Wireless LANs offer some significant benefits over traditional LANs, including mobility and cost savings. Wireless networking expert Jim Geier discusses the benefits of and most likely applications for this emerging technology.
This material is excerpted from Jim Geier's book, Wireless LANs: Implementing Interoperable Networks (Macmillan Technical Publishing, 1999).
The emergence and continual growth of wireless LANs are being driven by the need to lower the costs associated with network infrastructures and to support mobile networking applications that offer gains in process efficiency, accuracy, and lower business costs. The following sections explain the mobility and cost savings benefits of wireless LANs.
Mobility enables users to physically move while using an appliance, such as a handheld PC or data collector. Many jobs require workers to be mobile—these include inventory clerks, healthcare workers, policemen, and emergency care specialists. Of course, wireline networks require a physical tether between the user's workstation and the network's resources, which makes access to these resources impossible while roaming about the building or elsewhere. This freedom of movement results in significant return on investments due to gains in efficiency.
Mobile applications requiring wireless networking include those that depend on real-time access to data usually stored in centralized databases. If your application requires mobile users to be immediately aware of changes made to data, or if information put into the system must immediately be available to others, then you have a definite need for wireless networking. For accurate and efficient price markdowns, for example, many retail stores use wireless networks to interconnect handheld bar-code scanners and printers to databases that have current price information. This enables the printing of the correct price on the items, satisfying both the customer and the business owner.
Another example of the use of wireless networking is in auto racing. Formula-1 and Indy racecars have sophisticated data-acquisition systems that monitor the various on-board systems in the car. When the cars come around the track and pass the respective teams in the pit, this information is downloaded to a central computer, thereby enabling real-time analysis of the performance of the race car.
Not all mobile applications require wireless networking, though. Sometimes the business case doesn't support the need for mobile real-time access to information. If the application's data can be stored on the user's device, and if changes to the data are not significant, then the additional cost of wireless network hardware may not provide enough benefits to justify the additional expense. Keep in mind, though, that other needs for wireless networks may still exist.
Installation in Difficult-to-Wire Areas
The implementation of wireless networks offers many tangible cost savings when performing installations in difficult-to-wire areas. If rivers, freeways, or other obstacles separate buildings that you want to connect, a wireless solution may be much more economical than installing physical cable or leasing communications circuits, such as T1 service or 56Kbps lines. Some organizations spend thousands or even millions of dollars to install physical links with nearby facilities. If you are facing this type of installation, consider wireless networking as an alternative. The deployment of wireless networking in these situations costs thousands of dollars but will result in a definite cost savings in the long run.
The asbestos found in older facilities is another problem that many organizations encounter. The inhalation of asbestos particles is extremely hazardous to your health; therefore, you must take great care when installing network cabling within these areas. When taking necessary precautions, the resulting cost of cable installations in these facilities can be prohibitive.
Some organizations, for example, remove the asbestos, making it safe to install cabling. This process is very expensive because you must protect the building's occupants from breathing the asbestos particles agitated during removal. The cost of removing asbestos covering just a few flights of stairs can be tens of thousands of dollars. Obviously, the advantage of wireless networking in asbestos-contaminated buildings is that you can avoid the asbestos removal process, resulting in tremendous costs savings.
In some cases, it might be impossible to install cabling. Some municipalities, for example, may restrict you from permanently modifying older facilities with historical value. This could limit the drilling of holes in walls during the installation of network cabling and outlets. In this situation, a wireless network might be the only solution. Right-of-way restrictions within cities and counties may also block the digging of trenches in the ground to lay optical fiber for the interconnection of networked sites. Again in this situation, a wireless network might be the best alternative.
A problem inherent to wired networks is the downtime due to cable faults. In fact, cable faults are often the primary cause of system downtime. Moisture erodes metallic conductors via water intrusion during storms and accidental spillage or leakage of liquids. With wired networks, users may accidentally break their network connector when trying to disconnect their PC from the network to move it to a different location. Imperfect cable splices can cause signal reflections that result in unexplainable errors. The accidental cutting of cables can bring a network down immediately. Wires and connectors can easily break through misuse and normal use. These problems interfere with the users' ability to utilize network resources, causing havoc for network managers. An advantage of wireless networking, therefore, results from the use of less cable. This reduces the downtime of the network and the costs associated with replacing cables.
Reduced Installation Time
The installation of cabling is often a time-consuming activity. For LANs, installers must pull twisted-pair wires above the ceiling and drop cables through walls to network outlets that they must affix to the wall. These tasks can take days or weeks, depending on the size of the installation. The installation of optical fiber between buildings within the same geographical area consists of digging trenches to lay the fiber or pulling the fiber through an existing conduit. You might need weeks or possibly months to receive right-of-way approvals and dig through ground and asphalt.
The deployment of wireless networks greatly reduces the need for cable installation, making the network available for use much sooner. Thus, many countries lacking a network infrastructure have turned to wireless networking as a method of providing connectivity among computers without the expense and time associated with installing physical media. This is also necessary within the United States to set up temporary offices and "rewire" renovated facilities.
Long-Term Cost Savings
Companies reorganize, resulting in the movement of people, new floor plans, office partitions, and other renovations. These changes often require recabling the network, incurring both labor and material costs. In some cases, the recabling costs of organizational changes are substantial, especially with large enterprise networks. A reorganization rate of 15 percent each year can result in yearly reconfiguration expenses as high as $250,000 for networks that have 6,000 interconnected devices. The advantage of wireless networking is again based on the lack of cable: You can move the network connection by simply relocating an employee's PC.