IEEE 802.11
In June 1997, the IEEE finalized the initial standard for wireless LANs: IEEE 802.11. This standard specifies a 2.4GHz operating frequency with data rates of 1Mbps and 2Mbps. The initial 802.11 standard defines two forms of spread spectrum modulation: frequency hopping (802.11 FHSS) and direct sequence (802.11 DSSS).
In late 1999, the IEEE published two supplements to the 802.11 standard: 802.11a and 802.11b. IEEE 802.11b is a data rate extension of the initial 802.11 DSSS, providing operation in the 2.4GHz band at up to 11Mbps. Most wireless LANs implemented today comply with the 802.11b version of the standard.
The 802.11a standard defines operation at up to 54Mbps using orthogonal frequency division multiplexing (OFDM) modulation in the roomy 5GHz frequency band. The 802.11a standard has a wide variety of high-speed data rates available: 6, 9, 12, 18, 24, 36, 48, and 54Mbps; it is mandatory for all products to have 6Mbps, 12Mbps, and 24Mbps rates. Products implementing the 802.11a standard should begin appearing on the market in late 2001.
In this tutorial:
- Wireless Networks
- Mobility
- Installation in Difficult-to-Wire Areas
- Increased Reliability
- Reduced Installation Time
- Wireless LAN Applications
- Home and Small Office
- General Enterprise Systems
- Wireless Services
- Wireless LAN Technologies
- IEEE 802.11
- HiperLAN
- HomeRF SWAP
- Bluetooth
- Wireless LAN Implications
- Multipath Propagation
- Path Loss
- Radio Signal Interference
- Inward Interference
- Outward Interference
- Techniques for Reducing Interference
- Potential Frequency Interference Between 802.11 and Bluetooth
- Limited Battery Longevity
- System Interoperability
- Network Security
- Security Threats
- Security Safeguards
- Application Connectivity Problems
- Installation Issues
- Health Risks
- Wireless LANs: A Historical Perspective