March 2002 - Volume 2, Issue 2

The ABCs of Wireless Technology

What does "wireless" mean?

"Wireless" means transmitting signals over invisible radio waves instead of wires. Television remote controls were the first wireless devices to become a part of everyday life. Now the cordless keyboard and mouse, PDAs, and digital and cellular phones are widely used.

How do wireless networks work?

Wireless data is predominately transferred over two kinds of networks: wide area networks (WANs) and local area networks (LANs). These networks are similar to their wired counterparts-they just use radio waves instead of copper or fiber.

WANs can cover areas as large as several countries. Wireless LANs, already popular in airports and hotels, are often used to replace or enhance wired LANs. They can cover a range of 153 meters indoors and up to 305 meters outdoors. They may service a smaller area than their WAN cousins, but LANs can transfer data much faster, at speeds up to 11Mbps. Wireless LANs are used primarily for data; they do not usually support voice traffic.

What technologies are involved?

First a word about how wireless technologies are referred to. You'll read a lot about "generations" of wireless, which correspond to the rate and quality of data and voice transmission. The first generation was analog voice (the earliest cell phones).

The second generation is digital (such as more efficient cell phones with voice and data at rates of 9.6Kbps to 14.4Kbps). Currently carriers are working on what they call 2.5 generation, or 2.5G, transmission rates, which will carry data up to 114Kbps. The future is 3G, which will include multimedia and data transmission rates of up to 2Mbps to 5Mbps, advanced roaming capabilities, as well as the sought after (by some) "always-on" potential.

When it comes to WANs, an alphabet soup of technologies is used to send data through the air. One of the most used and talked about is wireless application protocol (WAP). WAP-enabled devices offer a limited version of the Web designed to work on the small black-and-white screens of phones and PDAs.

Within the current digital world of wireless, there are four primary technologies: code-division multiple access (CDMA), global system for mobile communication (GSM), integrated dispatch enhanced network (iDEN), which is used by Nextel, and time division multiple access (TDMA).

Bluetooth, a LAN technology, enables devices rather than a network to communicate. With an operating range of only 10 meters feet, Bluetooth can be used in a headset to wirelessly listen to audio on a computer and send photographs from a digital camera to the computer.

What's the difference between wireless and mobile?
A laptop is a mobile device. The Lotus Notes application on that laptop is mobile because it resides on the laptop but needs to connect through a wired modem connection before it can be used. A cell phone is a wireless device. The Lotus Notes application on that cell phone is wireless because it can receive data wirelessly-that is, without being plugged into a wired connection.

What can these technologies do for businesses?

Wireless applications include e-mail, paging, voice transmission and Web access. Companies currently use wireless technologies to connect laptops, mobile phones and PDAs to a wide variety of product and customer information.

What are the limitations?

First and foremost, you need to realize that wireless communications will never be perfect. The experience will never mimic what you're used to seeing on your PC.

When it comes to WANs, bandwidth and spectrum are major limitations. The networks are slow. When transmitting data, you're forced to send smaller bits of data just so the information moves as quickly as possible. The size of the device that's accessing the information is also an issue.

Phones and PDAs have small screens-often only a couple of inches in diameter-and it is not easy to see large documents on them. Think of a contractor trying to read an architect's blueprints on a job site.

When it comes to voice transmission, you need to remember that wireless is a radio-based technology, which calls for transmission towers and receivers that are positioned to dodge interference.

Do I need wireless?

Just because your company can go wireless doesn't mean it should-not every company needs wireless.

Critical, time-sensitive applications are the best candidates for WAN projects. If getting information in real-time makes or breaks a sale, give your salespeople access to that data. But remember that WANs are best suited for accessing small pieces of information because of bandwidth constraints.

Wireless LANs are often installed for convenience, such as when you don't want to wire the building, or when your staff is dispersed throughout the building. They are often used in hospitals, where doctors and clinicians can check in while on rounds or on the floor. Wireless LANs are faster and more reliable than WANs, and they can be similar in price to wired LANs.

What's a good strategy for getting a wireless project off the ground?
Start by figuring out what kind of information needs to be accessed, by whom and from where.

Evaluate how easily it will be to access the information that is going to be sent out to wireless devices. Is the information coming from a variety of sources? Is the information too large to be conveniently accessed on a PDA or phone?

Start small, with a pilot project. Not all projects will be scalable for a
larger rollout or more robust applications.

Keep realistic expectations in mind. Ask the following questions:
· Coverage-how large an area am I asking my wireless to cover?
· Speed and bandwidth needed to run an application-will I have enough?
· Device interface-does the application work well on a small screen?

What are the security risks associated with wireless technologies?
Most people with PDAs and phones don't use built-in security features, such as password protection and locking keypads, and the data on handheld devices is rarely encrypted. If a device is lost or stolen, all the information on it can be accessed by someone else.

For WANs, there is something called the WAP gap-the small window of time between decrypting and encrypting information (usually performed by the carrier, such as Sprint PCS) when there is vulnerability. However, the chances of a breach are very low.

The most significant risk is to LANs. The 802.11 family of specifications used for wireless LANs relies on a protocol that has been broken. Without the proper security measures in place, a wireless LAN can be accessed by anyone with cheap equipment and hacking skills.

What about using wireless technologies on a global level?

The idea of accessing wireless data services from anywhere around the world on the same device is still a dream. Several U.S. wireless carriers offer voice services on an international level, but they do not offer data services.

However, global enterprises could find faster wireless data services abroad. Services in Europe and Japan are a few steps ahead of those offered in the United States, which could make business applications more viable for companies with foreign offices. Just don't expect them to work seamlessly across national borders anytime soon.

What does the future look like?

As in all industries, the economic downturn has changed the priorities in the wireless world.

The industry is now focusing on providing better, faster data and introducing text services to consumers. Text messaging (known in Europe as short messaging service-SMS), which includes e-mails, instant messaging and paging services, already delivers alerts about things like flight delays, sports scores and stock prices.

These services are expected to grow in popularity as the technologies become more available. The most important characteristics of the technologies and services that are leading the wireless world into the future will be speed and constant connectivity.