Wireless Solution For Telecommunication In Underdeveloped Countries example essay topic

Sophie HUANG, Jimmy CHEN Abstract With 6 billion people in the world and only about 800 million telephone lines, access to modern communications service is still a dream for most people. We call this gap as "digital divide? which's between those who have access to the related information technologies in developed countries and those who have not in underdeveloped countries. The digital divide is now an accepted key factor that affects economic, society and knowledge development in both developed and underdeveloped countries. In this paper, we attempt to identify the opportunities to use low-cost wireless solution for telecommunication in underdeveloped countries. 1. Bridging the gap.

1.1 What's the digital divide? There " re various definitions of the digital divide with different emphasis. We give the term of digital divide a conclusion from many referenced sources: Digital divide describes that the world can be divided into people who do and people who don't have access to - and the capability to use - modern information technology, such as computer facilities, literacy and use skills, computer literacy skills, or appropriate information content. Internet facilities, telecommunications facilities, information While there is no doubt that information technology has been a benefit to many and helped the business world to prosper, it has also widened the gap between the developed and underdeveloped countries, creating a two-tier world of have and have-nots. Even within developed, there is a gap between cities and rural areas. If we fail to solve the digital divide problem, millions could be left out in the cold.

1.2 Why decreasing the digital divide through wireless? In developed countries the mobile data access is driven by a fundamental need for basic communications services. But they existed a server problem in the rural areas where telecom network are even more scare, and now faced with great challenges to fulfilling universal access objectives and provide advanced communications services. However, the basic communication infrastructure is still luxury and unavailable for underdeveloped countries. In this paper, we " ll focus on identify a cost effective solution of wireless to solve digital divide problem in underdeveloped countries. Wireless systems have recently become a cost-effective and easy to use solution for providing communications services when traditional cable-based public networks are unavailable.

Aside from use in the public network, new developments make possible for even a novice to set up a high-speed 2 Mbps data link. These can cost less than $2 000 for a simple point-to-point connection over a few kilometers, and there are even cheaper options when less bandwidth is required. Most people live in a distribution in underdeveloped countries which is different from those dense in developed countries so wireless solution ideally suits radio technology. In developed countries we know the majority of people live close together in cities, so using cable makes more sense and is more cost effective. However, in these underdeveloped countries the dense situation is largely reversed - most people are spread sparsely that may cover thousands of square kilometers. This situation makes cable development so expensive.

So wireless local loops (WLL) is an ideal alternative, even in developed countries where bandwidth limitations of cable systems continue to restrict efficient access to the Internet. Wireless capacity can be distributed over hundred square kilometers by building one base station in one particular location and can be shared efficiently by users. It is not necessary to know in advance the location and numbers of all potential subscribers and as demand grows it is very easy to add more capacity and add more base stations. The cost comparison between the traditional copper cable system and wireless telephony services is $2 000 and $500 per fixed line. Although public networks are spreading faster into rural areas through wireless, there are still many government offices, companies, schools located in remote areas which have little prospect access to the public network. In these situations, private wireless systems offer the immediate links with outside world.

Besides, private wireless link is increasingly being set up for broadband circuits because it cost lowly to the public network operator. Wireless offers the advantage of mobility. It's a useful feature in underdeveloped countries because it allows increased sharing of scarce resources, such as phone lines and Internet connections. A cellular phone can be handed around, or even moved around a village to meet the needs of the old and infirm. There " re various wireless communication systems optional available for underdeveloped countries such as Mobile Voice Radios / Walkie talkies, HF Radio, VHF and UHF Narrowband Packet Radio, Satellite Services, Stratospheric Telecommunication Services, Wideband, Spread Spectrum and Wireless LAN / MANs, Optic Systems, Electric Power Grid Transmission, Data Broadcasting, Gateways and Hybrid Systems, and Wireless local loop systems. Choosing the right wireless system is not a simple task.

The variety of factors involved is large and the topic can be highly technical. In this paper, we simply select LMDS, WLL, and Wi-Fi as our optimal solution for underdeveloped countries because of cost effective consideration. 2. The promising technologies in this area In most under developed countries accessibility is much more important than mobility, so instead of talking 3 G high mobility wireless solutions, the three promising technologies that we would introduce here are more or less 'fixed? wireless systems but with high accessibility and relatively low investment cost. 2.1 Local Multipoint Distribution System (LMDS) Local multipoint distribution system is a newly raised broadband wireless technology to provide versatile digital services to end-users. The acronym, LMDS actually gives us a very good explanation of the technology.

L (local) -LMDS system has a cellular network structure because the propagation characteristics of the signal at the frequency above 20 GHz limited the potential coverage of the cell size. But with in the cell area, it can offer high data rate transfer. M (multipoint)? the downlink of LDMS operates in a point-to-multipoint (broadcast) mode, while the uplink is point to point transmission. D (distribution) -the distribution of the signal may consists of simultaneous data, voice, IP (internet) and video, which is beauty of the system to be deployed in the developing countries. An example of LMDS system is shown in Fig 1. Fig 1.

LMDS system Besides the common advantages of other wireless solutions, LMDS provides the feature of multipoint broadcast and the versatile services, these made LMDS a very promising technology as an option to provide 'last mile solution? for the developing countries. Compared with the other point-to-point fixed wireless technologies, LMDS provide broadcast / multicast operation mode in the downlink, which gives the serviced provider additional business opportunities besides the conventional Date / Internet access, like digital TV service as a typical example, because normal solutions (e.g. Wi-Fi) can not provide effective and efficient multicast service with minimum overheads. Moreover, the nature of LMDS allows the system to transmit data, voice, IP packets, and video streaming simultaneously, such a broad range availability of services give those services providers, especially the service providers in the least developed countries an 'universal solution? for different subscribers with different service requirements. i.e. the service provider can server a home user basic telephone (voice) service and an enterprise office high speed Internet and VPN connection, while on top of that provide both users with digital television services. Additionally when users want to add or remove any of the services, the system can adapt to the change very quickly. Such flexibility, I believe, will turn out to be the largest beauty of the system in a fast changing market in most developing countries. As a raising technology, LMDS still need to face the following issues. A. Multiple standards, current there are 4 standards of LDMS from ETSI (Europe Telecommunication Standard Institute), ITU, etc.

Multiple standards may create difficulty for LDC in selecting adequate standard. B. Because of the propagation characteristics of microwave the signal at 28 GHz carrier frequency is most susceptible to rain effect in terms of signal quality level, therefore the rainfall statistics of the particular region should be took into consideration when designing the cell size and other technical parameters. C. Compared with WLL / Wi-Fi. LMDS is relatively expensive in capital investment to setup network infrastructures 2.2 Wireless Local Loop (WLL) Wireless Local Loop is another new technology that provides reliable, flexible and economical access to local telephone service. As a general technology, WLL can adopt a wide range of air interface including IS-95, IS-136 (CDMA), DECT (TDMA / TDD), PHS, etc. Fig 2 shows the basic infrastructure of a WLL system. Fig 2.

Network infrastructure of WLL system One of the biggest advantages of WLL is the economics. Like other wireless solutions, it is especially suitable to be deployed in a region that subscribers are widely dispersed, because the expense of provisioning service via WLL is not affected by the distance between the subscriber and the base station. Also WLL network can be deployed in a very quickly way, to setup and activate a complete WLL network starting from nothing in 3-4 month is feasible. it is a key advantage in a market where multiple service providers are competing for the same user base. Except for the advantages, WLL still have some disadvantages, basically WLL can accommodate only voice service and low speed data transfer, which greatly narrowed the application of the technology. Due to the pros and cons of WLL technology, it is best suitable in a fast deployment of basic voice solution to connect to local PSTN to the subscribers in the emerging economics.

2.3 Wi-Fi (I 802.11 x) Wi-Fi (802.11 b) and its family (including 802.11 a 802.11 g) is a range of standards that provide up to 54 Mbps data rate transfer in about 100 meter area in radius. Among these standards, Wi-Fi has been widely used in developed countries for wireless LAN connection in offices as well as in homes, due to the easy configuration and wide availability in the city, you can now use laptops or handhold device to surf on the internet through Wi-Fi network in airport, caf? restaurant, etc. Unlike the other two wireless technologies introduced above, the I 802.11 x family operates on 2.4 / 5 GHz frequency band, which is public spectrum. That means any individual of organization can use this frequency band without applying a government license.

The only restriction is the power of the radio was to be limited to One Watt in order to minimize radio interference. The system use an Access point (AP) to connect to the Ethernet and transmit radio signals, while client also has 802.11 b transceiver to talk to the AP, the network can operate in two different modes? Infrastructure and Ad hoc. When system runs in infrastructure mode the client only talks to the AP, while in the Ad hoc mode client can talk to another client. In some versions Wi-Fi, APs can talk to each other without a fixed line connection.

Nowadays, WiFi equipments are widely available at market with very low price. What makes WLAN technology so promising as an option to bridge the digital divide is a number of factors: 1. Rather than being financed by one or a few private companies, the cost of creating and managing the network is distributed among a multitude of participants. End-users themselves finance and own portions of the network. Through this collective investment model that the huge capital needed to connect the 50% of the world population living in rural areas can be made available. 2.

The typical model of WLAN in rural areas consists of a satellite station connected to the backbone of Internet, and a mesh of APs and client equipments that distribute the bandwidth to end-users, is recent years the satellite connection fee is reduced by 70%, which made the model more affordable in developing countries. 3. In the rural area APs can be powered by solar cells, therefore APs can operate without accessing the grid power, which made the deployment of AP more flexible. The major problem of Wi-Fi includes: service security, billing issue and government restriction on the frequency band.

3. Implementation issues 3.1 Purchasing equipment external Aside from the additional equipment which makes wireless system more costly, sourcing of wireless equipment for operator in underdeveloped countries is more difficult than developed countries. In those underdeveloped countries with high import, there's a tendency to bypass its local market and source suppliers in more developed countries. Besides they often require more skilled technicians to install, and network planning for efficient spectrum use in a public network.

Purchasing equipment external is a complex and costly exercise. Below are some advice for underdeveloped countries: ? Pre-sales and after-sales consulting. Obtain installation support and training for using equipment.? Power supply voltage and frequency compatibility with the destination country - 60 Hz equipment can have problems with 50 Hz power supplies, and 120 V equipment designed for the US market will require purchase of transformers if the equipment does not have a 240 V option.?

Transportation costs, Importation duties, license fees, Labor cost, etc? The need for power systems where the electricity grid is unavailable or unreliable. 3.2 Power system and battery Power system such as solar power and battery charging systems need to be considered for designing the wireless equipment. Power supply& battery is one of the most important factors and yet easily neglected components. Many distributed population areas in underdeveloped countries don't have access to reliable power supply systems. So they should consider to make alternative arrangements for electricity supply.

If grid power is available on an irregular basis, a simple battery charging system is the preferable solution. This uses banks of deep-cycle batteries which are topped up when power is available, and an inverter can be used to provide 240/120 V for equipment that requires it, such as PCs (many wireless systems operate on 12 V). So with low power consumption and with optional integrated standby power subsystems is the first priority. The mobility and portability of wireless requires electricity which could not rely on conventional wired power.

The requirements of battery power in mobile devices are running head of the improvements in battery capacity. When we are making advances in lower consumption of power for the same function, we are demanding more powerful functionality. Battery runs out rather quickly in most handheld devices. More data you send or more you voice messaging you use, more you run down the battery.

The faster is the data rate you want, faster is the rate at which battery is depleted. So underdeveloped countries may pay some attention to advances in using non-electric methods of charging e.g. solar energy or fuel cells. Solar power is a cheaper solution to operate than a motorized generator but its capital costs are usually higher and can increase the overall costs of the project. Some wireless equipment has a sleep-mode function when not in use and in this case the cheaper solar power can be used.

3.3 Environmental Factors The temperature and humidity indeed effect the operation of wireless equipment. We know many of wireless equipment is designed for the hot and humid environment of North America and Europe. Therefore the underdeveloped countries should pay more attention to the operating temperature and humidity specifications of the equipment planned for use when sourcing external. By the same token, measurements of wireless environmental factors in the location where the equipment is to be deployed need to be made where these are likely to be close to the maximal values for the equipment. If the sourcing equipment is above the extremes for the equipment, we should install air condition to withstand the impact of high temperature or humidity. Besides, the effect of wind speed, light and rain, hail or snow should be also considered.

Below are the checking list of environment factors and these distribution statistics should be collected for each base station each location. : ? Frequency of electrical storms? Average monthly temperature? Seasonal weather? Average humidity and temperature and the highest?

Average wind speed and the hightest? The rain / hail /snow rate in predict? presence of dust, insects, fungus; ? Adequate grounding for antenna and cable 3.4 Capital costs and Recurring costs The cost of a wireless system consists of three: capital costs, recurring costs and usage costs. In this report, we focus on the capital cost and recurring costs related to installation issues. Capital costs refer to purchase price, importation duties, installation costs, transportation costs, labor costs, etc. to set up the facility. Recurring charges is likely to be service charges ($/month) and occur in an annual license fee for radio spectrum use.

Adequate budget for installation costs are often overlooked. For underdeveloped countries, it may be necessary to contract the equipment supplier or hire more experienced technicians from developed countries. That may cost up to $800/day, plus travel and subsistence costs, for an experience US technician. Because of the below costs, the number of different equipment types should be kept as low as possible in order to maximise economies of scale and minimise operational costs. Warranties should be considered. The period of the contract can also have a big impact on charges, especially in the provision of satellite space segment.

Many satellite operators drop their rates dramatically as the length of the contract increases, with commitments of up to 15 years often available. Spared parts is also important in remote situation - from the basic radio, through cabling, connectors, antennas need on hand. 3.5 Public Health Issues Some discoveries of the potential health problems such as brain cancer caused by excessive use of cellular phones and the exposure to RF radiation has drawn attention to the possible dangers of wireless systems. While there is as yet no conclusive evidence that radiation from wireless equipment is a definite problem, it is wise to be cautious and minimize the proximity of users to powerful transmitters and adopt the innovation of precautionary principle.

Dense metal shielding can also be used where this is not possible. 4. Conclusion Citizens, businesses, and governments of emerging economies have a pent-up demand for relatively inexpensive, accessible, expandable telecommunications, ranging from simple voice services to multimedia applications. With the nature of wireless communication latest development in this area, we believe Wireless solution will play a very important role as an option to expand the conventional wired line communication network in various situations, especially in the emerging economies and areas where wired line network can be very cost ineffective. In order to bridge the digital divide, we must involve all the players including International bodies, state governments, equipments vendors and local service providers to work jointly to work out feasible solution according to the facts in the area, sometimes focusing on the long term interests instead of short-term profit is critical. 5.

Directory of Sources References: [1]"Wireless Telecom for Emerging Economics: An Opportunity and Challenge? Lee Moffitt [2]"Wireless Local Loop? International Engineering Consortium tutorial. [3]"Local Multi-point Distribution Service? [4] "Can Wireless Networks Bridge the Digital Divide? Mauro Calvi, CGNet [5] The digital divide website-about the digital divided.

Retrived Novemenber 24, 2000 from the web divide. gov / about. htm [6] The WIRC CISF website-Wireless and health -Public health, Retrived September 22, 2003 from the web / phealth. shtml [7]"Can Wireless network bridge the digial divide? written for HumaniNet by Mauro Calvi, CGNet Bio of Mr. Jimmy K Chen Mr. Chen received his B.S. in Optical-Electronics Engineering from University of Shanghai for Science and Technology. He is currently working for Associated British Nutrition & Agri-products (ABNA) as the head of the I.T. department. Bio of Sophie Huang Sophie HUANG received his B.S. in Civic Education from National Taiwan Normal University for Education. Currently she works for IEI China Branch as the head of the Marketing department.

[1]"Wireless Telecom for Emerging Economics: An Opportunity and Challenge? Bio of Sophie Huang Sophie HUANG received her B.S. in Civic Education from National Taiwan Normal University for Education.