A network device has a power saving function, wherein the network device shifts to a power saving mode depending on a transition condition and returns from the power saving mode depending on a return condition. Another subject matter of the invention is the use of said composition for augmentation of osteoporotic bone tissue and particularly preferably for vertebroplasty, kyphoplasty, and augmentation of drill holes in osteoporotic bone tissue, as well as a kit for producing said composition. A control means is provided to control a driving motor so as to produce assisting power commensurate with the detected displacement. Each ground station on the earth always communicates a satellite within a predetermined position of its apogee, and hence that satellite appears to the ground station to hover over the earth. The circle of influence data may impact edge weights of a graph search algorithm.