Optical mesh network
Encyclopedia
Optical mesh networks are a type of telecommunications network
.
Transport networks, the underlying optical fiber-based layer of telecommunications networks, have evolved from DCS (Digital Cross-connect Systems)-based mesh architectures in the 1980s, to SONET/SDH (Synchronous Optical Networking/Synchronous Digital Hierarchy) ring architectures in the 1990s. Technological advancements in optical transport equipment in the first decade of the 21st century, along with continuous deployment of DWDM systems, have led telecommunications service providers to replace their SONET ring architectures by mesh-based architectures. The new optical mesh networks support the same fast recovery previously available in ring networks while achieving better capacity efficiency and resulting in lower capital cost.
Optical mesh networks today not only provide trunking capacity to higher-layer networks, such as inter-router or inter-switch connectivity in an IP, MPLS, or Ethernet-centric infrastructure, but also support efficient routing and fast failure recovery of high-bandwidth services. This was made possible by the emergence of optical network elements that have the intelligence required to automatically control certain network functions, such as fault recovery.
Optical mesh networks enable a variety of dynamic services such as bandwidth-on-demand, Just-In-Time bandwidth, bandwidth scheduling, bandwidth brokering, and optical virtual private networks that open up new opportunities for service providers and their customers alike.
-based layer of telecommunications network
s, have evolved from Digital cross connect system
(DCS)-based mesh architectures in the 1980s, to SONET/SDH (Synchronous Optical Networking/Synchronous Digital Hierarchy)
ring architectures in the 1990s. In DCS-based mesh architectures, telecommunications carriers deployed restoration systems for DS3 circuits
such as at&t FASTAR (FAST Automatic Restoration) and MCI Real Time Restoration (RTR), restoring circuits in minutes after a network failure. In SONET/SDH rings, carriers implemented ring protection
such as SONET
Unidirectional Path Switched Ring (UPSR) (also called Sub-Network Connection Protection
(SCNP) in SDH
networks) or SONET
Bidirectional Line Switched Ring (BLSR) (also called Multiplex Section - Shared Protection Ring (MS-SPRing) in SDH
networks), protecting against and recovering from a network failure in 50 msecs or less, a significant improvement over the recovery time supported in DCS-based mesh restoration, and a key driver for the deployment of SONET/SDH ring-based protection.
There have been attempts at improving and/or evolving traditional ring architectures to overcome some of its limitations, with trans-oceanic ring architecture (ITU-T Rec. G.841), “P-cycles” protection, next-generation SONET/SDH equipment that can handle multiple rings, or have the ability to not close the working or protection ring side, or to share protection capacity among rings (e.g., with Virtual Line Switched Ring (VLSR).
Technological advancements in optical transport switches in the first decade of the 21st century, along with continuous deployment of dense wavelength-division multiplexing (DWDM) systems, have led telecommunications service providers to replace their SONET ring architectures by mesh-based architectures for new traffic. The new optical mesh networks support the same fast recovery previously available in ring networks while achieving better capacity efficiency and resulting in lower capital cost. Such fast recovery (in the tens to hundreds of msecs) in case of failures (e.g., network link or node failure) is achieved through the intelligence embedded in these new optical transport equipment, which allows recovery to be automatic and handled within the network itself as part of the network control plane
, without relying on an external network management
system.
s or optical switch
es ) for provisioning and recovery of services, new approaches have been developed for the design, deployment, operations and management of mesh optical networks.
Optical mesh networks today not only provide trunking capacity to higher-layer networks, such as inter-router or inter-switch connectivity in an IP
, MPLS
, or Ethernet
-centric packet infrastructure, but also support efficient routing and fast failure recovery of high-bandwidth point-to-point Ethernet and SONET/SDH services.
services. Multiple recovery mechanisms that provide different levels of protection or restoration against different failure modes are available in mesh networks. Channel, link, segment and path protection are the most common protection schemes. P-cycles is another type of protection that leverages and extends ring-based protection. Restoration is another recovery method that can work on its own or complement faster protection schemes in case of multiple failures.
In path-protected mesh networks, some connections can be unprotected; others can be protected against single or multiple failures in various ways. A connection can be protected against a single failure by defining a backup path, diverse from the primary path taken by the connection over the mesh network. The backup path and associated resources can be dedicated to the connection (aka Dedicated Backup Path Protection), or shared among multiple connections (aka Shared Backup Path Protection), typically ones whose primary paths are not likely to fail at the same time, thereby avoiding contention for the shared resources in case of a single link or node failure. A number of other protection schemes such as the use of pre-emptible paths, or only partially diverse backup paths, can be implemented. Finally, multiple diverse routes can be designed so that a connection has multiple recovery routes and can recover even after multiple failures (examples of mesh networks across the Atlantic and Pacific oceans).
. Inside a telecommunications office, the signals are then handled to and switched by a transport switch (aka optical cross-connect or optical switch) and either are dropped at that office, or directed to an outgoing fiber link where they are again carried as wavelengths multiplexed into that fiber link towards the next telecommunications office. The act of going through Optical-Electrical-Optical (O-E-O) conversion through a telecommunications office causes the network to be considered opaque. When the incoming wavelengths do not undergo an optical-to-electrical conversion and are switched through a telecommunications office in the optical domain using all-optical switches (also called photonic cross-connect, optical add-drop multiplexer
, or Reconfigurable Optical Add-Drop Multiplexer (ROADM) systems), the network is considered to be transparent
. Hybrid schemes can provide limited O-E-O conversions at key locations across the network.
Transparent optical mesh networks have been deployed in metropolitan and regional networks. In 2010, operational long distance networks still tend to remain opaque.
is a key control and operational aspect of optical mesh networks. In transparent or all-optical networks, routing of connections is tightly linked to the wavelength selection and assignment process (so-called routing and wavelength assignment, or "RWA"). This is due to the fact that the connection remains on the same wavelength from end-to-end throughout the network (sometimes referred to as wavelength continuity constraint, in the absence of devices that can translate between wavelengths in the optical domain). In an opaque network, the routing problem is one of finding a primary path for a connection and if protection is needed, a backup path diverse from the primary path. Wavelengths are used on each link independently of each other's. Several algorithms can be used to determine a primary path and a diverse backup path (with or without sharing of resource along the backup path) for a connection or service, such as shortest path
, including Dijkstra's algorithm
, k-shortest path, edge and node-diverse or disjoint routing
, including Suurballe's algorithm
, and numerous heuristics.
It also supports new network paradigms such as
in general and wireless mesh networking in particular.
Telecommunications equipment
Packet networking
Connection-oriented networking
Availability
Telecommunications network
A telecommunications network is a collection of terminals, links and nodes which connect together to enable telecommunication between users of the terminals. Networks may use circuit switching or message switching. Each terminal in the network must have a unique address so messages or connections...
.
Transport networks, the underlying optical fiber-based layer of telecommunications networks, have evolved from DCS (Digital Cross-connect Systems)-based mesh architectures in the 1980s, to SONET/SDH (Synchronous Optical Networking/Synchronous Digital Hierarchy) ring architectures in the 1990s. Technological advancements in optical transport equipment in the first decade of the 21st century, along with continuous deployment of DWDM systems, have led telecommunications service providers to replace their SONET ring architectures by mesh-based architectures. The new optical mesh networks support the same fast recovery previously available in ring networks while achieving better capacity efficiency and resulting in lower capital cost.
Optical mesh networks today not only provide trunking capacity to higher-layer networks, such as inter-router or inter-switch connectivity in an IP, MPLS, or Ethernet-centric infrastructure, but also support efficient routing and fast failure recovery of high-bandwidth services. This was made possible by the emergence of optical network elements that have the intelligence required to automatically control certain network functions, such as fault recovery.
Optical mesh networks enable a variety of dynamic services such as bandwidth-on-demand, Just-In-Time bandwidth, bandwidth scheduling, bandwidth brokering, and optical virtual private networks that open up new opportunities for service providers and their customers alike.
History of transport networks
Transport networks, the underlying optical fiberOptical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
-based layer of telecommunications network
Telecommunications network
A telecommunications network is a collection of terminals, links and nodes which connect together to enable telecommunication between users of the terminals. Networks may use circuit switching or message switching. Each terminal in the network must have a unique address so messages or connections...
s, have evolved from Digital cross connect system
Digital cross connect system
A digital cross-connect system is a piece of circuit-switched network equipment, used in telecommunications networks, that allows lower-level TDM bit streams, such as DS0 bit streams, to be rearranged and interconnected among higher-level TDM signals, such as DS1 bit streams...
(DCS)-based mesh architectures in the 1980s, to SONET/SDH (Synchronous Optical Networking/Synchronous Digital Hierarchy)
Synchronous optical networking
Synchronous Optical Networking and Synchronous Digital Hierarchy are standardized multiplexing protocols that transfer multiple digital bit streams over optical fiber using lasers or highly coherent light from light-emitting diodes . At low transmission rates data can also be transferred via an...
ring architectures in the 1990s. In DCS-based mesh architectures, telecommunications carriers deployed restoration systems for DS3 circuits
Digital Signal 3
A Digital Signal 3 is a digital signal level 3 T-carrier. It may also be referred to as a T3 line.*The data rate for this type of signal is 44.736 Mbit/s.*This level of carrier can transport 28 DS1 level signals within its payload....
such as at&t FASTAR (FAST Automatic Restoration) and MCI Real Time Restoration (RTR), restoring circuits in minutes after a network failure. In SONET/SDH rings, carriers implemented ring protection
Ring Protection
In Telecommunication networks, ring topology is often used. These ring networks can be self healing which is necessary to ensure up time in the telecommunication industry. There are two widely used protection architectures.- 1+1 Ring Protection :...
such as SONET
Sonet
Sonet may refer to:* Sonet Records, European record label* Synchronous optical networking * Saab Sonett...
Unidirectional Path Switched Ring (UPSR) (also called Sub-Network Connection Protection
Subnetwork Connection Protection
In telecommunications, subnetwork connection protection, or SNCP, is a type of protection mechanism associated with synchronous optical networks such as synchronous digital hierarchy....
(SCNP) in SDH
Synchronous optical networking
Synchronous Optical Networking and Synchronous Digital Hierarchy are standardized multiplexing protocols that transfer multiple digital bit streams over optical fiber using lasers or highly coherent light from light-emitting diodes . At low transmission rates data can also be transferred via an...
networks) or SONET
Sonet
Sonet may refer to:* Sonet Records, European record label* Synchronous optical networking * Saab Sonett...
Bidirectional Line Switched Ring (BLSR) (also called Multiplex Section - Shared Protection Ring (MS-SPRing) in SDH
Synchronous optical networking
Synchronous Optical Networking and Synchronous Digital Hierarchy are standardized multiplexing protocols that transfer multiple digital bit streams over optical fiber using lasers or highly coherent light from light-emitting diodes . At low transmission rates data can also be transferred via an...
networks), protecting against and recovering from a network failure in 50 msecs or less, a significant improvement over the recovery time supported in DCS-based mesh restoration, and a key driver for the deployment of SONET/SDH ring-based protection.
There have been attempts at improving and/or evolving traditional ring architectures to overcome some of its limitations, with trans-oceanic ring architecture (ITU-T Rec. G.841), “P-cycles” protection, next-generation SONET/SDH equipment that can handle multiple rings, or have the ability to not close the working or protection ring side, or to share protection capacity among rings (e.g., with Virtual Line Switched Ring (VLSR).
Technological advancements in optical transport switches in the first decade of the 21st century, along with continuous deployment of dense wavelength-division multiplexing (DWDM) systems, have led telecommunications service providers to replace their SONET ring architectures by mesh-based architectures for new traffic. The new optical mesh networks support the same fast recovery previously available in ring networks while achieving better capacity efficiency and resulting in lower capital cost. Such fast recovery (in the tens to hundreds of msecs) in case of failures (e.g., network link or node failure) is achieved through the intelligence embedded in these new optical transport equipment, which allows recovery to be automatic and handled within the network itself as part of the network control plane
Control plane
In routing, the control plane is the part of the router architecture that is concerned with drawing the network map, or the information in a routing table that defines what to do with incoming packets. Control plane functions, such as participating in routing protocols, run in the architectural...
, without relying on an external network management
Network management
Network management refers to the activities, methods, procedures, and tools that pertain to the operation, administration, maintenance, and provisioning of networked systems....
system.
Optical mesh networks
Optical mesh networks refer to transport networks that are built directly off the mesh-like fiber infrastructure deployed in metropolitan, regional, national, or international (e.g., trans-oceanic) areas by deploying optical transport equipment that are capable of switching traffic (at the wavelength or sub-wavelength level) from an incoming fiber to an outgoing fiber. In addition to switching wavelengths, the equipment is typically also able to multiplex lower speed traffic into wavelengths for transport, and to groom traffic (as long as the equipment is so-called opaque - see subsection on transparency). Finally, these equipment also provide for the recovery of traffic in case of a network failure. As most of the transport networks evolve toward mesh topologies utilizing intelligent network elements (optical cross-connectOptical cross-connect
An optical cross-connect is a device used by telecommunications carriers to switch high-speed optical signals in a fiber optic network, such as an optical mesh network.There are several ways to realize an OXC:...
s or optical switch
Optical switch
In telecommunication, an optical switch is a switch that enables signals in optical fibers or integrated optical circuits to be selectively switched from one circuit to another....
es ) for provisioning and recovery of services, new approaches have been developed for the design, deployment, operations and management of mesh optical networks.
Optical mesh networks today not only provide trunking capacity to higher-layer networks, such as inter-router or inter-switch connectivity in an IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
, MPLS
Mpls
MPLS or Mpls can refer to:* Minneapolis, Minnesota, United States* Multiprotocol Label Switching, a data-carrying mechanism in computer networking...
, or Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
-centric packet infrastructure, but also support efficient routing and fast failure recovery of high-bandwidth point-to-point Ethernet and SONET/SDH services.
Recovery in optical mesh networks
Optical mesh networks support the establishment of circuit-mode connection-orientedConnection-oriented
Connection-oriented communication is a data communication mode in telecommunications whereby the devices at the end points use a protocol to establish an end-to-end logical or physical connection before any data may be sent. In case of digital transmission, in-order delivery of a bit stream or...
services. Multiple recovery mechanisms that provide different levels of protection or restoration against different failure modes are available in mesh networks. Channel, link, segment and path protection are the most common protection schemes. P-cycles is another type of protection that leverages and extends ring-based protection. Restoration is another recovery method that can work on its own or complement faster protection schemes in case of multiple failures.
In path-protected mesh networks, some connections can be unprotected; others can be protected against single or multiple failures in various ways. A connection can be protected against a single failure by defining a backup path, diverse from the primary path taken by the connection over the mesh network. The backup path and associated resources can be dedicated to the connection (aka Dedicated Backup Path Protection), or shared among multiple connections (aka Shared Backup Path Protection), typically ones whose primary paths are not likely to fail at the same time, thereby avoiding contention for the shared resources in case of a single link or node failure. A number of other protection schemes such as the use of pre-emptible paths, or only partially diverse backup paths, can be implemented. Finally, multiple diverse routes can be designed so that a connection has multiple recovery routes and can recover even after multiple failures (examples of mesh networks across the Atlantic and Pacific oceans).
Transparency
Traditional transport networks are made of optical fiber-based links between telecommunications offices, where multiple wavelengths are multiplexed to increase the capacity of the fiber. The wavelengths are terminated on electronic devices called transponders, undergoing an optical-to-electrical conversion for signal Reamplification, Reshaping, and Retiming (3R)Optical communications repeater
An optical communications repeater is used in a fiber-optic communications system to regenerate an optical signal by converting it to an electrical signal, processing that electrical signal and then retransmitting an optical signal...
. Inside a telecommunications office, the signals are then handled to and switched by a transport switch (aka optical cross-connect or optical switch) and either are dropped at that office, or directed to an outgoing fiber link where they are again carried as wavelengths multiplexed into that fiber link towards the next telecommunications office. The act of going through Optical-Electrical-Optical (O-E-O) conversion through a telecommunications office causes the network to be considered opaque. When the incoming wavelengths do not undergo an optical-to-electrical conversion and are switched through a telecommunications office in the optical domain using all-optical switches (also called photonic cross-connect, optical add-drop multiplexer
Optical add-drop multiplexer
An optical add-drop multiplexer is a device used in wavelength-division multiplexing systems for multiplexing and routing different channels of light into or out of a single mode fiber . This is a type of optical node, which is generally used for the construction of optical telecommunications...
, or Reconfigurable Optical Add-Drop Multiplexer (ROADM) systems), the network is considered to be transparent
Transparency (telecommunication)
In telecommunications, transparency can refer to:#The property of an entity that allows another entity to pass through it without altering either of the entities....
. Hybrid schemes can provide limited O-E-O conversions at key locations across the network.
Transparent optical mesh networks have been deployed in metropolitan and regional networks. In 2010, operational long distance networks still tend to remain opaque.
Routing in optical mesh networks
RoutingRouting
Routing is the process of selecting paths in a network along which to send network traffic. Routing is performed for many kinds of networks, including the telephone network , electronic data networks , and transportation networks...
is a key control and operational aspect of optical mesh networks. In transparent or all-optical networks, routing of connections is tightly linked to the wavelength selection and assignment process (so-called routing and wavelength assignment, or "RWA"). This is due to the fact that the connection remains on the same wavelength from end-to-end throughout the network (sometimes referred to as wavelength continuity constraint, in the absence of devices that can translate between wavelengths in the optical domain). In an opaque network, the routing problem is one of finding a primary path for a connection and if protection is needed, a backup path diverse from the primary path. Wavelengths are used on each link independently of each other's. Several algorithms can be used to determine a primary path and a diverse backup path (with or without sharing of resource along the backup path) for a connection or service, such as shortest path
Shortest path problem
In graph theory, the shortest path problem is the problem of finding a path between two vertices in a graph such that the sum of the weights of its constituent edges is minimized...
, including Dijkstra's algorithm
Dijkstra's algorithm
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path problem for a graph with nonnegative edge path costs, producing a shortest path tree...
, k-shortest path, edge and node-diverse or disjoint routing
Edge disjoint shortest pair algorithm
Edge disjoint shortest pair algorithm is an algorithm in computer network routing. The algorithm is used for generating the shortest pair of edge disjoint paths between a given pair of vertices as follows:...
, including Suurballe's algorithm
Suurballe's algorithm
In theoretical computer science and network routing, Suurballe's algorithm is an algorithm for finding two disjoint paths in a nonnegatively-weighted directed graph, so that both paths connect the same pair of vertices and have minimum total length. The algorithm was conceived by J. W. Suurballe...
, and numerous heuristics.
Applications
The deployment of optical mesh networks is enabling new services and applications for service providers to offer their customers, such as- Dynamic services such as Bandwidth-on-Demand (BoD), Just-In-Time (JIT) bandwidth, bandwidth scheduling, and bandwidth brokering
- Optical virtual private networks
It also supports new network paradigms such as
- IP-over-optical network architectures
Related network architectures
Mesh networkingMesh networking
Mesh networking is a type of networking where each node must not only capture and disseminate its own data, but also serve as a relay for other nodes, that is, it must collaborate to propagate the data in the network....
in general and wireless mesh networking in particular.
See also
Telecommunications and networking- Computer networkComputer networkA computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
- Multiwavelength optical networkingMultiwavelength optical networkingMultiwavelength optical networking , is a method for communicating digital information using lasers over optical fiber. The method provides the next level of communication networks after SONET optical networks. MONET optical networks provide an even greater bandwidth capacity...
- Optical Transport NetworkOptical Transport NetworkITU-T defines an Optical Transport Network as a set of Optical Network Elements connected by optical fibre links, able to provide functionality of transport, multiplexing, switching, management, supervision and survivability of optical channels carrying client signals...
- Telecommunications
- Wireless mesh networks
Telecommunications equipment
- Cross-connect
- Wavelength division multiplexing
Packet networking
- Internet protocolInternet ProtocolThe Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
- Multiprotocol Label SwitchingMultiprotocol Label SwitchingMultiprotocol Label Switching is a mechanism in high-performance telecommunications networks that directs data from one network node to the next based on short path labels rather than long network addresses, avoiding complex lookups in a routing table. The labels identify virtual links between...
- Optical burst switchingOptical burst switchingOptical burst switching is an optical networking technique that allows dynamic sub-wavelength switching of data. OBS is viewed as a compromise between the yet unfeasible full optical packet switching and the mostly static optical circuit switching...
- Router
Connection-oriented networking
- Circuit switchingCircuit switchingCircuit switching is a methodology of implementing a telecommunications network in which two network nodes establish a dedicated communications channel through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the...
- Connection oriented
Availability
- AvailabilityAvailabilityIn telecommunications and reliability theory, the term availability has the following meanings:* The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e., a random, time...
Further reading
- "Site on Network Protection - network protection techniques, network failure recovery, network failure events" http://www.network-protection.net/
- “Mesh-based Survivable Transport Networks: Options and Strategies for Optical, MPLS, SONET and ATM Networking”, by Wayne Grover http://www.ece.ualberta.ca/~grover/book
- "Optical Network Control: Architecture, Protocols, and Standard", by Greg Bernstein, Bala Rajagopalan, and Debanjan Saha http://www.amazon.com/Optical-Network-Control-Architecture-Protocols/dp/0201753014/
- “Path Routing in Mesh Optical Networks”, by Eric Bouillet, Georgios Ellinas, Jean-Francois Labourdette, and Ramu Ramamurthy http://www.wiley.com/WileyCDA/WileyTitle/productCd-0470015659.html, http://books.google.com/books?id=zSSjFf-jZT8C
- "P-cycles: an overview", R. Asthana, Y.N. Singh, W.D. Grover, IEEE Communications Surveys and Tutorials, February 2010 http://dl.comsoc.org/livepubs/surveys/public/2010/jan/07asthana.html
- "Survivable networks: algorithms for diverse routing", by Ramesh Bhandari http://books.google.com/books?id=SIkfR0lAN1wC
External links
- Self-Healing Mesh Optical Nets Emerge http://www.eetimes.com/showArticle.jhtml?articleID=207402005
- AT&TAT&TAT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
Optical Bandwidth on Demand Gains Velocity with More Speeds for Customer Provisioning http://www.att.com/gen/pressroom?pid=4800&cdvn=news&newsarticleid=24555 - AT&TAT&TAT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
offering fully meshed optical service http://www.networkworld.com/news/2006/111606-att-meshed-optical.html - Verizon Business Enhances Trans-Atlantic Network http://www.verizonbusiness.com/about/news/displaynews.xml?newsid=21353
- Verizon Business Enhances Performance and Reliability of Pacific Undersea Cable Systems on Global Network http://www.verizonbusiness.com/about/news/displaynews.xml?newsid=25065
- The Internet2Internet2Internet2 is an advanced not-for-profit US networking consortium led by members from the research and education communities, industry, and government....
Dynamic Circuit Network (DCN)Dynamic circuit networkA dynamic circuit network is an advanced computer networking technology that combines traditional packet-switched communication based on the Internet Protocol, as used in the Internet, with circuit-switched technologies that are characteristic of traditional telephone network systems...
http://www.internet2.edu/network/dc/index.html - Intelligent optical mesh empowers digital media network http://www.lightwaveonline.com/about-us/lightwave-issue-archives/issue/intelligent-optical-mesh-empowers-digital-media-network-54890667.html
- VSNL and TataTata- Companies :* Tata Group, India's largest business group and multinational company** List of entities associated with Tata Group- People :* Tata family, an influential family of India owning the Tata Group** Jamsetji Tata, known as the father of Indian industry...
Teleservices Build First Nationwide Intelligent Optical Mesh Network in India Using Ciena's CoreDirector http://www.indiaprwire.com/pressrelease/telecommunications/200710235231.htm, http://www.ciena.com/news/news_2007pr_8630.htm - 360networks Deploys The World's Most Extensive Optical Mesh Network http://www.thefreelibrary.com/360networks+Deploys+The+World%27s+Most+Extensive+Optical+Mesh+Network-a067463903
- Verizon Business Circles Globe With Optical Mesh Network; Begins Extension to Middle East http://www.verizonbusiness.com/about/news/pr-25395-en-Verizon+Business+Circles+Globe+With+Optical+Mesh+Network;+Begins+Extension+to+Middle+East.xml
- Verizon Business Global Mesh Network Investment Pays Big Dividends for Enterprise Customers During Multiple Submarine Cable System Disruptions in Asia-Pacific Region http://www.verizonbusiness.com/about/news/pr-25372-en-Verizon+Business+Global+Mesh+Network+Investment+Pays+Big+Dividends+for+Enterprise+Customers+During+Multiple+Submarine+Cable+System+Disruptions+in+Asia+Pacific+Region.xml
- Verizon builds 18-city optical mesh http://connectedplanetonline.com/ethernet/news/verizon-optical-mesh-0310/