Challenges
with dynamic power management: Formation of asymmetric links and
increase in hidden terminals.
Dynamic Transmit Power Control in Wireless LANs |
We develop a novel dynamic power management technique for improving spatial reuse in managed wireless LAN (WLAN) deployments. WLAN deployments are often characterized by dense placement of access points (APs) to provide maximal coverage to clients. Such density, however, leads to interference between different simultaneous AP to client transmissions, thereby leading to low overall throughput. To mitigate interference, each AP chooses the lowest transmit power for each client sufficient for sending packets successfully. Further, we address two main problems introduced by dynamic power management—creation of asymmetric links and hidden nodes. Through a prototype implementation using a scheduling framework with GPS synchronized clocks, we demonstrate that spatial reuse is improved significantly. For instance, in a deployment of two APs with eight clients located randomly in different offices/cubicles in the building, our experiments show a cumulative throughput improvement of 40%.
Challenges
with dynamic power management: Formation of asymmetric links and
increase in hidden terminals.
System Architecture - All APs transmit packets at a common power
level at any instant of time using a coordinated packet scheduling
framework. A central controller computes the duration of usage for
each power level based on current traffic demands.
Envelope: Power level usage schedule for all APs.
Vishnu Navda, Ravi Kokku, Samrat Ganguly, Samir Das, Per-client Power Management for Spatial Reuse in WLANs, . Technical Report(pdf).
Samrat Ganguly, Ravi Kokku, Vishnu Navda, Samir Das, S3: Slotted Sectored Scheduling in WLANs, . Mobisys Poster(pdf).
Please
send all questions and comments to
Computer Science Department, Stony Brook University, NY-11794