2G and 3G sim systems

johnR

Below is the final screen from one of the powerpoint presentations from my USIM Training Course that I really do think answers your question.

"Some final thoughts. Not everything about USIM has been captured in this presentation. This presentation was never intended for that, simply because there are too many changes to be discussed in this three day course. It was intended however that students on this course become aware of some important changes that have taken place between GSM SIM and 3G USIM. Frankly those changes cannot be under estimated. It is equally important though that for those matters not discussed students make time to read the relevant standards. The answers are there and students only need apply themselves to reading the standards to comprehend what is happening with USIM. That equally means staying up-to-date with the latest releases in standards."

johnR

Below is the final screen from one of the powerpoint presentations from my USIM Training Course that I really do think answers your question.

"Some final thoughts. Not everything about USIM has been captured in this presentation. This presentation was never intended for that, simply because there are too many changes to be discussed in this three day course. It was intended however that students on this course become aware of some important changes that have taken place between GSM SIM and 3G USIM. Frankly those changes cannot be under estimated. It is equally important though that for those matters not discussed students make time to read the relevant standards. The answers are there and students only need apply themselves to reading the standards to comprehend what is happening with USIM. That equally means staying up-to-date with the latest releases in standards."

Hi trewmte,
Teacher the above is not teaching!
He asked a question and needs some clearance, you could have directed him where to get what to read. Pls help am interested!!!!!!!!!!!!!!!!!!

Ninja the way you replied to 'Ts' response is abit rude. be patiente as you will get an answer for the submitted question when other people get involved. I think what 'T' was trying to say is that there are alot of difference between the 2g SIMs and 3g USIMs and new changes are being put in place all the time. Meaning that there is not one source where you will find a list of all the differences. As changes are been made constantly and inorder to keep upto date with the changes research should be carried out on a regularly.

The nice thing about SIM cards is that they're well governed by standards, if you read and digest the standards then you're on good footing - you don't have that luxury with handsets where the manufacturers seem to pick and choose which of the published standards to adhere to, which to use variations of and, more often than not, just make up their own!

In terms of SIM/USIM cards here are some potentially useful links

http//www.3gpp.org/ftp/Specs/html-info/status-report.htm - list of the 3gpp standards and their revisions.

http//pda.etsi.org/pda/queryform.asp - you can download the standards here.

Otherwise my other favourite site when researching this sort of thing?

http//www.google.com

MobilePhoneForensic and AlexC - absolutely. I agree.

johnR, the points below are some of the hard bits you really need to know when searching about how USIM works. Comparison to GSM SIM thereafter should be fairly easy, but overall this is a time consuming exercise you have undertaken. I know that to be so because it took me along time to research the course material.

When I refer to standards, I am not referring to standards that define the interpretating or understanding of network data and commands etc, I am referring to standards about the actual device itself. As AlexC was highlighting, standards for USIM/SIM are defined for that purpose, handsets seem not to follow a particular qualifying standard/s (other than GSM/3GPP standards).

Where as the design, construction, layout, operating system etc for GSM SIM can, approximately, be defined by at least 5 standards, USIM is a different kettle of fish altogether. There are more than 15 standards that need to be considered for USIM and that is without the inter-related standards.

USIM requires external admin commands, Java CAT and various internal platforms that can be categorised as

- physical
- electrical
- UICC USIM/SIM common file structure
- Common STK
- TE Interface
- CAT-TP for Remote Host connection
- GSM files /Access Controls
- STK (SIM Toolkit)
- UICC CAT (Card Application Toolkit)
- UICC files/Access Controls
- UICC Security Layer for access Controls
- Environments (as they are termed) for USIM and SIM
- Logical access and global platform aid access and addressing.

When conceptualising GSM SIM for comparison to USIM it helps to identify the parts as separate blocks

GSM SIM has two distinct characteristics blocks

- module layer
- hardware layer)

USIM can have many different distinct characteristics blocks dependent on manufacture arrangements, such as

- n-number of hardware defined at the hardware layer.
- platform independent layer for UICC technology
- USIM & SIM blocks for the Application Layer

The filing system follows to some degree the typical architecture of inheritance tree, with file structure conditions prevailing. Formatting of files dependent upon data to be recorded.

Unlike GSM SIM, USIM uses optimised file sharing for location of data simplified by use of ef_pointers without using data repetition recording to prevent proliferation. This was necessary where multiple directories and/or applications combine in the operational state in a user environment.

Hey guys,

Thanks or the replies, they've been quite helpful. I've managed to gather a few articles together and start the research process. I've asked this question because I'm trying to get extend a peice of forensic software to read USIM. I'll review the standards and hopefully that provide me with a foot in the door to understanding what the data is stored and how to interrogate it for information.