Will wireless networks ever replace hard-wired networks? If we look at history, the answer is a qualified yes. Radio replaced the telegraph, satellites replaced undersea cables, portable phones replaced wired units, and cellular phones will replace them all.

But examine what has happened to television broadcasting. It started out wireless, but reception issues encouraged urban users to switch to cable systems. It was too expensive to string cable in rural areas so satellite dishes began to appear. In recent years, digital satellite systems have given cable operators a run for their money. Now cable has become the preferred medium for digital television networks. Are there any lessons to be learned here? You bet.

Hard-wired systems are more reliable (when they are intact). Satellite television reception is degraded during heavy rain or snow storms.

Hard-wired systems are more vulnerable to sabotage. All it takes is one break to render a 3000-mile undersea cable useless.

Hard-wired systems are more secure. Ask Newt Gingrich how he feels about discussing political strategy on a cell phone.

Hard-wired systems can support higher bandwidth. This is the second reason that makes cable TV preferable to satelliteI doubt well have digital video on demand delivered via satellite.

In the aftermath of cataclysmic events, standard (non-satellite) radio frequency communications would be the easiest to restore.

It appears that given the same requirements, there are advantages to both wireless and wired systems. In fact, each of my points above could probably be turned to support the opposite conclusion. Not only that, but I left out the most obvious advantage of wireless systems: convenience. The freedom to work away from the shackles of hard-wired systems has revolutionized the way we all do business. A few years ago, I had a conference call with a salesman in a downtown office. I was using a first generation cell phone in my vehicle, and the third party was on a cell phone in a kibbutz on the West Bank. For a guy who grew up with party lines, that was pretty amazing.

Two wireless options have emerged as solid enough to be useful for business. They do different things, and interestingly enough, both are short rangeboth tap out at a few hundred feet.

Fat Pipes
Most of us who use personal computers in the day-to-day operation of our business are connected by an Ethernet using copper wire or fiber cable. Typically, network connections are wired for 10 Mbps or 100 Mbps. (There are some gigabit networks out there, but they are few and far between.)

In a static office world, these networks are very efficient. Cable is inexpensive to run during construction. Once established, connections are reliable and fast; they can be made secure using both hardware and software security methods. They allow for shared resources such as printers, scanners, and Internet connections. They do require a certain amount of expertisenetworks geeks and gurus have become a necessary part of corporate life.

Bandwidth is not generally an issue, particularly when considering the types of documents and data typically transmitted over most company networks. Viewing high quality video over a 10 Mbps network is pushing the envelope, but jump that spec up to a 100 Mbps fiber optic network and you can watch video all day long (if your boss doesnt mind).

The wireless issue arises when we leave our modular, pre-wired, IT-controlled office or cubicle. What do we do when we leave that office with its hard-wired workstation? When we switch from a desktop or docking station to a laptop or PDA? Most of us have been on the road somewhere with our laptops but are unable to plug into the local network because of security or configuration problems.

How useful would it be to have a meeting in a hotel conference room where all involved parties can share data and presentations without having a guy with three earrings, two cell phones, and a pocket protector manually hook everyone up to the projector? Or how nice would it be to share electronic business cards with everyone at the meeting? What do you do when you open a small branch office in a 150-year-old building in the historic district? Do you really want to start boring holes in the walls, floors, and ceilings?

The solution to all of these items is wireless. There are two different but complementary wireless solutions available for use now, Bluetooth (www.bluetooth.com) and 802.11 (www.grouper.ieee.org/groups/802/11). There are, of course, other wireless protocols, notably infrared (IrDA) and HomeRf, but Bluetooth and 802.11 lead the way for business applications.

Bluetooth
In 1998, Ericsson Mobile Communications formed a special interest group (SIG) for the development of a standard to define a radio frequency interface. IBM, Intel, Nokia, and Toshiba were partners in that SIG, which was christened Bluetooth, after Harald Bltand (literally Bluetooth), a 10th century Viking king. Haralds claim to fame was that he united and ruled Denmark and Norway. The Bluetooth SIG hopes to convince disparate hardware and software vendors to accept its wireless communication standards. It was able to develop a proprietary communications standard for low power radio communication in the 2.4-2.4835 GHz banddedicated frequencies that allow unlicensed operation for industrial, scientific, and medical applications (ISM).

Communications are established among Bluetooth devices via a piconet. The default state of a Bluetooth device is standby. Whenever another Bluetooth device is encountered, they will automatically begin a communications link and establish an ad hoc piconet. Up to eight Bluetooth devices can connect in a single piconet; one device will be elected as a network controller and regulate traffic.

The power output of Bluetooth devices is very low (1 mW for personal-area applications). As a result, the effective range of a Bluetooth device is about 10 meters. This low range is a factor in decreasing interference between competing Bluetooth networks. The effective data transmission rate for a piconet is about 720 Kb per second. It is possible to have more than seven Bluetooth devices in the area served by a piconet but only seven will have the ability to actively communicate.

The radio frequency spectrum that Bluetooth uses is crowded. The ISM band is shared by other wireless standards (like 802.11), microwaves, portable phones, and an assortment of medical and manufacturing devices. This makes it absolutely necessary to address ways to deal with interference. Bluetooths solution is a channel hopping scheme, a common technique used by other radio frequency products and wireless LANs, that the Bluetooth people have refined. The theory is simple: Data are broken into small, discrete packets that are sent over a range of specific frequencies within a given band. By increasing the number of hops and the number of frequencies used, the potential for interference is reduced. If a particular packet is lost due to interference, that packet can be retransmitted. Bluetooth uses a high hop rate1600 hops per second over 79 hop channels.

Security is probably not a major issue with Bluetooth. The effective transmission range is so short that physical security measures will probably be adequate for most uses. There are, however, three methods of security available. Mode 1 security is no security at allthere are applications such as the automatic transfer of business cards that dont require any. Mode 2 security is a service- and device-level security scheme. It is possible to assign different levels of access to trusted and untrusted devices. I can assign my own PDA full access to a piconet controlled by my laptop and restrict access to other identical PDAs. Mode 2 also offers three service-level security services: those that require authorization and authentication, those that require authentication only, and those that are open to all devices. Mode 3 or link-level security is based on link keys. A link key is a 128-bit key stored individually for each pair of devices. Each time the devices communicate, the link key is used for authentication and encryption.

Bluetooth devices are currently available and ready for use. Unfortunately, the standard has not lived up to its initial expectations. A few years ago pundits were predicting Bluetooth-enabled devices everywhere. One scenario had a users Bluetooth cell phone (or Bluetooth PDA) activated when he walked into a store or approached a kiosk. The portable device would link to a fixed device at the kiosk and exchange information. A traveler could have local information (perhaps a conference schedule) automatically downloaded to her PDA. In a retail setting, the local device could identify the portable user, retrieve historical data on that user, and provide those data to a clerk who would know purchasing habits (and spending limits) of the customer. Pretty scary stuff! I can think of better uses.

Bluetooth communications are best suited for close proximity ad hoc communications. These devices require little power to operate, occupy a small footprint, and are inexpensiveall of which add up to a perfect match for truly portable devices such as laptop computers, personal digital assistants (PDAs), and cellular phones.

The business uses of such devices include ready to roll piconets in conference rooms already hard wired to projectors and Internet access. Information kiosks at conventions and in airports are a good fit. Bluetooth-enabled PDAs could be used to synchronize data obtained in the field with the master database at the agency or home office.

802.11b
Now theres an exciting name for a standard. If cool names were all we cared about, we could all adopt Bluetooth and be done with it. The problem is that Bluetooth only serves a small portion of our wireless needs. What we need is a wireless standard that can actually replace hard-wired networks, not just supplement them. This is provided by 802.110 from the IEEE (The Institute of Electrical and Electronics Engineers). Victor Hayes (of Hayes modem fame) initiated and chaired the group. One result is the 802.11b standardsnazzed up by some with the name Wi-Fiwhich is in use today.

802.11 wireless technologies are designed to replace hard-wired networks, not enhance them. Bandwidth is significantly higher than that provided by Bluetooth802.11b devices are designed for throughput of 11 Mbps, although actual performance is probably half that.

They have a much greater range (100-300 meters), and as you might imagine, they require a lot more power (100 to 350 mA versus 1-35 mA for Bluetooth devices). They also have a chip-set cost approximately three times that of Bluetooth. Actual device costs will be proportionally higher. 802.11b devices are also larger.

The devices use the same crowded ISM frequency band as Bluetooth. This is becoming interestingtwo similar devices, one inexpensive and small with limited range, one more costly and powerful both using the same frequencies. How does 802.11 handle the interference? The IEEE, like all good organizations, formed another committee to handle just that issue. The 802.15 Coexistence Task Group 2 (another exciting name) was formed to address those issues. The resulting methods are too detailed to go into here; suffice it to say that the anti-interference algorithm used by most 802.11 devices is known as direct sequence spread spectrum (DSSS).

Security is a problem with 802.11 networks. The RF transmissions are powerful enough that 802.11 network traffic is accessible outside the physical boundaries of the network. It has been said that running a wireless network is like having public RJ-245 jacks outside your building. That means that unless you are using triple DES encryption with large keys, you are vulnerable. Standard security consists of a Wireless Equivalent Protocol (WEP) built in to 802.11 devices. Word on the street is that WEP is a weak scheme and is easily broken. Right now hacking wireless networks has become a favorite pastime for geeks with a bad attitude and too much time on their handslook for them driving around high-tech neighborhoods looking for accessible networks and the free Internet access they permit.

Lack of security shouldnt be a show stopper unless youre passing sensitive (and unencrypted) medical, personnel, or financial data around your network. Not that wired networks are that safe; theyre a lot less secure than we like to believe, and most security breaks come from within an organization anyway.

Currently available 802.11b devices are relatively expensive, at least compared to their wired counterpartsaround $120 for an interface card and a bit more for a hub. Compared to a thumbnail-sized Bluetooth chip, they have a large footprint and are power hungry. These factors combine to make them unsuitable for handheld portable devices.

But 802.11b devices are both suitable and available for laptop and notebook computers. In fact, many new notebooks come with 802.11b networking and antennas built in, and companies such as Starbucks (and universities such as MIT) are offering wireless Internet access to people with such laptops.

Bluetooth and 802.11b are not mutually exclusive, either. In fact, Compaq is currently offering notebook computers that can be configured for both 802.11b and Bluetooth use.

So What?
Wireless is cool technology, but is it useful in the insurance industry? While wireless networking in the office would be useful anywhere, Bluetooth probably has more immediate uses than 802.11.

Many corporate headquarters could benefit from Bluetooth equipped conference roomsuser-friendly networking on demand, with the goal of sharing resources and information, is valuable. As far as wireless, 802.11b-based networks go, wait unless you have a compelling reason for using one (like having office space in a building where you simply cannot run CAT5). Security is a primary concern, and looming on the horizon are 802.11a devices (thats right, a comes after b in this case), which use the 5 GHz RF band and promises higher bandwidth (20-50 Mbps). Wait and see which standard gains widespread acceptance, and thus decreased expense, before investing in a corporate wireless network. Until then, stick with copper and fiber in the office space, but if you want to impress your friends, go wireless at home.

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