Competing Technologies

HomeRF also operates on the 2.4 GHz band and is capable of achieving transport rates of up to 1.6 Mbps from a distance of about 150 feet. But this technology is purely targeted toward the residential market segment. You might find HomeRF at work in residential gateways, but it will not rival networks designed to serve enterprise-class WLANs, public access systems, or fixed wireless Internet access.

Bluetooth is another technology sharing the 2.4 GHz band. Originally developed by Ericsson for communication between mobile phones and headsets, the technology is currently guided by Bluetooth SIG, an industry consortium consisting of more than 2,000 members.

Bluetooth creates Personal Area Networks (PANs) consisting of small devices like wireless phones, headsets, and peripherals. Designed to minimize power consumption and operate from a small footprint, Bluetooth can attain speeds of up to 780 Kbps within a 10-meter range.

Because competing technologies share the same spectrum, Bluetooth, Home RF and 802.11b products can interfere with each other. A study by Mobilian demonstrated that throughput dropped dramatically in 802.11b stations over 10 meters from an AP when a Bluetooth piconet was present. The IEEE 802.15 Coexistence Task Group is currently working on measures to avoid this type of interference.

Moving on up
The unlicensed 2.4 GHz band is a very crowded place. All sorts of devices, including microwave ovens and cordless phones, compete for airwaves in the spectrum. Regulations that constrain operations in this band ultimately limit WLAN throughput and range.

In the U.S., the Federal Communications Commission recently opened up three 100 MHz sub-bands in the 5 GHz region for unlicensed use by high-speed WLANs.

The IEEE is developing a new standard for 802.11a, specifying efficient modulation methods over indoor and outdoor wireless environments that and attain speeds of 54 Mbps. Attention all fixed wireless Internet service operators—this will be the operating area for you!

Even as we speak, vendors continue to combine 802.11b standards with proprietary innovations to increase range and throughput over wireless LANs. For example, ShareWave tweaked 802.11b to optimize the delivery of multimedia content. Meanwhile, Wave Wireless determined that 802.11b is too expensive a proposition for building outdoor inter-segment links, so it developed SPEEDLAN bridges and routers extending WLAN access for up to 20 miles.

802.11b products
Today, there are hundreds of products operating on the 802.11b standard. Here are just a few examples:

• Wireless Stations: 802.11b-compliant PC card and PCI/ISA adapters start at just $99. Vendors include 3Com, Apple, BreezeCOM, Cisco, Compaq, D-Link, Enterasys, Farallon, Intel/Xircom, Lucent, Nokia, Proxim, Zcomax, and many others. Key differentiators are cost and power consumption, particularly in PC cards used by mobile devices.
• Residential Gateways: Starting around $300, these 802.11b APs are SOHO routers that enable shared Internet access; they often include NAT and DHCP. Key differentiators are cost and simplicity; ISPs and DLECs may pair RGs with residential broadband offerings.
• Enterprise APs: 802.11b APs designed for enterprise use may include SNMP and/or web-based management and WEP encryption. Many carry power over a spare Ethernet pair to ceiling-mounted units. Entry-level products start around $300. Key features include enterprise-class administration, site survey tools, and confidentiality.
• Access Servers: For example, Lucent's AS-2000 includes RADIUS and automated key management, starting at $900. Features to look for in 802.11b public access servers include user-level authentication, support for usage-based accounting, and multi-vendor interoperability.
• Outside Routers: 802.11b APs designed for outside routing in point-to-point and point-to-multipoint topologies start around $1400. Cisco, OverLAN, and Lucent are a few of the vendors in this market. Considerations here include range, throughput, and access control.

This equipment list is not all encompassing, but it illustrates the breadth of products available on the market and suggests how the gear might be used to deliver high-speed Internet services.

New WLAN products are being introduced each week and prices are dropping fast. The 802.11b fixed wireless market is hot—we expect to see considerable innovation in the coming year—and there are no wires attached!

—End

Go to page 1: Market Opportunities	Go to page 3: Securing Wireless Transmissions
Go to page 2: Spreading the Spectrum	Go to page 4: Competing Technologies

     

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