Applications have always been there
SIM cards have been around for more than 20 years and all along they have been platforms for applications. The case might be that many people have not thought about the initial applications that were on the SIM cards, and still are. The main reason may be that people just do not know that the SIM contains the applications to cryptographically ensure the identification of the subscription to the network. Sound complicated? Maybe, but it is just another way of saying that the SIM is the entity that holds the subscription and regardless in which phone it is inserted it will ensure that your calls come to that phone.
I realize that that might sound basic and several readers think "I knew that". Of course you did! The question is if you also thought about the fact that that makes the SIM an application platform - right from the start - even if it does not directly interact with the user. So that is a pretty nice way in which the SIMs have been with us for a long time and inserting value into our phones without most people even thinking about it.
Another application on the SIM from the early days was the SIM application itself as some would say. The interface to information that is stored on the SIM is a file system. In this file system, information that is central to the behavior of the SIM is stored as well as information stored for the benefit of the subscribers such as address data and SMS. The ability to show files on the SIM is actually an application too.
Does the story end there? Of course it does not, the view of the SIM as application platform has evolved over the years and several applications have been added over the years, in many cases again without the subscribers necessarily thinking about. An early application to come along was remote file management or RFM for short. Using RFM, the files that reside in the SIM application can be updated and managed over the air. A remote server that communicates with the SIM can use commands that are sent over the air to the SIM card to order the RFM application to update files that are on the SIM card.
There are several reasons why one might be interested in updating files on the SIM. One example is the updating of information on the SIM that control the roaming behavior on the SIM. By remotely updating this information, the operator can steer the subscribers to more preferred roaming networks. Now, there is a use case that provides impressive value in the SIM in a simple way!
Initially, SIM vendors would add proprietary means for doing RFM to their SIM cards. This meant that any server that wanted to perform remote file updates to the SIM needed to implement SIM vendor specific protocols for communicating with the card. This naturally limited the value potential by the RFM use cases and initially the area of RFM was technical trials, as with any new technology. As a natural evolution, the RFM application became a standardized application on the SIM and the world could start doing away with SIM vendor specific RFM protocols to move to create a higher value.
So, once again I did go back a bit into history to tell a bit of SIM card environment and its evolution, value and application capabilities. Trust me; I will get back to it in future entries.
Meanwhile I cannot resist telling you that I saw a very interesting demo at the mobile world congress 2010 of what can be done using the SIM. It was a GPS inside a SIM card. Sure, many high-end phones have GPS built in but most phones do not. With a GPS module on the SIM I think that we can open up for a creative process of finding applications for it. I expect it will be exciting to see what this can bring to the SIM in the future. Will it be inserting value for all of us?