Self-Organizing Broad-Band Transport Networks

In a self-organizing system, behavior emerges at the large scale from the collective interaction of simple rules that apply at the smaller scale. The behavior that emerges is not directly apparent from inspection of the local rules or processes operating at the lower level. Few problems in engineering have been addressed with the specific idea of designing simple rules that operate in an isolated local manner to derive a desired self-organizing side effect. Some specific telecommunication network control problems recently have been addressed with this approach, however, in areas where conventional approaches are suffering from the “software mountain” phenomenon. In the applications of transport network restoration and traffic adaptation, this self-organizing approach promises better speed, accuracy, autonomy, and robustness than centralized control or explicit messaging-based distributed approaches. A key advance has been the development of a set of nodal rules for game-like operations on information tags (called statelets) borne on every link of the network. These rules spontaneously organize the resources of the transport network into a maximal set of simultaneously feasible paths between named points in the network. This process is adapted for restoration, provisioning, and traffic adaptation in a manner where the network is its own data base. The computational workload is distributed over the network as a whole, and external control is relaxed to focus only on large-scale tuning of what is operationally a self-organizing autonomous transport network. This paper is an applicationsoriented survey of the self-organizing concept and mechanism and its application to restoration, provisioning, network audit, and traffic adaptation.