What Is Preferable Access Technology In 5G Fronthaul And Backhaul?
Publisher: Administrator Date:2021-05-26
5G access requirements: Comparing the requirement for 5G access with fibre to the home and business access, there are some important differences. First of all, there will be strict delay requirements for 5G. Applications like autonomous cars and augmented reality dictates latency in the 1 millisecond range, but mobile fronthaul puts even stricter requirements to delay: Maximum 100 microseconds one-way delay between the Remote Radio Head (RRH) and the Base Band Unit (BBU). Secondly, the required capacity is likely to be 10 Gb/s or higher like 25 Gb/s, matching e.g. the bitrates defined in the eCPRI mobile fronthaul specification. Hence, both the delay and capacity requirements are fundamentally different from the access network we have today. Because of the high capacity required, also the cost per access point must be expected to be higher. These parameters dictate the suitability among available access techniques.
High availability of fibre resources: Comparing the different access techniques, it all comes down to cost and availability of fibre resources. If there are many fibres available at a low cost, dedicated fibres to each access point is typically the most cost effective solution. This solution is without compromises since it offers both the highest capacity and the lowest delay.
One important reason for point-to-point fibre becoming highly available is that fibrecables has become very cheap and compact. E.g. comparing with the diameter of a Twisted Pair (TP) cat-6 cable (approx. 6 m.m.), the fibrecable may contain e.g. 48 fibres and costs less than 4 Euro/meter. Hence, there is no reason saving on the fibre-pairs when digging down fibre for a few kilometre of distance.