1,428 research outputs found
Improving Energy Efficiency in MANETs by Multi-Path Routing
Some multi-path routing algorithm in MANET, simultaneously send information
to the destination through several directions to reduce end-to-end delay. In
all these algorithms, the sent traffic through a path affects the adjacent path
and unintentionally increases the delay due to the use of adjacent paths.
Because, there are repetitive competitions among neighboring nodes, in order to
obtain the joint channel in adjacent paths. The represented algorithm in this
study tries to discover the distinct paths between source and destination nodes
with using Omni directional antennas, to send information through these
simultaneously. For this purpose, the number of active neighbors is counted in
each direction with using a strategy. These criterions are effectively used to
select routes. Proposed algorithm is based on AODV routing algorithm, and in
the end it is compared with AOMDV, AODVM, and IZM-DSR algorithms which are
multi-path routing algorithms based on AODV and DSR. Simulation results show
that using the proposed algorithm creates a significant improvement in energy
efficiency and reducing end-to-end delay
Context Information for Fast Cell Discovery in mm-wave 5G Networks
The exploitation of the mm-wave bands is one of the most promising solutions
for 5G mobile radio networks. However, the use of mm-wave technologies in
cellular networks is not straightforward due to mm-wave harsh propagation
conditions that limit access availability. In order to overcome this obstacle,
hybrid network architectures are being considered where mm-wave small cells can
exploit an overlay coverage layer based on legacy technology. The additional
mm-wave layer can also take advantage of a functional split between control and
user plane, that allows to delegate most of the signaling functions to legacy
base stations and to gather context information from users for resource
optimization. However, mm-wave technology requires high gain antenna systems to
compensate for high path loss and limited power, e.g., through the use of
multiple antennas for high directivity. Directional transmissions must be also
used for the cell discovery and synchronization process, and this can lead to a
non-negligible delay due to the need to scan the cell area with multiple
transmissions at different directions. In this paper, we propose to exploit the
context information related to user position, provided by the separated control
plane, to improve the cell discovery procedure and minimize delay. We
investigate the fundamental trade-offs of the cell discovery process with
directional antennas and the effects of the context information accuracy on its
performance. Numerical results are provided to validate our observations.Comment: 6 pages, 8 figures, in Proceedings of European Wireless 201
Self-organization of Nodes using Bio-Inspired Techniques for Achieving Small World Properties
In an autonomous wireless sensor network, self-organization of the nodes is
essential to achieve network wide characteristics. We believe that connectivity
in wireless autonomous networks can be increased and overall average path
length can be reduced by using beamforming and bio-inspired algorithms. Recent
works on the use of beamforming in wireless networks mostly assume the
knowledge of the network in aggregation to either heterogeneous or hybrid
deployment. We propose that without the global knowledge or the introduction of
any special feature, the average path length can be reduced with the help of
inspirations from the nature and simple interactions between neighboring nodes.
Our algorithm also reduces the number of disconnected components within the
network. Our results show that reduction in the average path length and the
number of disconnected components can be achieved using very simple local rules
and without the full network knowledge.Comment: Accepted to Joint workshop on complex networks and pervasive group
communication (CCNet/PerGroup), in conjunction with IEEE Globecom 201
Fast Neighbor Discovery for Wireless Ad Hoc Network with Successive Interference Cancellation
Neighbor discovery (ND) is a key step in wireless ad hoc network, which
directly affects the efficiency of wireless networking. Improving the speed of
ND has always been the goal of ND algorithms. The classical ND algorithms lose
packets due to the collision of multiple packets, which greatly affects the
speed of the ND algorithms. Traditional methods detect packet collision and
implement retransmission when encountering packet loss. However, they does not
solve the packet collision problem and the performance improvement of ND
algorithms is limited. In this paper, the successive interference cancellation
(SIC) technology is introduced into the ND algorithms to unpack multiple
collision packets by distinguishing multiple packets in the power domain.
Besides, the multi-packet reception (MPR) is further applied to reduce the
probability of packet collision by distinguishing multiple received packets,
thus further improving the speed of ND algorithms. Six ND algorithms, namely
completely random algorithm (CRA), CRA based on SIC (CRA-SIC), CRA based on SIC
and MPR (CRA-SIC-MPR), scan-based algorithm (SBA), SBA based on SIC (SBA-SIC),
and SBA based on SIC and MPR (SBA-SIC-MPR), are theoretically analyzed and
verified by simulation. The simulation results show that SIC and MPR reduce the
ND time of SBA by 69.02% and CRA by 66.03% averagely.Comment: 16 pages, 16 figure
Fast Cell Discovery in mm-wave 5G Networks with Context Information
The exploitation of mm-wave bands is one of the key-enabler for 5G mobile
radio networks. However, the introduction of mm-wave technologies in cellular
networks is not straightforward due to harsh propagation conditions that limit
the mm-wave access availability. Mm-wave technologies require high-gain antenna
systems to compensate for high path loss and limited power. As a consequence,
directional transmissions must be used for cell discovery and synchronization
processes: this can lead to a non-negligible access delay caused by the
exploration of the cell area with multiple transmissions along different
directions.
The integration of mm-wave technologies and conventional wireless access
networks with the objective of speeding up the cell search process requires new
5G network architectural solutions. Such architectures introduce a functional
split between C-plane and U-plane, thereby guaranteeing the availability of a
reliable signaling channel through conventional wireless technologies that
provides the opportunity to collect useful context information from the network
edge.
In this article, we leverage the context information related to user
positions to improve the directional cell discovery process. We investigate
fundamental trade-offs of this process and the effects of the context
information accuracy on the overall system performance. We also cope with
obstacle obstructions in the cell area and propose an approach based on a
geo-located context database where information gathered over time is stored to
guide future searches. Analytic models and numerical results are provided to
validate proposed strategies.Comment: 14 pages, submitted to IEEE Transaction on Mobile Computin
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