PhD defence by Justas Podery

Title: Scalable Streaming Multimedia Delivery using Peer-to-Peer Communication



Principal supervisor: Assoc. Prof. José Francisco Soler Lucas, DTU Fotonik

Co-supervisor: Prof. Lars Dittmann, DTU, Denmark


Evaluation Board

Assoc. Prof. Michael S. Berger, DTU Fotonik, Denmark

Assist. Prof. Fidel Liberal Malaina, University of Basque Country, Spain

Assoc Prof. Qi Zhang, University of Aarhus, Denmark


Master of the Ceremony

Assoc. Prof Henrik L. Christiansen



Peer-to-Peer (P2P) refers to a communication paradigm, where each communication peer can act as a client and as a server. In P2P communication, information is disseminated from an information source to all the clients. At the same time, as information is stored in the client's device, the clients become an information source to other clients as well.

The origins of modern P2P communication are closely linked to file distribution. The first P2P communication programs that were widely adopted were used primarily to share non-streaming data, such as music recordings, films, games, and computer programs. However, with streaming multimedia gaining a larger and larger share of the global Internet data traffic (soon envisioned to reach 80\%), P2P communication is seen as a viable method to reduce the communication load on the streaming multimedia servers. By employing P2P communication along with distributed multimedia content delivery networks (CDN), high-quality multimedia data can be delivered to a larger number of users using the same amount of servers infrastructure.

This thesis investigates how P2P communication can be used to distribute streaming multimedia among multiple users. Specifically, it investigates how different algorithms, running in the Peer-to-Peer Streaming Peer Protocol (PPSPP) client, impact the start-up time and playback continuity of multimedia streams. As P2P communication is a cooperative process, this thesis investigates how requests for outstanding data should be divided among the connected peers to achieve high streaming continuity. During P2P multimedia streaming, in addition to receiving data from a multimedia server, clients also receive data from other peers. This thesis investigates how the Low Extra Delay Background Transport (LEDBAT) protocol can be tuned for use with P2P multimedia streaming while at the same time ensuring that the Internet connections of the connected peers are not congested. This thesis also presents ways to integrate P2P multimedia streaming with communication peers ranking provided by the Application Layer Traffic Optimization (ALTO) protocol.

The final two chapters of this thesis are dedicated to performance measurement of P2P multimedia streaming over different wireless communication technologies. This work investigates how P2P multimedia streaming can be performed over the Wi-Fi Peer-to-Peer connections. It also investigates methods of placing multimedia caches in the Long Term Evolution (LTE) network base-stations, along with possibilities of implementing Peer-to-Peer communication using the same LTE infrastructure.


Fri 25 May 18
13:30 - 16:30


DTU Fotonik


Lyngby Campus building 341 - Aud: 22