NeTS: Small: Random Access Heterogeneous MIMO Networks

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Existing 802.11n is inefficient whenever nodes with a different number of antennas share the medium. This research aims to develop an advanced 802.11n design that delivers as many concurrent transmissions as permitted by the MIMO transmitter with the maximum number of antennas. Such a design delivers performance gain while maintaining the fully distributed random access nature of today's 802.11n, i.e., its ability to support bursty traffic, distributed decisions, and ad hoc deployment. The research develops a novel carrier sense mechanism that enables MIMO nodes to detect whether they can transmit in the presence of an ongoing transmission without interfering with it. It then builds on this mechanism to deliver a random access protocol where MIMO nodes contend for both time and degrees of freedom, without any form of centralized coordination. Finally, it implements its design and evaluates it in a wireless testbed. By delivering a higher throughput for the same resource, this research advances the design of MIMO 802.11 networks and the corresponding industry.