3GPP packet-switched streaming service (PSS) is a standardized packet-based mobile streaming service, which is based on IETF RTSP/SDP standards. PSS can be implemented over GPRS networks; however these cannot usually guarantee any data rates or delay bounds, but allow sufficient bandwidth for mobile streaming. GPRS cell reselections pose additional challenges for streaming, since several seconds of data transmission breaks may occur, and data may even be lost. The level of error protection of GPRS is good enough for mobile streaming, if the correct quality of service (QoS) profile is configured. In this paper, we study the effect of different QoS parameters configurations to find optimal values for PSS over GPRS. The paper shows also a method for optimizing cell reselection management at the application layer, in order to provide seamless mobility. Results show that despite all the limitations of a GPRS environment, PSS is feasible with a decent quality of service.