Pn	total power consumption due to data processing;
${\mathcal{P}}_n$	total power consumption due to networking;
Xkn	task k processing workload, in MIPS, assigned to processing node n;
δkn	binary variable, δkn = 1 if task k is assigned to processing node n, 0 otherwise;
Lksd	traffic flow of task k sent from source node s to processing node d;
${\lambda }_{ij}^{ksd}$	traffic flow of task k sent from source node s to destination (processing node) d through physical link i and j.