-time of added delay for each packet, reducing throughput
- Acknowledgement reply timeout may cause failure of very long links
- Breakdown of carrier-sense based collision avoidance
Sometime soon (mid march) I'll probably post a background paper I'm writing for the scholarship skills class, regarding current research in ad-hoc wireless routing.
Presentations
Useful Links
- the Personal Telco Project, a Portland Oregon area wireless user group.
- the HostAP project - allowing Linux and BSD boxes to behave as access points
- the FCC ID database
- A few vendors for hard-to-find 802.11 gear:
- Superpass makes good cheap panel antennas
- Hyperlink has a wide variety of antennas and cables
- Zcomax sells 200mW 802.11 cards (the transmit power does not appear to be configurable from HostAP, but they seem to default to a high power setting)
- YDI has some useful calculation pages (free space loss, fresnel zone, etc...)