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Green home cinema: Streaming better than P2P

Published Sep 15, 2011

Watching movies with an IPTV solution might be a greener choice than downloading with peer-to-peer (P2P) networks. Researchers at KTH have for the first time calculated the climate impact of two popular ways of distributing movies.

IPTV streaming services (Live TV, Video on Demand) are today provided by most major media companies. Peer-to-peer networks are an alternative way of distributing movies with many providers to choose from. A project at KTH analysed the climate impact of both technologies.

- Our object of study was a two hour movie with 3 Gigabytes distributed and watched in Sweden, says Elisabeth Hochschorner, researcher at the Centre for Sustainable Communications (CESC).

For both systems electricity demand for end user equipment was the main contributor to greenhouse gas emissions. The production of end user equipment turned out to be another significant impact factor. Comparing the two systems, P2P had a higher environmental impact, especially when upload speed was low.

- In P2P systems, each user is simultaneously up- and downloading which extends the total time end-consumer devices are needed. Less greenhouse gas emissions could be achieved either through higher upload speed or through decreased movie size. Using the computer for other purposes while uploading also lowers the climate impact from P2P, says Elisabeth Hochschorner.

Elisabeth Hochschorner’s conclusions are based on a life cycle assessment (LCA) presented at the 3rd NorLCA Symposium 15-16 September 2011 in Helsinki. The study is part of the larger project “Next generation media” conducted by KTH (CSC/Media) in collaboration with TeliaSonera.