Cache enabled small cell network to reduce strain on backhaul

There’s been some interesting new research from the Centre for Wireless Communications in Finland, which has looked at how in-network caching in short range coverage models can improve cellular network performance.

The problems facing operators are well known (see our whitepaper on using 60GHz for LTE backhaul) and there is an urgent need to increase backhaul capacity here to meet the forecast demand from 4G customers.

Indeed, it is estimated that backhaul capacity needs to rise to 1Gbps (up from 35Mbps) in just five years to support the mobile data. This follows a trend for ever increasing data consumption with Cisco predicting 1.4 zettabytes flowing over global networks daily.

The Finnish research looked at small cell networks (SCN) and how they can bring capacity to networks without placing undue pressure and demands on backhaul – to implement small cells, the carrier would normally have to increase backhaul to cope with the extra base stations, or split the backhaul across a larger number of base stations.

This research posits that caching might provide a solution by reducing immediate demand on the backhaul network.

The small cell network, however, is a constrained environment: any caching deployed to a miniature base station has to fit within much tighter storage constraints.

The researchers created a model, which takes into account parameters like signal-to-interference-plus-noise ratio (SINR), base station location, target file bitrate, storage size and the popularity distribution of individual files.

They concluded that although the best way to improve end user performance is to build more base stations, with the right cache design, adding storage to the base station can mitigate the need to build out extra backhaul.