JiaLiang Zhang

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—This paper proposes and analyzes the performance of a simple frequency-agile CSMA MAC protocol. In this MAC, a node carrier-senses multiple frequency channels simultaneously, and it takes the first opportunity to transmit on any one of the channels when allowed by the CSMA backoff mechanism. We show that the frequency-agile MAC can effectively 1) boost(More)
Network Capacity, which is limited by interference between simultaneous transmissions of neighboring links, is a fundamental performance metric for wireless ad hoc networks. Ref. [1] showed that the capacity of wireless ad hoc networks with omnidirectional antennae does not scale well as the node density increases. Other related work ([2], [3], [4], etc.)(More)
—Most prior studies on wireless spatial-reuse TDMA (STDMA) link scheduling for throughput optimization deal with the situation where instantaneous channel state information (CSI) is available. Under fast fading, however, the channel may change too quickly for the scheduler to track the instantaneous CSI. In this paper, instead of the instantaneous CSI, the(More)
—Most current wireless IEEE 802.11 networks rely on a power-threshold based carrier-sensing multi-access (CSMA) mechanism to prevent packet collisions, in which a transmitter permits its transmission only if the locally measured aggregate interference power from all existing transmissions is below a pre-specified power-sensing threshold. However, such a(More)
—The increasingly dense deployments of wireless CSMA networks arising from applications of Internet-of-things call for an improvement to mitigate the interference among simultaneous transmitting wireless devices. For cost efficiency and backward compatibility with legacy transceiver hardware, a simple approach to address interference is by appropriately(More)
—It is known at a qualitative level that directional antennas can be used to boost the capacity of wireless ad hoc networks. Lacking is a measure to quantify this advantage and to compare directional antennas of different footprint patterns. This paper introduces the concept of the effective beam width (and the effective null width as its dual counterpart)(More)
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