  Joint communications and sensing (JCS) can improve the efficiency of power,
bandwidth and hardware usage. The conflict between communications and sensing
is analyzed in terms of bandwidth and power. It is found that the bandwidth is
approximately partitioned between communication and sensing, thus making an
almost zero-sum game, while the conflict in the power is marginal. The same
conclusion holds when the receiver and target are separated. The feasible
region and tradeoff boundary of JCS are obtaine.
