Double Click
The Wireless Jungle
An overview of what you need to know to survive and prosper in the world of wireless protocols and devices
FROM: SEP-OCT 2004 ISSUE | BY JOHN W. YU
By the end of 2003, there were more wireless communications users than land-based users. In the United States and Canada, wireless market penetration is about 50 per cent of the population, yet that is relatively low when compared to some Asian and European countries. Currently, the biggest problem with wireless is lack of bandwidth, but solutions such as AT&T's new 100Mb wireless service with sufficient bandwidth to carry video images are being developed.
Here's a quick rundown of some key information about wireless applications:
Mobile devices
Wireless phones and wireless personal digital assistants (PDAs) are the most common forms of wireless mobile devices. Some have sophisticated capabilities, such as the well-known Blackberry from Research In Motion, an Ottawa-based high-tech company that has taken the U.S. market by storm. The Blackberry is a multi-purpose wireless device that provides:
- PDA functions (calendar, address book, to-do list, memos, etc.)
- Wireless e-mail (can open Word and Excel attachments)
- Wireless digital phone
- WAP browser
- Wireless Web browser
- Short Messaging Service (SMS)
- Alarm clock
With proper set-up, Blackberry devices can be wirelessly integrated with Microsoft Exchange to provide wireless dynamic connections to office e-mail and calendar in Microsoft Outlook.
Other wireless PDAs include Hewlett-Packard's iPAQ, which uses Windows Mobile 2003 OS. Sony CLIÉ and Palm m505 are both based on Palm OS. Most would
agree that Blackberry leads the pack in terms of wireless capability. In fact, Blackberry has been approved for use by the National Security Agency in the United States because of the high quality encryption technology used in the Blackberry. See www.blackberry.com for more information.
Local devices
A number of technologies are used for wireless local devices such as cordless phones, wireless keyboards, and wireless mice. These include low frequency radio, infrared, and Bluetooth, which is increasingly capturing a significant segment of the market. Bluetooth is an inexpensive, low-powered, short-range frequency-hopping radio system that links small portable devices such as pagers, PDAs, cell phones, and notebook computers, enabling them to communicate without physical wiring.
What is unique about the Bluetooth protocol is that it uses a combination of circuit and packet switching. It is a small,low-powered radio in a chip that can be implemented in any number of devices, including desktop computers, notebook computers, PDAs, cellular phones, cordless phones, wireless keyboards, wireless mice, printers, fax machines, scanners, keyboards, headsets, modems, joysticks, and virtually any kind of electronic device that has some form of power source. Bluetooth is designed to replace the various proprietary cables that are currently used to connect one device to another, as its radio wave technology allows communications between devices through walls and furniture.
Another major advantage of the Bluetooth protocol is that devices can "handshake" with each other without human intervention, thus simplifying the installation of new devices. For example, two users of notebook computers could insert Bluetooth PC cards in their notebooks and share files or collaborate on documents within minutes — without any wires or any network infrastructure. For more information about Bluetooth, visit www.bluetooth.com.
LANs
Wireless LANs use a technology called Wireless Fidelity (WiFi). WiFi grew out of the IEEE 802.11 protocol (www.ieee.org). Three protocols are currently available: 802.11b, 802.11g, and 802.11a, and it is important to be familiar with these protocols when choosing wireless LAN products.
802.11b
- Relatively slow at 11Mbps as compared to 100Mbps used in high-speed LANs
- Range of 300 feet
- Used in wireless LANs
- Known generally as Wi-Fi
802.11g
- Released in mid-2003
- Speed to 54Mbps
- Compatible with 802.11b
- Vulnerable to radio frequency interference, (such as late model cordless phones)
802.11a
- High speed (54Mbps)
- Resistant to radio frequency interference
- Incompatible with 802.11b
- Future uncertain
Most of the wireless routers on the market are now compatible with 802.11b and 802.11g. WiFi is most commonly used for wireless LANs in small offices where LAN wiring is either too expensive or inconvenient to install.
Notebook computers
A significant development is the introduction of notebook computers with wireless Internet capability. Intel combines its Pentium 4M processor with wireless network and other components in a product it calls Centrino technology. Compaq, IBM, and Dell all have notebook computers with this feature, which enables users to connect to the Internet without a telephone line or cable connection. A wireless connection to the Internet is achieved through connection to a WiFi node, so it is necessary to be within range of a WiFi node as the link is dropped when you move out of range. In Canada, the wireless service providers include Bell, AT&T, and others. Most major Canadian airports have hot-spots for WiFi connections, and you can expect to find hot-spots more and more common.
Routers
Increasingly, when people set up a router and firewall for a cable or ADSL connection to the Internet, they opt for a wireless router instead of one that requires a wired connection. Typically, a wireless router supports up to four computers to share an Internet connection. Each computer must have a wireless LAN card, except notebook computers with Centrino technology, as wireless capability is built in.
It is important to set up a wireless router with appropriate levels of security. If you don't, it is very easy for neighbours to "hijack" your wireless connection to access your Internet connection service. And while it is quite easy to hijack a wireless connection, it can be a dangerous practice. Some hackers set up wireless hot-spots to lure unsuspecting hijackers in, then insert viruses on their computers, or take control of their computers.
Bear in mind that the wireless jungle offers many options, but as in any jungle there are hazards one needs to be aware of. By arming yourself with some background information on wireless protocols and products, you'll reduce potential pitfalls and will be able to make effective product decisions with confidence.
[ TOP ]
John W. Yu, MSc, CDP, FCGA, has been in the IT industry since 1970 in a broad range of roles in technology and in management. He is vice-president of IT at CGA-Canada and the co-ordinator of "Double Click."