2,502 research outputs found
Green Cellular Networks: A Survey, Some Research Issues and Challenges
Energy efficiency in cellular networks is a growing concern for cellular
operators to not only maintain profitability, but also to reduce the overall
environment effects. This emerging trend of achieving energy efficiency in
cellular networks is motivating the standardization authorities and network
operators to continuously explore future technologies in order to bring
improvements in the entire network infrastructure. In this article, we present
a brief survey of methods to improve the power efficiency of cellular networks,
explore some research issues and challenges and suggest some techniques to
enable an energy efficient or "green" cellular network. Since base stations
consume a maximum portion of the total energy used in a cellular system, we
will first provide a comprehensive survey on techniques to obtain energy
savings in base stations. Next, we discuss how heterogeneous network deployment
based on micro, pico and femto-cells can be used to achieve this goal. Since
cognitive radio and cooperative relaying are undisputed future technologies in
this regard, we propose a research vision to make these technologies more
energy efficient. Lastly, we explore some broader perspectives in realizing a
"green" cellular network technologyComment: 16 pages, 5 figures, 2 table
A survey of routing protocols for energy constrained ad hoc wireless networks
In this survey we review energy-aware routing protocols for wireless multihop ad hoc networks and critically discuss the main results in this area. The classification presented is in no case unique but summarizes the chief characteristics of the many published proposals for energy conservation. A common pitfall detected in most of the studies is the lack of unambiguous notion of network's lifetime and hence of clear objective of the designed algorithm. We, therefore, define first what operational lifetime for ad hoc networks means and then analyze the achievements from that angle. After getting insight into the different energy-aware routing protocols we point out another approach for extending network's operational lifespan, which has been overlooked in the relevant literature.Peer Reviewe
Continuum Equilibria and Global Optimization for Routing in Dense Static Ad Hoc Networks
We consider massively dense ad hoc networks and study their continuum limits
as the node density increases and as the graph providing the available routes
becomes a continuous area with location and congestion dependent costs. We
study both the global optimal solution as well as the non-cooperative routing
problem among a large population of users where each user seeks a path from its
origin to its destination so as to minimize its individual cost. Finally, we
seek for a (continuum version of the) Wardrop equilibrium. We first show how to
derive meaningful cost models as a function of the scaling properties of the
capacity of the network and of the density of nodes. We present various
solution methodologies for the problem: (1) the viscosity solution of the
Hamilton-Jacobi-Bellman equation, for the global optimization problem, (2) a
method based on Green's Theorem for the least cost problem of an individual,
and (3) a solution of the Wardrop equilibrium problem using a transformation
into an equivalent global optimization problem
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