How different 5G Service Based Architecture from 4G Point to Point Architecture?

New generation 5G architecture is unique in many ways. Normally 3GPP followed same model of development for 2G, 3G and 4G, where we have seen different reference point core architecture (s1ap, s11,s3,s5 etc), protocols and call flows to study any of the previous technologies, but with 5G everything is based on Service based interface and APIs. The following Control Plane interfaces within the 5G Core Network specified in 3GPP TS 23.501 [3] are defined as service based interfaces figure-1: Namf, Nsmf, Nudm, Nnrf, Nnssf, Nausf, Nnef, Nsmsf, Nudr, Npcf, N5g-eir, Nlmf. Yes, reference points are also there in 5G also like N1, N2, N3 etc, hopefully this is only during transition period for NSA mode of deployement.

"Major advantage in SBA figure-1, is instead of predefined interfaces between NEs, a service model is used in which one NF query a Network Repository Functions to discover and enable communication between different NFs, (NRF is not used in point to point model)." So scope of NRF is comes into picture when 5G core will be deployed in SA mode."

1.   Like 4G EPC, no specialized protocol like diameter or GTPvC etc in control plane, all communication between different network function based on rest based API framework, OpenAPI3.0, JSON for serialization, TCP, HTTP2.0 methods like POST, PUT,GET, DELETE, PATCH for API transport.

How Service Based Interface Protocol Stack look like ?

Advantage of above protocol stack, it is based on HTTP/2 which is a standard protocol used in many cloud native web applications, so it will reduce the time to implement any thing in 5G and due to usage of open APIs, development will be faster. Optimization aspect still more research needed, how diameter AVPs will be migrated to http based web APIs etc.

2.  Like Amazon webservice, Facebook, twitter now in 5G allowing 3rd parties to develop and deploy software in 5G network leveraging 5G core open APIs. So, network is act as a service platform for other service providers.

Example: I am a Netflix like content provider Dekho Inida, I may go to an operator and open the operator public GUI based dash board(Similar to amazon web-service dash board) and provide my requirement for new services, where I need a specific QOS for my content users for a duration, say one month. Based on my input, operator will create a dedicated slice and allow my subscriber to use it for the same period.

3. Operator roles not limited only owning and maintaining the network, now they are platform provider and enable others to provide the service. Here who will be benefited both operator and service provider like netflix, skypee etc. No buffer to watch netflix videos and no call drops for Skype users.

4.  5G network will be more agile, flexible, highly scalable and using automation(continuous integration) testing and integration time will reduces the time to market for bug fix, new feature and operator requested use cases or applications.

5.Together with some control functions (i.e. authentication, authorization), service based interface via NEF can be easily exposed to external users such as 3rd-party application provider.

6. Major advantage of using SBA is one NF can have multiple services running independently and each service is self managed without affecting to each other. Eg: healing and scaling.