This report describes a bachelor thesis in computer science performed at the system department within the product development unit for GSM (Global System for Mobile communication) at Ericsson in Linköping.GSM can be considered a mature technology but it is still updated with new features on a regular basis. This requires that the technology also continuously is being tested. One technique that is used to perform quality tests is called PESQ (Perceptual Evaluation of Speech Quality). PESQ is a standardized algorithm to perform speech quality tests; it gives a score based on how a human would percept speech quality.The purpose of this thesis was to enhance the speech quality analysis process used when testing the GSM network. One goal was to analyze if it was possible to record and inject sound into a phone call and verify the possibility to execute the PESQ algorithm using a smartphone. Another goal was to develop a smartphone application to perform the described tasks.In order to do so an application for Android was developed. The development process included an investigation whether the Android platform supplies the functionality required. The investiga-tion showed that no general solution for recording and injecting audio into a phone call could be found. Recording was possible on some smartphones, but the characteristics of the recorded audio were not as desired. No solution for injecting audio into a phone call could be found for any of the tested smartphones.However, even though no solution for recording and injecting was found, an application was developed. The application was decided to be more of a proof of concept on how an application of this kind would work. It would also be a good foundation for future development. Suggested future work in order to integrate the application into the existing testing environment is to find alternative solutions for recording and injecting, maybe with the help of smartphone manu-facturers.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:liu-78534 |
| Date | January 2012 |
| Creators | Andin, Karl, Ahl, Andreas |
| Publisher | Linköpings universitet, Interaktiva och kognitiva system, Linköpings universitet, Tekniska högskolan, Linköpings universitet, Interaktiva och kognitiva system, Linköpings universitet, Tekniska högskolan |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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