Cost Efficient Optical Ring Architectures - Results from
EURESCOM P615 Project
Antonio Ruiz Cantera - Telefonica I+D (Spain)
Dávid Arató and Tivadar Jakab - Hungarian Telecomm. Co.
8th International
Telecommunication Network Planning Symposium
Sorrento, Italy, 20 Oct. 1998
Motivations
♦ From point-to point optical transmission towards an optical network layer
♦ EURESCOM P615 Project
– Description, modeling, of different optical network architectures
– Analysis and comparison of different optical network architectures
– Guidelines for the introduction and development of optical network layer
♦ Problems for further studies concerning optical network
Outline
♦ EURESCOM
♦ Some results from EURESCOM P615 Project on analysis and comparison of optical and SDH
architectures
♦ OMSSP and CS Ring architectures
♦ Cost effective improvement of their availability performances
♦ Summary and conclusions
EURESCOM
European Institute for Research and Strategic Studies in Telecommunications GmbH
• Stimulate and co-ordinate pre-competitive and pre-
normative collaborative R&D Projects including field trials and pilot projects
• Enable the development of harmonised strategies by its Shareholders for the planning, operation and provision of future European public telecom networks & services
• Contribute to Europe-wide service deployment and service usage
• Contribute to European and world-wide standardisation
• Contribute to the work of international bodies and relevant European R&D programs
The EURESCOM Program Areas
Strategic Studies
Services and Applications
Middleware, Network and Service
Management
Networking Internet and
IP
Technology
Middleware Middleware Service
Service ServiceService ServiceService
network 1
network 1 network 2network 2 network 3network 3
Optical Networks Related EURESCOM Projects
♦ P413 Optical Networking 1994-96
– Initial studies (core, access)
♦ P614 Implementation Strategies for Advanced Access Networks 1996-98
♦ P615 Evolution Towards an Optical Network Layer 1996-98
– Core and metropolitan area networks – Modeling and analysis of architectures – Guidelines for introduction
♦ P709 Planning Optical Networks 1998 - 2000
– Planning methods and processes
Main results achieved in P615 project
2/1♦ More then 50% fibre savings can be obtained with optical network architecture
♦ Significant equipment cost savings (20 - 50%)
♦ Large reduction of first installation costs (30 -70%), increasing with increasing traffic demand
♦ Electrical equipments dominate the first installation costs (50-80%) and the availability (80 - 90%)
♦ Optical architecture (for SDH clients) with very similar availability performance as reference SDH ones
Visit EURESCOM Web Pages: www.eurescom.de
Main results achieved in P615 project
2/2♦ Promising optical architectures are available to introduce and develop an optical network layer
♦ Additional flexibility of the optical network layer
enables to improve capacity utilization and availability performance
♦ Significant fibre savings can be achieved with optical architectures (in comparisons with SDH ones)
♦ Optical architectures provide more cost effective
solutions (similar availability performance, less cost)
♦ Further studies are needed on management issues Visit EURESCOM Web Pages: www.eurescom.de Visit EURESCOM Web Pages: www.eurescom.de
Problems for further studies
♦ Availability performance of CS Ring and OMSSP Ring (for SDH clients) may need further improvement
♦ There are different solutions - Which ones to be applied?
Colored Section Ring
How to improve CS ring availability?
♦ Problem
– failed electrical routing functionality in intermediate nodes
♦ Solutions:
– 1+1 path protection (SDH)
– elimination of the need of electrical routing functionality in intermediate nodes (node reordering)
– combined
Optical Multiplex Section SHared Protected Ring
A B
D C
A B
D C
How to improve the availability of OMSSP ring serving an SDH client layer ?
♦ Problem
– no protection against the failures of SDH layer functionalities in a fully optical architecture
♦ Solutions
– standard SDH layer protection (PP, MSSP)
– 1+1 protection of the functional parts of SDH equipment
Availability characteristics of the different solutions
0.0000E+00 1.0000E-05 2.0000E-05 3.0000E-05 4.0000E-05 5.0000E-05 6.0000E-05 7.0000E-05
MSSP CSR CSRREO OMSSP OMSSP t OMSSP a OMSSP lte OMSSP all
DTR
1span 2span
Approach, assumptions
♦ Comparison on cost efficiency basis
– Realistic and symmetrical demand patterns – Availability: Network Performance Index
– Cost: Installation First Cost (only equipment)
♦ Cost efficiency: performance/normalised cost – normalizing cost: cost of the basic solution
Cost Efficiency of CS Ring in the Different Study Cases
6.0000000000E-01 6.5000000000E-01 7.0000000000E-01 7.5000000000E-01 8.0000000000E-01 8.5000000000E-01 9.0000000000E-01 9.5000000000E-01 1.0000000000E+00
Cost Efficiency Perfromance Index
CSB CSR CSR+P
Cost Efficiency of OMSSP Ring in the Different Study Cases
6.5000000000E-01 7.0000000000E-01 7.5000000000E-01 8.0000000000E-01 8.5000000000E-01 9.0000000000E-01 9.5000000000E-01 1.0000000000E+00
Cost Efficiency Perfromance Index
OMSB OMST OMSA OMST+A
Analysis of results
♦ CS Ring
– logical node reordering based on wavelength
routing improves the availability performance of CS ring
– combined application of node reordering and 1+1 path protection provides a cost effective solution to improve the availability performance of CS ring
♦ OMSSP Ring (SDH client layer, equipped with ADMs) – to protect client SDH layer functionalities 1+1 HW
protection can be applied
– protection of aggregate units is a cost effective solution for that
Summary and Conclusions
♦ EURESCOM P615 Project modelled, analised and compared numerous optical network architectures
♦ Based on EURESCOM P615 results promising architectures are identified to develop an optical network layer
♦ Further studies proved that cost effective solutions are available to improve the availability performance of studied optical ring architectures
