Going WirelessGoing Wireless

Presented By:Presented By:

Mohamed A. FarahatMohamed A. Farahat

By: Evan H. Shu, FAIA By: Evan H. Shu, FAIA

Web Address:Web Address:http://www.architectureweek.com/2004/1110/tools_1-1.htmlhttp://www.architectureweek.com/2004/1110/tools_1-1.html

Topic Number: 100Topic Number: 100

Date: Date: 10 November 2004  10 November 2004 

Does it feel like the air is extra "charged" these days?

The air waves are buzzing with communications from cellular telephones , remote control devices ,global positioning devices And wireless networks.

In many cities, you can go to some public place, open a suitably equipped laptop, and log into the Internet without physically plugging into anything. These wireless fidelity ("Wi-Fi") broadband connections are not only in computer stores but in coffee shops, public libraries, bookstores, and hotels.

The number of these free networks is growing rapidly. You can check out availability yourself at such sites as "Wi-Fi Free Spot," which has listings for cities all over the world.

These free network locations ("hot spots") are quickly growing in number because the cost of creating one is so inexpensive. We recently set up our own office Wi-Fi network for under $50

What Is Wi-Fi? Think of Wi-Fi as a little ham-radio station, operating in the 2.4-gigahertz band. This is 2,400 megahertz, in contrast to a typical FM radio station which operates at around 100 megahertz. Cell phones operate at 824 to 849; global positioning devices operate at 1,227 to 1,575 megahertz.

A key difference between Wi-Fi and a typical radio station is that the communication is two way, somewhat like in a walkie-talkie device. In ordinary cell phone conversations, two frequencies are used, one to talk and one to receive, so you can have overlapping speech.

A walkie-talkie or "direct-connect" device uses a single frequency with a push-button-to-talk and release-to-listen feature that tells the device whether to send or receive. In the same way, a Wi-Fi communication sends and receives, but not at the same time (although the "push-to-talk" all happens invisibly and at lightning speed).  

Once you have a laptop or personal digital assistant (PDA) set up to receive Wi-Fi transmissions, you can go to a free Wi-Fi location and ask your computer to show you the available networks.

Some networks may ask you to register or log in. For instance, the Boston Public Library asks you to provide your name and library card number. But other networks are simply open to all comers without restrictions

In some cases, you don't even have to go into the building. Before the Boston Public Library opened one Sunday morning, I found I could log into their wireless network from across the street. In New York City, Bryant Park is an outdoor Wi-Fi hot spot.

Locating Wi-Fi Hot Spots?

Setting up a Wi-Fi Network

Setting up your own Wi-Fi network is actually surprisingly simple. First you must have an Internet connection of sometype (preferably broadband:cable modem, DSL, or T1), or, simply a phone line.Then you need a "broadcaststation" (a wireless gateway, or router) at that "access point“and a wireless adapter at each workstation.

The wireless access point (WAP) is the gateway, or the point where the hardwired network ends and the radio transmission starts. This is where your wireless router is plugged in, usually between your cable modem or DSL connection and the computer (which may be a server) that connects to it. The router's setup software uses that computer to configure the router so that it works with your Internet connection and/or network.

Most wireless routers come with optional firewall and encryption software, called wired equivalent privacy (WEP), that will give you an added level of security — and complexity — if you feel you need it. But whatever protections you install, we recommend that you always think of wireless communications as an "open line."

The job of the wireless router is to be a traffic cop between all the stations and the Internet connection (and/or the rest of the network) and to regulate between the sending and receiving between station and Internet and between stations.

Wireless adapters are used on all other computers to which you want to providenetwork access. These adapters comein three forms: expansion cards for desktop machines, PC cards for laptops and also conveniently, USB jacks. USB jacks are small enough to fit on a keychain if you want to port your wireless connection from one computer to another.You can even get 802.11b flash cards toconnect your PDA to the wireless network.

Because your router is like a radio station, it has a transmission range that radiates out in a circular pattern. The range varies according to the model you purchase. Just like with radios, transmission and reception may be affected by interference from microwave ovens, cordless phones, and even tinted windows, so experiment a bit on router location before you settle on a spot.

Security

The biggest conceptual drawback to wireless networking is a potential lack of security. A wireless network is like a radio station that anyone can tune into. To protect yournetwork from outsiders using it, you should put up a firewall at your access point andactivate an encryption protocol. This capability is built into the Apple Airportimplementation, for instance.

Alternatively, if you are concerned about protecting your data but not about limiting access to your Internet connection, you can simply put up a firewall (like the excellentZoneAlarm) at each station. Windows XP also provides an optional firewall program.

The security issue is also important when you are using free public Wi-Fi hot spots. Unlike with a cable connection, you are broadcasting your data through the airwaves which can be tuned into by a knowledgeable hacker with the right equipment. Therefore, I recommend not doing any financial transactions over a free Wi-Fi connection. Wireless networking brings us tremendous new freedom in how we operate with our office networks and with our connections to the Internet. But, as with all new freedoms, it comes with new responsibilities and new dangers. Take a little extra care in setting up proper firewall protections and you will rest easy and enjoy immensely this new wireless environment.