RCS Advanced Course - Chat Sessions A to Z

In this lecture we go over the list of all the topics on which you will get a detailed understanding and in the end tie them together to show how  1to1 and 1toN Chat sessions work.

In this lecture we are talking about the main functions that the RCS client is supposed to take care of.

Here we are talking about what are the main parameters that need to be set and in which scenarios, the configuration Server is used to reconfigure the RCS client.

We covered all the Functional Entities in the IMS architecture that are responsible in selecting the right S-CSCF that will be able to serve the UE for all its RCS functions. 

Building the association of a messaging server with the RCS client on the UE is one of the goals of a successful IMS registration.  We tried to cover that aspect in this lecture.

The Call Flow diagrams are the best way to understand what is involved in a successful IMS Registration. That was the objective of this lecture to give you the flows starting from the registration request coming from the RCS client on the UE.

Which of the following steps is NOT typically involved in the IMS registration process for an RCS client? 

Here we talk about the Architecture for the Presence Server as defined in standards and how we can describe it in a more simplified way showing Presenters and Watchers entities.

Here we describe the Publishing of Capabilities with a simplified Call Flow diagram.

In this lecture we are talking about a sample of PUBLISH method example so that we can describe all the fields that constitute a PUBLISH method.

Here we describe call flows that take place when a subscriber A is trying to check the RCS capabilities of Subscriber B that may belong to another service provider.

To make it more clear, here we discuss a sample of SUBSCRIBE and NOTIFY method so that we could see all the fields that are part of these methods.

In this short duration of this course, we cannot discuss all details of each method involved in Presence Server functionality.  So I wanted to give some of the important RFCs that will be usually referenced if you are working in any RCS Chat session issues.

The last lecture in this section deals with the RLS Resource List Server which is responsible to update the Presence information for all the subscribers in the Contact list in your phone.

Here we shall test the students' knowledge of how the RCS capabilities are published and retrieved by subscribers using Presence Server.

After going through this lecture, you will know all the functions performed by a Messaging Server.

After this lecture you will know all the functions performed by the Message Store.

Here we are talking of key features of MSRP so that in next two slides you will appreciate how we make these features feasible.

Here we describe the role of PCRF that takes care of QOS requirement for the dedicated bearer path.

Here we go through the call flows explaining how all elements are involved to setup a dedicated bearer path.

Standalone Messaging is defined within RCS standards which allow messages to reach the destination if the recipient is not RCS compatible.

Pager Mode is a way to send the message using SIP MESSAGE method that carries the small text or image to the Messaging Server that then decides how to send it to the destination based on status of the recipient.

This is a way to send a larger message to the recipient even when the destination does not support RCS>. We shall describe this with a Call Flow diagram.

Here we see call flows of a successful 1 to 1 Chat session setup. This ties up all the functional elements that we discussed in previous sections.

In this lecture we are covering a 1to1 Chat session setup where the RCS client on user A had to fall back to Legacy  SMS/MMS because the recipient was not supporting RCS.

here we are seeing another version of 1 to 1 Chat session where after all the setup, somehow the MSRP packets are failing to reach the destination. So we try to fall back to legacy but that also is not reachable. So we use Message Store to save the message for later delivery.

In this lecture we discuss how a successful Group Chat session is established.

If I have an ongoing Group Chat session and one member wants to add a new member in the group, what is call flow related to that activity. Lets discuss that in this lecture.

In this lecture we discuss how a member can be removed from an existing ongoing group chat session. We shall discuss this with a call flow diagram.

This set of questions will cover all the topics that we covered in this course.