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The Telecommunications Revolution
So far in this module, we have discussed the issues of the information revolution, the concept of the information society and a brief discussion on the scope of ICTs. Telecommunications infrastructures are the major forces that drive developments in all of these issues. In simple terms, telecommunication can be defined as the process of communicating information via electronic means over a distance. The development in telecommunications is increasing at a spectacular rate. Investments in the telecommunication sector are accelerating, and multinational telecom corporations are expanding their activities globally.
Telecommunication has created a new wave of business and economics, with great profit maximisation: For instance in 1994, about a decade ago, when the telecom revolution took an upsurge drive, the ten largest telecom giants made bigger profits than the 25 largest commercial banks (The Economist, Telecommunications Survey 1995: 5). Observers believe that the development in telecommunications impacts on various spheres of human activities: the socio-economic decisions that people make, concepts of national borders, patterns of international trade and so forth.
Telecommunications issues have become items in national economic and social development agendas. More and more people are gaining access to telecommunications services: from basic telephony to various value- added telecommunications services.
Developments in telecommunications have seen the gradual transition from analogue to digital systems, for instance, using computers in switches. In the past telecommunications was considered a luxury by many governments and development planners, especially in developing countries.
The belief was that extending telecommunication networks to rural and remote areas, where most of the developing countries' population lives, was too expensive. Today, innovations in satellite and wireless telephony, coupled with solid state components for digital switching and end user equipment, have spectacularly lowered the costs of providing telecommunications facilities to any location, from the buzzing city centres to rural villages (Hudson 1997: 11).
Factors Responsible for the Growth of the Telecommunications Sector Two major issues contribute to the growth and changes in telecommunications: Technology and competition. The changes in technology and the shift to a more competitive environment /market contributes to the growth in the telecommunications sector globally.
Technology We can identify four major technological issues that contribute to growth in the telecom sector:
Capacity New technologies such as optical fibre have enormous capacity to carry information. They can be used for anything from entertainment and distance education to the transmission of highly detailed images for remote medical diagnosis. Satellites also offer a tremendous amount of bandwidth.
Digitization Telecommunication networks are becoming totally digital, so that any type of information, including voice and video, may be sent as a stream of bits in a compressed form and reconstructed for use at the receiving end. Compressed digital video can be used to transmit motion video over as little as two telephone lines (128 kbps) for teleconferencing and to deliver hundreds of digitised television channels via satellites.
Ubiquity Advances in wireless technology such as cellular radio, Personal Communications Services (PCS), and low earth orbiting (LEO) satellites will provide mobile and personal communications virtually anywhere. These technologies also make it possible to serve rural communities without laying cable or stringing copper wire
Convergence The convergence of telecommunications, data processing, and imaging technologies has ushered the era of multimedia. Voice, data, and images may be combined according to the needs of users, and the distinction between traditional sectors of telecommunications, information processing, and broadcasting are increasingly arbitrary and perhaps irrelevant (Hudson 1997). The use of mobile network has dramatically improved access to telecommunications in most developing countries. For instance there is a growing and thriving cellphone market in Africa. Previously unconnected people on the continent are getting connected to telecommunications services through the mobile phone network.
The technological changes in the telecommunication industry have two distinct effects: "to create glut instead of capacity shortages of the past and to reduce barriers to entry and make new sorts of competition possible" (The Economist, Telecommunications Survey 1995: 6). The increase in the capacity of telecommunications can be attributed to two issues: the first is the increasing use of fibre-optic cables. These cables carry more traffic than copper wire.
A single fibre, which is thinner than a hair strand can carry over 30,000 simultaneous telephone conversations. The second, switches -telephone exchanges- "have moved from eavesdropping operators and clunky electro-mechanical devices to become increasingly like computers, their costs are falling and their capability expanding inexorably" (The Economist, Telecommunications Survey 1995: 6).
Competition There was a time when telecommunications seemed to be natural monopoly worldwide. Now, the trend is changing; more and more national governments are liberalising and introducing competition. The introduction of competition has brought numerous advantages to the growth of the telecom sector. Prices are reduced, technological developments are enhanced and high quality standards of telecom service are maintained. With the introduction of competition, many service providers enter the market to provide a gamut of services. Competitors are diverse in their operations; they are not limited to telecommunications operators. Telecommunications operators have to compete with providers in parallel markets and vice-versa. An example is a telecom company providing Internet service.
The liberalisation of the telecom sector has brought competition to the telecom markets. Consequently, this has improved efficiency in performance, and reduced prices in service provision. It has also spurred technical advances and expanded network capability. As a result, the introduction of competition has contributed enormously to the growth of the telecommunications sector.
Wireless Technologies
The diffusion of wireless systems globally has greatly affected the use of cable technology. This is due apparently to the inherent characteristics of this system: physical connection is unnecessary, wireless systems function well with other applications, such as mobile telephony, which is impossible with the cable system. The wireless transmission system works by transmitting messages through the electromagnetic spectrum. The wireless transmission technologies include radio system, microwave systems and satellites systems. The radio system allows transmission in the form of radio waves.
There are different types of waves arranged according to their frequencies.
They vary from the extremely low frequency (ELF) to tremendously high frequency (THF) and within this range are UHF (ultra-high frequency) and the VHF (very high frequency). The radio systems, apart from transmission of messages, are used for broadcasting. Broadcast channels are located according to the different frequency ranges. The radio communication systems play an important role in mobile communication in our society, especially in local municipalities where police and fire services are critical. For a clearer understanding of the importance of radio communication, especially two way radio communication, one just needs to look at day-to-day examples: ship-to shore communication, police officer on patrol; the fire-fighter on an emergency call, the police on daily routine and etcetera.
Microwave
Microwave systems are high volume transmission systems that provide long-distance communication without wires. "Microwave systems transmit voice and data through the atmosphere as super-high-frequency radio waves" (Williams et al. 1999: 369). One particular characteristic of the microwave system is that it cannot bend around corners; therefore microwave antennas must be in "line of sight" of each other - that is, unobstructed. Microwave dishes and relay towers may be on the ground, however, they are usually situated atop high places, such as mountains or tall building, so that signals can be beamed over uneven terrain (ibid). Microwave systems can be very efficient in areas that are too remote to economically construct wired system.The following are some of the characteristics of the microwave system:
- High Volume
- Long distance transmission
- Point to point transmission
- High frequency radio signals are transmitted from one terrestrial transmitter to another
- Satellites serve as a relay station for transmitting microwave signals over very long distances. See figure 1.2
Satellite System Satellite technology plays an important role in communication globally. Satellites work by receiving and transmitting radio signals from one earth station to another. Satellite technology operates in a three-step approach: Messages are sent from one earth station to the satellite and from the satellite down to another receiving earth station. There are three main types of satellites: The geosynchronous satellites, these satellites remain in a fixed position and are about 36,000 km from earth; the Low Earth Orbital satellites (LEO's) are positioned closer to earth and the third is the Very Small Aperture Terminals Satellites (VSAT).
Satellite systems have the advantages of transmission from point to multipoint systems, which means transmissions can be beamed to areas that are geographically dispersed. Over the years, satellite communication has improved tremendously, especially the expansion of the capacity of transponders. Transponders are the devices that receive signals from earth and retransmit these signals across stations within its 'footprint'. This expansion of capacity has strengthened the signals emitted by satellite; consequently, satellite-receiving dishes have been reduced considerably in size. Satellite technology has the potential to beam signals across different countries; this has improved international telephony enormously. It has also improved television signal transmission as well; programmes are transmitted to television operators from one country to another through satellite technology (Bitner, 1985). Over the years satellite transmission for telephony has been considered inappropriate. This is due to the fact that the time taken to beam the signal to space and back to earth creates a short delay in the exchange of conversations; this also leads to an echo in telephonic conversations.
Satellite voice communication, for a long time was out of reach for rural subscribers in developing countries. However, developments over the years have made direct access voice services available on a large scale, even to rural subscribers. For example, these services can be accessed through a briefcase size potable terminal (Westerveild, 1994). Perhaps, the most interesting development from this scenario is the development of a fixed cellular system. This system is very beneficial to rural subscribers. This system uses the existing cellular mobile telecommunications system with fixed rural subscribers. Westerveild (1994: 205) notes that "rural subscribers in the vicinity of large urban areas and roads could be connected to a CMTS (cellular mobile telecommunication systems) and use the excess capacity of that system".The fixed cellular system, using satellite technology, has improved access to telecommunications tremendously in Africa. It has circumvented the physical connection through the laying of cables. This technology has become very appropriate for most developing countries, it comprises a briefcase-sized terminal connected to a telephone, which enables subscribers to make and receive calls irrespective of their geographical location. In South Africa, Vodacom, a private telecommunication provider in the country, is providing a fixed cellular facility in rural areas. The popularity of this technology in Africa is based on one inherent problem, which is associated with most developing regions of the world: the disparity in access to social amenities and infrastructure. This disparity is as a result of the inequality in economic power. A large percentage of the population in developing countries resides in the rural areas and they are confined to these areas due to the lack of economic power. Satellite communication, as stated earlier has the advantages of connecting points to points communication irrespective of the geographical location. That is, the arduous and capital-intensive task of laying cables up hill and down hill around the country can be circumvented. Secondly, satellite systems also enhance communication and mobility.
Wire and Cable Technology Copper Wire
Copper wire is one of the oldest transmission channels currently in use today. This system is basically used for voice transmission processes. Copper wire consists of a pair of twisted insulated wire, hence the name: twisted-pair wire. This wire is easy to install cheap to acquire, and affordable compared to more recent systems. This affordability is the major reason why most developing countries of the world use copper wire for telecommunications transmission. In South Africa, copper wire is still in use and it runs throughout the country, both in the urban and rural areas. Despite this affordability, copper wire has numerous disadvantages: the maintenance cost is high; it is susceptible to corrosion, rain and theft.In South Africa, theft of copper wire is a rampant phenomenon. This theft has continued to hamper telephony services in the country. In the year 2000, over 740 copper theft incidents were reported, due to this, more than 44 000 Telkom's customers were left without communication for days. Telkom is the major telecommunications service company. In May 2001, 3 290 customers were affected by cable theft for periods up to seven days (Telkom, 2001). The reason for this theft in South Africa has been associated to the use of these wires in manufacturing metal art and craft objects, which have a booming tourist market.
Coaxial Cables Coaxial cable provides a higher capacity than the copper or twisted-pair cables. Coaxial cables consist of two wires: The first, a copper wire, surrounded by an insulator, the second is surrounded by a metallic cylinder called the shield. This design provides the coaxial cable with a special advantage: electrical interference is reduced because the two conductors are shielded and confined separately. The coaxial cable has a greater capacity than the copper wire; it has the potential to also carry television signals (Bittner, 1985: 191).
Fibre Optics
Fibre optics utilises thin strands of glass fibre through which light waves travel. These thin strands of glass carry pulses of light rather than electric signals and as a result of this; they are not susceptible to any electromagnetic interference common to most electrical systems. Among the three main types of fibre-optic cables, Multi-mode graded-index fibre is the most common. It has broad bandwidths and a diameter of fifty to sixty-three micrometres (less than the thickness of human hair). The second, Multi-mode step-index fibres have less bandwidth - about 50 MHz- and are mostly used for digital communication. The Single-mode fibres are much thinner than the previous two, about five micrometres thick. Because of their small diameter, they are mostly experimental and they also create problem in installation and maintenance (Bittner, 1985). Fibre optic communication has many advantages over 'over-the-air-transmission' and the standard coaxial communication system. Bitnner (1985: 213) notes that fibre optic cable "is particularly useful where interference-free communication is necessary, and a single fiber-optic cable has a large channel capacity and therefore permits multiple uses". Fibre optic cable offers numerous advantages over the copper and coaxial cables: it provides a higher transmission capacity; it provides broad bandwidth; it is easily transportable; immune to electromagnetic interference and it provides capacity to transmit all forms of communication (voice, data and video).Due to the advantages that fibre optic cable offers, telecommunication companies all around the world are replacing their cable system with fibre optic. Negroponte (1995) notes that fibre optic cable is an idea transmission system for developing countries, because this system is faster, secure, more interactive than other cable systems and also, it can be linked directly to the end user terminals such as telephones, television sets and radios. Pauw (1994) also believes that fibre optic cables are applicable to most developing societies, he notes that "optical fibres specially made for rural applications are available, offering more bandwidth than coaxial cables at a not much higher cost. Also, it has the all-important immunity against lightning damage, that plague of metallic cables" (Pauw, 1994: 191).
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