Go Networks emerged from stealth at the cell industry trade show today, announcing their line of cellular-style Wi-Fi products for metro-scale outdoor deployment: In a briefing last week, the company explained that they use a combination of multiple radios and multiple antennas to provide broader areas of coverage than any mesh nodes on the market today. Their approach uses beam forming, originally pioneered as beam steering by defunct Vivato, which re-emerged as a technology in the era of multiple-antenna (MIMO) Wi-Fi. With beam forming, less power can be used to reach greater distances through redundant, targeted paths. Receive sensitivity is higher as well. (Full-on MIMO can send different data streams over divergent paths, reusing spectrum and increasing throughput at the expense of redundancy.)
The company calls its beam-steering technology xRF and its cellular routing system xCell. The firm uses the 802.11a (5 GHz band) for backhaul, and has base station models that sport multiple 802.11b/g radios. xCell allows them to segregate end users by traffic type, service level, or protocol (b versus g) in much the same way that some enterprise switched networks offer.
This doesn't require changes to the Wi-Fi adapter; rather, a combination of virtual and real SSIDs and built-in Wi-Fi protocol features let them control which network given devices connect to and even lets them force adapters to migrate to other networks. "Whatever devices you will have, whether it's a laptop or a handheld device, if it supports 802.11 or later on 802.16e, it will work with our equipment and you will get all the benefits," said Yuval Mor, director of marketing for the firm, and formerly with Cisco in their high-end routing group
Mor said that Go's approach will require 50 percent fewer nodes per square mile than competing solutions because of its antenna and routing approach, reducing capital expense and operating expense. Because each node can have multiple Wi-Fi radios, more service can be provided in any region covered by a single node. For those counting, Tropos's estimates tend to be 20 to 30 per square mile divided into clusters of about five, each cluster sporting a separate 900 MHz or 5 GHz uplink to a backbone network.
There are two types of outdoor nodes in Go's system: a micro base station and a pico base station. The micro base station features one backhaul radio and two Wi-Fi radios. The pico base station, intended as a niche space filler for underserved areas, has two backhaul radios to allow meshing and one Wi-Fi radio. The micro station can mesh as well, but Go is using mesh as a supplement to their approach. Mesh routing always occurs on the 5 GHz radios, as with BelAir, SkyPilot, and Strix equipment.
The micro base station uses 120-degree sectorized antennas to qualify under higher point-to-point signal limits in an FCC rule originally granted for Vivato. The pico station has an omnidirectional antenna. An indoor receiver is also available; it's designed to better relay service in from outdoor nodes. A back-office device aggregates control and handles xCell configuration among other features.
Mor said that the company is looking away from simple best-effort network access and into new markets that are developing "where you need a lot more guaranteed quality of service," such as voice over IP calling, video, and location-based services.
The company has had beta tests underway for several months in Asia and Europe, said. Mor said that the company views China as one of the largest potential growth markets, but will be actively competing in US and Europe as well.
I've been waiting for the first mesh/metro firm to deploy a beam forming approach with multiple antennas, because MIMO is clearly an effective technology in difficult RF environments. Although MIMO works best in areas with reflection, dense outdoor spaces should provide the multipath reflection that gives a "workaround" to areas of interference or obstacles that can't be penetrated with a direct beam.