[IEEE]
In this paper, we analyze the end-to-end communication activities of a modern mobile phone, Nokia N95, to understand how much energy different communication alternatives consume. In particular, we investigate the interactions when multiple connections are used in parallel. Parallel connections save energy but the gains vary depending on the technology. TCP downloads during 3G voice calls result into 75%-90% energy savings, TCP downloads during VoIP calls result into 30%-40% savings, and TCP downloads when other TCP streams are active at the same interface result into 0%20% savings. The results indicate that there is a significant potential to save energy if applications are engineered to take advantage of this phenomenon.