The concept of “Quality of Service” is well known by standard communications Operators, professionals and Vendors, but very few understand its impact on the user experience. Talking of QoS is easy when referred to a single network element or a Circuit Switched service, such as a Voice call under a GSM cellular network.
The concept of QoS dramatically impacts all the latest generation networks, such as UMTS/HSPA+ and LTE/LTE-Advanced. Thanks to a QoS driven approach, these networks really evolve from generic access technologies towards Next Generation Networks.
In the past, each network element Vendor claimed the unique set of features and performances of its products. The experience PRISMA has gathered in the recent years has shown that a stack of excellent network elements do not necessarily bring excellent networks! This because what really matters, i.e. the user experience and the measured QoS, heavily depend on the perfect interoperability between the various network elements, and more specifically on their behavior under heavy load conditions.
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 the radio interface. By doing so, all interfaces and network elements are involved, all the joint effects are investigated and the real user experience can be evaluated.
Thanks to the latest generation of Software Defined Radio solutions, i.e. MsSIM, 3GSIM and UeSIM, the same approach used for load and 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 to perform Inter-RAT tests.