Multi-IMSI SIM Roaming for MVNOs
To become a successful MVNO and allow your subscribers to call in different countries cheaper, you need to use Multi IMSI roaming solutions.
You can choose how to use the network’s resources in order to provide your subscribers the exact services they need. For example, the Multi IMSI technology is used for travel SIMs. There are a lot of MVNOs that built their business based on travelers. They are offering lower roaming prices for subscribers whom travel often.
Read on and find out how you can benefit from Multi-IMSI technology. This page will cover the following topics:
What is Multi IMSI?
IMSI (Multiple International Mobile Subscriber Identity) is a unique code used by a network to identify and authenticate a subscriber when they attempt to connect to the network. It has the following format:
Multi IMSI (Multiple International mobile subscriber identity) is used to switch between the identities of the SIM using just one card. The Multi IMSI technology allows to switch between up to usually 10 identities of the SIM using a single card and a single IMSI at a time.
To address this limitation, MVNOs need a technical expert of this technology to change the IMSI of the SIM. Luckily, this can be done by giving the SIM autonomous capabilities using Java-based applet. Another alternative is to allow the network to order the change of the IMSI via Over-the-Air (OTA) interfaces. Of course, there are cases when both ways are combined when you have, for example, the main IMSI that’s owned by the MVNO and also has some IMSIs taken from foreign donors. The donor IMSI can be from the MNO you interconnected with, or national operators of the countries your subscribers travel to.
Once the change of the IMSI has been executed successfully, the identity of the SIM changes, allowing authentication and registration of the subscriber. An applet in the SIM will enable switching the IMSI stored in the SIM to allow the subscriber to connect to the visited network without roaming costs.
Multi IMSI Roaming
The fact that multi-IMSI allows operators to switch from the primary IMSI to an IMSI of another country highlights its meaning for roaming.
With the multi IMSI technology, you can provide cheaper services to your subscribers, according to your business model. Traditionally, roaming was executed using a single SIM paired with a single MSISDN. The only problem is the high interconnection charges required by foreign operators to facilitate your connection. To mitigate this financial burden, you need to roam using a SIM with Multi IMSI functionality.
Multi IMSI can be used to switch the primary IMSI to another IMSI from the visited network’s range. This will allow the subscriber to be recognized and charged as a local subscriber. Usually, this shifting process is done by a Java applet. For example, this applet in the SIM will enable switching the MCC, MNC and MSIN to new numbers stored in the SIM.
When your subscribers are traveling to another country things get more complicated. This implies some requirements from the operator of that country. One of them is to have an MSISDN matching the visited network. This means it would change not only the SIM identity, but it would also change the subscriber’s known identity (MSISDN). In this case, whenever there is a Mobile-terminated call to the primary MSISDN and the visited network’s phone number is assigned to that subscriber, the GMSC sends the routing number request to the HSS/HLR.
Why is multi IMSI important for MVNOs?
Yate-based solution equipment for Multi IMSI
MiniCore - Core network for tests and research
The MiniCore is a small factor PC computer that can be used as a test LTE/GSM Core Network. It has installed the MSC/VLR, GMSC, MME/SGW/SGSN, PGW/GGSN, IMS CSCF software components. The MiniCore can also work as an AuC, HLR, HSS for Subscriber management.