“Our objective is to maximize throughput while ensuring that all users get similar ‘quality of experience’ from the wireless system, meaning that users get similar levels of satisfaction from the performance they experience from whatever applications they’re running,” says Parth Pathak, a Ph.D. student in computer science at NC State and lead author of a paper describing the research.
Multi-hop wireless networks use multiple wireless nodes to provide coverage to a large area by forwarding and receiving data wirelessly between the nodes. However, because they have limited bandwidth and may interfere with each other’s transmissions, these networks can have difficulty providing service fairly to all users within the network. Users who place significant demands on network bandwidth can effectively throw the system off balance, with some parts of the network clogging up while others remain underutilized.
Over the past few years, new technology has become available that could help multi-hop networks use their wireless bandwidth more efficiently by splitting the band into channels of varying sizes, according to the needs of the users in the network. Previously, it was only possible to form channels of equal size. However, it was unclear how multi-hop networks could take advantage of this technology, because there was not a clear way to determine how these varying channel widths should be assigned.
Now an NC State team has advanced a solution to the problem.
“We have developed a technique that improves network performance by determining how much channel width each user needs in order to run his or her applications,” says Dr. Rudra Dutta, an associate professor of computer science at NC State and co-author of the paper. “This technique is dynamic. The channel width may change – becoming larger or smaller – as the data travels between nodes in the network. The amount of channel width allotted to users is constantly being modified to maximize the efficiency of the system and avoid what are, basically, data traffic jams.”
In simulation models, the new technique results in significant improvements in a network’s data throughput and in its “fairness” – the degree to which all network users benefit from this throughput.
The researchers hope to test the technique in real-world conditions using 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 by former NC State master’s student Sankalp Nimborkhar. The paper will be presented June 12 at the 13th International Symposium on Mobile Ad Hoc Networking and Computing in Hilton Head, S.C. The research was supported by the U.S. Army Research Office and the Secure Open Systems Initiative at NC State.
Note to Editors: The presentation abstract follows.
“Channel Width Assignment Using Relative Backlog: Extending Back-pressure to Physical Layer”
Authors: Parth H. Pathak, Sankalp Nimborkhar, and Rudra Dutta, North Carolina State University
Presented: June 12, 2012, at the 13th International Symposium on Mobile Ad Hoc Networking and Computing in Hilton Head, S.C.
Abstract: With recent advances in Software-defined Radios (SDRs), it has indeed become feasible to dynamically adapt the channel widths at smaller time scales. Even though the advantages of varying channel width (e.g. higher link throughput with higher width) have been explored before, as with most of the physical layer settings (rate, transmission power etc.), naively configuring channel widths of links can in fact have negative impact on wireless network performance. In this paper, we design a cross-layer channel width assignment scheme that adapts the width according to the backlog of link-layer queues. We leverage the benefits of varying channel widths while adhering to the invariants of back-pressure utility maximization framework. The presented scheme not only guarantees improved throughput and network utilization but also ensures bounded buffer occupancy and fairness.
Matt Shipman | EurekAlert!
Green Light for Galaxy Europe
15.03.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
Tokyo Tech's six-legged robots get closer to nature
12.03.2018 | Tokyo Institute of Technology
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences