Wireless Networking

Wireless LAN
Mobility is important.Human beings like to be able to move around the office and think while staying in contact with our network.On factory and warehouse floors,we like to be able to hook into the network while out on the shop floor.Doctors in hospitals love the thought of being able to carry a live,dynamically updated patient chart around with them.

Unfortunately,wired networks can ’t readily provide these things.Wired networks tend to make the tacit assumption that a user works in one physical location and stays there during the course of their workday. However,new technologies spurred by the ratification of IEEE standard 802.11 for wireless networking have recently come onto the market.

Wireless networking holds a great deal of promise to connect workers who move around their workspace,such as doctors,police and fire personnel, factory workers,anyone who doesn ’t work in a fixed office location. Wireless networks enable people to have data where they need it,when they need it.The technologies are new and relatively expensive,but they herald a new phase of networking that ’s more focused on the user ’s needs than ever before.

Why Use Wireless Networks?
For most of us,a hardwired connection between our desktop computer and the rest of the network is sufficient.Basically,all most users need is a single connection to a network; almost no one carries a computer while walking around a workspace,expecting to remain logged into a network.After all,most of us work at our desks and leave our desks only to get additional materials with which to do our jobs.

That ’s all fine and well for office workers,whose jobs do fit the preceding description. But there is a small and steadily increasing group of people who have to be able to connect to networks from a variety of locations:in multiple locations in the office,while they ’re on the road,and so forth.Often,the dual solution of Ethernet in the office and dial-up networking on the road is inadequate for one reason or another,and then the poor network manager has to figure out how to provide the services his or her users require, which can be quite a conundrum.

Why?The simple answer is that wireless networking is complex and not entirely standardized. It ’s currently a relatively obscure branch of networking.Many administrators (and,of course,users)will forgo the convenience of near-universal connectivity when confronted with the complexity inherent in wireless networking. Recent advances in standardization (not technology)have leveraged wireless LAN technology with promises of interoperability between different vendors ’systems.The growth of the Web stirred interest in wireless Web access.That,combined with the push for wireless-network standardization over the last several years,has led to a surge of growth in the industry.It ’s still not a mainstream technology,but it ’s just a matter of time until it will be possible to order a new computer with a wireless network adapter.

What Is Wireless Networking?
But what exactly,you ask,is wireless networking?Here are some identifying features:
  • First and foremost,it ’s data carried over radio waves or with infrared light.
  • It ’s a plethora of standards built around the IEEE 802.11 standards and the TCP/IP protocol.IEEE 802 standards specify the physical layer of the OSI network model.TCP/IP does not care what underlying network media it runs over;between thetwo,it ’s possible to build a network that runs over any media,ranging from coaxialcable,unshielded twisted-pair wire, glass fiber, and, of course, radio waves and infrared light.
  • Wireless networks are versatile ways to transfer data.They can run over a varietyof radio waves, from the infrared spectrum to cellular phone bands.The most common uses of wireless networking,and the specific connection type most suited toservicing each of them, are described in this hour.
In-Office Wireless Networking Technologies
In the office,the two most common topologies are spread spectrum and infrared connections. Of the two,spread spectrum,a radio technology that uses the 902-to-928 MHz and 2.4-to-2.484 GHz Industrial,Scientific,and Medical (ISM)radio frequency (which, fortunately,requires no FCC license)is more useful for intraoffice mobile workers because it can connect all over a building.By contrast,infrared is used only for line-of-sight applications.

Out-of-Office Wireless Network Technologies
The third topology,radio modems,is currently in a state of flux.The technology used is called Cellular Digital Packet Data (CDPD),and it enables a user to send data packets using a cellular network similar to what is used for cellphones.CDPD is still in a nascent state.CDPD is the fastest wireless networking protocol available,but even so,it ’s limited to a 19.2 kilobits-per-second data transmission speed —quite a bit slower than today ’s regular wired modems and an order of magnitude slower than an Ethernet connection.

Nonetheless,the allure of being able to connect to a network without a phone jack is difficult to resist,and many corporate networkers are cautiously testing CDPD networking for their remote users. Some new wireless networking technologies offer 4 megabits per second speeds and true network connectivity.Cisco ’s AirLAN offers wide range and allows multiple systems access from a single access point.

Why Wireless Networks Are Attractive to Networkers
Wireless LANs offer a host of upsides for networkers,particularly in larger organizations.Several major benefits are outlined here:
  • Simplifies adds, moves, and changes. Currently, the add/move/change process in wired networks is comparatively cumber some.You have to run network wiring out to the area in which the user will be located if that user is outside the geographical limits of the local LAN, expensive repeaters that extend the reach of the local network are often necessary.Wired LANs, for all the freedom they give their users, are not so different from the old telegraph line you have to be on the wire to get the signals. If you have to move your network (or part of it) elsewhere, you have to bring all the cables, wiring, and so forth along, which makes transportable wired networks quite rare.
  • Quickly deployable.Wireless networking offers quite a contrast to the cumbersome earthbound wires of wired LANs.Wireless networks work well in situations in which the requirements state that the network must be transportable,rapidly deployable,and very reliable.
  • Offers mobility for users who don ’t work in a single location.In hospitals,for example,wireless networks enable nurses to monitor patients wherever they are; there ’s no need to be at a fixed network.Increasingly,doctors are using wireless PDAs,such as Palm devices or Windows CE devices,to connect to patient data; more than one metropolitan hospital now provides its physicians with such technology.

Is Wireless Networking Ready for Prime Time?
Is wireless networking mature enough to roll out on a production basis?The answer depends on your needs.If you have remote users who have to get connected now ,the answer is yes.The good news is that you can build a spread spectrum network that is reasonably reliable and can give your users the in-building mobile access they require. The downside is that the products you have to use to do it don ’t yet adhere to a standard as a result,once a standard is adopted by all the manufacturers,you may have to replace your equipment.

If you have only a few users who want their laptops to connect to the internal network while they are in their offices,yes,wireless networking is an option.Instead of the spread spectrum technology,this application calls for infrared networking.Infrared technology costs less and operates on line-of-sight.As long as users don ’t require the ability to move from room to room while on the network,infrared is perfectly functional.

If,on the other hand,you are working with a relatively low budget and can ’t afford to have to abandon existing technology when a standard emerges,the answer is no ,wireless networking is not yet ready for you.Although wireless networking has gotten less expensive, it ’s still too expensive to adopt if you can ’t afford to upgrade it in a couple of years.