Rates of Change in Ad hoc Networks

2011 ◽  
pp. 166-184 ◽  
Author(s):  
Alec Yasinsac
Keyword(s):  
Ad Hoc Networks ◽  
Short Duration ◽  
Ad Hoc ◽  
Dynamic Nature ◽  
Security Properties ◽  
Network Properties ◽  
Hoc Networks ◽  
Network Functionality ◽  
Link Availability ◽  
Dynamic Link

Ad hoc networks are inherently dynamic, with nodes entering, moving around, and leaving the network, often for short duration membership. This property of dynamic restructuring limits functionality and greatly complicates security. Here, we establish a foundation for analyzing ad hoc network functionality or security properties relative to their dynamic nature. The essential structure in any network is the links between nodes. Thus, our approach turns on measures of link availability to define network properties that govern functionality. In this chapter, we systematically address issues associated with changes that occur in ad hoc networks. We consider the functionality impact of change and address bounds on optimization that exist when change rates are high and provide definitions that allow reasoning about limits on functionality resulting from increasingly dynamic link activity.

OPTIMAL INTERCONNECTION OF AD HOC INJECTION NETWORKS

2008 ◽  
Vol 09 (03) ◽  
pp. 277-297 ◽  
Author(s):  
GREGOIRE DANOY ◽  
ENRIQUE ALBA ◽  
PASCAL BOUVRY
Keyword(s):  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Small World ◽  
Access Point ◽  
Clustering Coefficient ◽  
Mobility Patterns ◽  
Characteristic Path Length ◽  
Network Properties ◽  
Hoc Networks ◽  
Topology Control Problem

Multi-hop ad hoc networks allow establishing local groups of communicating devices in a self-organizing way. However, when considering realistic mobility patterns, such networks most often get divided in a set of disjoint partitions. This presence of partitions is an obstacle to communication within these networks. Ad hoc networks are generally composed of devices capable of communicating in a geographical neighborhood for free (e.g. using Wi-Fi or Bluetooth). In most cases a communication infrastructure is available. It can be a set of access point as well as a GSM/UMTS network. The use of such an infrastructure is billed, but it permits to interconnect distant nodes, through what we call “bypass links”. The objective of our work is to optimize the placement of these long-range links. To this end we rely on small-world network properties, which consist in a high clustering coefficient and a low characteristic path length. In this article we investigate the use of three genetic algorithms (generational, steady-state, and cooperative coevolutionary) to optimize three instances of this topology control problem and present initial evidence of their capacity to solve it.

scholarly journals Spectrum aware clustering in cognitive radio ad hoc networks

2018 ◽  
Vol 7 (2.30) ◽  
pp. 27
Author(s):  
Aishwarya Sagar Anand Ukey ◽  
Meenu Chawla
Keyword(s):  
Cognitive Radio ◽  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Cluster Formation ◽  
Clustering Algorithms ◽  
Radio Spectrum ◽  
Dynamic Nature ◽  
Secondary Users ◽  
Hoc Networks ◽  
Maintenance Process

Cognitive radio (CR) is an emerging technology developed for efficient utilization of the radio spectrum. CRN utilizes CR technology and enables the unlicensed users also referred as secondary users (SUs) to access free portions of the licensed spectrum in an opportunistic manner. To support scalability and stability in distributed CRNs also referred as cognitive radio ad hoc networks (CRAHNs), SUs are often organized into smaller groups known as clusters. Spectrum aware clustering is considered as the key technique to overcome numerous is-sues associated with the dynamic nature of CRAHNs. This article focuses on clustering in CRAHNs and presents a comprehensive review of various spectrum aware clustering algorithms presented in the literature. The article highlights notable clustering metrics and includes the description of cluster formation and maintenance process. The article also renders potential research gaps in existing research works and discusses open challenges and issues that need to be addressed for efficient clustering in CRAHNs. 

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