Vendors can't cut proprietary cord
With the IEEE standard stuck at 2Mbps, hardware makers are pushing speed over interoperability
By Stephen Lawton
Corporate users waiting for interoperable wireless LANs will soon get them, but they won't run at 10Mbps.
Despite the adoption of an IEEE wireless networking standard and the launch of standards-compliant devices, vendors continue to disagree over ways to let devices interoperate at speeds higher than 2Mbps.
The 1Mbps standard defined in the recently approved IEEE 802.11 standard, along with its 2Mbps option, is just too slow, claim vendors RadioLAN Inc. and WiLAN Inc.
But proponents tout 802.11 as the first step toward letting users link client hardware and access points from multiple vendors, and several vendors are gearing up to produce products based on the specification. Breeze Wireless Communications Inc., Lucent Technologies Inc., and Netwave Technologies Inc. have already announced standards-compliant access points and client hardware that will ship early next year.
For these vendors, the passage of 802.11 is not the end for this seven-years-in-the-making standard, said Angela
Champness, director of product marketing at Lucent's wireless development center in Nieuwegein, Holland. Champness said that a project-authorization request (PAR) has been submitted to the IEEE for an extension of 802.11 that will define speeds of up to 1Mbps, and that another PAR is being submitted for a 20Mbps wireless standard in the 5.2GHz range.
Even with the standard, customers must shop carefully if they plan to use devices from more than one vendor. That's because the 802.11 standard defines three different physical-layer connections for the spread-spectrum links: one for infrared and two for radio.
The two radio designs are frequency hopping and direct sequence, and each design has its proponents. The frequency-hopping technique transmits the signal over a single, narrow band, but the band changes frequently over multiple frequencies. With the direct-sequence approach, the signal is spread over 22MHz.
Are we transmitting?
Lucent advocates the direct-sequence method. Direct sequence can reach 10Mbps, Champness said, but Lucent has yet to deliver that class of products. Frequency hopping, she said, becomes saturated at 3Mbps.
Pleasanton, Calif.-based Netwave uses the frequency-hopping approach, which the company claims provides better security and interference immunity than its direct-sequencing counterpart. Rather than be tied to the proprietary vs. standards debat e, Netwave President Jerry Ulrich said his first 802.11-compliant offerings, the AirSurfer Plus PC Card and the access point (see "
Networking, unplugged "), will incorporate both technologies so users can upgrade gradually from the older, proprietary technology to the standards-based technology.
Standards-based hardware is not expected to begin shipping in volume until the first quarter next year, at the earliest. A group of vendors that use frequency hopping, including Breeze Wireless, Netwave, Raytheon Wireless Solutions, and Symbol Technologies Corp. have already begun compliance and interoperability testing at the Interoperability Labs at the University of New Hampshire, located in Durham.
Additionally, several direct-sequence manufacturers, including Lucent, Intermec Technologies Corp., Digital Equipment Corp., Harris Semiconductor Products, Advanced Micro Devices, and Aironet Wireless Communications Inc. have banded together for their own interoperability testing, but have yet to select the time or location for the compliance and interoperability tests.
One vendor withholding support for the initial 802.11 specification is Sunnyvale, Calif.-based RadioLAN. Marketing Vice President Mike Bosse said that RadioLAN's hardware works at full Ethernet speeds of 10Mbps, so moving backward to supporting the 1Mbps standard would not make sense. However, the company has joined the 802.11 committee and is working to increase the speed to 10Mbps, he said. The trade-off for opting for RadioLAN's technology, Bosse said, is a near 20 percent reduction in transmission distances vs. the 1Mbps standards-based devices.
Speed, distance--and cost
But the distance/speed issue becomes moot if users factor in the price difference between his products and those from other 802.11 vendors, Bosse said. For example, the price of a RadioLAN wireless card for a notebook computer is approximately $150 less than Netwave's 802.11-compliant
AirSurfer Plus. Additionally, the RadioLAN offering does not require an access point, because the network is peer to peer. Each Netwave access point adds $1,499 to the network cost. However, Netwave offers greater range from an access point to the PC, and it lets users move from access point to access point.
The speed/distance debate is not lost on users. Richard Hoffman, lead applications engineer at the American Red
Cross in Falls Church, Va., said that the issue of speed vs. distance is an important consideration in his current evaluation of wireless products. The American Red Cross now uses Proxim Inc.'s RangeLAN2, but Hoffman said that he is also testing wireless systems from RadioLAN and Lucent. The wireless networks are used for two primary applications: within warehouses where Red Cross goods are stored and onsite at disasters where the Red Cross sets up emergency centers.
Normally, he said, rescuers simply open a case with four to eight notebook computers, turn them on, and are up and running with the wireless network.
Although he is generally happy with Proxim's 1.6Mbps offering and the company's announced plans to be 802.11-compliant, Hoffman is considering RadioLAN's proprietary approach. Proprietary technology is "limiting," he said, but the 500 percent performance increase is compelling. Hoffman said he would prefer a standards-based system at the higher bandwidth.
Cam Grant, president of Grant Engineering in Aurora, Ontario, does not have an issue with proprietary hardware.
Grant runs an Internet service in the town of Collingwood, Ontario, which is on the banks of the Georgian Bay, 30 kilometers northwest of Toronto. ISDN is not available in the town and the cost of dedicated T-1 lines is $800 to $900 per month per drop, so Grant opted for a wireless network from Calgary, Alberta-based WiLAN to connect several town offices, an adult-learning center, and the engineering company to the Internet.
The wireless LAN let him install the network in less time and at far less cost per location, he said. It also provides slightly better speed than T-1 (2Mbps vs. 1.544Mbps) for his approximately 150 users; home users have dial-up access to the Internet using conventional 28.8Kbps mode ms. Thus far, Grant said, he has not had any serious outages on his wireless network. If significant problems did arise, he said, he might be inclined to look at other options, but it would still have to be wireless.
Grant acknowledges that he is somewhat limited by WiLAN's proprietary technology, but said he would consider the 802.11-based products when the town upgrades its hardware to take advantage of the additional frequencies provided in the standard. But, he said, "There's no pressure to change right now."
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