Article Preview
Top1. Introduction
The Evolved Packet System (EPS) is defined as a 3rd Generation Partnership Project (3GPP) standard which features ubiquitous access to multimedia services from any device. The main prerequisite is Internet Protocol (IP) connectivity that may be achieved through any access network both fixed and mobile, narrowband and broadband. EPS is aimed to provide full integration of voice and data services with the requisite quality of service (QoS), which increases productivity and overall effectiveness (Ekstron, 2009). The development of innovative applications is stimulated by opening the network interfaces for third party, which allows third party providers from an IT domain to create applications that use network connections, streaming, messaging and multimedia (Lam, 2012; Petry, 2009).
The increasing requirements to multimedia streaming applications provided on IP based infrastructure impose challenging requirements to signalling protocols in the network. The traditional approach relies on Real Time Streaming Protocol (RTSP) (Shibeshi, 2010; Marungwana, 2009; Khan, 2007), while more advanced solutions study the usage of Session Initiation Protocol (SIP) for multimedia session management (Zheng, 2012; Pleshkova, 2010; Gabin, 2010). From the content provider point of view, the deployment scenario for multimedia streaming applications needs to provide means for control on the streaming content e.g. to start media stream, to control media stream, to receive notification about media stream status etc. Such type of control may be provided by Parlay X “Multimedia Streaming Control” web service (3GPP TS 29.199-19, 2009).
EPS allows both service and subscriber differentiation based on efficient QoS solution ensuring that user experience of each service is acceptable. This solution applies a mechanism for authorization and usage control of bearer resources intended for multimedia traffic and it is called Policy and Charging Control (PCC) (Balbas, 2009; Quellette, 2011). PCC is based on Diameter protocol signaling. Third party application may request a session with required QoS. For example, the open access to QoS management allows provisioning of multimedia content with quarantined QoS (Tugara, 2006). The “Application-driven Quality of Service” (ADQ) is a Parlay X web service that allows applications to dynamically control the QoS available on user connection(s) (3GPP TS 29.199-17, 2009). Configurable service attributes are upstream rate, downstream rate and other QoS properties specified by the service provider and may be applied temporary for defined period of time, or by default.