  We consider a Gaussian multiple access channel (GMAC) where the users are
sensor nodes powered by energy harvesters. The energy harvester has no buffer
to store the harvested energy and hence the energy need to be expended
immediately. We assume that the decoder has perfect knowledge of the energy
harvesting process. We characterize the capacity region of such a GMAC. We also
provide the capacity region when one of the users has infinite buffer to store
the energy harvested. Next we find the achievable rates when the energy
harvesting information is not available at the decoder.
