Sponsored networks and outbound roamer steering

There are different solutions allowing small operators to be able to inter-operate with quite large number of partner operators without the need of individual interworking agreements. Such solutions enable the new operators a global coverage with the support of the sponsor network.

Both sponsored and sponsor networks employ some products (which some might be called as roaming replicator), to make the message originated from sponsored network look like it is sponsor network’s traffic. Sponsor network route the traffic for the sponsored network properly too, which allows the sponsored network to access all the partners of the sponsor network.

As shown in the figure, when a subscriber attempts to camp to a network which receives service from a sponsor network, the registration request arrives from sponsor network to the HPLMN HLR. As the replicator products change both SCCP calling and VLR addresses with IMSI, from the point of HPLMN the subscriber is like being abroad in sponsor network country.

Issues with steering
Operators may prefer their outbound roamers to register to certain operators even though they may have roaming agreements with many operators in the same country. The motivation of having “preferred” partners can be cost (having discounts) or technical reasons (like better Camel / data support).

Steering solutions determine the country of the outbound roamer and try to steer the subscriber to a preferred partner using different methods. While one of the methods is network based steering which intercepts the subscribers’ registration messages, another method is SIM based steering which updates the preferred list of the subscriber’s SIM properly for the country.

For the sponsored network as the VPLMN, the HPLMN believes that the subscriber is trying to register to sponsor network actually. Besides this confusion, concluding the subscriber is at another country (Country Y instead of X) is a worse problem. There might be different settings for two countries and if the parameters are looser for the sponsor network’s country, this will cause problems for you.

The sponsor network might be a preferred partner and this prevents you to steer the subscriber to the preferred partners in country X. This may not be a problem if the sponsor network is “more preferred” than your preferred partners in the sponsored network’s country. But for the other case, this may mean that you lose some revenue.

Even though the sponsor network is more preferred than any preferred partner in the sponsored network’s country, you still should fix this case with configuration of the steering solution; to be able to retrieve correct reports grouped by countries.

Solution
Sponsor networks let the partners know about the sponsored network in general. They may publish the sponsorship as well the GT prefix for the VLRs used for that sponsored network. What you should do is to look for such publications from partner networks and alter the settings for your steering solution.

You will possibly need to create a new network to represent the sponsored network with the published GT range from the sponsor network's GT range. Considering your steering solutions allows that, then you should assign this new created network to the country / zone of the sponsored network.

With such setting, you will be able to correctly perform steering configuration for both sponsor and sponsored networks' countries. As roaming business is a considerable part of the revenues of the operators, having correct steering settings can be crucial to keep the costs minimized.