5G Architecture

With the advent of a new cellular technology comes the realization that for many mobile network engineers, a whole raft of new acronyms and concepts will have to be learned.

5G is no exception, with pretty much the entire architecture anew, at least in name if not necessarily in function. Although 50 networks worldwide are running “5G”, many if not all of these networks are running the “Non-Standalone” version of 5G, which with the exception of some 5G RAN components is largely based on 4G.

With respect to Standalone 5G, at a basic level we have the three main components of the 5G System Architecture: the 5G New Radio (air interface), the NG-RAN (Next Generation – Radio Access Network) and the 5GC (5G Core). This screenshot shows these elements represented in NetX, but we’d recommend taking our trial of NetX so you can see the detail:

The NG-RAN remains a straightforward design in terms of architecture; the gNB is the main RAN node, which can operate in Dual Connectivity mode with other gNBs or 4G eNBs.

It is the 5G Core where the most significant architectural changes take place:

• The Mobility and Session Management capabilities of the MME (Mobility Management Entity) in 4G are now undertaken by separate logical functions in 5G; the AMF (Access and Mobility Management Function) performs Mobility Management, whereas the SMF (Session Management Function) performs, as you may surmise, Session Management.
• The user plane elements of 4G, namely the S-GW (Serving Gateway) and P-GW (PDN Gateway), are now consolidated into one function termed the UPF (User Plane Function). Note that the control elements of the S-GW and P-GW are now found in the SMF.
• The central repository of subscriber information is now the UDM (Unified Data Management), whereas in 4G we have the HSS (Home Subscriber Server).
• Policy control is just as prominent in 5G, with the PCF (Policy Control Function) performing the policy controlling role that the PCRF (Policy and Charging Rules Function) performs in 4G.

There are many additional functions which are found in the 5G architecture, all of which are featured in NetX and explained in the comprehensive 5G training courses that we offer.

However, perhaps the most compelling change is the notion of the Service Based Architecture, which is the basis upon which the control elements of the 5GC will operate. That is, instead of traditional hardware platforms performing dedicated roles, the 5GC control plane will be completely virtualized, with each virtualized network function offering its services to other network functions via standardized APIs based on RESTful.

This article is simply scratching the service of what the end to end 5G architecture is and how it operates. For the detail, we can offer a wide range of telecoms training courses (from beginner to advanced), using several delivery options (LiveOnsite, LiveOnline and OnlineAnytime).

Standalone 5G will be here sooner than you may think – let us help you prepare for it.