Presenter Profile Born in Paris, France, in 1957 Graduated from - PowerPoint PPT Presentation

conference & convention enabling the next generation of networks & services Presenter Profile • Born in Paris, France, in 1957 • Graduated from Mc Gill University in Montréal, Canada after studying optical components using numerical analysis Place • Started work on undersea systems in 1987 picture as R&D engineer at MPBT for the design of here TAT-9 Undersea Branching Multiplexers on TAT-9 Undersea Branching Multiplexers on AT&T platform • Senior Technical Consultant for CANTAT-3 and FLAG (1993-2000) Daniel WELT Joined Nortel in 2000 as Senior Adviser for • Title: Senior Engineer the development and acquisition of undersea systems technologies daniel.welt@tatacommunications. Re-joined Teleglobe Canada in 2004 and • Tel: +1 514 868 7846 now responsible for the engineering of new Mobile: +1 514 515 2652 undersea networks at TATA Communications

conference & convention enabling the next generation of networks & services The case for Undersea OADM Branching Units with Bandwidth Re-use A CARRIER PERSPECTIVE Daniel Welt

conference & convention enabling the next generation of networks & services INTRODUCTION The purpose of this presentation is to demonstrate that undersea networks need “true” OADM functionality, and this functionality needs to reside in the undersea branching unit. In the context of that presentation, “true” means with context of that presentation, “true” means with wavelength re-use This is the vision of a User. TATA Communications is a carrier and not an equipment supplier, the objective is to set principles and justify requirements, not engineer a solution

conference & convention enabling the next generation of networks & services Observation no. 1: There are 4 good reasons to deploy true “wet” OADM solutions 1. The tolerance of traffic to branch cuts is improved: only the traffic to and from the branch is affected 2. Bandwidth is re-used and the overall capacity is increased 3. Round trip delay is minimized 4. Transit through intermediate stations is eliminated, simplifying administration

conference & convention enabling the next generation of networks & services Observation no. 2: “true” undersea OADM functionality is feasible RE-USE Blocking Filter All what are needed are optical filters, TRUNK TRUNK technology already technology already used and qualified, “Privacy” well known by Filter (Optional) Suppliers. They need no power and use DROP ADD very little space NEW ADD/DROP SITE

conference & convention enabling the next generation of networks & services Illustration 1. The tolerance of traffic to branch cuts is improved: only the traffic to and from the branch is affected branch is affected

conference & convention enabling the next generation of networks & services OADM CASE STUDY: Topologies 1 BU1 3 BU2 5 BU3 7 BU4 9 BU5 11 T1 T7 N : Shallow 2 4 6 8 10 M : Deep CLASSIC T2 T3 T4 T5 T6 2FP Traffic Paths from node 1 to node 5, (primary and restoration) 1 OADM 3 OADM 5 OADM 7 OADM 9 OADM 11 T7 T1 BU1 BU2 BU3 BU4 BU5 2 4 6 8 10 N : Shallow M : Deep OADM T3 T5 T6 T2 T4

conference & convention enabling the next generation of networks & services OADM CASE STUDY: Parameters • Length of deep water sections (sections 3, 5, 7 and 9): 1,000 km each • Length of branch sections (sections 1, 2, 4, 6, 8, 10 and 11): 200 km (in shallow water) 10 and 11): 200 km (in shallow water) • Probability of fibre cut in deep water: 0.025 per 100 km per year • Probability of fibre cut in shallow water: 0.25 per 100 km per year • Repair time: 10 days

conference & convention enabling the next generation of networks & services OADM CASE STUDY: DOWN TIME

conference & convention enabling the next generation of networks & services OADM CASE STUDY: SIMULTANEOUS FAULTS HISTOGRAM 900 800 700 uency 600 500 500 Freque With OADM With OADM 400 No OADM 300 200 100 0 0 1 2 3 4 Number of Faults at a Given Time Probability distribution for the occurrence of simultaneous failures in 10 years for DLS T1 to T5, with and without OADM, simulated

conference & convention enabling the next generation of networks & services Illustration 2. Bandwidth is re-used and the overall capacity is increased capacity is increased

conference & convention enabling the next generation of networks & services Spectrum Slices

conference & convention enabling the next generation of networks & services OADM: Comparing with and without bandwidth re-use: number of DLSs versus number of spectrum slices, 1 FP Number of DLSs = N*(N-1)/2, N is the number of nodes The number of spectrum slices is the maximum number of DLSs to be supported on a segment, typically in the middle of the system. There are DLSs that do NOT occupy the same part of the fibre, for example all DLSs from one node to its adjacent node

conference & convention enabling the next generation of networks & services OADM: Comparing with and without bandwidth re-use; impact of guard bands RE-USE GAIN versus GUARD BAND 100% 80% 60% % GAIN 40% With guard band 3% 20% Ideal With guard band 5% 0% 2 3 4 5 6 7 8 -20% -40% -60% Number of Nodes Gain = total bandwidth (re-use)/total BW (no re-use)

conference & convention enabling the next generation of networks & services OADM: Sharing OADM with bandwidth re-use on several fibre pairs to maximize capacity OADM with bandwidth bandwidth re-use always wins

conference & convention enabling the next generation of networks & services “True” OADM: Solve the Problem The undersea telecommunications “community” should put aside traditional Supplier differences and define an optical architecture for a “universal” OADM undersea network. To do so, a standard sub-band architecture should be defined and agreed in order for all future systems to be able to support optimized OADM traffic if so chose the Customers.

conference & convention enabling the next generation of networks & services OADM: The “simple” solution and why it is not good enough TRUNK TRUNK Capacity is wasted Capacity is wasted This spectrum slice is reserved Channels are DROP ADD broadcasted to all sites ADD/DROP SITE

conference & convention enabling the next generation of networks & services OADM: The “simple” solution and why it is not good enough (2) noise noise Without filtering and equalization, repeaters “added” traffic may be lost DROP ADD noise

conference & convention enabling the next generation of networks & services OADM: A “repeater” friendly optical block for an “active” branching unit EDFA/ Blocking Noise Filter coupler splitter source Bandpass Filter Bandpass “privacy” EDFA/ Filter Noise (Optional) source ADD DROP

conference & convention enabling the next generation of networks & services OADM: Trunk Fault Handling of the “active” BU EDFA/ Blocking Noise Filter coupler splitter source Bandpass noise Filter Bandpass “privacy” EDFA/ Filter Noise source (Optional) NEW ADD DROP

conference & convention enabling the next generation of networks & services OADM: Branch Fault Handling of the “active” BU EDFA/ Blocking Noise Filter coupler splitter source Bandpass Filter noise Bandpass “privacy” EDFA/ Filter Noise source (Optional) NEW DROP ADD

conference & convention enabling the next generation of networks & services CONCLUSION • This presentation illustrated the simple principles that support the architecture of undersea systems based on OADM technology with bandwidth re-use • Although these principles may appear simplistic to some, they are often ignored at the time of system some, they are often ignored at the time of system design and the equipment offered by suppliers do not always satisfy all the requirements • The net gains in system availability, total capacity, latency and elimination of unnecessary transit should justify the modest developments required to establish industry standard “true” OADM capabilities in undersea systems

conference & convention enabling the next generation of networks & services THANK YOU THANK YOU