CYBERCARE
A Wireless World
You've heard of this "wireless" thing, but how much do you know about it? Here's an introduction.
Richard Hom, O.D., F.A.A.O.

Wireless -- it's the greatest thing since sliced bread. It lets you connect computers to each other and to the Internet without having to install all of those silly cables. But what's wireless all about?

This month, I'll explain the basics of wireless communication, and I'll continue next month with part two of wireless and describe how to put it to use in an optometric office.

A look at the market

The wireless market is huge. The International Data Corporation, a leading industry analyst, predicts that the fixed wireless market will grow to $7.4 billion in 2003 from $767 million in 1999.

According to Network Computing magazine, most of these deployments of wireless will be in data communication. With that in mind, I'll concentrate on data communication this month, rather than on voice communication.

Connecting with wireless

Wireless can connect individual computers together in local area networks (LANs) or two or more LANs in a Wide Area Network (WAN), such as connecting two offices. Each office has a LAN and connecting the two means WAN. You can even use wireless to connect an individual computer to the Internet if your Internet Service Provider (ISP) offers wireless communication. Because we're talking about data communication, we'll focus on the use of wireless communication to connect:

• two separate offices
• computers in one office.

Types of wireless

In general, wireless communication is either mobile or fixed.

Mobile wireless. This form of wireless uses battery packs for power. Although you can use it in a fixed location, the lower power of mobile wireless reduces its efficiency in a fixed-use mode. Mobile wireless can also define cellular phone or paging usage, but the data carrying ability of this mode is extremely limited.

Fixed wireless. Generally, fixed means that the operation derives its power from a stationary utility or main power source. This usually means the AC power is coming out of the wall as opposed to a mobile battery source. It can also mean that the connection is between two stationary wireless users, which means that both antennae are fixed and stationary.

Fixed wireless can simulate a traditional wired (wireline) connection such as a Digital Subscriber Line (DSL) or a cable connection. Wireless uses the same protocols and transport mechanisms as wireline (traditional cabling) such as T1/T3, Ethernet, frame relay, and TCP/IP.

An optometric office would most likely use fixed wireless. However, if the office staff members are using a mobile cellular phone to connect to computers or communicate among themselves, then they'd be using mobile wireless communication.

Fixed wireless systems

Two major types of fixed wireless systems are private licensed links (called microwave) and public unlicensed links (called spread spectrum).

1. Microwave. This type of system is traditionally used as the backbone of fixed wireless systems and existed long before the term "broadband" became popular.

Microwave links operate in the 1.7-GigaHertz (GHz) to 40 GHz frequency range and have no practical limit to their data load capability (up to 155 megabits per second [Mbps]). They're expensive and mainly used by telephone companies.

2. Spread spectrum. This type of fixed wireless system operates mainly in the 2.4-GHz band and offers a more modest transmission rate of 1 to 10 Mbps. This is the most common wireless system used by small businesses for connecting to multiple locations. Therefore, this is the type of system you'd use if you wanted to connect two of your office locations.

Both microwave and spread spectrum wireless systems use finite radio frequencies. The number of users and available bandwidths usually limit the use of one application at a time. Wireless systems also use frequencies that require free line-of-sight or no obstructions such as foliage or buildings between the two antennas. This usually translates to a practical distance limitation of about 20 kilometers.

Big potential

Wireless systems have a tremendous potential in the healthcare market. Where medical practitioners require maximum mobility and instant access to information, it's a market that can only grow in a short period of time.

Join me again next month when I put this month's information to use and explain how wireless systems can make your office more efficient.

DR. HOM HAS A RICH BACKGROUND IN E-COMMERCE. HE CURRENTLY PRACTICES PART TIME IN SAN FRANCISCO, EXCLUSIVELY CARING FOR COMPLICATED CONTACT LENS PATIENTS. HE'S ALSO A PARTNER AND BUSINESS DEVELOPMENT MANAGER FOR NETWORK APPLIANCE IN SUNNYVALE, CALIF.