Coverage Analysis of Skype VoIP Services over HSUPA

Popular Voice-over-IP (VoIP) services such as Skype are frequently being accessed over cellular networks using a variety of radio technologies, of which High Speed Packet Data (HSPA) is one of the most commonly used by smartphones and other mobile devices. HSPA’s uplink (HSUPA) is based on a highly flexible air interface with many settable parameters. This work analyzes HSUPA from the point of view of VoIP in order to formulate recommendations aimed at maximizing voice coverage while maintaining a quality of service that is comparable to that of standard circuit-switched (CS) cellular voice services. Moreover, it quantifies coverage for a number of vocoders used by Skype and compares it with conventional CS voice service provided over 3G cellular networks. Results show that a moderate penalty in cell coverage probability must be paid when switching from CS voice to Skype VoIP over HSUPA, even as its radio parameters are adjusted in order to maximize coverage.