Field of invention:
The present invention relates to a system and method of optical transmission system, more particularly a multi-rate coarse multiplexing optical transmission device for multiplexing multiple optical input wavelengths in the coarse wavelength division multiplexing (CWDM) stand-d range to offer east times bandwidth multiplication, thereby saving fiber cores/cables. Prior Art:
Networks in which optical fiber transport is used over substantially the entire path to the subscriber, which may include fib^ to the home, fiber to the Krebs and fiber to the multiple tenant unit arrangements, hold the neatest promise for meeting this anticipated need for bandwidth. To increase the information carrying capacity of each optical fiber in such networks and foot in order to deliver different services to different subscribers over the same segment(s) of optical fiber, various multiplexing teclmiques such, for example, as time, wavelength, or sub-carrier frequency multiplexing have been used or considered. A particular class of optical network topologies which continues to receive a considerable amount of investigative attention is the use passive optic teclmologies. Passive cuticle network sea optical network configurations in which there are no intervening active components between tile host digital terminal, central office or other dream network node, and customer premises equipment. In outlier words, a passive optical network requires no active components for directing optical sisals between the central office and a network subscriber's terminal equipment. Passive opted networks, therefore, require no power or processing in the field to direct optically encoded information to its destination. Typically, a passive optical network includes a first fiber star formed as a plurality of optical paths extending biome the central office to a remote node. Optical signals are transmitted biome the

central office to the remote, where the signal is passively spit and distributed to one of a plurality of units of network subscriber equipment. The network units may transmit optically encoded signals upstream to the remote node to form a multiplexed signal for distribution to the central office. Lasers are generally used to generate light used to form the transmitted hits sepals.
Although CWDM technology allows multiplexing 8 wavelengths, the solution offers only point to point connectivity without any method for redundancy or alternate optical path.
This leaves the solution to be only passive for optical path and provides no redundancy and management.
Also since opted commotions between optical modules can only be achieved by actually using fiber optic cables all prior systems typically use many cables to interconnect and multiplex or de-multiplex the optical signals especially at the CWDM level This comp Cates the fiber management since there are stringent requirements on the chassis to meet Fiber bend radius specifications thereby increasing chassis size and complexity.
A separate management chasmal per device is to be made available explicitly from each remote node unit for management and is typically the same path for data also. If data path is not available^ the management path is also not available for troubleshooting. Also a separate out of band management access is required to reach each of the nodes participating in the ring or linear topology network. Commonly available CWDM transport units do not give flexibility in choosing optics or if available require lots of configuration to enable them. Prior art technologies offer connectivity and doesn't offer more information required by Service providers during optical digital circuit provisioning.

Penman like optical hinder budge, which are essential for configuring and
{unlinks mad troubleshooting pin poses.
Offering modular and flexible solution meant to find devices in chassis format
Really on envying rack spaces in the range of 2RU to 6RU.
Devices supporting multiple and deltiology meant to have different VO
cards to support vied requirement.
Therefore the objective of the assent invention is to develop a transport unit,
white could multiplex mummy optical channels with redundant path for user
equipments, to increase bridwidth and save investment and maintenance on fiber
optic cores and cables.
Another object of the offset invention is to provide the device having support for
management Dianne totally Out Of Band, white enables clam- data Dianne for
another object of the present invention is to provide the device to offer higher
level of redundancy for on evade user ports and resilient paths with flexibility to
choose primary day path few each channel.
Still another object of the nisei invention is to provide management connection
either via copper interface (RJ45) or fiber interface (SFP) at 100Mbps and have an
internal suicide fabric for apprising all ports, events and monitoring functions
for repeating via exclusive OOB (out of band channel).
Further object of the present invention is to allow user prefab wavelength
support on optical ports (850nm, I310nm, 1550nm or a mix) to suit end
equipments like swaddles, routers. Digital cross connects etc., and offers flexibility
in choosing loop back diagnostics at all levels for easy trouble shooting.

Another object of the present invention is to provide rack size efficient, IRU, 19"
enclosure for its category and support bit-rate tom 100Mbps to 2.5Gbps for
Ethernet and SDH accordingly.
Still another object of the present invention is to compute and display Optical
power budget, on a per channel basis for easy provisioning or commissioning and
also enable NMS to acknowledge device failure due to power loss with dying-gasp
feature.
Further object of the present invention is to accept AC or DC power with
redundancy and hot-swap feature on Puss to enable removal and insertion without
affecting the fiction it of the unit.
Anorthic of the present innovation is to provide a common management
channel forming an Theme ring, managed by standard RSTP protocol (for
standards camphene) for link failure detection, for management traffic and a
proprietary protocol for sub 50ms for Theme loop detection.
Further object of the present invention is to support for channel configuration to
enable 1:1 redundancy or 1+1 support (as in the case of Ethane channel bundling
as per IEEE802.3ad) and enable less than 20milliseconds data traffic switchover
for optical redundancy on each channel.
Further object of the present invention is to provide exhaustive troubleshooting
mechanism to enable work side loop testing, user side loop testing etc., and
using the same port for Ethane or SDH/PDH digital channels.
Still another object of the present invention is to sense temperature sensing of tlie
premed circuit art at three different points & FAN control support for effective
thesauri monitoring.

Submarine of investor:
Accordingly, it is one embodiment of the present invention is to provide a multi-rate coarse wavelength division multiplexing, optical transmission system and method to transport optical data for 8 channels over a single pair of optical fibers and all user ports use 1310nm (or specific wavelength) optical connectors. Another embodiment of the present invention is to separate the data path and management path for un-interrupted service per customer or application channel, thereby scoffing them and to manage them with a common management channel, tartly, out of band.
Another embodiment of the present invention is to provide that each optical port of the unit are monitored and managed in terms of administration and criticality, along with optical power budgeting for easy provisioning
Another embodiment of the present invention is to provide tiled if power is shutdown on inter-mediate node (either for maintenance or local power unavailability), the traffic destined to that particular node or location alone is eliminated & signals for other nodal points are bypassed passively. Another embodiment of the present invention is to provide that the devices qualify for both active & passive optical networking requirements deriving the best of both ways to benefit end users.
Further embodiment of the present invention is a multi-rate coarse multiplexing optical transmission system providing high bandwidth capable of transporting 8 optical circuits over single pair of fiber cores wily port and path redundancy and front optical ring network comprising; an optical transmission terminal including optical transmitters which generate optical signals and two ports are provided to receive the optical signals wherein one main and knottier redundant port, eaglets redundant optical signals can be fed to user ports wherein the said ports associated

with traffic flow in the main or redundant path as indicated by configuration; a head node having eight modules of wavelength converters wilt redundant path management wherein the said radiant aptly management provide management connect eighth through copper interface (RJ45) or fiber interface (SFP) at lolls and have an internal switched fabric for supervising all ports, events and monitoring functions for reporting through exclusive out of band chasmal; a input transceiver of standard wavelength will also be of SFP to accommodate different types of requirements from the customer like SM, MM or different wavelength outliers than 1310nm wavelength; a multiplexer which multiplexes the optical signals output from said optical transmitters, to send out a coarse wavelength division multiplexed high to a transmission path; and an optical reception terminal including a demultiplexer which demultiplexes the coarse wavelength division multiplexed high transmitted from said optical transmission terminal throb he tiled transmission path and optical receivers which receive optical signals of respective wave lengiftss output from said first demultiplexer; the electrical signals derived from the fiber transceiver are switched between the other two CWDM transceivers based on the FPGA citron sisals wherein the link availability status based on the LOS signals from the fiber transceiver. Brief Description of The Drawings
Aspects of the present invention are pointed out with particularity in the appended claims. The present invention is illustrated by way of example in the following drawings in which like references indicate similar elements. The following drawings disclose various embodiments of the present invention for purposes of illustration only and are not intended to limit the scope of the invention. For purposes of clarity, not every component may be labeled in every figure. In the figures:

Fig 1 diagram showing a configuration multiplexed optical network system
according to a first embodiment of the present invention.
Fig 2 is a block diagram of multiplexed optical network system.
Fig 3 is a topology ' of connectivity and optical connectivity diagram of multiplexed
optical network system.
Fig 4 illustrates Connection Method for multiplexed optical system in a network.
Fig 5 illustrate Node Connectivity Diagram.
Description of the inventions as per the drawings and diagrams:
Embodiments of the present invention will be described, with reference to the
appended drawings. The same reference denotes the same or equivalent parts in all
drawings.
The device of the present invention work as a passive as well as active device of
the iRIS-16 (Mux-DeMux) mid iRIS-Ols (OADMs) offer a complete managed
optical transports siestas with iRIS-16s offering up to 16 optical user ports and
iRIS-Ols offering redundant single channel denegation while participating in a
ring.
An embodiment of the present invention is to provide a method to transport optical
data for 8 channels over a single pair of optical fibers. All user ports could be of
commonly used 1310nm optical connectors for simplicity as shown in Fig-1
Acceding to the present invention, up to 8 retardant optical signals can be fed to
user ports named lab & IB through 8A & 8B, where A & B are ports associated
with traffic flow in the mxm or redundant path as per configuration.
Another embodiment of the present invention is to separate the data path and
management path for un-intermitted service per customer or application channel,
thereby securing them & to manage them with a common management channel,
totally out of band.

Another embodiment of the present invention is to ensure that each optical port of the unit are monitored and managed in terms of administration and criticality, along with optical power budgeting for easy provisioning.
Another embody of the present invention is to ensure that if power is shutdown on inter-mediate node (either for maintenance or local power unavailability), the traffic destined to that particular node or location alone is eliminated & signals for other nodal points are bypassed passively. iris is an optical transport system offering enhanced bandwidth usage on a single pair of optical cable, which otherwise are wasted or underutilized. iris is a managed optical multiplexer working with CWDM optical multiplex technology working as per CWDM standard and using central frequencies from }471nm to 161 I’m with a spacing of 20nm between wavelengtlis. The product offers scalability from lOOMegabits to up to 2.5Gigabits per channel and are used for Ethernet and SDH transports
The devices of this invention are categorized as Multiplexer and de-multipliers and Optical Add/Drop multipliers(OADM) depending on the irrationality and usage and are used interchangeably in central office and remote locations, as the need be. Typically, the Multiplex and de-multiplex units, take in user traffic via User ports, multiplex them and send the multiplexed traffic via the network ports (East, West), throw a pair of optical fiber cores. The OADMs are specific to wavelengths and can terminate specific wavelengths of local interest, leaving other wavelengths to pass through for proper termination.
The devices of this invention support up to 8 chimers of CWDM wavelengths to be multiplexed and devices of this invention specific to individual wavelengths terminate them for local connectivity.

Snottier embody of the present invention is to ensure that the devices qualify for both active & passive optimal networking requirements deriving the best of both miss to briefest end users. A multi-rate coarse multiplexing optical transmission sestet providing high width capable of treasuring 8 optical circuits over single pair of fiber cores with port mid path redundancy and form optical ring network comprising; an optical transmission terminal including optical transmitters which generate optical signals and two ports to receive the optical signals wheaten one main mid another redundant port. Eight redundant optical signals caddis be fed to user ports wherein the said ports associated with traffic flow in the main or redundant path as indicated by configuration; a head node having eight modules of wavelength cone with redundant path management; wherein management clinician kith through copper interface (RJ45) or fiber interface (SFP) at 100Mbps and have a intend switched fabric for sup viding all ports, events and monitoring fictions for throe exclusive out of band camel; an input transceiver standard wavelength will also be of SFP to accommodate differ types of requirements food the customer like SM, MM or different vravelength other titian 1310nm wavelength; a multiplexer which multiplexes the optical signals output food sad optical transmitters to send out a coarse wavelength division multiplexed light to a transmission path; and an optical reception terminal including a demultiplexer which dwnultiplexes the chose weeknight division multiplexed hot transmitted from said optical transmission terminal through the transmission ppm aid optical receivers which recede optical signals of respective wavdesigfts output from said first demultiplexer; the electrical sisals derived from the fiber transceiver mc switched between the other two CWDM transceivers based on the FPGA control signals wherein the link availability status based on the LOS astrals from the fiber transceiver.

The multiplex and de-multiplex 8 optical channels over a pair of optical cables extended through fate East and West network ports to form optical ring connectivity. The said system is managed by SNMP protocol, a standard for network management and complete management with Traps forwards for third party OT nor& bound integrated Servers. Each node there comprises two Adam’s (Optical Add Drop Mux/De-Mux) with add and drop channels with a particular frequency, the ring is passed through the OADM and drop a particular wavelength to the node master and add the return data to the ring appropriately. The mechanism to automatically switch between tie main and the redundant path is implemented in the nodes tinfoil a CPLD and ties OSC channel two also be dropped and added accordingly which will go to the sitting circuit for adding management info from the local node. The said system is managed using Lakeview a Linux based Network management tool.
The data traffic channels and management channel are isolated and provide utmost availability even in the absence of accessible management channel. The redmidaney is ensued by providing load shared power supple redundant user ports and configurable redundant optic path for customer or application data traffics on a per port basis. The multiplexing of signals offer 8 times more bandwidth to transport the said multiplexed sisals over a pair of optic fibers. The protocol transparency for digital data traffic to enable transport of native application traffic^ as it is and the said protocol transparency allows the device to support STM-1, STM-4, STM-16, and Fast Ethernet and Gigabit Ethernet in a mix and matrix as required. The multiplexed signal are transported to the user devices whimpering the signals are terminated on user equipments via 1310nm and 1550imi interfaces. Cities redounds it port supports 1:1 or 1+1 redundancy based on individual

camels or ports. The redundant path management that maintain Management traffic of all units flow all along the ring by standard RSTP protocol for ring protection offering sub 50ms loop detection and switchover. The Optical data patio switchover time is about 20ms.The multiplexed optical sisals carry a total raw optical bandwidth of about 20Gbps protected and about 40Gbps unprotected. The head node has eight modules with in-built wavelength converters wilt redundant path management. The input transceiver of standard wavelength will also be of SFP to accommodate different types of requirements from the customer like SM, MM or deficient wavelength other than 1310nm wavelength. The electrical sits derived from the fiber transceiver are switched between the other two CWDM transceivers based on the FPGA control signals. Urns is done on the link availability status based on the LOS signals from ties fiber transceiver. The topology of connectivity and optical connectivity dada are shown in figure 3. N e Connectivity
In each node there will be two Oat’s (Optical Add Drop Mux/De-Mux) with add and drop channels wait a particular frequency. The ring is passed through the OADM. It will drop a particular wavelength to the node master mid add the return data to the rag appropriately. The machismo to automatically switch between the main and the rotundity path is implemented in the nodes tiring a CPLD. The OSC channel will also be dropped and added accordingly which will go to local Ethernet switching chip for transporting management info from the local node. FPGA Implementations
The Field Programmable Gate Array implementation in the IRIS is the heart of the control mechanism in the IRIS Multiplexer De-multiplexer units. It manages the main and the redundant link switch over function as it serially collects the information from tie fiber transceiver about the optical link characteristics like

transmit power, received power etc and loads these values into the local static RAM. When may abrupt change happens in the link status it rises an interrupt to the processor, which the processor can acknowledge and inform the NMS server through SNMP or other stand-d mechanism. Also a busy flag will be implemented to indicate the processor that the FPGA is not ready with the data, when the processor polls the FPGA for any particular data. The communication between the processor and the FPGA is through parallel address and data memory mapping. The LED indications are also managed by the FPGA. Apart from all the above the FK5A also gives the following status of all channels
• Link Status of each channel
• Wavelength of the channels
• Nominal Baud Rate based on the transceiver
• Alarms (Temperature, Voltage, Receive & Transmit Power) of the Transceiver
• Module Temperature, TX power & Rx sensitivity
• Tux Disable state, Tux Fault and Loss of Signal conditions
Network Management Software
The iris series of multiplexer and de-multipliers and add/drop multipliers are SNMP manageable units that can be managed with Lit view - a Linux based network management software from Motet. The management software offers all standards based management modules like Fault, Configuration, Alarm, Performance and Security management as applicable and offers interactive GUI for easy managemnent. Hierarchical user account management helps administrators to monitor and manage units as per privileges.

Novelty of the lavation
The system offers a single device solution for today's and tomorrows optical transport requirement. The optical transport system such as iRIS-16 and iRIS-01 as p& the invention: -
1. Does not need more rakes space (foci y nags only lug) with redundant power supply AC or DC with redundant port and path configuration option, making it bully redundant.
2. Are used in metro and provider network expansion or saves huge bandwidth by carrying 40Gbps of raw optic^ bandwidth with just a single pair of fiber cores forming optical rings.
3. iris as 'active' devices offers frill management of all optical points and during power failures behaves as 'passive'^ transparently bypassing other wavelength chimes.
4. Optical backbone data path switchover in less than 20ms for today's converged application transport requirements and loop fine detection of management comely within 50ms wittily MRORPP protocol, apart food standard based RSTP to inte^ate management channels of third party devices to be transported over the optical m augment channel.
5. The device in its Y-connect mode (1:1), pumps data on both main and redundant path or ports and during network events, recovery happens in oimd 20ms time suitable for today's and tomorrow's real-time or near real-time Triple play & Multi-play apperception demands. Each device channel supports two modes of configuration, the Y-connect (1:1) and H-connects (1+1) modes.
6. The optical connection between the wavelength converter modules and the passive optical add drop multiplexes are integrated internally to

avoid external optical cabling requirements and thereby reducing installation time and zero cost and maintenance of such external cables.

We claim
1. A Befit-rate coarse wavelength vivisect multiplexing optical trans mission sixteen providing Might bandwidth abide of 8 optical circuits over single pair of fiber effuse with port and path ring network comprising; an optical transmission terminal including quad transmitting which generate optical sepals and two network ports are font to receive the optical signals wherein one main and another rudiment port, east rednndmit optical signals cm be fed to user axe rocs when the said ports associated with tabby flow in the main or redundant path as enchanted by configuration; a head node having east modules of wavelength converters with ranchman path management wherein the said redacts path provides management connection either through copper interface (RJ45) or fib interface (SFP) at Lomb’s and have an internal switched fabric for supervising all ports, events and motoring functions for reportage tomb exclusive out of bid decimal; a input transceiver of standard wavelength will also be of SFP to accommodate different types of requirements from the customer like SM, MM or different wavelength cero dean Aloofly wave ; a multiplexer which multiplexes the optical signs output from said Cortical fro sisters to send out a coarse wavelength division multiplexed list to a trans mission path; and an optical reception terminal including a demultiplexer which demultiplexes the coarse wavelength division multiplexed light transmitted from said optical to ansnttssion tertiary through the transmission path ^d a optical receivers which receive optical signals of respective wavelengths output from said first deanultiplexer; the electrical signals derived from the fiber transceiver" are switched between the crofter two CWDM transceivers base on the FPGA

control sisals wherein the link availability status based on the LOS signals from the fiber transceiver.
2. The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, wherein the multiplex and de-multiplex 8 optical channels over a pair of optical cables extended through the East and West network ports to form optical ring connectivity.
3. The multi-rate coarse multiplexing optical transmission system as claimed in clan 1, wherein the said system is managed by SNMP protocol, a standard for network management and complete management with Traps forwards for third party or north bound integrated Servers
4. The multi-rate coarse multiplexing optical trmismission system as claimed in claim 1, wherein each node there comprises two Odem’s (Optical Add Drop Mux/De-Mux) with add and drop channels with a particular frequency, the ring is passed through the OADM and drop a particular wavelength to the node master and add the return data to the ring appropriately.
5. The multi-rate coarse multiplexing optical transmission system as claimed in claim 4, the mechanism to automatically switch between the main and the redundant path is implemented in the nodes through a CPLD and the OSC channel will also be dropped and added accordingly which will go througli the switching circuits for adding management info from the local node.
6. The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, wherein the said system is managed using Lakeview, a Linux based Network management tool.
7. The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, wherein the data travels channels and msttiagement channel are

isolated and provide utmost availability even in the absence of accessible management channel.
8. The mushy-rate coarse multiplexing optical transmission system as claimed in claim 1, wherein the device provides redundant port, load shared power supplies, redundant user ports and configurable redundant optic path for customer or application data traffics on a per port basis.
9. The multi-rate coarse multiplexing optical transmission system as claimed in (Adam 1, wherein the multiplexed signals offer 8 times more bandwidth and transporting the said multiplexed signals over a pair of optic fibers.
10. The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, wherein the protocol tarns any for digital data traffic to enable transport of native application traffic as it is and the said protocol tramps any allows the device to support STM-1, STM-4, STM-16, and Fast Ethernet and Gigabit Ethernet in a mix and match as required.
11. The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, the multiplexed signal are transported to the user devices wherein the signals are with commonly available wavelengths such as 1310nm said 1550nm.
12.Tlie multi-rate coarse multiplexing optical transmission system as claimed in claim 1, wherein the redundant port supports 1:1 or 1+1 redundancy based on individual channels or ports.
13.The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, wherein the cuticle connection at the CWDM level is integrated internally within the device between the eight wavelength converter modules and Passive optical Add drop multiplexer.

14.The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, redundant path management that maintain Management traffic of all units flow all along the ring by standard RSTP protocol for fast convergence or MROPP (MROTEK Protection Protocol) for ring is election offering sub 50ms loop detection and switchover.
15.The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, the Optical data path switchover time is about 20ms. The multi-rate coarse multiplexing optical transmission system as claimed in claim 1, the multiplexed optical signals chary a total raw optical bandwidth of about 20Gbps protected and about 40Gbps unprotected.