Advances in Mobile Cloud Computing Systems

Toward Energy-Efficient Task Execution in Mobile Cloud Computing 95

dispatcher dispatches the transcoding task to the ith service engine at

time slot t, the energy consumption on the ith service engine is the

product of the transcoding time and the power A

i

(t)κs

γ

i

, where the

power κs

γ

i

is a convex function of CPU speed s

i

[9,41]. Normally, γ is

set to be 3 [9]. In addition, without loss of generality, we set the con-

stant parameter κ = 1. If the service engine has no transcoding tasks to

process, the service engine can be set to sleep mode, resulting in very

small energy consumption that can be negligible. Thus, the energy

consumption for completing the ...