Wireless ad hoc network management - Essay Example

1 Introduction Our organization runs an ad hoc wireless network system. At the present moment, and consequent to problems which arose from previousnetwork management systems, the organization is engaged in the implementation of a policy-based management framework for wireless ad hoc networks with focus on Quality of Service [QoS] management. Until the completion of implementation, the ICT director informed me that the questions I was posing were irrelevant. They were irrelevant because they were related to operational automatic network management systems, currently not in place in our organization. Accordingly, the information collected from the ICT director, and which determined the direction of this report, centered around the management of wireless ad hoc networks and policy-based management frameworks. 2 Wireless Ad Hoc Network Management In designing and deciding upon a wireless ad hoc network management system, it is important to keep an eye on the desirable operational features sought in a management system for deployment in a wireless ad hoc network environment. These features, as elucidated by the ICT director and supported in the literature on the topic, are discussed below. 2.1 Efficient Signaling Mechanism According to Tian and Cox (2004), any network management system involves a certain amount of additional control traffic to regulate the various operational characteristics of the network. In bandwidth-constrained wireless networks, it is extremely important to minimize this signaling overhead, ensuring that the links are not congested with management traffic. Thus, as Cardei, Cardei and Du (2005) emphasize, the constrained bandwidth in wireless ad hoc networks greatly influences the choice of the mechanisms or protocols used for the various managerial tasks. 2.2 Lightweight Ad hoc networks generally have nodes with limited battery life, and may have limited storage and/or processing capabilities (Zhang, Hu and Fujisu, 2006). Hence, as emphasized by the ICT director, the organization needs a management system that does not burden the resource-limited network nodes with undue storage and processing requirements. Efficient signaling and minimal computation requirements will substantially alleviate the demand on the limited battery power. 2.3 Automated, Intelligent and Self-Organizing The ability for self-organization is one of the key aspects in the successful deployment of any application in an ad hoc network environment. Indeed, as our ICT Director stressed, given the dynamic nature of most ad hoc networks, an adaptive management framework that automatically reacts to changes in network conditions is required. In order to accomplish this, the management system should be able to automatically learn about the diverse capabilities of the nodes involved, and use this information as one of the criteria to assign appropriate roles to the different types of nodes. The implication here is that, as Zhang, Hu, and Fujisu (2006) stress, dynamic policies need to be supported for automated network control based on dynamic re-evaluation of communication capabilities and assets of an ad hoc network. 2.4 Secure and Robust Finally, an ad hoc network management system should be secure and robust. It should allow secure exchange of management data among authorized users, and enhance the overall survivability of the network (ICT Director). This may require the means to authenticate and authorize users, and support encryption capabilities. In addition, the system should allow reliable transmission of management data with means to detect failure and provide fault-tolerance (ICT Director). 3.0 Policy-Based Network Management In designing and deciding upon our network management architecture, our ICT Department was guided by the concerns outlined in the preceding section. Using these concerns as a roadmap for the determination of the format of our organization's ideal network management system, the ICT department identified policy-based network systems as the optimal option. The reason lies in that the aforementioned network management system facilitates the implementation of QoS. According to our ICT Director, the design of our network management system was driven by the imperatives of implementing QoS. Indeed, the importance of a network management system which embraces QoS is attested to in the literature on wireless as hoc network management. According to this literature, one approach for QoS provisioning and management in the Internet that has met with considerable interest in the networking community is Policy-Based Network Management (PBNM) (Randhawa and Hardy, 2001; Tian and Cox, 2004; Cardei, Cardei and Du, 2005; Zhang, Hu, and Fujisu, 2006). A pilot implementation in our organization confirmed Zhang, Hu, and Fujisu's (2006) statement that PBNM configures and controls the network as a whole, providing the network operator with a simplified, logically centralized and automated control over the entire network. PBNM has made administration of complex operational characteristics of a network, such as Quality of Service (QoS), access control, network security, dynamic IP address allocation, much easier. The advantages of policy-based network system, according to our ICT Director, primarily lie in its Policy Management Tool (PMT). As Tian and Cox (2004) explain, PMT provides the network administrator with an interface to interact with the network. A network administrator uses the policy management tool to define the various policies or policy groups. It is typically the function of the PMT to validate the syntactic and semantic correctness of the administrator input, to ensure consistency among the high-level policies and to check for compatibility of the various policies. Further, the PMT typically determines the association between the policies and the various network elements where these policies are to be enforced, determines which low-level policies can be used to support the specified high-level policies and ensures that the specified policies are comprehensive enough to cover all the relevant scenarios. The policies specified at the PMT are then stored in a policy repository (Tian and Cox, 2004). A policy repository, according to Cardei, Cardei and Du (2005), can be defined as a data store or a model abstraction that holds policy rules, their conditions and actions, and related policy data. Its advantage, as our ICT Director emphasized, lies in its facilitation of data management, network policy and rule management and operationalization and, above all, its provision of QoS. It is, thus, that the organization finally settled on the implementation of a PBNM system. 4.0 Conclusion On the basis of the information presented in this report, it is evident that decisions pertaining to the design of a network management system are highly complex and complicated. They must be founded upon an accurate assessment of the organization's needs versus the advantages and disadvantages of the available network management systems, on the one hand, and the nature of the network in place, on the other. Even then, as our ICT director emphasized, final decisions cannot be rendered without a pilot testing of the network management system in question. This was the path that our organization pursued in its design and decision to implement a PBNM system. References Cardei, M., Cardei, I. and Du, D. (2005). Resource Management in Wireless Networking (Network Theory and Applications. New York: Springer. Randhawa, T.S. and Hardy, S. (2001) Network Management Systems in Wired and Wireless Networks. New York: Springer. Tian, K.Q. and Cox, D.C. (2004). Mobility Management in Wireless Networks: Data Replication Strategies and Applications (ERCOFTAC). New York: Springer. Zhang, Y., Hu, H. and Fujisu, M. (2006). Resource, Mobility, and Security Management in Wireless Networks and Mobile Communications. Boca Raton: Taylor and Francis. Read More