“Our objective is to maximize throughput while ensuring thatall users get similar ‘quality of experience’ from the wirelesssystem, meaning that users get similar levels of satisfaction fromthe performance they experience from whatever applications they’rerunning,” says Parth Pathak, a Ph.D. student in computerscience at NC State and lead author of a paper describing theresearch. Multi-hop wireless networks use multiple wireless nodes to providecoverage to a large area by forwarding and receiving datawirelessly between the nodes. However, because they have limitedbandwidth and may interfere with each other’s transmissions, thesenetworks can have difficulty providing service fairly to all userswithin the network. Ford DVD Sat Nav
Users who place significant demands on networkbandwidth can effectively throw the system off balance, with someparts of the network clogging up while others remain underutilized. Over the past few years, new technology has become available thatcould help multi-hop networks use their wireless bandwidth moreefficiently by splitting the band into channels of varying sizes,according to the needs of the users in the network. Previously, itwas only possible to form channels of equal size. However, it wasunclear how multi-hop networks could take advantage of thistechnology, because there was not a clear way to determine howthese varying channel widths should be assigned. Now an NC State team has advanced a solution to the problem. China Hyundai Sat Nav
“We have developed a technique that improves networkperformance by determining how much channel width each user needsin order to run his or her applications,” says Dr. RudraDutta, an associate professor of computer science at NC State andco-author of the paper. “This technique is dynamic. Thechannel width may change — becoming larger or smaller — as thedata travels between nodes in the network. China Suzuki Sat Nav
The amount of channelwidth allotted to users is constantly being modified to maximizethe efficiency of the system and avoid what are, basically, datatraffic jams.” In simulation models, the new technique results in significantimprovements in a network’s data throughput and in its”fairness” — the degree to which all network usersbenefit from this throughput. The researchers hope to test the technique in real-world conditionsusing CentMesh, a wireless network on the NC State campus. The paper, “Channel Width Assignment Using Relative Backlog:Extending Back-pressure to Physical Layer,” was co-authored byformer NC State master’s student Sankalp Nimborkhar. The paper willbe presented June 12 at the 13th International Symposium on MobileAd Hoc Networking and Computing in Hilton Head, S.C.
The researchwas supported by the U.S. Army Research Office and the Secure OpenSystems Initiative at NC State.