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Throughput and energy-aware routing for 802.11 based mesh networks
Get PDFIn this paper we propose a novel routing algorithm for 802.11 based wireless mesh networks called Energy and Throughput-aware Routing (ETR). The design objectives of ETR are (i) to provide flows with throughput guarantees, and (ii) to minimize the overall energy consumption in the mesh network. To achieve these objectives, we first analyze the throughput performance of the mesh network. Based on this analysis, we target obtaining the set of feasible allocations in the wireless network, i.e., the capacity
region, which results in a set of complex non-linear equations that are not adequate for optimization algorithms.
To overcome this computational complexity we derive a set of linear constraints (referred to as linearized capacity regions) which provides a much simpler formulation at a slightly reduced accuracy. By feeding these linear constraints into an integer programming formulation, we then propose a routing algorithm that admits as many flows as possible while satisfying their throughput guarantees. This algorithm is further extended to account for energy considerations by devising a routing algorithm that uses
as few nodes as possible, which allows switching off the unused nodes and thus save energy. The proposed approach is thoroughly evaluated and shown to outperform previous approaches very substantially both in terms of throughput and energy consumption.
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Opportunistic Information Dissemination in Mobile Ad-Hoc Networks: Adaptiveness vs. Obliviousness and Randomization vs. Determinism
Get PDFIn this paper the problem of information dissemination in
Mobile Ad-hoc Networks (MANETs) is studied. The problem is to disseminate a piece of information, initially held by a distinguished source node, to all nodes in a target set. We assume a weak set of restrictions on the mobility of nodes, parameterized by α, the disconnection time, and β, the link stability time, such that the MANETs considered are connected enough for dissemination. Such a connectivity model generalizes previous models in that we assume much less connectivity, or make explicit the assumptions in previous papers.
In MANETs, nodes are embedded in the plane and can move with
bounded speed. Communication between nodes occurs over a collisionprone single channel. We show upper and lower bounds for different types of randomized protocols, parameterized by α and β. This problem has been extensively studied in static networks and for deterministic protocols. We show tight bounds on the randomized complexity of information dissemination in MANETs, for reasonable choices
of α and β. We show that randomization reduces the time complexity of the problem by a logarithmic or linear factor, depending on the class of randomized protocol considered.TRUEpu
Providing throughput guarantees in heterogeneous wireless mesh networks
Get PDFIn this paper, we propose to provide throughput guarantees in heterogeneous wireless mesh networks by jointly optimizing routing and Medium Access Control configuration. Our solution is based on the notion of linearized capacity region, which provides a technology-independent way of representing the capacity of a wireless link (thereby hiding the technology specifics to the upper layers). From the available capacity of the underlying links as given by the linearized capacity region, we propose two routing algorithms (based on multipath and single path) that find optimal paths for all the flows in the network given their throughput requirements. The throughput allocation resulting from routing is then provided to each link, which uses this information to optimize its technology-specific Medium Access Control parameters. The proposed approach is evaluated in a heterogeneous scenario comprising Wireless Local Area Networks (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) technologies and is shown to outperform previous solutions by (at least) a factor of 2.Copyright © 2012 John Wiley & Sons, Ltd.pu
The emerging energy web
Get PDFThere is a general need of elaborating energy-effective solutions for managing our increasingly dense interconnected world. The problem should be tackled in multiple dimensions -technology, society, economics, law, regulations, and politics- at different temporal and spatial scales. Holistic approaches will enable technological solutions to be supported by socio-economic motivations, adequate incentive regulation to foster investment in green infrastructures coherently integrated with adequate energy provisioning schemes. In this article, an attempt is made to describe such multidisciplinary challenges with a coherent set of solutions to be identified to significantly impact the way our interconnected energy world is designed and operated.TRUEpu
LFA applicability in SP networks
Get PDFLFA Applicability: Pierre Francois was the editor of RFC 6571 [2], "LFA applicability in SP networks", co-edited with Clarence Filsfils, distinguished engineer at Cisco Systems. This RFC presents an analysis of the applicability of an IP Fast Reroute technique called "Loop-free alternates" in Internet Service Provider Networks. This work has been performed in collaboration with Cisco Systems, France Telecom - Orange, AT&T, and Deutsche Telekom.In this document, we analyze the applicability of -Loop-Free
Alternates in both core and access parts of Service Provider
networks. We provide design guides to favor their applicability where relevant, typically in the access part of the network.Internet Engineering Task Force (IETF)pu
A Control Theoretic Scheme for Efficient Video Transmission over IEEE 802.11e EDCA WLANs
Get PDFThe EDCA mechanism of the IEEE 802.11 standard has been designed to support, among others, video traffic. This mechanism relies on a number of parameters whose configuration is left open by the standard. Although there are some recommended values for these parameters, they are fixed independent of the WLAN conditions, which results in suboptimal performance. Following this observation, a number of approaches in the literature have been devised to set the EDCA parameters based on an estimation of the WLAN conditions. However, these previous approaches are based on heuristics and hence do not guarantee optimized performance. In this paper we propose a novel algorithm to adjust the EDCA parameters to carry video traffic which, in contrast to previous approaches, is sustained on mathematical foundations that guarantee optimal performance. In particular, our approach builds upon i) an analytical model of the WLAN performance under video traffic, used to derive the optimal point of operation of EDCA, and ii) a control theoretic designed mechanism which drives the WLAN to this point of operation. Via extensive simulations, we show that the proposed approach performs optimally and substantially outperforms the standard recommended configuration as well as previous adaptive proposals.TRUEpu
Greening wireless communications: Status and future directions
Get PDFIn recent years, concerns on energy consumption and greenhouse pollution due to the operation of
wireless devices have triggered a vast amount of research work on the so called green wireless technologies,
leading to new, energy-aware proposals. Even for the case of battery powered devices, where
energy conservation is a key design goal, new approaches have been proposed, based on a better understanding
of the cost-performance trade-offs introduced by energy efficient operation, while increasingly
focusing on emerging communication technologies, e.g., body sensor networks, MIMO, or LTE. This
paper presents a survey of the recent proposals for green wireless communications, with a view to understanding
the most relevant sources of inefficient energy consumption and how these are tackled by
current solutions. We introduce a classification of the existing mechanisms based on their operational
time-scale, discuss the most important techniques employed to date from this perspective, analyze
the employed evaluation methodologies and undertake a quantitative comparison of their performance
gains. Following this analysis, we identify the key challenges yet to be addressed by the research
community, as well as several possible future directions towards greener communications.TRUEpu
The Fair Allocation of Power to Air Conditioners on a Smart Grid
No full textOur objective is to allocate power to air conditioners
fairly when demand exceeds supply or when the load in regions of the network exceeds the capacity of the links. This is an alternative to the current practice of brown outs or black outs and the proposed pricing mechanisms. We hypothesis a smart grid in which the power company can communicate with the customers, measure the temperature and power consumption of each residence, and remotely set each thermostat. We develop simple techniques to predict changes in power consumption for modest changes in the setting of a thermostat, algorithms to apply two fairness metrics used in communications networks to power allocation, and an algorithm to assign power to different parts of a network on a capacity constrained local distribution network. We also propose a practical procedure to apply these algorithms.TRUEpu
An Economic Side-Effect for Prefix Deaggregation
Get PDFThe injection of artificially fragmented prefixes
through BGP is a widely used traffic engineering technique.
In this paper we examine one particular economic side-effect
of deaggregation, namely the impact on the transit traffic bill. We show that the use of more-specific prefixes has a traffic stabilization side-effect which translates into a decrease of the transit traffic bill. We propose an analytical model in order to quantify the impact of deaggregation on the transit costs. We validate our results by means of simulations and through the extensive analysis of real BGP routing information data.TRUEpu
VoIPiggy: Implementation and evaluation of a mechanism to boost voice capacity in 802.11 WLANs
Get PDFSupporting voice traffic in existing WLANs results extremely inefficient, given the large overheads of the protocol operation and the need to prioritize this traffic over, e.g., bulky transfers. In this paper we propose a simple scheme to improve the efficiency of WLANs when voice
traffic is present. The mechanism is based on piggybacking voice frames over the acknowledgments, which reduces both frame overheads and time spent in contentions. We evaluate its performance in a large-scale testbed consisting on 33 commercial off-the-shelf devices. The experimental results show dramatic performance improvements in both voice-only and mixed voice-and-data scenarios.TRUEpu