Switch broadens wireless capabilities

Vivato offering blurs distinction of what wireless switches can do.

SAN FRANCISCO - Start-up Vivato last week released details of what it calls the first true Wi-Fi switch - details that add fuel to a simmering debate over just what constitutes a wireless LAN switch.

The company this week will begin shipping to beta testers its wall-mounted, indoor device, which features specialized antenna technology designed to direct, focus and quickly shift narrow radio beams among 802.11b clients.

By contrast, recently announced wireless switches from Aruba Networks (see story), Proxim (see story) and others are in essence Ethernet switches with software that centralizes and manages security and access policies, and applies higher-layer switching functions, such as quality of service, to wireless packets. Most of these vendors also plan to deploy streamlined access points that are little more than 2.4-GHz radios tethered to the switch.

To continue reading, register here and become an Insider. You'll get free access to premium content from CIO, Computerworld, CSO, InfoWorld, and Network World. See more Insider content or sign in.

SAN FRANCISCO - Start-up Vivato last week released details of what it calls the first true Wi-Fi switch - details that add fuel to a simmering debate over just what constitutes a wireless LAN switch.

The company this week will begin shipping to beta testers its wall-mounted, indoor device, which features specialized antenna technology designed to direct, focus and quickly shift narrow radio beams among 802.11b clients.

By contrast, recently announced wireless switches from Aruba Networks (see story), Proxim (see story) and others are in essence Ethernet switches with software that centralizes and manages security and access policies, and applies higher-layer switching functions, such as quality of service, to wireless packets. Most of these vendors also plan to deploy streamlined access points that are little more than 2.4-GHz radios tethered to the switch.

Vivato, which started up in late 2000 and has collected more than $25 million in venture and other funding, blends an Ethernet switch with an 802.11b access point, and a phased array antenna. That combination is designed to let the switch perform a number of tasks unique among indoor wireless LANs.

The sensitive antenna locks on to wireless clients and then directs one of up to three narrow, focused 11M bit/sec radio beams to each client. The beams can jump, on a per-packet basis, from one client to another, according to Vivato.

If there are several clients in the beam path, the 802.11 protocols take over, and the clients automatically share the available bandwidth, says Phil Belanger, vice president of marketing.

The switch's design lets the radio beams reach 900 feet inside a typical office building, depending on construction materials and furnishings, Belanger says. By contrast, most 802.11b access points, using a less-sensitive omnidirectional antenna, have a maximum range of 300 feet.

Belanger says extra range means a single Vivato box can "light up" an entire office floor, eliminating the need to spread traditional access points, priced from $300 to $1,200, all over the space, and then spend still more money to cable them into a wiring closet. The Vivato switch costs roughly $9,000.

All these products are so new that the claims, or counterclaims, can't be sorted out yet. "This [Vivato] technology seems to be an outdoor technology, similar to that used by ArrayCom and others in cellular networks," says Keerti Melkote, vice president of product management for rival start-up Aruba. "But it's not proven indoors."

Melkote questions whether, even if the phased array antennas can transmit successfully over such distances, the client adapter cards, with their omnidirectional antennas, have enough power to reach the Vivato switch. Another issue with longer distances, he says, is how Vivato handles the time limit for acknowledgements between access point and client.

Aruba's approach relies on the standardization and dropping costs of wireless access points, he says. This trend will let enterprise users pack inexpensive access points in fairly dense concentrations, to ensure that all users have optimal throughput.