Chapter 33: Wireless Internet

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Accessing the Internet services from our desktops at the office or at home is now taken for granted. Through a dial-up line or a leased line, we are connected to the server of the Internet service provider and access the various services. The drawback of this access method is that we are constrained to one place-there is no mobility. If we can access the Internet services while on the move-while traveling in a car, bus, train or airplane, it would be an immense value addition. The wireless device can be a mobile phone, a laptop, or a palmtop. However, to achieve this, we face lots of challenges-the mobile phone has a small display and small memory, the mobile networks support very low data rates, and delays are high in the wireless networks. But then, the need for mobile access to the Internet is growing rapidly, and it is expected that the number of wireless devices accessing the Internet will exceed the wired devices. This market demand is paving the way for exciting developments in wireless Internet services and technologies, which are discussed in this chapter. With the present-day mobile networks, the data rates supported are very low but, in the next few years, the mobile networks are expected to support high data rates, paving the way for multimedia content to be accessed by mobile devices. This chapter discusses the roadmap for achieving anywhere, anytime access to Internet services.

33.1 WIRELESS ACCESS TO INTERNET

At present, most of us access the Internet through our desktop computers or our corporate LANs through wired connections (dial-up or leased lines). Our desktops have high processing capability, large primary storage (RAM), and secondary storage. So, we can run a browser such as Internet Explorer or Netscape Navigator, which requires huge system resources (hard disk and RAM). The monitors are capable of displaying high-resolution color graphics. And, the wired connection can support high data rates, anywhere between 64kbps and 2Mbps. Hence, accessing the Internet is lots of fun, with lots of multimedia content, fast downloading of files, and fast and easy navigation.

The drawback of wired access to the Internet is the lack of mobility. Even when we move with our laptops, we have to look around for a telephone jack-in a hotel room or at an airport. If wireless access to the Internet is provided, users can be mobile, and accessing the Internet anywhere, anytime would be possible. The mobile device can be just a mobile phone, a personal digital assistant (PDA), a laptop, or a palmtop. But then, providing the Internet services over these mobile devices is a pretty challenging task. The following section will explain this.

Desktops have high processing power, large memory, and a large screen, so accessing the Internet through wired connections that support high-speeds is a lot of fun. The only drawback is the lack of mobility.

33.1.1 Challenges in Wireless Access to the Internet

Accessing the Internet (particularly the Web service) has many problems at present. These problems are:

• There are various protocols for the wireless networks, such as TDMA, CDMA, GSM, and PDC etc. the protocols for wireless access to the Internet need to be independent of the underlying cellular network protocols.

• Present wireless networks support very low data rates, ranging from 300bps to 14.4kbps. Accessing a Web page with multimedia will take ages! The round-trip delay is also very high in wireless networks.

• The wireless devices (mobile phone, palmtop and such) have limited capabilities:

  • Small screen, generally 4 lines with 8 to 12 characters per line.

  • Screen with low resolution and no support for color.

  • Low power because the device has to operate from a battery.

  • Keypad with a very limited functionality. Hence, inputting text is difficult.

• The wireless devices vary widely-different processors (8-bit, 16-bit, or 32-bit), different operating systems, different memory capacities, and so on.

Due to these problems, developing protocols and applications for wireless access of Internet services is a real technical challenge. The software industry created a lot of hype in the late 1990s for wireless access to the Internet, but it has been realized that lots of work needs to be done in enhancing the speeds of the wireless networks, developing efficient protocols, and creating useful and appealing applications.

Accessing Internet content through wireless devices poses many challenges due to the variety of wireless network protocols, low-speed connections, high delay, and limited capabilities of the mobile devices.

Note 

Wireless devices are characterized by low processing power, small displays, and keypads with very limited functionality. As a result, new protocols and new markup languages are required for accessing Internet content through mobile devices.

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