Electronic Design

Enhanced Interoperability, 802.11b Devices Stimulate Growth Of Wireless LANs

Developments for wireless networking are proliferating, as evidenced at the Networld+Interop Conference in Atlanta in September. More companies are beginning to use wireless LANs as better products become available and their prices drop to acceptable levels. One estimate is that the wireless networking segment of the LAN market will grow to over $1.5 billion by 2004. That represents a growth rate of over 100% per year.

Wireless LAN technology has been propelled by the widespread use of the IEEE-802.11b wireless Ethernet standard. This specification uses direct-sequence spread-spectrum (DSSS) methods in the 2.4-GHz ISM band with a data rate of 11 Mbits/s. Inexpensive network interface cards (NICs), compatible with PCMCIA ports for notebooks as well as ISA, PCI, and USB ports for desktops, have become available from many companies. The low costs of these NICs, virtually all of which are interoperable with one another, are making wireless connectivity a viable alternative to direct cable connections.

This interoperability has been spurred by the Wireless Ethernet Compatibility Alliance (WECA). This organization promotes interoperability of 802.11b products and sponsors a formal testing and certification program. It awards Wireless Fidelity (Wi-Fi) certification to those products that meet its stringent test conditions. Any Wi-Fi certified product will work with any other. To date, more than 44 wireless LAN products have been certified. At the Networld+Interop Conference, WECA sponsored a special pavilion where member companies showcased and demonstrated their Wi-Fi products.

One of WECA's members, Wayport, produces wireless Ethernet access systems for travelers. These systems are now becoming available in airports, hotels, and conference centers. Wi-Fi certified, Wayport's equipment lets anyone with a notebook computer and a 802.11b-compatible NIC sign on for access to e-mail and the Web.

Another sign that wireless LANs are flourishing is Intersil's September announcement. A supplier of radio chips used in a high percentage of 802.11b LAN products, Intersil said that it had shipped over 2 million of its popular PRISM II chip sets. This five-IC chip set includes the HFA3983 power amplifier and detector, the HFA3683A RF/IF converter and synthesizer, the HFA3783 I/Q modulator/demodulator and synthesizer, the HFA3661B baseband processor with a Rake receiver, and the HFA3842 media-access controller (MAC). Users can add RAM, ROM, a host controller, and a clock for a complete 802.11b-compliant NIC. Intersil's newest chip set, the PRISM 2.5, reduces the chip count to four by combining the baseband processor and MAC circuits on a single chip.

Another major player in the wireless LAN arena is Lucent. In addition to making the chip sets for 802.11b NICs, Lucent's ORiNOCO Division also produces the infrastructure systems that connect to any 10Base-T Ethernet LAN. For example, Lucent ORiNOCO just announced its AP-500 Access Point bridge, which permits wireless access within a building or small campus. An external antenna is available to extend the communications range.

Also, Lucent is offering its RG-1000 Residential Gateway for homes and small offices. The Gateway has a standard modem (RJ-11) port and an Ethernet (RJ-45) port for connection to the Internet. It allows multiple PCs to have wireless access over a 150-ft. radius (see the figure).

The recent acquisition of Alantro Communications of Santa Rosa, Calif., by Texas Instruments gives TI's Broadband Access Group wireless LAN capability. The primary product is a baseband processor for 802.11b radios. This is the first such chip to support the proposed 22-Mbit/s data rate increase for this standard. Yet it remains to be seen if the FCC will approve this data rate increase. If it does, TI says it is ready to go with a product for higher-speed NICs.

While 802.11b interfaces are becoming the de facto standard for wireless Ethernet LANs, several new companies have announced wireless LAN chip sets to implement the IEEE-802.11a standard. This spec uses the 5-GHz ISM band with orthogonal frequency division multiplexing (OFDM) to achieve data rates up to 54 Mbits/s. Startup Atheros Communications recently announced its AR5000 radio-on-a-chip (RoC) product. It uses two CMOS chips to form a complete 802.11a NIC. Radiata, another new company, also announced its all-CMOS "wireless engine" chip set to make a complete wireless LAN NIC 802.11a-compliant.

As the 2.4-GHz band gets crowded with more 802.11b NICs, Bluetooth-enabled products, and the many cordless phones that use this band, wireless LANs probably will eventually migrate to the 5-GHz band. Wireless LAN chip suppliers such as Intersil, Lucent, TI, and others are no doubt working on products for this band as well.

TAGS: Intersil
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