A set of additional components are provided together with the OpenEPC project. Although many of these are not essential for the functionality, they are performing important roles not only enhancing, but also showcasing the advantages of the EPC architecture.
1. Video Streaming Application with Adaptive Bitrate
To demonstrate how an application would benefit from receiving events and hand-over information from the EPC IP connectivity provider, we have developed a simple and effective demonstrator which can illustrate the effect of switching between Access Networks with different bandwidth and latency characteristics.
At the front of this application, a gstreamer script provides video streams with various from a single live video source, like a webcam. This acts as a Content Provider for an Application Function (Media Delivery Function) controlled through a SIP interface that is capable of relaying the incoming video streams to unicast/multicast IP addresses as specified in the SIP’s message SDP. The main feature of this application function is that it reacts to callbacks from the PCC to adapt the bitrate to the conditions of the link or to user policies. The AF is prepared to react to the following events:
- PCC Session Termination: ends the specified media session.
- PCC QoS change: changes the session bandwidth to a higher or lower value.
- PCC Loss: the streaming is paused.
- PCC Recovery: the streaming session is resumed.
2. Simplified Deep Packet Inspection (DPI) demonstrator with HTTP interceptor acting as a Traffic Detection Function (TDF)
Besides serving applications which are specifically designed to inter-work with it, the EPC architecture is capable to accustom also for Over-The-Top (OTT) applications. In order to demonstrate such a scenario where a Deep-Packet-Inspection (DPI) tool analyzes transparently the traffic, we have developed a simple look-alike demonstrator by reusing the Squid HTTP proxy and hooking it to the PCRF through an adapter and the Rx interface.
3. VoLTE demonstrator using OpenEPC and OpenIMSCore, with additional features for VoWiFi as well as 2G/3G IMS Centralized Services
For the purpose of providing telephony services in the context of LTE networks, IMS is being regarded currently as a premier choice (VoLTE). To demonstrate the good integration and interoperability between the IMS and EPC layers, the Open Source IMS Core Project has been extended and is fully supported for the purposes of experimentation with OpenEPC.
The setup consists of an Open IMS Core testbed and myMONSTER IMS clients or alternative RCS/RCS-e clients. For service authorization and resource reservation the Rx interface of the P-CSCF is enabled and configured to use the PCRF from OpenEPC. Signaling bearers as well as media bearers are transparently negotiated and managed between the IMS and EPC architectures. Any IMS application, not just telephony, can be directly used accordingly with EPC, without requiring changes. Additionally, through the use of EPC, the IMS procedures are greatly optimized by the EPC provided features of mobility, QoS signaling and enforcements, charging and so on.
The 2G/3G MSC also provides an unified solution for telephony, with the SS7-free direct translation to an IMS-ready SIP/RTP interface. Calls and SMS can be routed from/to IMS, enabling as such a unified telephony core solution for all 3GPP generations and even more, with non-3GPP access being support just as well.