Rethink Non-Line-of-Sight

Real-performing networks require real-performing backhaul.

Ericsson has proven that MINI-LINK in traditional frequency band outperforms traditional NLOS solutions.

New backhaul challengeThe evolution to denser radio-access networks with small cells in cluttered urban environments has introduced new challenges for microwave backhaul. A direct line of sight does not always exist between nodes, and this creates a need for near- and non-line-of-sight (NLOS) microwave backhaul.

Break the mythThe traditional belief in the telecom industry is that sub-6 GHz frequencies are required to ensure performance in locations where NLOS conditions exist. One problem is that the available spectrum below 6 GHz is very limited and would be insufficient for small-cell backhaul.

Ericsson Research has performed a study comparing a MINI-LINK system working at 28 GHz and a traditional NLOS system working at 5.8 GHz, looking at how the systems perform in different NLOS situations.

High performing NLOS solutions enable operators to deploy sites in a more optimal place from radio plan-ning point of view, at the same time enabling 4-6 times more capacity in backhaul compared to traditional NLOS solutions.

Two interesting test cases were reflection and diffraction. In the reflection case, a link with 100 meters hop length was set up with a reflection in the wall of a building. A stable throughput of 400 Mbps was measured with the 28 GHz system, while the 5.8 GHz system showed a degradation to 70 Mbps due to multipath fading.

In the diffraction case, a link was set up with a 150 meters hop length, diffracting the signal on the edge of a building and down to street level. The 28 GHz system had a maximum throughput of 400 Mbps even with a 30 degree diffraction angle, while the 5.8 GHz system showed more than 50 percent reduction in throughput in the same diffraction angle.

With this study Ericsson has proven that MINI-LINK in traditional frequency bands, above 20 GHz, outperforms traditional NLOS solutions. The myth is crushed and there is a need to rethink NLOS.

Real performanceBackhaul is a key element creating real performance for networks. User experience could be limited by capacity in the backhaul independently of investments in the radio access. Backhaul availability determines the feasible placements of cells, impacts installation costs, as well as time needed for site acquisition and installation.

High performing NLOS solutions enable operators to deploy sites in a more optimal place from a radio planning point of view, at the same time enabling four to six times more capacity in backhaul compared to traditional NLOS solutions.

Realize itThe MINI-LINK is designed for hops over several kilometers and this with a superior system gain in a very narrow beam. By using these capabilities in very short hops and by using the environment in a smart way, diffraction and reflections can be used to overcome obstructions between the macro (often on top of a high building) and small cells (street level). The throughput will be very high and stable, which is very important for mobile backhaul.

With all of this in place, you can create a network that performs the way your customers expect it to – we call it Real Performance.

Learn moreVideo: Dispelling the NLOS mythsEricsson Business Review: Non-line-of-site microwave backhaul for small cellsCampaign site: Real Performance

Four ways to bypass obstacles

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