NLOS backhaul, the key to solving the coming capacity crunch
It’s no secret. Mobile data traffic is growing at an exponential rate. By 2015, wireless broadband traffic is expected to reach 6.3 exabytes per month – a 26 fold increase from 2010.
For mobile network operators these are indeed extraordinary times. The evolution of mobile networks from voice, to text, and now video is putting unprecedented strain on service providers as they struggle to keep up with the unrelenting demand for more capacity and better coverage.
To cope with these pressures, carriers have been forced to re-think their networks. In urban corridors, traditional macrocell deployments are giving way to smaller, more tightly concentrated microcells and picocells. How far carriers will be able to take this strategy however has been an open question.
While equipment manufacturers have made great strides in reducing the size and cost of microcell and picocell equipment in recent years, the primary challenge for the industry has been finding practical solutions for backhaul.
Fiber, when it’s available, is often the first choice of carriers. It’s reliable, and offers virtually unlimited capacity. The problem is that while there is generally a great deal of lit fiber in urban centers, it’s rarely terminated in areas where it is needed, and the time and cost of extending a link to a street level microcell or picocell (when possible) is prohibitively expensive.
Microwave backhaul on the other hand, offers greater flexibility than fiber, but it too suffers severe limitations. The primary drawback for microwave links is that they require line of sight between the two nodes. For street level, small cell deployments this is not practical since this is typically where the greatest degree of clutter exists – foliage, billboards, street signs, etc., all of which severely limits microwave performance and the number of locations where microwave links can be deployed. In addition, microwave equipment tends to be bulky which makes it impractical for attaching to street furniture or the sides of buildings.