5 key facts about 5G radio access networks

New functional splits

First, for the higher bands, 5G antennas are integrated with the radios (2 in the figure 1). Furthermore , significant parts of baseband HW (hardware) and SW (software) are integrated with the antenna. The higher integration enables highly capable and efficient implementations of massive MIMO, beam forming and beam tracking that are necessary to efficiently use the comparatively high 5G frequencies. This is not possible to do with traditional passive antennas. Some of the 5G antennas integrated with radios pack high computational capability, and include several billion transistors. In addition, 5G also provides improved performance in the lower bands and in classic radios.

Secondly, some functionality that today is placed in the basebands can be virtualized, i.e. the functions operate on Commercial OffThe-Shelf HW, (3 in the figure 1) and can be implemented at the CN sites, rather than at the base station site, for example. For industrial and enterprise 5G applications this is foreseen to be a major deployment case. In fact, some RAN functions can be deployed on the same cloud infrastructure already in 4G, and is further considered for 5G deployments to fully utilize a cost optimized deployment and to leverage low latency capabilities. This means that RAN software can be deployed on the same infrastructure as Core software and managed as a single solution. Hence, 5G RAN and 5G Core are critical, sensitive and significant from a security point of view.

Thirdly, the radio access network is increasingly SW dependent. A base station has millions of lines of code. New SW based functionality is continuously added to enable new use cases, such as Internet-of-Things, or to enable greater capacity and coverage as mobile traffic continues to grow. In many cases, the SW needs to be consistently upgraded across the entire network. This means that not only Core network sites but also baseband and antenna-integrated radios are increasingly SW dependent on compiled code.

In fact, the software complexity of RAN in a baseband exceeds that of Boeing 787 aircraft.