Fast optical Layer mesh protection using pre-cross-connected trails

Conventional optical networks are based on SONET rings, but since rings are known to use bandwidth inefficiently, there has been much research into shared mesh protection, which promises significant bandwidth savings. Unfortunately, most shared mesh protection schemes cannot guarantee that failed traffic will be restored within the 50-ms timeframe that SONET standards specify. A notable exception is the p-cycle scheme of Grover and Stamatelakis. We argue, however, that p-cycles have certain limitations, e.g., there is no easy way to adapt p-cycles to a path-based protection scheme, and p-cycles seem more suited to static traffic than to dynamic traffic. In this paper we show that the key to fast restoration times is not a ring-like topology per se, but rather the ability to pre-cross-connect protection paths. This leads to the concept of a pre-cross-connected trail or PXT, which is a structure that is more flexible than rings and that adapts readily to both path-based and link-based schemes and to both static and dynamic traffic. The PXT protection scheme achieves fast restoration speeds, and our simulations, which have been carefully chosen using ideas from experimental design theory, show that the bandwidth efficiency of the PXT protection scheme is comparable to that of conventional shared mesh protection schemes.

[1]  Yufei Wang,et al.  Optical network design and restoration , 1999, Bell Labs Technical Journal.

[2]  Eric Bouillet,et al.  Stochastic approaches to compute shared mesh restored lightpaths in optical network architectures , 2002, Proceedings.Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies.

[3]  Wayne D. Grover,et al.  Optimal capacity placement for path restoration in STM or ATM mesh-survivable networks , 1998, TNET.

[4]  Filip De Turck,et al.  Dimensioning of survivable WDM networks , 1998, IEEE J. Sel. Areas Commun..

[5]  Hiroyuki Saito,et al.  Optimal design and evaluation of survivable WDM transport networks , 1998, IEEE J. Sel. Areas Commun..

[6]  Hong Huang,et al.  A series of Hamiltonian cycle-based solutions to provide simple and scalable mesh optical network resilience , 2002 .

[7]  Muriel Médard,et al.  Generalized loop-back recovery in optical mesh networks , 2002, TNET.

[8]  Murti V. Salapaka,et al.  A practical approach to operating survivable WDM networks , 2002, IEEE J. Sel. Areas Commun..

[9]  Wayne D. Grover,et al.  Cycle-oriented distributed preconfiguration: ring-like speed with mesh-like capacity for self-planning network restoration , 1998, ICC '98. 1998 IEEE International Conference on Communications. Conference Record. Affiliated with SUPERCOMM'98 (Cat. No.98CH36220).

[10]  Thomas E. Stern,et al.  Automatic protection switching for link failures in optical networks with bi-directional links , 1996, Proceedings of GLOBECOM'96. 1996 IEEE Global Telecommunications Conference.

[11]  T. V. Lakshman Capacity design of fast path restorable optical networks , 2002, Proceedings.Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies.

[12]  Kazutaka Murakami,et al.  Comparative study on restoration schemes of survivable ATM networks , 1997, Proceedings of INFOCOM '97.