The importance of a “QoS oriented” testing approach

The concept of “Quality of Service” is well known by Service Providers, Vendors and professionals, but very few understand its impact on the user experience. Referring to QoS is easy when this concept applies to a single network element or a Circuit Switched service, such as a Voice call under a GSM cellular network.
The concept of QoS impacts dramatically on all the latest generation networks, such as UMTS/HSPA+ and LTE/LTE-Advanced. Thanks to a QoS driven approach, these networks make an important leap forward evolving from generic access technologies to Next Generation Networks.

Network-wide QoS investigations

In the past, each network element Vendor claimed the unique set of features and performances of its products. PRISMA’s experience gathered through the years has proven that a stack of excellent network elements does not necessarily guarantee an excellent network. This situation is due to the fact that what really matters to Service Providers, i.e. the user experience and the measured QoS, considerably depend on the perfect interoperability between the various network elements, and more specifically on their behaviour under heavy load conditions.

The ideal testing methodology

QoS testing can be performed at different levels and with different methods. Given the complexity and the size of current traffic mixes, the method which is closest to the live network behavior involves operating at the radio interface. In this manner, all interfaces and network elements are involved, all the joint effects are investigated and the real user experience can be evaluated.

Radio interface load & stress testing

Thanks to the latest generation of Software Defined Radio solutions, i.e. MsSIM, 3GSIM and UeSIM, the same approach used for load & stress over the wired interface can be applied to the radio interfaces. Moreover, thanks to the flexible architecture of PRISMA’s solutions, the same hardware can be reused (with the proper configurations) to test different 3GPP standards and perform Inter-RAT tests.