Unleashing Bandwidth
ITU Secretary General Yashio Utsumi cited the following reasons for raising level of communications in developing countries: wireless communications, the plummeting cost of bandwidth and the efficiencies of the Internet.
In the new Internet economy, bandwidth consumption and usage will perhaps be the greatest single indicator of economic growth. To achieve the ambition of becoming an IT super power, everyone must be able to access bandwidth to reap the benefits of Internet for personal as well as professional growth. Availability of affordable of quality bandwidth will trigger the use of Internet and in turn, the demand for bandwidth itself. Networks need to handle bandwidth hungry multimedia applications including video-on-demand and videoconferencing, besides high speed Internet and data access.
They have done it
China has been doubling the number of Internet subscribers every six months. In July 1999, it had over 4 million subscribers and would probably cross 10 as the new millennium begins. A small country like Singapore with 3 million population is believed to have more than twice the number of Internet subscribers as in India with similar proportion of bandwidth used. And its per capita income is almost twenty times of that of India.
The many parts of a telecom network---required to set up a communication---including international, domestic long distance and ‘the last mile’ or the local loop. All of them together need to provide seamless connectivity for an efficient link. If a user is unable to efficiently connect Internet or download a ‘gif’ file, the problem can lie in any one of them---somewhere bandwidth is lacking or unmatched.
Information Superhighways ready for the new millennium
India had the world’s longest information superhighway---a submarine fibre-optic pipe---which arrived at its shores two years ago in end 1997 when Internet usage had barely begun. It is the FLAG system (Fibre-optic Link Around The Globe) having a capacity of 10 Giga bits per second (or 10,000 Mega bits per second). FLAG is also building a 5 Tera bit per second cable, using DWDM technology, across Atlantic.
In Asia-Pacific region, six new cable systems are coming up in the next two years---four of them trans-pacific to deliver a total of 280 Gbps (10 times the existing capacity between Asia and North America) and two intra-Asia with 160 Gbps (also about 10 times the current bandwidth). The race is on to catch up with the emerging demands of liberalisation process and alternative carriers. And this will not be the only pressure on the players. The bandwidth needs to be affordable. To let the masses taste the fruits of Internet and make it an integral part of their lives. Besides affordability, quality is needed too to meet the demands of e-commerce, multimedia and other delay-sensitive applications.
The Access bottleneck
The next leg of the information pipeline---the long distance network or backbone---has to be fibre-optic for similar reasons of capacity and quality. There is substantial fibre-optic capacity built over last few years by Department of Telecom (DoT). More is expected to come up soon---not only by DoT, but also by the Railways and the Power Authorities---using their right-of-way, the key factor for setting up the long distance networks fast. However, the bandwidth is delivered to the end user, by the last leg called "the last mile" or the local loop. And the upcoming multimedia applications like pay-per-view videos, interactive TV, video conferencing, etc. require large bandwidth per user. It is not easy to lay optical fibres to the homes or the buildings---due to the constraints of cost, time and complexity of digging (and right-of-way) involved. It is therefore important to use not only the embedded infrastructure which comes in form of legacy telephone copper wires or coax cables for cable TV but also any other networks in place like the radio or cellular.
Technologies galore
The rest of world has passed through the same route. Asian countries like China, Japan, Singapore, Korea, Malaysia etc. have been quick to realise the need to connect their people to the information superhighways, quickly adopting the upcoming technologies. There is now a rich tapestry of technologies available using different transmission media available:
ADSL supports data rates---on conventional copper lines (POTS)---of up to 8 Mbps when receiving (downstream) and up to 640 Kbps when sending (upstream), using ADSL modem. It is becoming popular for megabit applications like video-on-demand (VoD), and high speed Internet/data access. The new G.Lite or G.992.2 standard---also called DSL Lite or Universal ADSL---approved by ITU is a simplified plug-and-play version with target speed of 1.5 Mbps downstream and 384 Kbps upstream.
Cable modems attached to HFC (Hybrid Fibre Coax) networks allow a subscriber to download data at speeds of up to 10 Mbps (although the average is around 2 Mbps). HFC network is a combination of fiber and coaxial cable. Service transport is delivered by ‘fiber’ and the local subscriber access is by ‘coaxial cable’ generally put by cable TV operators.
GSM using HSCSD (High Speed Circuit Switched Data) enables data rates of up to 64 Kbps on existing GSM cellular infrastructure. GPRS (General Packet Radio Service) enables transferring of data, on a GSM network, in packet mode. It provides data rates of up to around 150 Kbps, opening the door for the introduction of new applications like multimedia on the existing GSM cellular infrastructure. UMTS (Universal Mobile Telecommunication System) is the European 3rd Generation (3G) cellular system---a migration path for GSM in line with ITU’s 3G standard IMT-2000 and enabling 2 Mbps applications. In the interim, WAP enabled mobile phones will provide stripped down version of Internet---due to limited air bandwidth and mobile’s display and processing capabilities---allowing fixed mobile convergence .
Local Multipoint Distribution Service (LMDS) is one of the wireless broadband solutions working around 27/29 GHz band. Though such high frequencies offer high bandwidth (data rates of up to 155 Mpbs), the distances are very small (~3-4 Km). These are used in dense urban areas (buildings not reached by optical fibres) for point-to-point or point-to-multipoint links. However, as it uses ‘line of sight’ and cannot penetrate buildings, conventional wiring is used within the building.
With almost equal population of ‘telephones’ and ‘cable TV’ connections in India there may be neck-to-neck race for the technologies to use these networks to deliver high speed Internet and multimedia applications. We hope that with all the initiative being taken, Indian masses would enter the Information Age in the new millennium ahead of others.
Niraj K. Gupta,
Communications Today, Jan-Feb 2000.