5G Call Flow : Registration Procedure (Part-1)

-

 Let's have a look on 5g call flow of registration procedure .


Source-ScienceDirect.com

As you can see in the above image that UE has to register itself before using the 5g services . The registration are of several types which are listed down below:
  1. Initial Procedure Registration
  2. Periodic Procedure Registration
  3. Mobility Procedure Registration
  4. Emergency Procedure Registration
In Initial Procedure, when UE is Power-On and ready for registration .Periodic procedure is to keep watch of UE status , if it become inactive , due to some reasons like battery discharge .Mobility procedure is when UE move to another location and then it have to register it, under this procedure.Emergency procedure is when there is any emergency like situations ,then this procedure is used.


Now lets a deep dive how a UE Register itself to a 5g network for using its services.


1. For a registration from UE , it send a registration request to RAN(gNB). Now RAN sends this request to the AMF(Access and Mobility Function).Now how RAN know which AMF it would transfer this request.

So, there are two scenarios : first , if UE has any registration before , it has assigned a identifier , GUTI(Globally Unique Temporary Identifier) ,through which RAN can know the correct AMF which serve this UE before .

Second, if this is the first time of UE registration with the network then, through NSSAI(Network Slice Selection Assistance Information) Slice identifier , RAN search and found which AMF can serve this type of slice and connect to it and sends this request to that appropriate AMF.

2. Now consider the case if UE move to another location then , how things will work. So in this case the UE trying to update its registration and connect to the new AMF , so as it is a mobility triggered process , there is already UE context with the old AMF so this UE context will transfer from old Amf to the new one , and now UE communicate to the new AMF .

3. Now AMF authenticate and authorised UE through, communicate to UDM(Unified Data Management) .

4. As the new AMF has taken the charge of UE , so new AMF will register itself to the UDM and tell it , now I am serving the UE , so that is can take the subscriptions and other updates from UDM regarding the UE. As old AMF has nothing to do with this UE has it is being serve by other one , So UDM notify old AMF to deregister itself regarding this UE and PCF(Policy and Control Function) will no longer serve to this old AMF as its no required policy regarding this UE.

5. The new AMF fetch the policy regarding the access and mobility functions from the PCF for UE to serve . If there is any PDU(Protocol Data unit Session) regarding this UE then, new AMF will communicate to SMF (Session and Management function) to continue the session , if there's any mismatch in it , the PDU Session terminate using session release management and new PDU session will  created according to the need of UE wants.

6.When AMF authenticate UE from UDM then, it sends a message of registration acceptance and UE also sends a acknowledgement of registration acceptance to the AMF for it to know that registration acceptance message has send to the intended UE.





Comments

Post a Comment

Popular posts from this blog

5G Call Flow : Deregistration Procedure and PDU Session Establishment

-
Image
  For Part 1: https://tomar102003.blogspot.com/2022/10/5g-call-flow-registration-procedure.html As in part-1 we have already discussed Registration procedure . Now we will discuss Deregistration Procedure and PDU Session Establishment . So, First Start with Deregistration. We know that if UE(User Equipment) wants to use services of 5G then it have to first register it with the network through the registration procedure . But there is a time when UE  don't want to take services, and wants to deregister from the network so it have to sends the request for deregistration or if a network want to kick out particular UE then, this procedure is also used in this case . ProDeveloperTutorial.com 1. As you can see in the above image that UE sends the deregistration  request   to AMF through RAN.Now AMF sends the request to the SMF for releasing any User related context or any PDU Session associated with this UE. 2. SMF sends the request to the UPF for releasing any ongoing PDU session associ
Read more

All about Docker .

-
Image
# A 10 min read will make you learn about containerisation. Let start!. Overview what we study in this whole: What is Docker. Docker Components. Docker Architecture.   Docker Hub. Docker Registry. Docker Network. What is Docker ? Docker , it is a tool by which we can make containers of the image that are present on the docker hub. It give the way to the developers to package the applications with all its dependencies and operating system to execute the same in any platform and environment.  By using this open source tool  we as a user , get rid of downloading the applications make it to run on our system by downloading all its dependencies and after doing lot of effort , if the application failed to run and error comes , we waste our time in resolving that error by surfing all around . Thus in this fast technology something should be there to do  all these things with ease and time efficient .So, Docker is use for this purpose . Docker Components Docker client and Sever. Docker image .
Read more

BRIEF OF VIRTUALISATION

-
Image
VIRTUALIZATION Virtualization is the way through which you can create many environments by which you can run different operating systems on one platform. It is the layer which is abstracted from the systems that uses System hardware more efficiently . In Virtualization it is seems to us that the virtual machine we are working on our host operating systems , is the dedicated machine. A computer machine has basically three major and huge terms which are more significant are listed  below: Computation. Storage. Network. People uses Virtualization for many purposes. Many people uses it to run application programs which is meant to that operating systems(on which they are not working ) without being reboot from the host operating systems . Virtualization is achieved through Hypervisor which are also of two types , usage of them are depending on the conditions which are listed down below: Types of Hypervisor : Type-1 and Type-2. Type-1 Hypervisor are used in case of your Bare metal(BM)
Read more