Existing Wireless LAN Standards

With a wide variety of devices available today, each produced by a different company, manufacturers realized the need to make their devices interoperable with one another or at least to follow a given standard.

At first, some vendors introduced wireless LAN solutions based on the proprietary technology; these solutions were not interoperable with devices from other vendors and required entire infrastructure to be purchased from one specific vendor.

The IEEE recognized a need for a standard that utilizes the limited wireless RF bandwidth in the most efficient manner.

  • IEEE 802.11 - To address the need for some uniformity in operability of different types of wireless LANs, the IEEE committee responsible for Local Area Network standards and Metropolitan Area Network standards, known as the 802 LAN/MAN Standards Committee, formed a new working group called 802.11 to explore standards for the wireless LANs.

In 1997, IEEE drafted the 802.11 standard for wireless local area networking. The IEEE 802.11 standard defines the transmission infrared light and two types of radio transmission within the unlicensed 2.4−GHz frequency band.

  • IEEE 802.11 b - In 1999, the 802.11b standard was drafted and accepted by the networking industry, and products for wireless networking over the 2.4−GHz frequency began being produced. 802.11b uses the ISM band and operates up to 11 Mbps with a fallback to 5.5, 2, and 1 Mbps.

802.11b uses DSSS as its spread spectrum technology. 802.11b also supports Wired Equivalent Privacy (WEP) for confidentiality of data transmitted over the wireless LAN.

802.11b is also known as wireless fidelity (Wi−Fi). Most wireless LAN device manufacturers and the Wireless Ethernet Compatibility Alliance (WECA) are promoting this standard.

  • IEEE 802.11 a - 802.11a is the upcoming product of the IEEE 802.11 working group. The standard was formalized to develop a physical layer that operates in the newly allocated UNII band.

This is an extension to 802.11 that applies to wireless LANs and provides up to 54 Mbps in the 5−GHz band. 802.11a uses an orthogonal frequency division multiplexing encoding scheme rather than FHSS or DSSS.

Almost all major vendors have now introduced their line of 802.11a devices. Most 802.11a devices are targeted toward the enterprise market.

  • HomeRF - HomeRF also operates in the same 2.4−GHz ISM band as 802.11b and 2.4−GHz cordless telephones. HomeRF uses FHSS as its spread spectrum technology. HomeRF networks provide a range of up to 150 feet, sufficient to cover the typical home, garage, and yard.
  • Bluetooth - Bluetooth is one of the most recent wireless standards. Bluetooth is a strong candidate for the personal area network or PAN devices. PAN is defined as a wireless network ranging from a few inches to up to 10 feet; essentially a network around one's personal space.

Bluetooth also operates in the ISM band. Current applications for Bluetooth include data synchronization for handheld personal digital assistants, wireless headsets, and similar gadgets.

Wireless LAN equipment radiates electromagnetic energy. The health of a living being may be adversely affected by such waves. A good device would provide the lowest possible hazard.

Before purchasing or using any device that uses electromagnetic energy, carefully read the equipment manual and look for information regarding the radiated output power of the device.

If a device comes with an FCC ID, you can obtain information regarding emission disclosure and frequency usage from the FCC Web site. At the site, just enter the FCC ID of the device, which consists of the three−character grantee code and the equipment product code, or EPC (up to fourteen characters long) for example: FCC ID: ABC12345678901234

Wireless LANs normally use the Wired Equivalent Privacy (WEP) for providing confidentiality of the data transmitted over the air. WEP is a security protocol, specified in the IEEE Wi−Fi standard that is designed to provide a wireless LAN with a level of security and privacy comparable to what is usually expected of a wired LAN.

A wired LAN is generally protected by physical security mechanisms (controlled access to a building, for example) that are effective for a controlled physical environment, but may be ineffective for wireless LANs because radio waves are not necessarily bound by the walls containing the network.

WEP seeks to establish similar protection to that offered by the wired network's physical security measures by encrypting data transmitted over the wireless LAN.

This way even if someone eavesdrops at the wireless packets, he or she will not be successful in understanding the content of the data being transmitted over the wireless LAN.

However, a research group from the University of California at Berkeley recently published a report citing "major security flaws" in WEP that left wireless LANs using the protocol vulnerable to attacks.

But the Wireless Ethernet Compatibility Alliance (WECA), an organization formed by major 802.11 equipment manufacturers to promote the use of wireless LANs and perform equipment interoperability among its members, claims that WEP was never intended to be the sole security mechanism for wireless LANs.