4 research outputs found
Directional antennas improve the link-connectivity of interference limited ad hoc networks
We study wireless ad hoc networks in the absence of any channel contention or
transmit power control and ask how antenna directivity affects network
connectivity in the interference limited regime. We answer this question by
deriving closed-form expressions for the outage probability, capacity and mean
node degree of the network using tools from stochastic geometry. These novel
results provide valuable insights for the design of future ad hoc networks.
Significantly, our results suggest that the more directional the interfering
transmitters are, the less detrimental are the effects of interference to
individual links. We validate our analytical results through computer
simulations.Comment: 6 pages, 7 figures, conference proceedings of PIMRC'201
On Connectivity of Wireless Sensor Networks with Directional Antennas.
In this paper, we investigate the network connectivity of wireless sensor networks with directional antennas. In particular, we establish a general framework to analyze the network connectivity while considering various antenna models and the channel randomness. Since existing directional antenna models have their pros and cons in the accuracy of reflecting realistic antennas and the computational complexity, we propose a new analytical directional antenna model called the iris model to balance the accuracy against the complexity. We conduct extensive simulations to evaluate the analytical framework. Our results show that our proposed analytical model on the network connectivity is accurate, and our iris antenna model can provide a better approximation to realistic directional antennas than other existing antenna models
Connectivity of Underlay Cognitive Radio Networks with Directional Antennas
In cognitive radio networks (CRNs), the connectivity of secondary users (SUs)
is difficult to be guaranteed due to the existence of primary users (PUs). Most
prior studies only consider cognitive radio networks equipped with
omni-directional antennas causing high interference at SUs. We name such CRNs
with omni-directional antennas as Omn-CRNs. Compared with an omni-directional
antenna, a directional antenna can concentrate the transmitting/receiving
capability at a certain direction, consequently resulting in less interference.
In this paper, we investigate the connectivity of SUs in CRNs with directional
antennas (named as Dir-CRNs). In particular, we derive closed-form expressions
of the connectivity of SUs of both Dir-CRNs and Omn-CRNs, thus enabling
tractability. We show that the connectivity of SUs is mainly affected by two
constraints: the spectrum availability of SUs and the topological connectivity
of SUs. Extensive simulations validate the accuracy of our proposed models.
Meanwhile, we also show that Dir-CRNs can have higher connectivity than
Omn-CRNs mainly due to the lower interference, the higher spectrum availability
and the higher topological connectivity brought by directional antennas.Comment: 9 pages, a full version to appear in IEEE Transactions on Vehicular
Technology 201