The disclosure relates to a transmission scheme for nodes in a network. More specifically, the disclosure relates to an acknowledgment scheme that minimizes energy requirements for an acknowledgment of a transmission between nodes. The disclosure describes that an energy constrained node may transmit to other nodes in a network and may only require that an acknowledgment of that transmission is received from at least one of the proximal recipients, which may or may not be the ultimate target. In order to minimize the complexity of the receiver in a node and its energy requirements, the acknowledgment scheme may employ simple on-off keying (OOK) irrespective of the modulation technique of the sending transmission. The acknowledgment comprises a series of OOK pulses sent at a specified time after receipt of the transmission. In addition, simultaneously received acknowledgments can be processed and verified without confusion.