WIRELESS TECHNOLOGY

Wireless communications helps businesses stay in touch with customers, suppliers and employees and supports more flexible arrangements for organising work. Wireless technology has also led to the creation of new products and services.

The Growth in Wireless Communications

Increasingly individuals and businesses are turning to wireless devices such as cell phones, wireless handheld devices, and laptops with wireless network connections to communicate and to obtain information and data.

Mobile phones are cheaper, more powerful and usage has exploded world wide. According to the International Telecommunication Union (ITU); as of Dec 2010, there are some 5.5 billion mobile subscribers worldwide, as well as about 1.268 fixed access lines, with the vast majority of new subscriptions being mobile as opposed to fixed. The number of mobile subscribers is expected to top 6 billion in 2012.

Mobile phones are no longer used exclusively for voice communications; they have become mobile platforms for delivering digital data, used for recording and downloading photos, video and music, Internet access and sending and receiving e-mail. An array of technologies

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are available that provide high-speed wireless access to the Internet for PCs, mobile phones and other wireless handheld devices. Businesses are increasingly using wireless networks and applications to cut costs, increase productivity and flexibility, and create new products and services.

Business Value of Wireless Networking

There are a number ways in which wireless technology can provide business value which includes:

 Wireless technology helps businesses stay more easily in touch with customers, suppliers, and employees and provides more flexible arrangements for organising work.

 Wireless technology increases productivity and worker output by providing anytime, anywhere communication and access to information.

 Companies can save on wiring offices and conference rooms by using wireless networks because they do not have to pull cables through walls. Wireless networks also make additions, moves, and changes much easier.

 Wireless technology has also been the source of new products, services, and sales channels in a variety of businesses.

Devices for Wireless Transmission Devices for wireless transmission include:

E-mail hand held devices: These devices include a small display screen and a keypad for typing short messages. Some versions of these devices have a built in organiser, web and voice transmission features and the ability to integrate with corporate applications. An example of an E-mail wireless handheld device is the Blackberry.

Cellular telephones (Cell phones): These work by using radio waves to communicate with radio antennas (usually located in towers or masts) placed within adjacent

geographical areas called cells. A telephone message is transmitted to the local cell by the cellular telephone and then passed to the cell of its destination where it is transmitted to the receiving telephone. As the cellular signal travels from one cell into another (as the location of the mobile phones moves) a computer that monitors signals from the cells switches the conversation to a radio channel assigned to the next cell.

Short message service (SMS) is a text message service used by a number of digital cell phone systems to send and receive short alphanumeric messages less than 160 characters in length. Like e-mail, SMS messages can be forwarded and stored for retrieval later.

Smart phones: This class of digital communications device combine the functionality of a Personal Digital Assistant (PDA) with a digital cell phone and require a cellular phone service connection. These smart phones can handle voice transmission and e-mail, save addresses, store schedules, access a private corporate network, and access information from the Internet. Smart phones include Web browser software that enable digital cellular phones to access Web pages formatted to send text or other information that is suitable for small screens. Increasingly smartphones are also fitted with built in WiFi which can be used to provide high speed access to the Internet at a designated WiFi enabled location.

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Personal computers are also starting to be used in wireless transmissions – most new laptops are now Wi-Fi enabled.

Cellular Network Standards and Generations

Major cellular standards include Code Division Multiple Access (CDMA), which is used primarily in the United States, and Global System for Mobile Communication (GSM), which is the standard in Europe and much of the rest of the world.

Cellular networks have evolved from slow-speed (1G) analogue networks to speed high-bandwidth digital packet-switched third-generation (3G) networks with speeds ranging from 144 Kbs to over 2 Mbps for data transmission. Second-generation (2G) cellular networks are digital networks used primarily for voice transmission, but they can also transmit data at ranges from 9.6 to 14.4 Kbps. 2.5G networks are packet-switched, use many existing infrastructure elements and have data transmission rates ranging from 50 to 144 Kbps. A 2.5G service called General Packet Radio Service (PRS) transports data over GSM wireless networks and improves wireless Internet access. 2.5G also improves data transmission rates for CDMA. See figure 7.5 for a summary of these generations.

Generation Capacity Description

1G Low Analogue cellular networks for voice communication

2G 10 to14Kbps Digital wireless networks, primarily for voice communication; limited data transmission capability 2.5G 50 to144 Kbps Interim step toward 3G in the US similar to GPRS in

Europe

3G 144 Kbps to 2+ Mbps High speed, mobile, supports video and other rich media, always on for e- mail, Web browsing, instant messaging

4G Up to 100Mbps This is the next evolution of wireless cellular networks

Figure 7.5: Wireless Cellular Generations

Wireless Computer Networks and Internet Access

This section discusses the major standards for wireless networks and for wireless Internet access. The Institute of Electrical and Electronics Engineers (IEEE) has established a hierarchy of related standards for wireless computer networks. These include:

 Bluetooth (802.15) for small personal area networks,

 Wi-FI (802.11) for Local Area Networks (LANs),

 WiMax (802.16) for Metropolitan Area Networks (MANs).

Bluetooth

Bluetooth is a telecommunications industry specification that describes how mobile phones, computers, and personal digital assistants (PDAs) can be easily interconnected using a

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range wireless connection. Bluetooth can link up to eight devices within a 10-meter area using low-power, radio-based communication and can transmit up to 722 Kbps in the 2.4 GHz band. Wireless phones, keyboards, computers, printers, and PDAs using Bluetooth can communicate with each other and even operate with each other without direct user intervention. Through this technology, users of cellular phones, pagers, and personal digital assistants can buy a three-in-one phone that can double as a portable phone at home or in the office, get quickly synchronised with information in a desktop or notebook computer, initiate the sending or receiving of a fax, initiate a print-out, and, in general, have all mobile and fixed computer devices coordinated completely.

Bluetooth is designed for personal area networks that are limited to a 10-meter area. It has low power requirements, so it is better for battery-powered appliances.

Wi-Fi

Wi-Fi stands for Wireless Fidelity and refers to the 802.11 family of wireless networking standards.

The 802.11a standard can transmit up to 54Mbps in the unlicensed 5GHz frequency range and has an effective distance of 10 to 30 meters. The 802.11b standard can transmit up to 11 Mbps in an unlicensed 2.4 GHz band and has an effective distance of 30 - 50 meter area, providing a low-cost flexible technology for creating wireless LANs and providing wireless Internet access.

A Wi-Fi system can operate in two different modes:

 Infrastructure Mode: In this mode, wireless devices communicate with a wired LAN using access points. An access point is box consisting of a radio receiver/transmitter and antennas that link to a wired network, router, or hub. Each access point and its wireless devices are known as a Basic Service Set (BSS).

 Ad-hoc Mode: In this mode, also known as peer-to-peer mode, wireless devices communicate with each other directly and do not use an access point. Most Wi-Fi communications use an infrastructure mode.

Wi-Fi hotspots which are located in hotels, restaurants, airports, libraries, college campuses, and other public places provide mobile access to the Internet. Hotspots generally consist of one or more access points positioned on a ceiling, wall or other spot in a public place to provide maximum wireless coverage for a specific area. Users within range of the hotspot can then access the internet from their laptop or mobile device. Most laptops, smart phones and tablet computers come equipped with wireless network interface card (NIC) built–in radio that can send and receive Wi-Fi signals.

Wi-Fi networking costs have declined so that a basic network can be setup relatively cheaply.

Benefits of Using Wi-Fi The benefit of Wi-Fi include:

 Can be used create low-cost wireless LANs and to provide Internet access from conference rooms and temporary workstations.

 Helps individual companies extend their networking to new areas and obtain Internet services at a low cost.

Page 80 Challenges of Using Wi-Fi

The challenges of using Wi-Fi include:

 Transforming Wi-Fi from a wireless hit-or-miss phenomenon into a sustainable business.

 Users cannot freely roam between hotspots if they use different Wi-Fi network services.

 Public and private hotspots need to be transformed into interoperable, dependable networks with billing systems, roaming agreements, and technical standards that will enable users to plug into hotspots at will.

 Overcoming weak security features that make Wi-Fi wireless networks vulnerable to intruders.

 Susceptibility to interference from nearby systems operating in the same spectrum.

WiMax

WiMax, which stands for Worldwide Interoperability for Microwave Access, is the popular term for IEEE Standard 802.16, which is known as the ―Air Interface for Fixed Broadband Wireless Access Systems.‖

WiMax antennas are able to beam high-speed Internet connections to rooftop antennas of homes and businesses that are miles away. WiMax has a wireless access range of up to 31 miles and a data transfer rate of up to 75 Mbps, making it suitable for providing broadband Internet access in areas lacking DSL and cable lines. Whereas Wi-Fi is vulnerable to penetration by outsiders, WiMax (802.16) has robust security and quality of service features to support voice and video.

Radio Frequency Identification (RFID)

Radio frequency identification (RFID) systems use tiny tags that have embedded microchips that contain data about an item and its location. The tag transmits radio signals over a short distance to special RFID readers. The RFID readers then pass the data over a network to a computer for processing (As shown in Figure 5.6). This technology provides value to a business by capturing data on the movement of goods as these events take place and by providing detailed, immediate information as goods move through the supply chain.

RFID and Privacy Issues

Privacy activists have objected to RFID technology applications that could lead to more tracking and monitoring of individual behaviour. They fear it could someday enable marketers, the government, or insurers to compile details about individuals‘ shopping habits or even assist in tracking people‘s movements.

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Figure 5.6: A Radio frequency identification (RFID) system Wireless in Health Care

Health care systems have traditionally been dominated by paper based processes. The vast majority of hospitals have communications networks but still have problems getting essential information to the right place at the right time.

Mobile technology can provide some solutions. Some Hospitals are installing wireless LANs in emergency rooms and treatment areas and are equipping staff with Wi-Fi enabled laptop computers or wireless handheld devices and Smart phones.