8. Conclusion
In this paper, we solve the energy-consumption problem by proposing PGNA to predict the network traffic and then try to shut off the links as long as the network constraints are satisfied. In PGNA, a sHMM is used to model the network, and a deep-sleep method is proposed to shut off the near idle links as many as possible. In order to evaluate the performance of our solution, we used two real ISP topology from the SNDlib and the Rocketfuel, respec- tively. Two typical sets of traffic matrices were generated and real traffic demands from SNDlib were used to test the PGNA. The re- sults show that our solution are effective for energy saving, es- pecially when the network is during off-peak time. Comparing to anther energy-saving approach, namely HESA, PGNA works much better in both topology. For instance, when the network is in idle time, the energy PGNA saves is about twice as much as HESA in GERMANY50.