Intelligent Optical Networks

1. Intelligent Optical Networks • Michal Debski • Rami Abielmona • ELG 7187 • Wednesday November 21, 2001 • Prof. Dan Ionescu

2. Presentation Breakdown • Intelligent Network (IN) Breakdown • Optical Network (ON) Breakdown • IN + ON = ION • Features of IONs • Current and Future Leaders • Challenges and Outlook on Technology • Limitations and Conclusions

3. Introduction to intelligent networks (INs) • Service-independent telecommunications network, capable of operating and provisioning new services. • Initiated by Bellcore in USA in 1985 [1], with an initial goal of providing network operators with the ability of introducing and managing new services through a central database. • Basic concept involves the schism between the service providers and the telecommunication networks andequipment vendors, in order to seamlessly distribute and provision new services in various equipment. • Work has to be done to ensure that the generic components can easily interface to each other on different vendors’ equipment, through a published, open-interface standard. • The CCITT approved and published a more organized structure of intelligent networks in 1993, naming the entity the advanced intelligent network (AIN)

4. Intelligent network benefits • Rapid service introduction • Reduces latency of introducing new services throughout a network • Robust service customization • Services are adaptable and depend on the customer needs • Established vendor independence • Same equipment, different services, OR different equipment, same services • Portable open interfaces • Market is notdominated by one or two vendors, since service providers can run their products using open interfaces

5. Intelligent network concept • Basic service is enhanced through added network intelligence • Provides for very rapid service turnover

6. Intelligent network architecture • Intelligent peripherals remotely manage the network • Allows for a dynamic insertion of new services into the network

7. Evolution of network transmission technology • 1st Generation: Copper media • Slow data rates • Susceptible to noise, high loss • 2nd Generation: Optical fibre, (late 80s) • Supports higher data rates • Allows for longer link lengths • Dense Wavelength-Division Multiplexing (DWDM, 1994): • Multiplexing of many data streams using different wavelengths • 3rd Generation: Intelligent optical networks (1999-on) • Integrated routing and signaling for optical paths • Optics provide an underlying flexible layer to provide network services

8. DWDM • DWDM – Dense Wavelength Division Multiplexing • Physical layer for today’s intelligent optical networks • Multiplexes multiple waves of light onto single fibre • Able to transmit data faster and further: • 10 - 40 Gb/sec per wave • 160 waves per fibre • 1000s km per haul w/ use of amplifiers • --> 160 * 40 Gb/sec =6.4Tb/sec • (100,000,000 simultaneous phone calls)

9. Accompanying Laser Technology • Flat gain semiconductor optical amplifiers (+20dBm) • Narrowband Tunable Lasers (1530nm-1565nm) • Tunable filters • Wavelength shifters • Optical cross-connects • Thin-film Substrates • Fiber Bragg Gratings • Bragg Optical Multiplexer

10. DWDM System Example • DWDM Optical System with Amplifiers ITU Channel Spacing:

11. IONs: Merging Intelligent and Optical Networks • Ring architectures being applied to the optical network domain • Built-in network intelligence has two aspects: node-based and network-based

12. Aspects of intelligence in IONs • Node-based • Used to refer to the network elements’ intelligent software capable of sensing a module failure or a break in a fibre connection and automatically routing traffic in the opposite direction of the ring • Networks are currently capable of routing 40 optical signals in less than 50 milliseconds [3] • Network-based • Used to refer to the network’s capability of deploying new services without physical intervention • Main driver is Gigabit Ethernet (GE) and 10GE • “Point and configure” capabilities brought all the way to the end user increase value added, as customer is directly involved in the service definition

13. Advantages in IONs • Centralized service control • Rapid customization and deployment of services • Remote control intervention of services • Customer intervention in service definition Challenges in IONs • Centralized …. • Classic central control problems, where if control logic is down, then service is down for the whole network • Rapid … • Rapid introduction of services could be costly from a design and testing perspective • Remote … • Security involved in allowing customers remote control has to be of the highest priority • Customer … • Increased reliance on customer feedback and telecommunication in general

14. Challenge: Routing and Wavelength Assignment (RWA) • The challenge is to route light paths through the network • Each light path on a link has to be of a different wavelength • Wavelength conversion allows an efficient way to route a light path through the network without collisions • Routing inefficiencies can occur in the absence of wavelength conversion

15. Current Implementations of IONs • Current trend to design Opticaly Transparent Switches which feature low latency and signaling independence • Intelligent Optical Backplanes: • Provide the ability to Transport, Process and Filter Terabits of data per second • Use Dynamically Reconfigurable and Scalable Field-Programmable Smart Pixel Arrays • Scalable Architecture to provide ‘Bandwidth on Demand’

16. The Intelligent Optical Backplane • A switching fabric composed of an parallel array of smart pixel arrays

17. Smart Pixel Array • A smart-pixel array is a two-dimensional array of optoelectronic devices that combine optical inputs and outputs with electronic processing circuitry • A field-programmable smart-pixel array (FP-SPA) is a smart-pixel array capable of having its electronic functionality dynamically programmed in the field.

18. Smart Pixel Array • Supports hundreds of pixels at hundreds of Mb/sec • Provides reconfiguration, packet processing, filtering, buffering, broadcasting, flow-control and error detection

19. Current Market Leaders • CIENA Corporation (www.ciena.com) • CoreDirector (intelligent optical networking core switch) • LightWorks (intelligent network management software) • Sycamore Networks (www.sycamorenet.com) • SN 16000 (intelligent optical switch • SILVX (software intelligence built into NMS) • Nortel Networks (www.nortelnetworks.com) • Alteon (used across networks built on independent switching platforms) • Agilent Technologies (www.agilent.com)

20. Future outlook (1) • Service providers are faced with the challenge of managing fast growing networks while keeping operating costs and provisioning times • The old SONET/SDH network architectures and management solutions are inappropriate for the aforementioned trend • ION provides optical cross-connects (OXCs), enabling the market demand for scalable and adaptable services OXC Innovations Switching capacities matching DWDM needs Supports large mesh technologies Software driven route management User selectable priority levels Standard UNI provides automatic provisioning Figure from slide 9

21. Future outlook (2) • IONs will provide for ubiquitous computing architectures, as subscribers are getting used to their services • IONs also will provide for on-demand service deployment, allowing for a great reach for the Internet • Telecommunications Information Networking Architecture (TINA) is a consortium of the top telecommunications players focused on delivering services using next-generation software. Other consortiums will aid in the transition to IONs

22. Challenges of Today’s IONs • Currently used optical rings are not topologically flexible and not scalable. • Wavelength router-switches are more flexible and can subsume both point-to-point and ring add-drop functionalities. • Trend to switch from ring to mesh or multi-ring topologies, allowing for more flexibility and better resource allocation.

23. Future of IONs • Wavelengths will routed more optimally, finding the best path and then remembering it • Optical networks will use optical framing or digital wrapper technology for signaling, enabling wavelength on demand, so transmission traffic throughout the network can match the capacity. • MPlS (multi-protocol lambda switching), A "data-aware" framework that will allow for subsuming connection routing and protection activities under the IP traffic-engineering framework and will provide optimum IP-WDM layer integration. Specifically, short-reach optical interfaces on terabit IP routers will connect directly with DWDM cross-connects and will allow higher-layer protocols to request/release bandwidth in an automated manner.

24. Limitations of IONs • Network operators and equipment vendors must be convinced before technology can be widely deployed • Software glitches, network configuration faults and the like can have dire consequences on both a network and a technology • IONs go through a series of testing and verification phases, higher in level than the usual schemes: • Functional and regression • Conformance and interoperability • Stress and performance • Alpha and beta trial • Installation and commission

25. Conclusions • Initiatives are being taken in order to deploy IONs as a core infrastructure for core-networks • Fixed mobile convergence is under way, where mobility systems are being married to INs in order to take advantage of the inherent network intelligence of INs • Reliability is the major concern for any optical network operator, and IONs have to be rigorously tested from the outset, in order to reach a certain comfort level • New services can be now deployed on-demand, and with minimal physical intervention. As well, IONs allow for a continuous link between the customer and the network operator • The open interfaces allow providers to run their services on numerous equipment

26. References • [1] Harju, Jarmo, Karttunen, Tapani and Martikainen, Olli. “Intelligent Networks”. Chapman & Hall: Cornwall, UK, 1995. • [2] Thorner, Jan. “Intelligent Networks”. Artech House: Norwood, MA, 1994. • [3] Alcatel White Paper: “Optical Networks”. • [4] Tecorida Technologies White Paper: “Intelligent Network (IN)”. • [5] Tecorida Technologies White Paper: “International Intelligent Network (IN)”. • [6] Prof. Ted Szymanski, Intelligent Optical networks Group, “Intelligent Optical Backplanes “ • [7] Kumar N. Sivajaran, Tejas Networks, “Trends In Optical networks” • [8] Sorrento Networks White Paper, “Metropolitan Optical Networks”