Tarana Wireless is claiming that trials in Manhattan of its AbsoluteAir Non Line Of Site (NLOS) backhaul technology have shown “unmatched” results.
NLOS backhaul has an obvious advantage over line of site technologies – siting of nodes and base stations can be more flexible than where line of site or near line of site is required. In an area with lots of tall buildings like Manhattan, that can be a key advantage.
A drawback of NLOS has been that it has mostly been deployed in sub 6GHz frequencies, and that means that the high capacities required for dense urban backhaul are hard to achieve. (NB There are some claims that higher frequencies can be used for NLOS microwave by making use of techniques such as penetration, reflection and refraction.)
That has lead some companies to focus on providing NLOS solutions that provide greater capacities, or solutions that provide both NLOS and LOS functionality, such as the “Any line of site” company Fastback Networks.
Tarana calls its technical approach Concentrated Multipont (CMP), in which a Concentrator Node (typically sited on a rooftop) provides simultaneous links to a number of End Nodes on a single channel, by exploiting Tarana’s frequency re-use technology.
Tarana’s claim is that this provides spectral efficiency of 30 bits per second per hertz (600 Mbps across 8 links in 20 MHz spectrum) – or a simultaneous 75Mbps to each End Node connected to the Concentrator Node. This differs from other “typical” Point to Multipoint technologies, Tarana says, where capacity to the hub node is shared.
The Manhattan trial tested multiple simultaneous channel links in a 10MHz channel, with Tarana claiming that full rate transmission was achieved in each case “without degradation of quality.”
For the tests, one end of the wireless connection was an AbsoluteAir (Concentrator) node statically mounted on top of a 40 story building. Additional End Nodes were mounted on two metre poles located on mobile vehicles. Vehicles were driven to more than 30 randomly selected locations at distances ranging from 100 metres to 3.0 km from the concentrator node. Tarana claimed that in all instances, the wireless links tested were blocked completely by multiple, and in many cases dozens, of buildings. At each location, the vehicle was stopped, the antenna coarsely aligned, and the links automatically established enabling comprehensive link quality measurements.
For the spectral efficiency test, the concentrator node connected to two different EN nodes operating in the same 10 MHz channel and located less than 1 km away. Both links performed at full capacity and link quality, Tarana said.
Another aspect of the product is aimed at a key issue of small cell deployment – cost of installation and ownership. Taran claims that its End Nodes antennas are self-aligning, allowing for “zero touch” commissioning. Tarana said, “With only coarse alignment at one end, all links were established, fully optimized and carrying traffic within 5 minutes of arrival at each test site. Such “instant” zero-touch installations essentially eliminate costly deployment planning and time consuming manual fine-tuning of antennas required by other products.”
You can request a copy of Tarana’s test results here.
