Upgrading and Repairing Networks

Why Wireless Networks Have Proliferated

If you still don't already use some type of wireless device, it won't be long until you do. As with any typical purchase of computer/network equipment, it's the applications that drive the purchases, especially in a business environment. Wireless technology is already the preferred method for networking homes and small businesses, and large enterprises, particularly those with multi-building campuses, are using wireless networking to extend the reach of their existing 100Mbps and Gigabit Ethernet-wired LANs to cover every part of the campus, indoors or outdoors. Wireless networking is now fast enough that it is being used instead of wired networking in new installations where there was no existing wired network.

Laptop computers provided the first true mobility for computer users. Support for linking these powerful platforms to a computer network is usually built in to today's laptops, but if your laptop doesn't have built-in wireless support, it can be accomplished easily by means of either a PC Card/CardBus network adapter or a docking station. By using DHCP to assign network configuration information, it's easy to move a portable computer from one location to another and still provide a simple connection to the network. However, until the advent of wireless network connectivity, this kind of mobility still depended on a wired connection of some sort. By adding wireless capability to an existing wired network, the mobility and usefulness of the notebook computer are increased dramatically.

For a technology to grow, it must solve some kind of problem. That is, it must be useful in some way. As described previously in the discussion of the types of devices that now use wireless networking, the most obvious benefit this kind of networking provides is mobility. Wireless LANs have become a mainstay networking infrastructure for many SOHO networks as well as home networks where multiple computers may share a single Internet connection. Other benefits that you might get from wireless networking include the following:

• Faster installation when compared to cabled networks. Just configure the network adapter (and Access Point if you have one) and start networking with others.

• Adaptability in a dynamic environment.

• The capability of sharing an Internet or other WAN connection.

• The continuing development of new electronic devices (or newer versions) that use wireless technology, such as PDAs; network-ready, all-in-one devices; and digital projectors.

• With the widespread deployment of wireless Access Points that are being constructed in public places, you can now access the Internet from most any place that has a sizable population. In some cases, you might need to use a commercial network on a per-hour, per-day, or per-month access charge basis through various commercial providers. These are common in truck stops, airports, and some restaurants, coffee shops, and copy shops. Some locations offer free service for their customers, so you can surf the Web while you drink a cup of java or grab lunch. Also, some localities are constructing community-wide wireless networks, and many public and university libraries offer open wireless LANs that can be used by anyone in the vicinity. The terms hotspot and hotzone are often used to indicate locations that offer wireless Internet access.

• Reduced costs in many situationsfor example, to avoid having to install cabling throughout a building.

One caveat to keep in mind is that security is a big issue with wireless networking. Although 802.11b hardware supports Wired Equivalent Privacy (WEP) security, newer and much more secure standards have been developed and are supported by most 802.11a- and 802.11g-based network hardware. See Chapter 23 for more information.

In a typical LAN setup, it is necessary to install and configure the networking software on the client computer and provide the wiring from the network switch to the user's work area. With a wireless LAN, you only need to install the wireless NIC and configure the computer's networking software. You don't have to string cables through the building for each user. In an environment that changes rapidly, this can be an advantage. For example, point-of-sale terminals in a large store can be reconfigured easily for seasonal adjustments, such as the end-of-the-year Christmas buying spree. Hand-held devices can be used for inventory control and for creating checkout tickets that can be presented to a cashier to speed up the process of paying for merchandise. In a warehouse, the floor layout might change during the year for similar kinds of reasons. Relocating computers is much easier when there are no cabling issues to deal with. After the initial investment is made in wireless LAN devices, the capability to reconfigure the physical network topology can result, in many cases, in reduced costs over time.

An ad hoc network or temporary setup (see the following list) is another important aspect. For example, if you are in the consulting business and need to have several consultants exchange information, you can use wireless networking to set up your own local network and bypass your customer's wired network. Knowing this allows your client to worry less about security than if the client has to go through the typical paperwork and other management functions to get your consulting team connected to the company network.

In addition to these kinds of environments, you will find wireless LANs increasingly being used in situations such as the following:

• Hospitals Patient information can be obtained easily using a standard laptop computer, a specialized terminal, or a Tablet PC. Instead of having to return to a central location, such as the nurse's station on the hospital floor, doctors and nurses can get information quickly as they make their patient rounds.

• Older buildings In some cases, it can be difficult to wire the premises for a traditional network. Some older buildings that do not have plenum areas in the ceiling can be difficult to adapt. Using wireless communications makes networking in this kind of environment an easy task.

• Temporary setups This feature was mentioned in the introductory paragraph to this list. You can extend it further to such situations as a trade show, where the network is usually set up for only a few days; the computers can be configured ahead of time so that the only thing your company representative has to do is turn them on.

• Warehouse and factory floors Laptop computers and handheld bar-code scanners that use wireless LAN technology can quickly return the investment needed for their implementation. In this kind of situation, however, it is important to test the equipment first to ensure that no other machines or devices in the area can interfere with the wireless transmissions.