A Green Distributed Cooperation for Network and Content Management
, Ibrahim Matta
Dipartimento di Elettronica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
Computer Science Department, Boston University, 111 Cummington Street, Boston, MA 02215, USA
We propose a distributed approach in which an Internet Service Provider (ISP) and a Content Provider
to minimize total power consumption.
Our solution is distributed between the ISP and
the CP to limit shared information, such as network topology and servers load. In particular, we develop
diFerent algorithms adopting dual decomposition and Benders decomposition techniques. We investigate
the performance of the proposed solutions on realistic case-studies.
We compare our algorithms with a
centralized model, whose aim is to minimize total power consumption. We ±rst adopt convex functions to
model power consumption of devices: all the distributed algorithms ±nd optimal solutions in this scenario.
We then introduce the possibility of powering oF devices. Results show that in this case the distributed
algorithms are close to the optimal solution, with a power eﬃciency loss less than 18%.
²or the proposed algorithms we speculate on the trade-oF between the complexity of cooperation and
that of the implementation. In particular, with the dual decomposition approach only the Lagrange multi-
pliers associated with the traﬃc demands and users delay are shared between the ISP and CP, but a real
implementation requires a trusted third-party server and careful tuning of parameters. On the contrary,
with a Benders decomposition technique both the traﬃc demands and the ISP power consumption need to
be shared, but this information is exchanged directly. Moreover, the parameters are easy to set, but the
computational time grows linearly with the number of iterations. ²inally, we investigate improvements to
balance the power savings between the ISP and the CP.
Energy-eﬃcient communication has become a challenging problem in the last few years. According to
recent studies  the average temperatures in the world will consistently rise in the next century, global
warming being the principle cause of this phenomenon. Therefore, actions to mitigate the release of
gases in the atmosphere are becoming imperative, and key processes to achieve this goal are the reduction
of power consumption and improvements in energy-eﬃciency.
Technical Report BUCS-TR-2010-008.
Preprint submitted to Elsevier
March 31, 2010