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On the Connectivity of Finite Wireless Networks with Multiple Base Stations. Sergio Bermudez and Prof. Stephen Wicker School of ECE, Cornell University International Conference on Computer Communications and Networks, August 3-7, 2008. Agenda. Introduction Wireless Networks Connectivity
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On the Connectivity of Finite Wireless Networks with Multiple Base Stations Sergio Bermudez and Prof. Stephen Wicker School of ECE, Cornell University International Conference on Computer Communications and Networks, August 3-7, 2008
Agenda • Introduction • Wireless Networks Connectivity • Approaches to Analyze Connectivity • Model and Results • Assumptions • Main Result • Simulation Results • Conclusions "Connected Sub-networks," Sergio Bermudez
Introduction Connectivity is a fundamental quality of a wireless network. Any two nodes are able to communicate between them, either single- or multi-hop. "Connected Sub-networks," Sergio Bermudez
Previous Work on Connectivity • Focus on the connectivity of wireless networks having a single connected component. • Approaches on the number of nodes for random deployments: • Asymptotic • Finite "Connected Sub-networks," Sergio Bermudez
Asymptotic Connectivity Analysis Gupta and Kumar: n uniformly distributed nodes, letting n → ∞, finite area. Percolation theory. Bettstetter: Infinite network, constant node density, analyzing finite area. Geometric random graphs theory. "Connected Sub-networks," Sergio Bermudez
Finite Connectivity Analysis Desai and Manjunath: network over a line segment, nodes distributed uniformly, geometrical argument. Godehardt and Jaworski: random interval graphs in the unit interval, combinatorial theory. "Connected Sub-networks," Sergio Bermudez
Multiple Base Stations Scenario • Envisioned application of sensor networks is monitoring Physical Infrastructure • It is feasible that those networks have base stations. • Example in systems like water quality monitoring, electricity generation plants. • In general, due to factors like: • Increase network capacity • Manage large deployment area • Enhance network reliability "Connected Sub-networks," Sergio Bermudez
Considering multiple base stations It is intuitive that having more than one base station provide less stringent requirements on the numbers of nodes needed to have a connected network. "Connected Sub-networks," Sergio Bermudez
Model for Analysis • We will focus on: • analysis of connectivity with sub-networks • one-dimensional deployments • Connected Sub-network • connected components of the network realization that are able to communicate with at least one BS. "Connected Sub-networks," Sergio Bermudez
General Assumptions Uniformly random deployment of n nodes over a line segment [0,S] m base stations at given location yi Fix communication radius r Boolean communication link model "Connected Sub-networks," Sergio Bermudez
Problem Statement • Given n nodes with communication radius r , and m base stations and their locations, what is the probability that the network realization is connected? • We consider a network as connected if its composing sub-networks are connected. "Connected Sub-networks," Sergio Bermudez
Problem Decomposition Conditioning on the number of nodes in a sub-segment, nodes are uniformly distributed. Independence on the probability of sub-network connectivity. "Connected Sub-networks," Sergio Bermudez
Probability of Connectivity • C: all nodes in the network reach at least one base station. • Ci : all nodes inside segment wi reach at least one base station. • There are two general cases: • border and inner connectivity "Connected Sub-networks," Sergio Bermudez
Main Formula • border and inner connectivity term By the Law of Total Probability "Connected Sub-networks," Sergio Bermudez
Simulation Setup Segment [0,1] Deployment with n nodes Use different locations for the base stations Monte Carlo method with 105 random replications "Connected Sub-networks," Sergio Bermudez
One Base Station Network "Connected Sub-networks," Sergio Bermudez
Two Base Stations Network "Connected Sub-networks," Sergio Bermudez
Summary Used the concept of connected sub-networks. Presented a formula to calculate the probability of connectivity for wireless networks with infrastructure. "Connected Sub-networks," Sergio Bermudez
Further Reading • “On the Connectivity of a Random Interval Graph,” E. Godehardt and J. Jaworski, Random Structures and Algorithms, 137–161, 1996. • “On the connectivity in finite ad hoc networks,” M. Desai and D. Manjunath, IEEE Commun. Lett., 425–436, 2005. "Connected Sub-networks," Sergio Bermudez
Border and Inner Connectivity Border-Connectivity Formula Inner-Connectivity Formula "Connected Sub-networks," Sergio Bermudez