Optimal Spare Capacity Preconfiguration for Faster Restoration of Mesh Networks

Several distributed real-time methods have beenproposed for restoration from single span failures indigital transport networks. These methods have thepotential to avoid user service outages due to such failures, if they operate quickly enough. Forexample, switched 64 kbps connections will not bedisconnected if the network can be restored before thetime at which calls in progress are dropped, typically 1-2 seconds after a failure. However, it willbe difficult to achieve the goal of sub-secondrestoration if cross-connects cannot operate crosspointsquickly enough, either due to large workloads during a restoration response, or because ofimplementation choices such as testing eachcross-connection while in the midst of a serious outage.The results in this paper demonstrate that it can beuseful to pre-operate selected cross-points between thespare links of a mesh-restorable network before anyfailure has occurred, putting the network into astatistically optimal state of readiness. When a failure occurs, some of the preconfigured restorationpath bundles can be used immediately. If morerestoration paths are needed, they can be obtained by areal-time restoration process. The first advantage of preconfiguration is that the number ofcross-connection operations may be greatly reduced oreliminated for a portion of the affected traffic. Thiswill reduce restoration time significantly. Secondly, after utilizing preconfigured restorationpaths, the workload of a real-time restoration processwill be lower because it will be searching for fewerpaths. This paper demonstrates that preconfiguration can supply a significant proportion of thereplacement capacity required after a span failure. Theresults are obtained through integerprogramming.     

System Concept and Simulation Model for a Proposed Class of Delay-Tolerant Variably-Priced Network Services

We describe a system concept for therevenue-producing disposition of surplus capacity atoff-peak times in real trunking networks. The idea is toapproximate a competitive market for distribution of the networks' time-varying excess capacity with apricing strategy controlled by the network. The schemeis intended to allow network operators to stimulatebackground traffic loads to gain new revenues from otherwise idle time on existing installedresources. The concept is suitable for low prioritydelay-tolerant or opportunistic applications such asremote backups, software distribution, dispatchingbatched faxes, disseminating newsgroup updates,updating web page caches or routing tables. Backgroundservice subscribers are notified of price reductions atoff-peak times to elicit additional traffic for the network. Traffic aggregators act on behalf ofsubscribing organizations or groups of users. Thebackground service is completely subordinate to theconventional tariff-priced on-demand calling services and the variable background pricing merges withthe foreground under suitable total load. This paperfocuses on the network problem of price setting tocontinually maximize the price-volume product in a time-varying price-sensitive trafficenvironment such as this concept implies. Aprice-stimulated offered traffic environment issimulated in which time of day, price, and hidden demandlatency and demand curve characteristics all affect the offeredtraffic. An analytically optimum strategy is availablefor the particular traffic model used and theperformance of a fuzzy logic price controller is tested against the revenue-optimal strategy. Dependingon econometric assumptions for latent traffic demand andprice-volume curves, increases in revenue from 4%-20%are obtained in simulation of a 30-trunk group having a typical daily load pattern.     

A Framework for Designing Distributed Management Applications

This paper presents a methodology for thespecification and design of multi-domain managementsystems that control, monitor and administer users andservices in a distributed telecommunication environment. It presents a framework, which serves as ablueprint for the design and implementation ofdistributed management applications. It defines a set ofconcepts and methods for guiding the analysis, design, and implementation phases of managementapplications, which are distributed over heterogeneoussystems. The framework is based on concepts ofTelecommunications Management Networks and OpenDistributed Processing, and is partially developed withinthe Pan-European Reference Configuration for IBC(Integrated Broadband Communication) Services Management(PRISM) project.     

TINA and the Software Infrastructure of the Telecom Network of the Future

The overall goal of the TelecommunicationsInformation Networking Architecture (TINA) is to defineand specify a software architecture for thetelecommunications infrastructure which encompassesnetworking, network services, and operations, to handle theincreasingly distributed nature of software in networks.The purpose of this paper is to describe how TINA may bepositioned in the software infrastructure of future telecommunications networks, with thefocus on the infrastructures of Public TelecommunicationOperators (PTOs). An architecture for a new PTO networkinfrastructure is proposed and the needs that this architecture satisfies are discussed.The concept of the programmable network isintroduced to satisfy the PTO need to quickly trial anddeploy new services. Five aspects of this targetarchitecture are discussed, namely: a client/serverarchitecture, a service creation architecture, anapplication architecture, a PTO federation architecture,and a new management architecture. The potential role of TINA in each aspect is described, and thepotential benefits of TINA to PTOs aresummarized.