Energy-efficient caching strategies in ad hoc wireless networks

Abstract

In this paper, we address the problem of energy-conscious cache placement in wireless ad hoc networks. We consider a network comprising a server with an interface to the wired network, and some nodes requiring access to the information stored at the server. In order to reduce access latency in such a communication environment, an effective strategy is caching the server information at some nodes distributed across the network. Caching, however, can considerably impact the system energy expenditure; for instance, disseminating information incurs additional energy burden. Since wireless devices have limited amounts of available energy, we need to design caching strategies that optimally trade-off between energy consumption and access latency. We pose our problem as an integer linear program. We show that this problem is the same as a special case of the connected facility location problem, which is known to be NP-hard. We devise a polynomial time algorithm which provides a sub-optimal solution. The proposed algorithm applies to any arbitrary network topology and can be implemented in a distributed and asynchronous manner. In the case of a tree topology, our algorithm gives the optimal solution. In the case of an arbitrary topology, it finds a feasible solution with an objective function value within a factor of 6 of the optimal value. This performance is very close to the best approximate solution known today, which is obtained in a centralized manner. We compare the performance of our algorithm against three candidate caching schemes, and show via extensive simulation that our algorithm consistently outperforms these alternative schemes. * This work was partially funded by

High performance, low complexity cooperative caching for Wireless Sensor Networks

“…Figures 7,8,9,10,11,and 12 show the performance comparison of the protocols for a sensornet with 100 nodes, while Figs. 13,14,15,16,17, and 18 for a sensornet with 500 nodes. The Figs.…”

“…Nuggehalli et al [15] addressed the problem of energy-conscious cache placement in wireless ah hoc networks, and [16] considered the cache placement problem of minimizing total data access cost in ad hoc networks with multiple data items, and presented a polynomial-time centralized approximation algorithm to attack the problem, since it is NP-hard. Similarly, the work in [17] adresses the problem of cache placement in wireless sensor networks by constructing a static multicast tree based on the Steiner tree concept.…”

Optimal deployment of caches in the plane

“…Other work on caching in wireless networks is, for instance, [5]- [7]. In [5] the authors analyze the trade-off between energy consumption and the retrieval delay of data from caches.…”

Benefit-Based Data Caching in Ad Hoc Networks

“…Here, |V | is the size of the network. In other related work, Nuggehalli et al [22] formulate the caching problem in ad hoc networks as a special case of the connected facility location [27].…”