The fastest growing segment of wireless these days is the IEEE 802.11b 11-Mbit/s wireless-LAN-enabled products that operate in the unlicensed 2.4-GHz band. With this standard, laptops can access nearby enterprise local-area networks (LANs), home networks, and a growing number of wireless-access ports in hotels, airports, and coffee shops.
Also on the rise is the number of PCs enabled with the 802.11a standard that operate in the 5-GHz band and supply data rates up to 54 Mbits/s using orthogonal frequency-division multiplexing (OFDM). Growth is also expected in products that support the most recent IEEE wireless standard, 802.11g, which handles data rates up to 54 Mbits/s in the 2.4-GHz band using OFDM.
Chips that support all three standards weren't available until the arrival of the AR5001X chip set. Developed by Atheros Communications, the set automatically selects the nearest detected carrier. It consists of the AR2111 2.4-GHz radio chip, the AR5111 5-GHz radio chip, and the AR5211 baseband chip, which is designed to interface to PCI, mini-PCI, or CardBus buses.
Atheros says that four of the top five laptop manufacturers—IBM, Hewlett-Packard, NEC, and Toshiba—have adopted the chip set in their latest versions, giving these laptops immediate access to any of the available standards. Atheros also recently received full dual-band Wi-Fi certification by the Wi-Fi Alliance for the AR5001X CardBus reference design board and the AR5001AP Access Point reference design. (For more details on Wi-Fi, visit www.wi-fi.org).
While the greatest volume of wireless-LAN (WLAN) activity is in the 2.4-GHz band, more users are expected to move to the 5-GHz band and its larger spectrum. Today, 802.11b users have to share the limited 83-MHz bandwidth with Bluetooth, HomeRF, cordless telephones, microwave ovens, industrial data modems, and many other wireless services. As the numbers of WLAN and personal-area-network (PAN) users increase, more interference is expected.
Atheros Communications, Inc.
www.atheros.com (408) 773-5200