  This work introduces a new perspective for physical media sharing in
multiuser communication by jointly considering (i) the meaning of the
transmitted message and (ii) its function at the end user. Specifically, we
have defined a scenario where multiple users (sensors) are continuously
transmitting their own states concerning a predetermined event. On the receiver
side there is an alarm monitoring system, whose function is to decide whether
such a predetermined event has happened in a certain time period and, if yes,
in which user. The media access control protocol proposed constitutes an
alternative approach to the conventional physical layer methods, because the
receiver does not decode the received waveform directly; rather, the relative
position of the absence or presence of energy within a multidimensional
resource space carries the (semantic) information. The protocol introduced here
provides high efficiency in multiuser networks that operate with
event-triggered sampling by enabling a constructive reconstruction of
transmission collisions. We have demonstrated that the proposed method leads to
a better event transmission efficiency than conventional methods like TDMA and
slotted ALOHA. Remarkably, the proposed method achieves 100\% efficiency and
0\% error probability in almost all the studied cases, while consistently
outperforming TDMA and slotted ALOHA.
