Beginner’s Guide to 3G-324M MONA

By Oren Libis

MONA is a call setup time reduction technique used in 3G-324M. In the past several weeks I have noticed that a lot of handset developers and operators out there – not members of the IMTC, are a bit confused at what MONA is and how it really works.

The 3G-324M Activity Group in the IMTC is working hard in the past year on MONA. We’re doing interoperability testing whenever we can and we are going to meet again during October 8-12 for a face-to-face interoperability event with MONA as one of the main items.

What is MONA?

MONA is a call setup time reduction specification for 3G-324M. It is a set of 3 different techniques: MPC, SPC and ACP. I won’t go into the technical aspects of each, but it is important to understand the following points:

1. Each of these techniques alone can reduce call setup time to below 1 second.
2. Each of these techniques has its advantages and disadvantages – this is why MONA specifies three different techniques and not only one.

MONA Classes

3G-324M MONA specifies in addition to these 3 techniques, 3 different classes. 3G-324M products need to support only one of these classes. Each class indicates which of the 3 techniques (MPC, SPC and ACP) need to be implemented:

• Class 1, which requires MPC, SPC and ACP
• Class 2, which requires MPC and ACP
• Class 3, which requires SPC and ACP

The different MONA classes are interoperable with each other. For example, if two handsets support MONA, one supporting class 1 and the other supporting class 2, the call that will be established will either end up using MPC or ACP; if one supports class 2 and the other supports class 3, the call will simply use ACP.

What does is mean to you?

• If you are a developer, you should choose to develop the class that makes the most sense to you in terms of resources, footprint, memory and time to market.
• If you are a mobile operator, you should not force vendors to support a specific class – let your vendors choose their own class – in the end result, you will still get below 1 second of call setup time and you will be giving the vendors some flexibility.

Technorati Tags: 3G-324M, MONA, IMTC, Interoperability, Oren Libis

Interoperability in the Real World, Part 2

By Oren Libis

Last time, I tried to explain my view on the GCF test cases. As these are test cases that you need to pass before deploying your product (by going to GCF test labs), no matter how farfetched they are, you need to handle them. But there are another important interoperability issues that the GCF doesn’t handle. These are the real deployments out there today.

There are a large and growing number of 3G handsets out there and they are coming from several handset vendors. Each one has its own behavior and quirks. You’d be amazed how much effort it takes when you develop a 3G-324M stack to handle all of these quirks and how much you need to invest on the codec level and application level to get things done right.

Difference in behavior

This difference in behavior happens due to the complexity and richness of 3G-324M. Granted – it does only a video call, in a straightforward enough scenario, but the amount of options that this single scenario has is almost unlimited:

• It supports multiple types of codecs each with its own set of configurable parameters
• There are H.245 messages flowing
• Media quality needs to be handled differently by the various media systems out there
• Different developers have implemented 3G-324M, each one understanding the standard in his own way

Server side equipment

There are also servers on the network. These most of the time are using circuit switched networks in front of the handsets, where they are running 3G-324M, but they are also using IP based standards such as H.323 and SIP on the network side, when interacting with media servers for example. They have a different kind of behavior than handsets and they have a different decision making processes designed into them, bringing in more interoperability issues to bear.

What do you do?

The most important suggestion I can give developers of 3G-324M products is to do the GCF test cases that they must in order to get validated, but to focus and invest a lot on the handsets and servers interoperability. Try to get your hands on as much information as possible during your development regarding the differences in behavior of the handsets and servers and make sure you test against as many handsets as possible before you try to deploy your product through an operator.

Technorati Tags: 3G-324M, WCDMA, Interoperability, GCF, Oren Libis