A mobile network without strong fibre support – and fibre backhauling – can’t meet the needs of today and tomorrow. However, power is also required. How to solve backhaul as well as power issues in the most efficient way possible?

 

The most relevant requirements to fulfil the 5G enhanced Mobile Broadband (eMBB) use case are area traffic capacity (Mb/s/m2), the peak data rate (Gb/s) and the user experience data rate (Mb/s). These values need to increase 100, 20 and 10 times respectively, compared to the LTE-Advanced values (see fig. 1). To obtain the required high peak data rate 5G employs mmW. To increase the area traffic capacity and user experience data rate, however, this requires extreme cell densification with an inter-site distance of 200 m or less.

 

This cell densification faces three challenges: right of way, power and data backhauling. Let’s take a closer look power and data backhauling.

 

Small cells should be installed in a specific location, as required by the radio plan. Bringing power to a specific location in which it is not already present can be so expensive that is becomes unfeasible. 5G also demands high radio link reliability, so each small cell should be equipped with a battery back-up, which is bound to make the CAPEX and OPEX skyrocket.

 

One solution is to bring power and fibre from a remote location over one single cable. In that way, MNOs are independent from the power utility and can also concentrate battery back up in a single point. Furthermore, data transport benefits from this centralization: the computational base band resources can be optimized and steered where needed. This concept is called C-RAN (Centralized RAN).

 

Prysmian has developed a cable that can be blown into a 10 mm duct, and which features six copper cores with a cross section area of 1 mm2 and up to 36 optical fibres. This makes it possible to deliver up 1.2 kW over 300 meters or 300 Watt over 1200 meters. The cable can be used for conventional DC electricity as well as innovative and safe-to-touch Digital Electricity™. Coexistence of fibre and copper in the same cable is possible thanks to Prysmian BendBrightXS™ technology, which makes the fibres immune to so-called ‘micro bending’ that may occurs when the fibre is close to a stiff support like copper.