Abstract

As a key problem in wavelength-switched optical networks (WSONs), in which wavelengths are the most important resources, the routing and wavelength assignment (RWA) problem has been researched extensively. Due to the advantages of path computation in multilayer and multidomain networks, especially in multiconstraint scenarios, the path computation element (PCE) has been introduced into WSONs, which provides a better approach to the solution of the RWA problem in WSONs. This paper focuses on the RWA problem in PCE-based WSONs. A PCE-based routing framework and two PCE-based routing models are first designed, and then two distributed resource reservation schemes based on forward reservation protocol (FRP) and backward reservation protocol (BRP) are proposed and simulated in a PCE-based WSON. Finally, eight PCE-based RWA schemes are proposed in WSONs, the performances of which have been investigated and validated using the discrete event simulation tool OMNeT++. Numeric results show that the RWA (first-fit) scheme has the best performance in terms of blocking probability and average delay time.

© 2010 Optical Society of America

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References

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  1. A. Farrel, J.-P. Vasseur, J. Ash, “A path computation element (PCE)-based architecture,” RFC4655, Aug. 2006.
  2. J. Ash, J. L. Le Roux, “Path computation element (PCE) communication protocol generic requirements,” RFC4657, Sept. 2006.
  3. J. L. Le Roux, “Requirements for path computation element (PCE) discovery,” RFC4674, Oct. 2006.
  4. J. L. Le Roux, “Path computation element communication protocol (PCECP) specific requirements for inter-area MPLS and GMPLS traffic engineering,” RFC4927, June 2007.
  5. J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “IS-IS protocol extensions for path computation element (PCE) discovery,” RFC5089, Jan. 2008.
  6. J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “OSPF protocol extensions for path computation element (PCE) discovery,” RFC5088, Jan. 2008.
  7. N. Bitar, R. Zhang, K. Kumaki, “Inter-AS requirements for the path computation element communication protocol (PCECP),” RFC5376, Nov. 2008.
  8. I. Bryskin, D. Papadimitriou, L. Berger, J. Ash, “Policy-enabled path computation framework,” RFC5394, Dec. 2008.
  9. J. P. Vasseur and J. L. Le Roux, eds., “Path computation element (PCE) communication protocol (PCEP),” RFC5440, Mar. 2009.
  10. J. P. Vasseur, R. Zhang, N. Bitar, J. L. Le Roux, “A backward-recursive PCE-based computation (BRPC) procedure to compute shortest constrained inter-domain traffic engineering label switched paths,” RFC5441, Apr. 2009.
  11. S. Sivabalan, J. Parker, S. Boutros, K. Kumaki, “Diffserv-aware class-type object for the path computation element communication protocol,” RFC5455, Mar. 2009.
  12. E. Oki, T. Takeda, A. Farrel, “Extensions to the path computation element communication protocol (PCEP) for route exclusions,” RFC5521, Apr. 2009.
  13. R. Bradford, J. P. Vasseur, A. Farrel, “Preserving topology confidentiality in inter-domain path computation using a path-key-based mechanism,” RFC5520, Apr. 2009.
  14. Y. Yamada, H. Hasegawa, K.-I. Sato, “Hierarchical optical path network design considering waveband protection,” in 33rd European Conf. and Exhibition on Optical Communication, Berlin, Germany, 2007, pp. 189–190.
  15. I. Nishioka, S. Ishida, Y. Iizawa, “End-to-end path routing with PCEs in multi-domain GMPLS networks,” presented at the 4th Int. Conf. on IP & Optical Network, Tokyo, Japan, 2008.
  16. Y. Lee, G. Bernstein, J. Martensson, T. Takeda, T. Otani, “PCEP requirements for WSON routing and wavelength assignment,” IETF working draft, Feb. 2009.
  17. G. Bernstein, Y. Lee, “Extending GMPLS/PCE for use in wavelength switched optical networks,” in Optical Fiber Communication Conf., 2008, paper NME1.
  18. A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.
  19. S. Arakawa, K. Miyamoto, M. Murata, H. Miyahara, “Delay analyses of wavelength reservation methods for high-speed burst transfer in photonic networks,” in 5th Asia-Pacific Conf. on Communications and 4th Optoelectronics and Communications Conf., Beijing, China, 1999, pp. 445–449.
  20. L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
    [CrossRef]

2008

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Arakawa, S.

S. Arakawa, K. Miyamoto, M. Murata, H. Miyahara, “Delay analyses of wavelength reservation methods for high-speed burst transfer in photonic networks,” in 5th Asia-Pacific Conf. on Communications and 4th Optoelectronics and Communications Conf., Beijing, China, 1999, pp. 445–449.

Ash, J.

A. Farrel, J.-P. Vasseur, J. Ash, “A path computation element (PCE)-based architecture,” RFC4655, Aug. 2006.

J. Ash, J. L. Le Roux, “Path computation element (PCE) communication protocol generic requirements,” RFC4657, Sept. 2006.

I. Bryskin, D. Papadimitriou, L. Berger, J. Ash, “Policy-enabled path computation framework,” RFC5394, Dec. 2008.

Berger, L.

I. Bryskin, D. Papadimitriou, L. Berger, J. Ash, “Policy-enabled path computation framework,” RFC5394, Dec. 2008.

Bernstein, G.

A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.

Y. Lee, G. Bernstein, J. Martensson, T. Takeda, T. Otani, “PCEP requirements for WSON routing and wavelength assignment,” IETF working draft, Feb. 2009.

G. Bernstein, Y. Lee, “Extending GMPLS/PCE for use in wavelength switched optical networks,” in Optical Fiber Communication Conf., 2008, paper NME1.

Bitar, N.

J. P. Vasseur, R. Zhang, N. Bitar, J. L. Le Roux, “A backward-recursive PCE-based computation (BRPC) procedure to compute shortest constrained inter-domain traffic engineering label switched paths,” RFC5441, Apr. 2009.

N. Bitar, R. Zhang, K. Kumaki, “Inter-AS requirements for the path computation element communication protocol (PCECP),” RFC5376, Nov. 2008.

Boutros, S.

S. Sivabalan, J. Parker, S. Boutros, K. Kumaki, “Diffserv-aware class-type object for the path computation element communication protocol,” RFC5455, Mar. 2009.

Bradford, R.

R. Bradford, J. P. Vasseur, A. Farrel, “Preserving topology confidentiality in inter-domain path computation using a path-key-based mechanism,” RFC5520, Apr. 2009.

Bryskin, I.

I. Bryskin, D. Papadimitriou, L. Berger, J. Ash, “Policy-enabled path computation framework,” RFC5394, Dec. 2008.

Castoldi, P.

A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.

Chen, X.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Cugini, F.

A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.

Farrel, A.

A. Farrel, J.-P. Vasseur, J. Ash, “A path computation element (PCE)-based architecture,” RFC4655, Aug. 2006.

R. Bradford, J. P. Vasseur, A. Farrel, “Preserving topology confidentiality in inter-domain path computation using a path-key-based mechanism,” RFC5520, Apr. 2009.

E. Oki, T. Takeda, A. Farrel, “Extensions to the path computation element communication protocol (PCEP) for route exclusions,” RFC5521, Apr. 2009.

Gao, G.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Giorgetti, A.

A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.

Gu, W.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Hasegawa, H.

Y. Yamada, H. Hasegawa, K.-I. Sato, “Hierarchical optical path network design considering waveband protection,” in 33rd European Conf. and Exhibition on Optical Communication, Berlin, Germany, 2007, pp. 189–190.

Iizawa, Y.

I. Nishioka, S. Ishida, Y. Iizawa, “End-to-end path routing with PCEs in multi-domain GMPLS networks,” presented at the 4th Int. Conf. on IP & Optical Network, Tokyo, Japan, 2008.

Ikejiri, Y.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “IS-IS protocol extensions for path computation element (PCE) discovery,” RFC5089, Jan. 2008.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “OSPF protocol extensions for path computation element (PCE) discovery,” RFC5088, Jan. 2008.

Ishida, S.

I. Nishioka, S. Ishida, Y. Iizawa, “End-to-end path routing with PCEs in multi-domain GMPLS networks,” presented at the 4th Int. Conf. on IP & Optical Network, Tokyo, Japan, 2008.

Kumaki, K.

S. Sivabalan, J. Parker, S. Boutros, K. Kumaki, “Diffserv-aware class-type object for the path computation element communication protocol,” RFC5455, Mar. 2009.

N. Bitar, R. Zhang, K. Kumaki, “Inter-AS requirements for the path computation element communication protocol (PCECP),” RFC5376, Nov. 2008.

Le Roux, J. L.

J. P. Vasseur, R. Zhang, N. Bitar, J. L. Le Roux, “A backward-recursive PCE-based computation (BRPC) procedure to compute shortest constrained inter-domain traffic engineering label switched paths,” RFC5441, Apr. 2009.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “OSPF protocol extensions for path computation element (PCE) discovery,” RFC5088, Jan. 2008.

J. Ash, J. L. Le Roux, “Path computation element (PCE) communication protocol generic requirements,” RFC4657, Sept. 2006.

J. L. Le Roux, “Requirements for path computation element (PCE) discovery,” RFC4674, Oct. 2006.

J. L. Le Roux, “Path computation element communication protocol (PCECP) specific requirements for inter-area MPLS and GMPLS traffic engineering,” RFC4927, June 2007.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “IS-IS protocol extensions for path computation element (PCE) discovery,” RFC5089, Jan. 2008.

Lee, Y.

Y. Lee, G. Bernstein, J. Martensson, T. Takeda, T. Otani, “PCEP requirements for WSON routing and wavelength assignment,” IETF working draft, Feb. 2009.

G. Bernstein, Y. Lee, “Extending GMPLS/PCE for use in wavelength switched optical networks,” in Optical Fiber Communication Conf., 2008, paper NME1.

Liu, Y.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Martensson, J.

Y. Lee, G. Bernstein, J. Martensson, T. Takeda, T. Otani, “PCEP requirements for WSON routing and wavelength assignment,” IETF working draft, Feb. 2009.

Miyahara, H.

S. Arakawa, K. Miyamoto, M. Murata, H. Miyahara, “Delay analyses of wavelength reservation methods for high-speed burst transfer in photonic networks,” in 5th Asia-Pacific Conf. on Communications and 4th Optoelectronics and Communications Conf., Beijing, China, 1999, pp. 445–449.

Miyamoto, K.

S. Arakawa, K. Miyamoto, M. Murata, H. Miyahara, “Delay analyses of wavelength reservation methods for high-speed burst transfer in photonic networks,” in 5th Asia-Pacific Conf. on Communications and 4th Optoelectronics and Communications Conf., Beijing, China, 1999, pp. 445–449.

Murata, M.

S. Arakawa, K. Miyamoto, M. Murata, H. Miyahara, “Delay analyses of wavelength reservation methods for high-speed burst transfer in photonic networks,” in 5th Asia-Pacific Conf. on Communications and 4th Optoelectronics and Communications Conf., Beijing, China, 1999, pp. 445–449.

Nishioka, I.

I. Nishioka, S. Ishida, Y. Iizawa, “End-to-end path routing with PCEs in multi-domain GMPLS networks,” presented at the 4th Int. Conf. on IP & Optical Network, Tokyo, Japan, 2008.

Oki, E.

E. Oki, T. Takeda, A. Farrel, “Extensions to the path computation element communication protocol (PCEP) for route exclusions,” RFC5521, Apr. 2009.

Otani, T.

Y. Lee, G. Bernstein, J. Martensson, T. Takeda, T. Otani, “PCEP requirements for WSON routing and wavelength assignment,” IETF working draft, Feb. 2009.

Paolucci, F.

A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.

Papadimitriou, D.

I. Bryskin, D. Papadimitriou, L. Berger, J. Ash, “Policy-enabled path computation framework,” RFC5394, Dec. 2008.

Parker, J.

S. Sivabalan, J. Parker, S. Boutros, K. Kumaki, “Diffserv-aware class-type object for the path computation element communication protocol,” RFC5455, Mar. 2009.

Sato, K.-I.

Y. Yamada, H. Hasegawa, K.-I. Sato, “Hierarchical optical path network design considering waveband protection,” in 33rd European Conf. and Exhibition on Optical Communication, Berlin, Germany, 2007, pp. 189–190.

Sivabalan, S.

S. Sivabalan, J. Parker, S. Boutros, K. Kumaki, “Diffserv-aware class-type object for the path computation element communication protocol,” RFC5455, Mar. 2009.

Takeda, T.

E. Oki, T. Takeda, A. Farrel, “Extensions to the path computation element communication protocol (PCEP) for route exclusions,” RFC5521, Apr. 2009.

Y. Lee, G. Bernstein, J. Martensson, T. Takeda, T. Otani, “PCEP requirements for WSON routing and wavelength assignment,” IETF working draft, Feb. 2009.

Valcarenghi, L.

A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.

Vasseur, J. P.

J. P. Vasseur, R. Zhang, N. Bitar, J. L. Le Roux, “A backward-recursive PCE-based computation (BRPC) procedure to compute shortest constrained inter-domain traffic engineering label switched paths,” RFC5441, Apr. 2009.

R. Bradford, J. P. Vasseur, A. Farrel, “Preserving topology confidentiality in inter-domain path computation using a path-key-based mechanism,” RFC5520, Apr. 2009.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “OSPF protocol extensions for path computation element (PCE) discovery,” RFC5088, Jan. 2008.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “IS-IS protocol extensions for path computation element (PCE) discovery,” RFC5089, Jan. 2008.

Vasseur, J.-P.

A. Farrel, J.-P. Vasseur, J. Ash, “A path computation element (PCE)-based architecture,” RFC4655, Aug. 2006.

Wang, L.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Yamada, Y.

Y. Yamada, H. Hasegawa, K.-I. Sato, “Hierarchical optical path network design considering waveband protection,” in 33rd European Conf. and Exhibition on Optical Communication, Berlin, Germany, 2007, pp. 189–190.

Yao, Y.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Zhang, J.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Zhang, R.

J. P. Vasseur, R. Zhang, N. Bitar, J. L. Le Roux, “A backward-recursive PCE-based computation (BRPC) procedure to compute shortest constrained inter-domain traffic engineering label switched paths,” RFC5441, Apr. 2009.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “IS-IS protocol extensions for path computation element (PCE) discovery,” RFC5089, Jan. 2008.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “OSPF protocol extensions for path computation element (PCE) discovery,” RFC5088, Jan. 2008.

N. Bitar, R. Zhang, K. Kumaki, “Inter-AS requirements for the path computation element communication protocol (PCECP),” RFC5376, Nov. 2008.

Zhao, Y.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

IEEE Commun. Lett.

L. Wang, J. Zhang, G. Gao, Y. Liu, X. Chen, Y. Zhao, Y. Yao, W. Gu, “A collision-aware wavelength assignment scheme for GMPLS-based WDM networks,” IEEE Commun. Lett., vol. 12, no. 8, pp. 593–595, 2008.
[CrossRef]

Other

A. Farrel, J.-P. Vasseur, J. Ash, “A path computation element (PCE)-based architecture,” RFC4655, Aug. 2006.

J. Ash, J. L. Le Roux, “Path computation element (PCE) communication protocol generic requirements,” RFC4657, Sept. 2006.

J. L. Le Roux, “Requirements for path computation element (PCE) discovery,” RFC4674, Oct. 2006.

J. L. Le Roux, “Path computation element communication protocol (PCECP) specific requirements for inter-area MPLS and GMPLS traffic engineering,” RFC4927, June 2007.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “IS-IS protocol extensions for path computation element (PCE) discovery,” RFC5089, Jan. 2008.

J. L. Le Roux, J. P. Vasseur, Y. Ikejiri, R. Zhang, “OSPF protocol extensions for path computation element (PCE) discovery,” RFC5088, Jan. 2008.

N. Bitar, R. Zhang, K. Kumaki, “Inter-AS requirements for the path computation element communication protocol (PCECP),” RFC5376, Nov. 2008.

I. Bryskin, D. Papadimitriou, L. Berger, J. Ash, “Policy-enabled path computation framework,” RFC5394, Dec. 2008.

J. P. Vasseur and J. L. Le Roux, eds., “Path computation element (PCE) communication protocol (PCEP),” RFC5440, Mar. 2009.

J. P. Vasseur, R. Zhang, N. Bitar, J. L. Le Roux, “A backward-recursive PCE-based computation (BRPC) procedure to compute shortest constrained inter-domain traffic engineering label switched paths,” RFC5441, Apr. 2009.

S. Sivabalan, J. Parker, S. Boutros, K. Kumaki, “Diffserv-aware class-type object for the path computation element communication protocol,” RFC5455, Mar. 2009.

E. Oki, T. Takeda, A. Farrel, “Extensions to the path computation element communication protocol (PCEP) for route exclusions,” RFC5521, Apr. 2009.

R. Bradford, J. P. Vasseur, A. Farrel, “Preserving topology confidentiality in inter-domain path computation using a path-key-based mechanism,” RFC5520, Apr. 2009.

Y. Yamada, H. Hasegawa, K.-I. Sato, “Hierarchical optical path network design considering waveband protection,” in 33rd European Conf. and Exhibition on Optical Communication, Berlin, Germany, 2007, pp. 189–190.

I. Nishioka, S. Ishida, Y. Iizawa, “End-to-end path routing with PCEs in multi-domain GMPLS networks,” presented at the 4th Int. Conf. on IP & Optical Network, Tokyo, Japan, 2008.

Y. Lee, G. Bernstein, J. Martensson, T. Takeda, T. Otani, “PCEP requirements for WSON routing and wavelength assignment,” IETF working draft, Feb. 2009.

G. Bernstein, Y. Lee, “Extending GMPLS/PCE for use in wavelength switched optical networks,” in Optical Fiber Communication Conf., 2008, paper NME1.

A. Giorgetti, F. Paolucci, F. Cugini, L. Valcarenghi, P. Castoldi, G. Bernstein, “Routing and wavelength assignment in PCE-based wavelength switched optical networks,” in 34th European Conf. and Exhibition on Optical Communication, Brussels, Belgium, 2008, paper Th.1. E.3.

S. Arakawa, K. Miyamoto, M. Murata, H. Miyahara, “Delay analyses of wavelength reservation methods for high-speed burst transfer in photonic networks,” in 5th Asia-Pacific Conf. on Communications and 4th Optoelectronics and Communications Conf., Beijing, China, 1999, pp. 445–449.

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Figures (15)

Fig. 1
Fig. 1

Three solutions of the RWA problem in WSON.

Fig. 2
Fig. 2

Routing procedure in the PCE-based architecture.

Fig. 3
Fig. 3

PCE-based routing models in WSONs: (a) end-to-end routing, (b) per-domain routing.

Fig. 4
Fig. 4

Tandem signaling scheme.

Fig. 5
Fig. 5

Parallel signaling scheme with PCE participation.

Fig. 6
Fig. 6

Topology of the simulation platform.

Fig. 7
Fig. 7

Blocking probability of different schemes.

Fig. 8
Fig. 8

Average delay time of different schemes.

Fig. 9
Fig. 9

Procedure of WA with priority queuing.

Fig. 10
Fig. 10

NSFNET network topology.

Fig. 11
Fig. 11

Blocking probability of FF versus RF in different schemes: (a) distributed WA, (b) R + WA , (c) RWA, (d) RWA with priority queuing.

Fig. 12
Fig. 12

Average delay time of FF versus RF in different schemes: (a) R with distributed WA, (b) R + WA , (c) RWA, (d) RWA with priority queuing.

Fig. 13
Fig. 13

(a) Blocking probability and (b) average delay time of FF in four classes of schemes.

Fig. 14
Fig. 14

(a) Blocking probability and (b) average delay time of RF in four classes of schemes.

Fig. 15
Fig. 15

(a) Blocking probability and (b) average delay time of the priority queuing mechanism.

Tables (1)

Tables Icon

Table 1 Protocol Extension of Different RWA Problem Solutions