Soft-TDMAC: A Software TDMA-Based MAC over Commodity 802.11 Hardware

—We design and implement Soft-TDMAC, a software Time Division Multiple Access (TDMA) based MAC protocol, running over commodity 802.11 hardware. 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 network wide synchronization. With, out-of-band, network wide synchronization Soft-TDMAC can schedule arbitrary TDMA transmission patterns. We summarize hundreds of hours of testing Soft-TDMAC on a multi-hop testbed. Our experimental results show that Soft-TDMAC synchronizes multi-hop networks to within a few microsecond sized TDMA slots. Soft-TDMAC can schedule transmissions to take end-to-end demands into account and in a way that decreases end-to-end delay [1], [2]. With no collisions, under good channel conditions, TCP achieves almost the full wireless channel bandwidth.

• Type: Conference
• Year: 2009
• Where: INFOCOM
• Authors: Petar Djukic, Prasant Mohapatra
• Keywords: Communications, INFOCOM 2009, Network Wide Synchronization, Soft-TDMAC Achieves Network, Wide Synchronization Soft-tdmac