Overview on wireless communication

Overview On Wireless Communication: A Gateway to Digital Bangladesh

1.0

Introduction

This is a study of wireless communication and networking as a gateway to digital Bangladesh in the perspective of the country and its available resources.

Digital Bangladesh is a dream for a system based on technology for management, administration and governance to ensure transparency, accountability and answerability at all levels of society and state.

It signifies the availability of all information to all citizens at all times. To make this possible all citizens must be connected by a net of technology. In other words an advanced communication system is required.

Currently in the perspective of Bangladesh it can be said that in terms of communication the country is still lagging in the dark ages. The country is still using back-dated wired communication systems and primitive forms of wireless technology. This is a waste of available technology of the present day.

It is also highly inefficient as it does not allow transfer of information as fast as might be possible.

Wired communication has the drawback that it is not easily accessible in all kinds of terrain. To carry on using these forms of technology would be a severe hindrance to setting up a truly digital nation.

In that context this study was carried out to find the different types of advanced wireless communications systems available this day, analyze their respective qualities, speeds and efficiencies and to give a general outline for the setting up of the most feasible of the technologies in case of Bangladesh.

In gathering data, questions were set to analyze whether advanced technology is really necessary at the time being and whether or not people would be willing to move on to advanced technology considering the obvious cost increase in the initial stages. Based on information gathered it was deduced that most people who are not yet under wireless communication would like to join in sooner rather than later while a vast majority would rather have adequate returns for their money in the form of a standard communication system rather than an obsolete system.

In the following pages the data of the different types of wireless technologies, their comparisons, the present infrastructure in Bangladesh and the possible future steps are upheld.

2.0 Wireless Technology In the modern world wireless technology is the most advanced way to connect with each other. Its superiority over wired technologies is inherently obvious. Wired technology fails in various landscapes. Mountains, plateaus, remote areas all of these are places where wired technology can never reach despite the best efforts. Wireless technology is not hindered by any of these problems due to its work at range effect. The relative size of wireless devices is also small which makes them easy to carry, low of cost and easy to run and maintain. Also the mobility afforded by wireless technology is most important in the modern day perspective.

Almost all wireless technologies follow the same working process. A base tower must be set up, from which the wireless signal will be distributed. The signal is received by and antenna in the users device which is processed and then reproduced as data or audio or visual aid which is understandable to the user. The user can then produce his own feedback which will be returned to the base via the same route. The signals propagate at the speed of light which makes the transfer of data unimaginably fast.

It is this aspect of wireless communication which makes it so desirable to bring a country forward into the digital age.

Though the general concept is same, based on different signal bandwidths, data transfer rates, range of transmission and energy consumption there are quite a few types of wireless networks available at the present time. Set up costs of these different systems also vary widely. A description of these different technologies along with a comparison follows.

2.1 GSM GSM stands for Global System for Mobile Communication. It is a cellular network which means that cell phones connect to it by searching for cells/bases in the immediate vicinity. One of the key features of GSM is the Subscriber Identity Module (SIM), a detachable smart card containing the user’s subscription information. This allows each person access to his or her own personalized network.

GSM has been upgraded recently to GPRS (General Packet Radio Service) and even more recently to EDGE (Enhanced Data Rates for GSM Evolution). All of these technologies transmit their signals in the frequency bandwidth of 900 MHz to 1800 MHz’s. The range of a typical base station would be about 10-15 miles.

GSM features include “always on” internet access, point to point service or interworking with the internet, push to talk over cellular and multimedia messaging service. Its major disadvantage is its low data transfer rate with the best of GPRS systems reaching a transfer rate of 30 SMS per minute.

However at the moment the GSM/EDGE system is the most widely used system available. Relatively low cost for set up and maintenance as well its large range makes it suitable as a startup system for further upgrading at later times. But as its signal gets crowded out faster transfer rates and larger bandwidth is necessary. Yet still at the moment there are 413 GSM/EDGE networks in 177 countries with 79.674 million users of GSM/EDGE system in Bangladesh.

2.2 CDMA CDMA is the abbreviation of Code Division Multiple Access. It is a wireless technology almost similar to GSM but with a few technical differences. While the GSM system uses a continuous signal the CDMA system uses a packet system for transmission of signals. The signal is first broken down into a seemingly random code which is then sent to the receiver along with the necessary rebuilding code. The receiver is then able to re-assemble the code and produce it in an understandable way. The code sent over CDMA technology can be digitized voice, ISDN channel, internet data etc.

The use of an independent code and synchronous reception allows multiple users to access the same frequency band at the same time. This gives it very large advantage since jamming up of the signal rarely occurs. It also makes the system highly efficient and its transfer speed means that it doubles its output in the same time corresponding to GSM. However it has its drawbacks too. The signal occupies a bandwidth much greater than that which is necessary to send the information. This means that any base station must be built to withstand the extra bandwidth necessary. Also the extra usage of bandwidth means extra cost. CDMA devices have low battery life since high transfer rates mean higher energy consumption. CDMA signals also have a problem that they tend to cause self interference sometimes disrupting communications. This also means that audio type and data types cannot be sent at the same time.

The range of a typical CDMA base station is in the range of 100 miles while its data transfer rate can range in 2Mbit/s.

2.3 3G The 3G network is the third generation of mobile networking and telecommunications. It features a wider range of services and advances network capacity over the previous 2G network.

3G has provided a new way of life among mobile phone, handset and computer users. 3G is changing the way one looks at network, with the various features and effects.

3G represents a paradigm shift from the voice centric world of the previous generations of wireless networks to the multi-media centric world of 3G. Reflecting the high 3G bandwidth and the fact that it is packet based, 3G devices will offer capabilities that are a combination of a phone, PC, and a TV. With 3G technology, one can get to enjoy data transmission speed leading up to 2Mbit/s, It also gives you high degree of connectivity and higher networking, plus resistance to noise. The technology has enhanced the bit rate, allowing service providers to give high speed internet facilities. Silicon Press notes that 3G is more than 10 times faster than the maximum speed of 2G devices for its higher bandwidth. Another advantage of 3G technology is that it can utilize packet-based Internet protocol connectivity. This means mobile devices will always be online and ready for Internet access. But, one does not have to actually pay for the connection until he starts sending or receiving data packets, such as sending an email or looking at a webpage. 3G is also great with its security. It offers greater security than their 2G predecessors.

However to support 3G technology, updates need to be made to the current cellular infrastructure.

According to 3G Internet, this means installing new 3G equipment at every current cellular base station and acquiring new frequencies for 3G transmissions. Besides, new base stations are needed to be built closer because 3G yet maintains a lower range than predecessors. Both of these undertakings are extremely expensive and could take a long time to complete fully. In addition, in order to utilize all of the new features 3G technology has to offer, customers must purchase 3G-compatilible handsets, which are generally more expensive than their 2G counterparts. In addition to being more

expensive, 3G handsets also require more power than most 2G models. These limitations do not make 3G the most desirable for initial set up.

2.4 WiFi WiFi is the abbreviated form of wireless-fidelity. WiFi is the mechanism for wirelessly connecting electronic devices to the internet via wireless network points. The WiFi technology available today extensively uses the IEEE 802.11 standards. WiFi can be set up anywhere using a router modem from a wired network using any of the IEEE standards. Currently most in use is the IEEE 802.11g standard router.

WiFi uses a 2.4 GHz signal to connect devices over 11 to 13 channels throughout the range. The IEEE 802.11g standard allows a data transfer rate of 6-54 MBit/s over a range of 140 meters while the newer IEEE802.11n standard allows from 7.2-72.2 MBit/s over 250 meters. Range of WiFi signal ranges about 32 meters indoors. For long distance signals WiFi range can be extended by using special antennas. Currently under test is the WiLD(WiFi over Large Distances) system, which allows data to be sent over 5-15 km region. WiFi is considered much more secure than other wireless networks. The previous standard of WEP having failed, WPA2 security system was created in 2010 which till date has been found to be secure provided the password is strong.

However WiFi has its disadvantages as well. It has a very short range in comparison to other technologies. It is very sensitive to interference and as very poor signal penetration. Hence its antenna’s must be placed high above ground level, sacrificing some of its already limited range. As well as that WiFi consumes huge amount of power to provide the high rate of data transfer possible.

This causes serious problem to hand-held devices reducing their battery life. Yet still WiFi is gaining in popularity and about 700 million people use WiFi nowadays worldwide.

2.5 WiMAX WiMAX Technology is also one of the emerging wireless technologies that provide us high speed mobile data and telecommunication services. WiMAX stands for Worldwide Interoperability for Microwave Access and it is based on IEEE 802.16 standards. WiMAX provides very good signals therefore higher data rate can be achieved with multiple antennas. There is no need for line of sight connection between subscriber terminals and the base station in WiMAX technology and it can support hundreds if not thousands of subscribers from a single base station. WiMAX Technology works same as WiFi does but it is more improved and efficient then Wi-Fi and also permits usage at much greater distances. It is a part of a “fourth generation,” of wireless-communication technology.

The most suitable frequency band for WiMAX is 3.5 GHz, followed by 2.2-5.2 GHz band. It is expected that a 2.5-2.7 GHz band could be used for some countries. WiMAX far surpasses the 30metre (100-foot) wireless range of a conventional Wi-Fi local area network (LAN), offering a metropolitan area network with a signal radius of about 50 km (30 miles). WiMAX offers datatransfer rates of up to 75 Mbit/s, which is superior to conventional cable-modem and DSL connections technology. WiMAX is sometimes referred to as “WiFi on steroids” and can be used for a number of applications including broadband connections, cellular backhaul, hotspots, etc.

Cost of deployment of WiMAX depends how it will be used. There are two ways WiMAX can be implemented – as a zone for wireless connections that single users go to when they want to connect to the Internet on a laptop (the non-line-of-sight “super WiFi” implementation), or as a line-of-sight hub used to connect hundreds of customers to a steady, always-on, high-speed wireless Internet connection. Under the “super WiFi” plan, cities might pay to have WiMAX base stations set up in key areas for business and commerce and then allow people to use them for free. They already do this with WiFi, but instead of putting in a bunch of WiFi hot spots that cover a few hundred square yards, a city could pay for one WiMAX base station and cover entire financial district.

2.6 Comparison Technology

Transfer Rate

Range

Bandwidth

Setup Cost

Maintenance Cost

Energy Consumption

Security

GSM

200Kbit/s

15 Km

900-1800 MHz

Low

Low

Low

Low

CDMA

2Mbit/s

100 Km 1.25 MHz

Low

High

High

Low

3G

2Mbit/s

15 Km

9001800MHz

High

Low

Medium

High

WiFi

Up to 50 Mbit/s

5 Km

2.4 GHz

High

Low

High

High

WiMAX

75Mbit/s

50 Km

3.5 GHz

High

High

Medium

High

3.0 Present Infrastructure Though not yet a fully digital nation, Bangladesh already has a very good infrastructural backbone on which to complete its digitalization. Even though most of the communication systems are currently wired networking, the future plans which have already been set into motion point to the necessity of wireless networks and availability of this network to the mass people. The existing technology of communication in case of our country and the future plans to involve all citizens in networking are upheld in following points, which points invariably to the necessity of wireless networking in the country.

3.1 Existing Technology The situation of mobile phones in Bangladesh is seeing a very fast growth spurt, with a rate of almost 30% increase per year. There are 6 operators functioning at the moment in Bangladesh, 5 of these using GSM/EDGE technologies while the remaining 1 uses CDMA technology. Their coverage at the

moment is just on the boundary of standard, as their range covers almost all of the country. However quality of their service is currently not up to world standard. Keeping their existing technology and expecting a greater service would be highly improbable. Upgrading to newer and better technologies will not be too costly due to the fact that their initial set up has already been completed.

WiMAX has just been introduced into the country on a private basis however its range is still very limited, while the introduction of 3G is facing some indecision on behalf of the government. Yet at the moment the country has been connected to the Sub-Indian Ocean submarine cable allowing connectivity up to 43.8 Gbit/s. this opens up the horizons for setting up high–speed networks like WiFi which are based on a wired backbone.

3.2 Existing Future Plans Future plans on behalf of the government to uplift Bangladesh to the status of digital nation includes :

1. Development of Wireless industry and it services by providing all possible assistance to talented young people.

2. Inclusion of compulsory IT education at secondary level by 2013.

3. Set up of High-tech Park, software Technology Park, ICT incubator and computer villages in the country.

4. Digital government for citizen services with the help of wireless communication.

5. Creation and distribution of digital content through choosing suitable wireless platforms. (TV, Radio, video, community radio etc.)

6. Establishment of low cost wireless communication services for connecting citizens.

7. Establishment of E-Citizen services which requires innovative service design; suitable delivery channel.

8. Establishment of wireless technology in business which requires access to market; promotion of ICT Business to support Digital Bangladesh; promotion of software and ITES services; Support other component of digital Bangladesh.

9. Increasing telecom access, and internet users through mobile.

10. Informative and interactive websites of all the entities under Ministry of Education.

11. Bringing schools and colleges under wireless communication very soon.

All of these plans point to the necessity of wireless communication to allow people access to mass information.

4.0 Conclusion We the people of 21st century are now dreaming for a digital Bangladesh. But it will be wrong if anyone thinks that digital Bangladesh is a matter of time without taking proper steps. The whole process requires lots of tasks, for which we have to be prepared. After all, digitization is the only pathway to economic success, quality education, public health and also generating transparency in governance with full public participation. So, our goal is how we build this digital Bangladesh.

To pave the way of digital Bangladesh, the very first thing would be to ensure the connectivity of Information and Communication Technology all over the country disregarding urban rural barrier or rich poor divide. Everyone should be given access to the reach of information. In that case we must need a strong communication network which will give people easy, instant, cheap and fast access to information. And there is no rival of wireless network system on this regard.

Wireless communication is a rapidly growing segment of the communication industry, with the potential to provide high-speed high-quality information exchange between portable devices located anywhere in the world. It has the ability to reach the remote area of our country with its advantages which a wired communication system does not have. So, our necessary information and connection will be available whenever we need.

Though there are lots of challenges to set up a countrywide wireless network system, pre-planned and intelligent steps will be able to go over all the obstacles of our way and we will be able to proceed to our dream, digital Bangladesh. The more we will be digitalized the more the country will be vulnerable in terms of security and governance.

5.0 Recommendations 5.1 Suggestions

1.

Based on the existing infrastructure it would be wise to emphasize on the GSM network for the non distant future. First of all network for everybody should be ensured before speed or quality of coverage.

2.

For a future plan rather than upgrading via an obsolete system to reduce cost, it would be preferable to incorporate up-to-date technology.

3.

Comparing the speed of coverage available the suggestion would be to target a 3G system.

4.

Due to the cost of set up it would be unwise to look for a purely governmental set up to bring everyone under wireless coverage. Private sector should be encouraged to supply their own technology.

5.

Based on quality, security and range of systems it would be recommended to use WiFi systems as a low cost alternative in small regions where high quality is needed. However its high power consumption does not make it suitable for wide-spread use in a country like Bangladesh.

5.2 Precautions

1.

Government policy should be fixed with a set goal in mind also with a fixed time schedule.

Taking too much time to set up an infrastructure might lead to the technology becoming obsolete and unworthy of use in the face of more modern technology. However planning keeping in mind the possibility of upgrading the system would reduce unnecessary wastage of resources.

2.

Complete wireless technology would be highly unfeasible for Bangladesh. A wireless network built on a back bone of wired networking would be the best solution. However that means a strong wired network must be built up first to support the wireless network.

3.

To supply necessary security and availability of network the set up of the infrastructure i.e. towers, wired backbone and bandwidth must be made as secure as possible.

4.

Environmental hazards due to the set-up of wireless towers and antennas must be kept in mind while setting up the system. Radiation contamination, pollution and risks must be brought into consideration before implementing any plan.

5.3 Arguments

1.

Wired technology is providing better speed and quality. But, it is not able to go to the remote corners of our country. So for the coverage of all area of our country with a network system wireless system is more preferable.

2.

It is true that, once wired technology provided more security than wireless technology. But, recent technological improvement has overcome this barrier and wireless technology now provides enough security.

3.

There is a strong possibility of environmental hazard by wireless communication because of its radiation. Again, it will be difficult to bring transparency to all information without wireless. So wireless network system should be set up keeping the hazard at a minimum.

4.

Initial cost for wireless communication is really high. But we should consider the future advantages and the moving world. Unless it is implemented sooner than later the emergence of Bangladesh as a digital nation will not be achieved.

5.

It will be a challenge for the young generation to keep aloof themselves from the different dark attractions of the internet if they have the instant access to it. Awareness, carefulness and proper management will be able to control the situation.