1,711 research outputs found
Reliable machine-to-machine multicast services with multi-radio cooperative retransmissions
The final publication is available at Springer via http://dx.doi.org/10.1007/s11036-015-0575-6The 3GPP is working towards the definition of service requirements and technical solutions to provide support for energy-efficient Machine Type Communications (MTC) in the forthcoming generations of cellular networks. One of the envisioned solutions consists in applying group management policies to clusters of devices in order to reduce control signaling and improve upon energy efficiency, e.g., multicast Over-The-Air (OTA) firmware updates. In this paper, a Multi-Radio Cooperative Retransmission Scheme is proposed to efficiently carry out multicast transmissions in MTC networks, reducing both control signaling and improving energy-efficiency. The proposal can be executed in networks composed by devices equipped with multiple radio interfaces which enable them to connect to both a cellular access network, e.g., LTE, and a short-range MTC area network, e.g., Low-Power Wi-Fi or ZigBee, as foreseen by the MTC architecture defined by ETSI. The main idea is to carry out retransmissions over the M2M area network upon error in the main cellular link. This yields a reduction in both the traffic load over the cellular link and the energy consumption of the devices. Computer-based simulations with ns-3 have been conducted to analyze the performance of the proposed scheme in terms of energy consumption and assess its superior performance compared to non-cooperative retransmission schemes, thus validating its suitability for energy-constrained MTC applications.Peer ReviewedPostprint (author's final draft
Efficient Cooperative Anycasting for AMI Mesh Networks
We have, in recent years, witnessed an increased interest towards enabling a
Smart Grid which will be a corner stone to build sustainable energy efficient
communities. An integral part of the future Smart Grid will be the
communications infrastructure which will make real time control of the grid
components possible. Automated Metering Infrastructure (AMI) is thought to be a
key enabler for monitoring and controlling the customer loads. %RPL is a
connectivity enabling mechanism for low power and lossy networks currently
being standardized by the IETF ROLL working group. RPL is deemed to be a
suitable candidate for AMI networks where the meters are connected to a
concentrator over multi hop low power and lossy links. This paper proposes an
efficient cooperative anycasting approach for wireless mesh networks with the
aim of achieving reduced traffic and increased utilisation of the network
resources. The proposed cooperative anycasting has been realised as an
enhancement on top of the Routing Protocol for Low Power and Lossy Networks
(RPL), a connectivity enabling mechanism in wireless AMI mesh networks. In this
protocol, smart meter nodes utilise an anycasting approach to facilitate
efficient transport of metering data to the concentrator node. Moreover, it
takes advantage of a distributed approach ensuring scalability
Reliable Broadcast to A User Group with Limited Source Transmissions
In order to reduce the number of retransmissions and save power for the
source node, we propose a two-phase coded scheme to achieve reliable broadcast
from the source to a group of users with minimal source transmissions. In the
first phase, the information packets are encoded with batched sparse (BATS)
code, which are then broadcasted by the source node until the file can be
cooperatively decoded by the user group. In the second phase, each user
broadcasts the re-encoded packets to its peers based on their respective
received packets from the first phase, so that the file can be decoded by each
individual user. The performance of the proposed scheme is analyzed and the
rank distribution at the moment of decoding is derived, which is used as input
for designing the optimal BATS code. Simulation results show that the proposed
scheme can reduce the total number of retransmissions compared with the
traditional single-phase broadcast with optimal erasure codes. Furthermore,
since a large number of transmissions are shifted from the source node to the
users, power consumptions at the source node is significantly reduced.Comment: ICC 2015. arXiv admin note: substantial text overlap with
arXiv:1504.0446
Energy Efficiency Analysis in Amplify-and-Forward and Decode-and-Forward Cooperative Networks
In this paper, we have studied the energy efficiency of cooperative networks
operating in either the fixed Amplifyand- Forward (AF) or the selective
Decode-and-Forward (DF) mode. We consider the optimization of the M-ary
quadrature amplitude modulation (MQAM) constellation size to minimize the bit
energy consumption under given bit error rate (BER) constraints. In the
computation of the energy expenditure, the circuit, transmission, and
retransmission energies are taken into account. The link reliabilities and
retransmission probabilities are determined through the outage probabilities
under the Rayleigh fading assumption. Several interesting observations with
practical implications are made. It is seen that while large constellations are
preferred at small transmission distances, constellation size should be
decreased as the distance increases; the cooperative gain is computed to
compare direct transmission and cooperative transmission.Comment: Proc. IEEE WCNC2010, Sydney, Australia, April, 201
Centralized and Cooperative Transmission of Secure Multiple Unicasts using Network Coding
We introduce a method for securely delivering a set of messages to a group of
clients over a broadcast erasure channel where each client is interested in a
distinct message. Each client is able to obtain its own message but not the
others'. In the proposed method the messages are combined together using a
special variant of random linear network coding. Each client is provided with a
private set of decoding coefficients to decode its own message. Our method
provides security for the transmission sessions against computational
brute-force attacks and also weakly security in information theoretic sense. As
the broadcast channel is assumed to be erroneous, the missing coded packets
should be recovered in some way. We consider two different scenarios. In the
first scenario the missing packets are retransmitted by the base station
(centralized). In the second scenario the clients cooperate with each other by
exchanging packets (decentralized). In both scenarios, network coding
techniques are exploited to increase the total throughput. For the case of
centralized retransmissions we provide an analytical approximation for the
throughput performance of instantly decodable network coded (IDNC)
retransmissions as well as numerical experiments. For the decentralized
scenario, we propose a new IDNC based retransmission method where its
performance is evaluated via simulations and analytical approximation.
Application of this method is not limited to our special problem and can be
generalized to a new class of problems introduced in this paper as the
cooperative index coding problem
Reliable data delivery in low energy ad hoc sensor networks
Reliable delivery of data is a classical design goal for reliability-oriented collection routing protocols for ad hoc wireless sensor networks (WSNs). Guaranteed packet delivery performance can be ensured by careful selection of error free links, quick recovery from packet losses, and avoidance of overloaded relay sensor nodes. Due to limited resources of individual senor nodes, there is usually a trade-off between energy spending for packets transmissions and the appropriate level of reliability. Since link failures and packet losses are unavoidable, sensor networks may tolerate a certain level of reliability without significantly affecting packets delivery performance and data aggregation accuracy in favor of efficient energy consumption. However a certain degree of reliability is needed, especially when hop count increases between source sensor nodes and the base station as a single lost packet may result in loss of a large amount of aggregated data along longer hops. An effective solution is to jointly make a trade-off between energy, reliability, cost, and agility while improving packet delivery, maintaining low packet error ratio, minimizing unnecessary packets transmissions, and adaptively reducing control traffic in favor of high success reception ratios of representative data packets. Based on this approach, the proposed routing protocol can achieve moderate energy consumption and high packet delivery ratio even with high link failure rates. The proposed routing protocol was experimentally investigated on a testbed of Crossbow's TelosB motes and proven to be more robust and energy efficient than the current implementation of TinyOS2.x MultihopLQI
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