While the technology may not be ready to take over wired networks due to spotty performance, security and interference shortcomings, it seems industry groups are working on the drawbacks. Let's see where they stand.

Hardware and interoperability

Pro: Wi-Fi certification is here. At www.wi-fi.org you can find more than 1,500 Wi-Fi-certified products that use standardized 802.11 technologies in their wireless networking products. If components are Wi-Fi certified for the same frequency band (such as 2.4GHz), you can mix and match wireless LAN products produced by different manufacturers.

It is easy to install a home or office wireless network. My home has structured cabling with Category 5 cable and coax to every room. There is also a wireless access point (connected to the Ethernet network) in one room that enables me to roam about the house with a wireless-enabled laptop and hop onto the Internet in any room at any time.

Cons: The 802.11 standards coming out of Institute of Electrical and Electronics Engineers (IEEE) for wireless applications are confusing at best. 802.11a, with a speed up to 54 Mbps, operates at the 5 GHz frequency, while 802.11b operates with a speed of 11 Mbps at the 2.4 GHz frequency, and 802.11g operates with a speed up to 54 Mbps at the same 2.4 GHz frequency.

You can look to the Wi-Fi Alliance to certify devices that work together, but 802.11g is only backward compatible with 802.11b devices.

You may purchase all wireless devices in the United States so they can be interoperable here, but if you go abroad, there is no guarantee they will operate because of their different regulations or assignment of frequencies for nonpublic use.

Interference

Pro: Wireless LAN radios (two-way radios or pagers) are low-power devices and operate at power levels lower than most cell phones or handheld radios (very high frequency). They operate on a noninterference basis, meaning they cannot cause harmful interference, but they must be able to accept harmful interference.

Wireless LAN devices are less likely to be used in proximity to hearing aids or pacemakers under normal operating conditions-therefore they will not cause feedback. Safer pacemakers are available that have the appropriate level of radio frequency immunity to protect against interference.

Tests have been done to show that 802.11b and 802.11g devices working in the 2.4 GHz band did not interfere with systems operating in the 900 MHz band, such as cell phones.

Con: 802.11b and 802.11g devices in the 2.4 GHz frequency band and other devices operating in this range could cause interference. Examples of products that could cause interference in that range are cordless telephones, wireless video cameras and wireless audio speakers.

In the medical community, if devices susceptible to radio interference are not properly hardened from the operating frequencies and power levels of the radio device, they could be affected by interference from a WLAN device. There is also the challenge of determining just which devices should be upgraded or purchased new for wireless communications. Budgets need to be considered. Radio interference tests need to be conducted to avoid potential immunity-related interference.

Performance

Pro: The 5 GHz frequency band that 802.11a uses is longer-range, although it can be susceptible to interference from other RF devices such as cordless phones.

There is a trend to replace access points with dumb switches where all the network's activity (smarts) is trapped in the switch for network management. A large company's users would benefit from this management.

Con: To increase the coverage area, you can lower the bandwidth. In other words, as distances increase, throughput decreases. That is because the lower signal strength results in dropped packets and a general decrease in network efficiency.

Even with today's improvements, the actual speeds are lower than what is needed to reasonably move large graphics files or streaming video. Plus, the hardware is expensive. As a general rule, throughput speed is usually about half that stated in a standard.

Wireless applications

Pro: You can roam with notebook computers and share files and printers with a LAN. You can connect to the Internet using another computer or network. Some multimedia devices support wireless networking, including digital cameras and hardware media players. This gives you increased portability and convenience around the home or office without needing to be “wired” to a LAN.

Con: The more users working off one access point, the more degradation in the network's performance.

Enhanced 911 wireless calls

Pro: The Federal Communications Commission (FCC) is requiring that wireless carriers (for cellular) provide precise location information to public safety answering points (PSAPs) to be accurate to within 50 to 300 meters. This will be implemented in stages.

Con: Users need to verify their carrier's plans before committing to their service.

Access points (AP)

Pro: An access point has its own IP address and can be connected to other PCs on the LAN.

The AP is the wireless network's center. Wireless devices in the vicinity are connected to the AP through radio waves and those transmissions are converted by the AP into IP (Internet protocol) traffic on the network. Some APs can be used to extend a WLAN's range.

Con: The AP has to be wired back to the operating LAN, and the AP may be ineffective for the user at 150 feet. Also, the AP may still interfere with another system 500 feet away.

Security

Pro: Security has been improved since the late 1990s for wireless communications. The first method used was the WEP (wired equivalent privacy) security for Wireless-B devices. Then came WPA (Wi-Fi Protected Access, an interim standard now replaced by 802.11i) to address the known vulnerabilities in WEP and also provide user authentication, which is not performed by WEP.

WPA offered standards-based, Wi-Fi-certified security, ensuring users that the certified devices would be cross-vendor compatible. Today, the WPA2 (Wi-Fi Protected Access 2) is second-generation WPA security and is also backward compatible with products that support WPA.

It gives enterprise and consumer Wi-Fi users an assurance that only authorized users can access their wireless networks. WPA2 also includes the new Advanced Encryption Standard (AES) that satisfies U.S. government security requirements.

Con: WEP can be easily decrypted. There are hackers who can crack into a WEP-protected network, but WEP does a good job of protecting many home and business networks from the general public. The use of standard 802.11 WEP for networks where there is low risk of attacks is a minimum security policy.

The main difference between wired and wireless networks is the uncontrolled coverage areas between the endpoints. This allows attacks not found in traditional wired networks such as eavesdropping (gathering information on the network under attack); jamming (intentional or unintentional interference that overpowers communications links, effectively rendering them useless); injections (adding data to an existing connection to hijack the connection or send corrupt data or bad commands); sniffing (to get passwords, read e-mail, monitor Web traffic and search for open wireless LANs); and rogue access points used to impersonate a network resource.

What the future holds

While there have been improvements, some drawbacks still exist in wireless technology. In the beginning, there were major concerns about being able to receive other people's or businesses' communications because of a lack of protection. Here we have looked at the many ways hackers can operate in the wireless environment, and your knowledge of security measures will go a long way in protecting your own wireless LAN.

Francis Rabuck, president of Rabuck Associates, a Philadelphia wireless consultant, recently said, “Of the many positives that come from putting in a wireless network, you are allowed the flexibility of moving about without wires, it's less costly to install, and security is no longer an issue because of WPA2. Add a VPN (virtual private network) layer, and you can ensure end-to-end security of the client's traffic.”

In a recent report on the industry, wireless printing was discussed as an option because wireless printers are independent of cabling and a wired network-they can be used virtually anywhere and relocated in minutes. Modern manufacturing and supply-chain operations can use this type of flexibility-think of how convenient it would be to print barcode labels on demand wherever they are needed.

It is a good time to be a worker in the strong and growing wireless-communications field. This is true for new subscriber services, but it could also mean more wireless access to these services.

A report on the technologies for fixed wireless, WiMax and Wi-Fi consumer devices said those markets may have been slowed in the past by the inadequate security features of the original WPA protocol, but the Wi-Fi device market has now been given a boost by the new security protocol WPA2. The primary difference between WPA and WPA2 is that WPA2 uses the much stronger encryption technique called AES.

The outlook is exciting and the opportunities are many. As long as we remain aware of the pitfalls, we can look forward to using more wireless devices in our future. EC

MICHELSON, president of Jackson, Calif.-based Business Communication Services and publisher of the BCS Reports, is an expert in TIA/EIA performance standards. Contact her at www.bcsreports.com or [email protected].