Small Cell Backhaul
Small Cell backhaul is the transmission link between the small cell and the mobile network operator's core network. This can take many forms:
For residential and many enterprise small cells, this can be almost any broadband internet service, including DSL and Cable. Sometimes mobile operators mandate that only their own fixed broadband service can be used with their residential small cells, but at least 50% don't. The performance of the broadband link can affect the quality of service, but residential femtocells have been found to work with as little as 256kb/s broadband throughput. Sometimes, a benchmarking performance test is conducted during the online sale of a residential small cell, to ensure this will be adequate. In live operation, small cells monitor the bandwidth available and restrict their own capacity to handle calls where there is insufficient available - for example, limiting to one or two concurrent calls rather than multiple.
For metrocells, deployed in streets and other public areas, a combination of wireless (for the last few hundred metres) and fibre seems ideal. A wide variety of technologies are being considered or adapted for this purpose, and we explain how a toolkit approach to metrocell backhaul is most likely. In particular, the last few hundred metres from a remote metrocell to the nearby hub will be a wireless link, and this (dubbed "fronthaul" or "streethaul") has attracted the most attention.
For rural small cells, an existing broadband wireline service can also be used. However, for the more remote locations, satellite backhaul is now a cost effective option. A related use case involves dealing with natural disasters, where satellite connected small cells can quickly restore service.
ThinkSmallCell resources for Small Cell Backhaul:
In addition to the articles outlined further below, you may find some of these specific links worthwhile:
- Small Cell Wireless Backhaul Vendor Landscape for Metrocells
- List of Wireless Backhaul Vendors
- NGMN white paper outlining small cell backhaul requirements
- Small Cell Forum white paper discussing backhaul technologies (approx 80 pages)