Download A study on Intelligent Optical Networks

Intelligent Optical Networks
Michal Debski
Rami Abielmona
ELG 7187
Wednesday November 21, 2001
Prof. Dan Ionescu
Presentation Breakdown
1. Intelligent Network (IN) Breakdown
2. Optical Network (ON) Breakdown
3. IN + ON = ION
4. Features of IONs
5. Current and Future Leaders
6. Challenges and Outlook on
Technology
7. Limitations and Conclusions
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 and equipment 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)
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 not dominated by one or two vendors,
since service providers can run their products
using open interfaces
Intelligent network concept
Basic service is enhanced through
added network intelligence
Provides for very rapid service turnover
Intelligent network architecture
Intelligent peripherals remotely manage the
network
Allows for a dynamic insertion of new services into
the network
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
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)
Accompanying Laser
Technology
Flat gain semiconductor optical amplifiers
(+20dBm)
Narrowband Tunable Lasers (1530nm1565nm)
Tunable filters
Wavelength shifters
Optical cross-connects
Thin-film Substrates
Fiber Bragg Gratings
Bragg Optical Multiplexer
DWDM System Example
DWDM Optical
System with
Amplifiers
ITU Channel Spacing:
IONs: Merging Intelligent and Optical
Networks
Ring architectures being applied to the optical
network domain
Built-in network intelligence has two aspects: nodebased and network-based
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
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
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
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
The Intelligent Optical
Backplane
A switching fabric composed of an
parallel array of smart pixel arrays
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 smartpixel array capable of having its electronic functionality
dynamically programmed in the field.
Smart Pixel Array
Supports hundreds of pixels at hundreds
of Mb/sec
Provides reconfiguration, packet
processing, filtering, buffering,
broadcasting, flow-control and error
detection
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)
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
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 nextgeneration software. Other consortiums will aid in the
transition to IONs
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.
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 "dataaware" 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, shortreach 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.
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
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
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”