This chapter covers:
Overview of Wireless Networking
Setting up an automatic wireless network
Connecting to an existing wireless network
Using the Wireless Link
Configuring Wireless Clients
One of the most significant trends in the telecommunication field is the rapidly expanding use of wireless networks. Wireless technology allows you to convert a network signal into a high frequency radio wave. Through the use of compression and a wide range of frequencies, wireless networks have been able to exceed speeds of 54 mbs. While not quite as fast as a tangible hardwired network, which can reach 1,000 mbs (using fiber), the home and business communities alike are enamoured of the concept.
Advantages of Wireless Networking
Wireless networks provide several advantages. For example, a wireless device does not require a physical wire connecting it to the rest of the network. In situations where the server is located in the next room, or across the street, going wireless can solve your connectivity problem. Similarly, wireless conference rooms or classrooms do not need individual wires running between each and every workstation.
Types of Wireless Networks
Wireless networks are similar to wire-based networks. The following provides a brief description of the different types:
WWAN: The Wireless Wide Area Network is a public or private network of computer devices that exists over a large area, such as a city, state, or country. An example of these is the 2nd generation (2G) systems that are made up of cellular devices or other similar devices that have a low bandwidth requirement. Although this use is still in development, which makes it difficult to use due to lack of coverage and due to competing communication standards, there are plans for a 3G system that will help to eliminate these problems (unless 3G is usurped by the military). Another example of a WWAN was Ricochet, the wireless subscription-based ISP that was tested in many large cities in the US. Although the business did not succeed, the concept was proven successful.
WMAN: A Wireless Metropolitan Area Network is used to connect office buildings together over several blocks using radio frequency, microwaves or Infra Red. Typically, this type of network is used as a backup in case the hardwired network fails or if a wireless connection is cost-effective compared to other options.
WLAN: The Wireless Local Area Network is a confined network that typically exists within a building's walls. Used as an extension of the local network, the WLAN allows users to move about without losing their connection. Schools, businesses, and entertainment companies can use a WLAN to provide service to anyone with a wireless network card.
WPAN: The Wireless Personal Area Network is a very localized (30ft or less) network that allows devices to communicate directly with each other. Although the largest WPANs can expand to cover the range of a home or small business, they are typically confined to PDA's and other small devices that use infrared as their mode of data transfer.
Types of Wireless Connections
In addition to delineation by network topography, there are also different classes of wireless networks as defined by their connection type. These include the following:
Access Point: An access point is a central device through which several clients can connect and can access the network services. This can be a set of devices that act to route signals to and from clients, or it could be simply one device that limits its client to a short range. Typically, this requires that the client have a pass phrase to be permitted access. However, the pass phrase is not required and this could allow anyone with a wireless network card to access the network.
Computer to Computer (Ad Hoc): This type of wireless network is a simple connection between two devices. Personal Data Assistants (PDAs) usually fall in to this category since they often pass files and other small amounts of information between each other. This type of network is most useful when only a temporary network is needed to pass data.
Access Point/Computer to Computer Combo: In the case that a user requires flexibility, this is the suggested type of configuration. The computer will first search for any wireless access points and if none are found will use the Ad Hoc method of data transfer. An example of this is when a computer is part of a wireless network at work, but the computer also must be able to connect at home. This connection configuration will allow a user's computer to connect to what ever network is available.
The Wireless Link
Along with other new wireless features, Windows XP adds support for infra-red. Infrared data transfer is not a new technology. Many remote controls, PDAs and other small devices use this mechanism to transfer short bursts of data. Due to the 3 meter or less distance limitation, infrared is only used in situations where it is cost effective or more efficient than a wired network.
However, since it is part of Windows XP we will make a brief mention of how to use it. The setup and configuration of a wireless link is simple. In fact, once an infrared device is detected as installed by XP, the operating system provides a link icon on the taskbar (figure 6-1) and even presents a Wireless Link icon on the desktop (Fig. 6-2) when another infrared device is within its vicinity.
Fig. 6-1: Infrared Device Link
Fig. 6-2: Infrared Device Present Link