To keep up with the competition in the industry telecom operators are investing more and more in infrastructure development and it creates opportunities for the subscribers to utilize the services in economical rates. However, the impact on the telecom industry becomes higher due to Over the Top (OTT) services as those are offered in so called free charges and regulators in many countries are gradually considering to block the OTT services. In this situation roaming infrastructure, a duly complex but compulsive technology, can play a vital role in increasing operator’s revenue and interest among the subscribers.

As per the experiences that multiple telecom operators and roaming service providers (IPX and GRX) face in their roaming infrastructure as well as based on many articles related with roaming and voice traffic analysis, there are still need of exploring the underutilized portions of roaming performance indicators and testing platforms. There is a simultaneous need for fighting with OTT services as well as cost depletion and as per Pierro F Irrera in GSMA there are complexities as follows:

1. Multiple legacy network costs towards an interconnected all-IP world.
2. Ambiguity of specifications and variety of user profiles (e.g. messaging). Sometimes it is difficult to identify genuine user as it is common for one subscriber to have multiple SIM cards from more than one operator, which in the end is troublesome in identifying the user profile.
3. Definition of a simplified interconnection charging model to replace the current model. However, there are issues in new charging model as well. Ever since operators based in EU have ‘so called’ removed the roaming tariff, they may satisfy their subscribers by virtue of reducing ARPU.

The existing IREG (International Roaming Expert Group) end to end functional capability testing tool can test most of the options of international roaming, however, the test result does not guarantee the threshold values for all the required QoS parameters. Testing of High Speed Packet Access / LTE data roaming, Diameter Testing, TAP (Transferred Account Procedure) files are still challenge for GSMA assigned existing IREG testing tool.

As per the current practice by many IPX and GRX service providers perform the IREG testing as per following phase.

1. After the roaming agreement with the roaming partner has been signed, IRX/GRX sends out the work orders to the service provider’s operations and billing team in order to make the necessary configurations in the HPMN and VPMN network
2. Inbound IREG testing: IPX/GRX inserts roaming partners’ SIM cards into MUX (SIM Multiplexer) and virtualizes them onto probe in HPMN/VPMN network. Sometimes there is an APMN (Associated Public Mobile Network) acting as third party network (or for specific function, such as SMS) to offer restricted network access to perform troubleshooting (VLR/SGSN print) and to perform the common testing.
3. Outbound IREG testing: It is done by third party network of probes and/or by following-up the testing at the roaming partners. The probes can provide with Layer 3 Tracing, as such troubleshooting is done by IREG experts.

As the demand of international voice and data roaming services keeps on increasing, supporting QoS aware services over roaming platform is essential now. Furthermore, pre-testing raw data exchange between the operators are required for international voice traffic analysis.

To understand more on International Roaming, please do not hesitate to contact Telecontran to attend workshops on any of the following topics:

• Workshop on Roaming and International Voice Traffic
• Workshop on International Roaming with Commercial and Technical Coordination