Policy-based self-management of wireless ad hoc networks

Abstract

Wireless ad hoc networks pose major research challenges because of their increasing ubiquity and user-initiated formation. The motivation of this thesis emanates from the need for unrestricted wireless communication in a scalable and predictable manner. This need is accentuated by the increasing users' demand for spontaneous communication and the deficiencies of existing management frameworks. The objective is to propose a management framework able to leverage the potential of wireless ad hoc networks as an alternative communication method allowing them to coexist with other networks and to emerge as their flexible extension. In the context of this thesis, Wireless ad hoc netw>orks consist of a majority of end-user devices, capable of multihop communication, and optionally supported from limited infrastructure. The policy-based management (PBM) paradigm is employed to facilitate their self-management, combining design and theory with testbed implementation and simulation studies. The thesis contribution can be identified in tlnee areas: (1) Design o f a context-aware policy hierarchy and a hybrid role-based organisation model: The integration of policies with contextual feedback enables the creation of a closed control loop at different organisational levels, forming the basis for self-management. (2) Deployment o f distributed PBM functionality: The management of wireless ad hoc networks is possible with the decentralisation of traditional PBM concepts, based on the design and implementation of a Distributed Policy Repositoiy (DPR). The DPR assists in the coordination of dispersed policy decision points (PDPs) by facilitating the synchronisation of policies and offering a uniform view of management objectives to the PDPs. (3) Validation o f PBM functionality fo r self-management: A case study addresses the deployment of a wireless ad hoc network on a testbed, attempting to overcome the lack of central coordination and the occurrence of interference, by using policies to control its dynamic channel assigmnent. Finally, the framework is extended for service management, implementing adaptable service provisioning and offering service customisation to end-users. The elements of this thesis contribution are combined under a unified policy-based framework for the self-management of wireless ad hoc networks.

Supporting Unified Distributed Management and Autonomic Decisions: Design, Implementation and Deployment

“…The authors in [20] propose a PBM-based mechanism to facilitate scalable management, combining design and theory with testbed implementation and simulation studies. The availability of policies has been increased with the design and implementation of the Distributed Policy Repository (DPR).…”

“…where L and U represent the lower and upper time limit previously adjusted as reference (e.g. [10][11][12][13][14][15][16][17][18][19][20]), and P i;d represents the total number of devices at hop distance (d) in the partial view of a device i. Moreover, (H i ) is the time interval which can increase or decrease according to the total number of discovered devices in the network without crossing the limits L and U.…”

Autonomic Management of Mobile and Wireless Networks

“…This can result in quicker reaction times and policy decisions for users, thus resulting in more stability. For more details on the implementation and evaluation of DPBM, the reader is referred to [7] and references within.…”

Management challenges for emerging networks and services

“…This includes automatic fault detection and remediation as well as automation of component configuration. Self-management is appropriate in managing such dynamic and complex networks [11].…”