Towards building a next generation voice/data network for NorthEast

[TamilNet, Thursday, 09 January 2003, 02:18 GMT]
Building a state of the art Telecommunication infrastructure for North East is vital for development, industrial growth, advancement in education, general economic progress and to maintain a competitive edge in a global business environment. With the emergence of a new political configuration, NorthEast administration is rightly positioned to consider building a well designed communication network to connect the NorthEast with the rest of the globe. This article provides technical possibilites and key strategies to consider when designing such network.

SEA-ME-WE III fiber cable network (Click for a larger picture)

As with other NorthEast utilities under central government control, communication infrastructure of the NorthEast remained underdeveloped in North East. War destroyed even the rudimentary deployment of telephone links. Further, despite promises, project e-Sri Lanka's vision of taking the fruits of information technology to 'every village' is likely to bypass the villages of NorthEast.

NorthEast development authority has to grasp the current opportunity to ensure that NE is fitted with a data voice network with state-of-the-art technologies easily scalable to meet the bandwidth needs of the 3 million NorthEast population now and for several more decades.

Sri Lanka Telecom's (SLT) connectivity to the outside world is through Mount Lavania landing point of undersea SEA-ME-WE-III (SMW-III, South East Asia- Middle East – Western Europe) fibre optic cable link managed by French and Singapore telecom. The SMW-III network supports 40Gbps bandwidth with two fiber pairs using SDH (Synchronous Digital Hierarchy, the European equivalent of SONET) format in WDM (Wave length Division Multiplexing) technology, covering 41 landing points in 35 countries.

Paddukka Satellite station

The fiber link is augmented by three digital satellite links at Paddukka, Colombo. Several private VSAT (Very Small Apperture Terminals) installations supported by Hughes subsidiaries in India are also in operation catering point to point commercial needs.

NorthEast network architecture should be developed as a standalone network with 'international' exchange points that can tie into SLT or with independent feeds from SMW-III link or an NorthEast based satellite hub. An independent fiber feed would be to a town like Mannar near the Bus-45 feed in Segment-4 of the 10-segment SMW-III network.

With the impending urgent development and resettlement activities, adopting a two track strategy to rebuild the communication infrastructure appears prudent:

• To fill the urgent short term needs existing technology can be augmented by adding new point to point microwave links to key towns that are administrative centers overseeing North East reconstruction and re-development work. New lines needs to be urgently added to towns such as Kilinochi, Jaffna and Trincomalee. Promise of 'Project Hope' of SLT to install upto 5000 lines, if it materializes, will fall into this category.
• Longer term infrastructure planning should begin with the development of a policy framework assuming a functionally independently operating regional communication authority for NE. International exchange points anchoring the top level nodes that would provide flexible entry from either SLT nodes or independent feed from Satellite or trans-oceanic cables need to be established. A fiber-optic backbone network that links major towns should serve as the transport on which voice network and data network should be overlayed.

Proposed layout of first two tiers of fiber optic network (Click for a larger picture)

The mission for the designers should be: “Build a network that provides universal access to instant voice communication from anywhere in NorthEast to anywhere in the globe possible, provide instant access to every child the best educational resources, to law enforcement personnel the information on every potential suspect, to citizens the government information and services, to every employer the information company needs and to every employee the best learning resources, to make North East a great place to live, work, and play.”

While the developed world is facing dramatic network re-engineering efforts to transition from traditional circuit-switched based voice networks, where billions of dollars worth of investment still resides on legacy equipment, towards packet based networks, designers of NorthEast communication infrastructure can directly begin constructing a converged data/voice network.

Main architectural considerations that drive the NorthEast network and the need for training technical work force to develop the network can be summarized as follows:

• Fiber optic ring network that interconnects major cities in the North East should form the backbone of data/voice network. The total length of underground cabling is unlikely to exceed 600 to 800km. Enough dark fibers to be deployed in anticipation of future bandwidth needs.
• Local fiber rings at each of the major cities should form a second tier of the network architecture
• This two-tier architecture should provide the framework for supporting broadband access at the network edge using access technologies like DSL, ATM and wireless technologies
• The voice network architecture to be based on Carrier convergence switches with integrated VoATM gateway and VoIP gateway which can peer with softswitch based voice networks. Installing new class-5 switches and their complementary extensions, RSU (Remote Subscriber Units) must be avoided except for integrating legacy equipment with new network for cost benefits.
• Network design should be flexible to accommodate and promote independent ISPs (Internet Service Providers) and independent mobile operators for cellular communications.
• Establishment of a small but effective affiliated Technical Center where work towards future network growth, performance modelling and consolidation of network fault identification investigations are carried out. This group will make recommendation for network upgrades and continued evolution of network and adoption of new technologies.

Wireless Local Loop and wireline/DSL to subscriber homes (Click for a larger picture)

The capacity of the network should anticipate providing projected bandwidth of atleast 1Mb/sec to every home in North East.

The architecture of the network should promote local service competition. The dramatic cost reduction in international telephone calls that was made possible by the Voice over IP (VoIP) technology is an example of how packet switched networks with the synergy of local providers can enrich customer choices of services at vastly reduced costs compared to traditional telephone monopolies. This model should be allowed to operate wherever possible.

Expatriate technical and business professionals must endeavour to start small scale entrepreneurial initiatives centered on the voice/data network. Innovative applications development for mobile data, web-based applications and basic tools for the increasing buildup of industrial sector are some examples.

For NorthEast to prosper it is essential that we remain technologically current.

External Links:

1. How DSL works
2. How IP Telephony works
3. How Fiber Optics works

Glossary of Terms:

1. Bandwidth: denotes the capacity of a communication link. For voice transmitted in analog form we need 8kbps (8000 bits per second) the normal capacity of copper lines to our homes. Digital voice needs 64Kbps. Internet connections can vary from basic 38.kbps dialup to higher rates eg. 400kbps in DSL over the same copper link
2. circuit-switched: traditional technology where the path and the capacity of the path to carry voice is setup when the call is made and remains 'static' until we hang up.
3. packet network: normally used for data networks where information is 'packetized' and packets from multiple connections are sent multiplexed over the same physical link.
4. Convergence: Newer technologies allow transporting voice and data over the same network
5. ATM: Asynchronous Transfer Mode, a type of packet data technology where information is segmented into fixed length packets before transmission.
6. IP: Internet Protocol, another packet data technology where variable length packets are used. Internet is primarily based on IP technology.
7. DSL:Digital Subscriber Loop. Technology that allows data speeds up to 1-2Mbps over current copper wires.
8. VoIP: Voice-over-IP, digitized voice is carried over IP networks
9. VoATM: Voice-over-ATM, digitized voice is carried over ATM link
10. Softswitch:Generic term used to denote equipment that perform call control functions in a packet voice network
11. fiber: Carries information at speed of light with different technologies
12. VSAT:Very Small Aperture Terminals
13. WLL:Wireless local loop, where instead of running copper or fiber links from the central switch (node) to subscriber home (what is called the 'last mile') use of wireless technologies to complete the last mile.
14. Class-5 switches:Switches that connect the telephone network (PSTN: Public Switched Telephone Network) to subscriber homes.

     

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