Streaming is a service by which real-time data traffic is transferred between the streaming server and the wireless/wired device. Streaming was initially designed for broadband Internet audio and video transmissions, which soon expanded to cover mobile networks as well. The third Generation Partnership Project (3GPP) was created in 1998, which embodied collaboration agreements of numerous telecommunication standardization organizations and bodies, initially targeted for evolved GSM and UMTS (WCDMA) networks. The 3GPP Packet Switched Streaming (3GPP-PSS) specifications define the framework for streaming capabilities for 3GPP mobile devices and networks, including the functionality, interoperability, media types and compatibility specifications. This chapter embodies the chronological advances of 3GPP-PSS and discussions on the general specifications of different releases, including Release 4, 5, 6, 7, and 8 with a focus on the Quality of Service (QoS) support.