Optimal beam scheduling for multicasting in wireless networks

Abstract

We consider the problem of efficient link-layer multicasting in wireless networks with switched beamforming antennas. The inherent tradeoff between multicasting and beamforming -the broadcast advantage of low-gain omni-directional transmissions versus the high-gain but spatially restricted transmissions of beamforming antennas -makes this problem especially challenging. In this paper, we design and evaluate optimal algorithms, and easy-to-implement greedy algorithms with performance guarantees, that generate and schedule efficient beam patterns for multicast transmissions. These algorithms are built upon the novel usage of composite beams that provide a knob to control the operating point of the tradeoff curve. This is in contrast to the sub-optimal usage of either purely directional or omni-directional beams by existing schemes. We further consider two models for composite beam pattern generation: one in which transmit power is (a) equally split, and (b) asymmetrically split between the constituent main lobes. A systematic evaluation, using real world traces obtained from measurements using an eight element switched beamforming antenna in an indoor office environment, indicates significant gains of about four folds over omni and two folds over prior art schemes.

On the Performance of Cooperative Routing in Wireless Networks

“…However, we neither discussed joint routing and cooperation across different flows, nor did we discuss MAC-layer scheduling under the MCB model. Specifically, due to beamforming, the nature of interference is different from the interference caused by omnidirectional wireless broadcasts, and hence the scheduling problem requires special treatment [12].…”

Dynamic beam steering using directional antennas in mmwave wireless networks

“…In [2], an online routing through multicast communication is proposed in order to maximize the lifetime of a network. In [3], a multicast model is defined using a composite beam pattern, which is defined depending on whether the beam's transmission power is equally split or asymmetrically split.…”

Indoor Wireless Planning Using Smart Antennas

“…Moreover, by concentrating the transmission energy in a specific direction, beamforming creates a signal that is orders of magnitude stronger than that of the signals in other directions. One can further reduce interference in a network by combining beamforing feature with power control [5] and scheduling [1], [6].…”

“…Moreover it considers only a restricted form of sensors in which a sensors covers only a single directional beam. It has been shown that such a restriction for antennas results in a sub-optimal network performance [6]. In this paper, we consider a general antenna model and find the optimal wireless plan that satisfies a prespecified performance constraint for all the network users.…”