Optical Networks

Mithilesh Pamnani

Chiranjib Dhar

Shoaib Naik

Prabhat Singal

Abhishek Singh

Nagalakshmi S

What is Optical Network?

• Optical networks are high-capacity telecommunications networks based on optical technologies and components that provide routing, grooming, and restoration at the wavelength level as well as wavelength-based services

• It uses Optical Fibers for data transmission

FTTH - why did it come into picture

•As the quality of the optical fibre was improving, efficient transmitters and receivers appeared, it seemed possible to build an access network that would be based on the optical technology.

•Due to the lack of active units in the light path, the architecture of the system was simple, cost effective and offered bandwidth that was not, and still is not, possible to achieve by other access methods.

History

In 1950’s scientists developed glass fibers that included a separate glass coating

In 1957, Gordon Gould popularized the idea of using lasers In 1970, Drs. Robert Maurer, Donald Keck, and Peter Schultz succeeded in

developing a glass fiber that exhibited attenuation at less than 20 dB/km In the early 1970’s, the U.S. Navy installed a fiber optic telephone In 1977, AT&T installed fiber optic telephone systems in Chicago and

Boston respectively At the 1994 Winter Olympics in Lillehammer, Norway, fiber optics

transmitted the first ever digital video signal In 1998, researchers transmitted 100 simultaneous optical signals, each at

a data rate of 10 gigabits (giga means billion) per second for a distance of nearly 250 miles (400 km)

The important factor in these developments is the increase in fiber transmission capacity, which has grown by a factor of 200 in the last decade

Comparison with other media

Transmission Capacity

Bandwidth - Scalability

Advantages of Optical Fiber

• Enormous bandwidth.

• Less susceptible to signal degradation than copper wire. • Less weight.

• Data can be transmitted digitally.

• Lower-power transmitters can be used instead of the high-voltage electrical transmitters used for copper wires.

• No Crosstalk.

• Because no electricity is passed through optical cable it is non-flammable, and immune to lightning.

• High Signal Security. Difficult to tap signal from optical cable

• Light can travel from one computer to another over a single fiber.

Disadvantages

• Fibre optics are that the cables are expensive and difficult to install(But cost can be reduced when installed over long distances)

• The termination of a fibre optics cable is complex and requires special tools.

• They are more fragile than coaxial cable.

Types Of Optical Networks

• There are basically two broad categories of optical networks –

– Passive Optical Networks (PON)

– Active Optical Networks (AON)

GPON• The need for larger bandwidths and the

unquestionable complexity of ATM forced a revised approach an hence new standard called GPON3 was released in 2003.

• Uses Generic framing procedure and not ATM• Provides both voice and data oriented services• Transfer rates of up to 2.48 Gbps in the

downstream as well as the upstream direction.

Ethernet PON (EPON)• Released in September 2004 with a main goal to

achieve a full compatibility with other Ethernet based networks.

NEXT GENERATION OF ACCESS NETWORKS

WAVELENGTH DIVISION MULTIPLEXING ACCESS PASSIVE OPTICAL NETWORKS

– Ultimately, they can offer the largest bandwidth at the lowest cost– The architecture of WDM PON is similar to PON. The main difference is

that ONUs operate on different wavelengths and hence higher transmission rates can be achieved

– Requires manual reconfiguration which significantly increases the cost of maintenance

– The disadvantage of WDM PONs is the high cost of equipment

WAVELENGTH DIVISION MULTIPLEXING TIME DIVISION MULTIPLEXING PASSIVE OPTICAL NETWORKS

Developed in an attempt to serve more customers.A hybrid of both WDMA and TDMA

Less complex and expensive equipment was needed than in WDM PONs with a similar number of connected customers

Comparison of different FTTH architectures

PON (Passive Optical Network)

Different Topologies

Network Topologies with PON

AON (Active Optical Network)

Network Topologies with AON

AON vs PON

Comparison - AON vs. PON

• Bandwidth

• Security and quality of services

• Business case aspects

• Investment costs (CAPEX) comparison

• Operating expenses (OPEX) comparison

• Flexibility and scope for usage

• Summary

Bandwidth

Security and quality of services

Security and quality of services

Security and quality of services

Business case aspects-Investment costs (CAPEX)

Comparison of operating expenses (OPEX)

Flexibility and scope for usage

Summary

GPON-ENCAPSULATION

EPON Vs. GPON

 PARAMETER EPON GPON

Standard IEEE803.2ah ITU-TG.984

Bandwidth Symmetric 1GbpsDownstream 1.25-2.5Gbps

Upstream 155Mbps-2.5Gbps

DownstreamEfficiency

72%8B/10B encoding (20%)

Overhead & Preamble (8%)

92%NRZ scrambling (no encoding)

Overhead (8%)

Revenue BW 900 Mbps 2300 Mbps

Transmission Ethernet ATM, Ethernet, TDM

EPON Vs. GPON cntd..

 PARAMETER EPON GPON

Split ratio 1:32 1:64, (1:128 planned)

SecurityNone specified. AES used by

various vendors.128-bit AES is part of the

standard.

Interoperability None specified FSAN and ITU-T

Network Management

OAM&P OAM is optional and minimally supports: failure

indication, loop-back and link monitoring to the ONT.

Provisioning andservices are out of scope.

OMCI is mandatory.Full FCAPS on ONT and

services.

QoS No PrioritizationFragmentation for High- Priority

Packets

Fragmentation for High- Priority Packets

GPON/EPON Framing

DEPLOYMENT OF OPTICAL N/W S

• Fiber To The Home (FTTH) deployments continue to enjoy accelerated growth worldwide

• Alcatel-Lucent is engaged in over 95 FTTH projects around the world, over 80 of which are with GPON (as-of Q2, 2009)

BPON- GPON • The United States (Verizon, Calix)• The UK

EPON • Japan (Nippon Telegraph and Telephone

Corporation [NTT])• Korea (Korea Telecom)• China (Huawei, ZTE)

USAGE ACROSSS THE WORLD

• B-PON, E-PON, and G-PON are close derivatives of the original TDM PON concept.

• The IEEE 802.3 Ethernet PON (EPON or GEPON) standard was completed in 2004

• EPON 802.3 Ethernet frames with symmetric 1 gigabit per second upstream and downstream rates

• Drift from EPON to GPON because GPON supports triple play

TDM PON

• Bandwidth will be much more higher then copper line connection so we will have access to internet much more faster

• Low OPEX and CAPEX• No active components-which translates into low

maintenance and replacement costs• Competitive pricing• PON provides a faster connection to internet

because of this large firms profits more because time is money

IMPORTANCE OF PON

GPON

• Gigabit PON • It is an evolution of the BPON standard • It is a PON technology operating at bitrates of

above 1 Gb/s • It supports higher rates, enhanced security, and

choice of Layer 2 protocol (ATM, GEM, Ethernet) • worldwide gigabit passive optical network

(GPON) deployments have increased seven-fold- Dell’Oro Group.

• WDM-PONs can serve distances up to 80–100 km without the need for optical amplification in addition to blistering b/w

• The other advantage of WDM-PON is a huge increase in the potential number of end-users served.

• The high cost of WDM-PON equipment is still a major stumbling block to widespread deployment

WDM PON

• Calix - leader in the fast-growing GPON fiber-fed mobile backhaul

• Telecom provider CenturyLink (CenturyTel Inc.) has selected the new Calix 766GX, 766GX-R, and 765G-R GPON optical network terminals (ONTs) for fiber-fed mobile backhaul services in 33 states.

• Broadcom – come up with optical network chips• Verizon - to introduce an advanced FTTP

architecture

• Broadcom – come up with optical network chips• Verizon - to introduce an advanced FTTP

architecture – • faster Internet services, and set the table for

future IP-based video services, • more bandwidth-intensive HDTV fare • expanded VOD capabilities.

NORTH AMERICA

• Nortel –LG JV, acquired WDM-PON equipment maker Novera Optics in August 2008.

• German metro specialist ADVA Optical Networking entering the market with a product that exploits coarse WDM in September 2008

• Cable operators and other CLECs using GPON for business services have been able to compete very effectively for small- and medium-size businesses, as well as for backhaul to cellular sites

• Nokia Siemens Networks eschewing existing PON technology- in favor of WDM-PON.

• Tellabs is concentrating on WDM-PON through its involvement in its research project, drifting away from GPON

• Nortel announced in September that UNET will deliver high-speed internet for homes and businesses in the Netherlands using its WDM-PON solution

• WDM-PON is still not standardized, and that puts it at a disadvantage compared with the established PON technologies.

EUROPE

• Proxim Wireless Corporation -quadruple play, announced its new 4G Backhaul product lines -- the Tsunami™ QB-8100 point-to-point (PtP) and the Tsunami™ MP-8100 point-to-multipoint (PtMP).

• Exceeds the ITU requirements for 4G throughput speeds

• High performance and very low latency over long distances, eliminating expensive recurring leased line charges

KOREA

• More than 10 million fiber-to-the-home (FTTH) subscribers

• Alcatel-Lucent -Suo Cable deploying GPON- the first commericial GPON deployment in Japan

• Result in speeds around 2.5 GBPS

JAPAN

INDIA

• Bharti Airtel and BSNL are looking to switch over to GPON by the end of 2010

• Challenges :

• Cost associated with gaining permission to build new ducts and lay the fiber

• Gaining access to buildings - one that could lead to high-speed broadband access networks being deployed in local pockets, rather than being widespread

• ZTE unveiled a WDM-PON prototype – commercialization before the end of 2009

• CNC China selected the Gigabit PON (ITU-T G.984.x) GPON Optimate platform from FlexLight Networks, Inc

• Optimate - economical Gigabit PON (GPON) solution- economical triple play

• Access over a single fiber access facility.

CHINA

Future development of PON

• In Japan, the PON market is well established and growing at a rate of 300% year to year

• By comparison DSL is growing 150% year to year in the U.S.

• Top companies like Verizon, SBC and Bell South have all announced some type of PON deployment

• The PON market in North America is just starting to emerge

• Industry analysts expect an equally large take rate by North American consumes