Software-based 802.11 Overlay TDMA MAC Protocol with Microsecond Synchronization
Department of Systems and Computer Engineering
Friday, May 7, 2pm
Location: BAB024 (Bahen Centre Basement)
We implement a new
software-based multi-hop TDMA MAC protocol (Soft-TDMAC) with microsecond
synchronization using a novel system interface for development of 802.11
overlay TDMA MAC protocols (SySI-MAC). SySI-MAC provides a simple,
kernel independent, message based interface for overlay MAC protocol
implementations to schedule transmissions, send packets, and receive packets.
The key feature of SySI-MAC is that it provides near deterministic timer
scheduling and transmission times, which allows for implementation of highly
synchronized TDMA MAC protocols. Building on SySI-MAC's predictable
transmission times we implement Soft-TDMAC, a software based 802.11 overlay
multi-hop TDMA MAC protocol. Soft-TDMAC has a synchronization mechanism, which
synchronizes all pairs of network clocks to within microseconds of each other.
Building on pairwise synchronization, Soft-TDMAC achieves tight network-wide
synchronization. With network-wide synchronization independent of data
transmissions, Soft-TDMAC can schedule arbitrary TDMA transmission patterns.
For example, Soft-TDMAC enables schedules that decrease end-to-end delay and
take end-to-end rate demands into account. We summarize hundreds of
hours of testing Soft-TDMAC on a multi-hop test-bed, showing the
synchronization capabilities of the protocol and the benefits of flexible
Djukic received B.A.Sc., M.A.Sc. and Ph.D. degrees from the University of
Toronto in 1999, 2002 and 2007, respectively. From 2008 to 2010 he was a
postdoctoral researcher at the Department of Systems and Computer Engineering,
Carleton University, Ottawa, Canada. From 2007 to 2008 he was a postdoctoral
researcher at the Department of Computer Science, University of California,
Davis. From 1999 to 2001 he worked as a software designer in Ottawa, Canada. His
research interests are in wireless multi-hop scheduling, radio access network
resource management, and testbed implementations of new wireless MAC protocols.
Host of Talk:
Shahrokh Valaee (firstname.lastname@example.org)