  For the next generation of mobile communications systems, the integration of
sensing and communications promises benefits in terms of spectrum utilization,
cost, latency, area and weight. In this paper, we categorize and summarize the
key features and technical considerations for different integration approaches
and discuss related waveform design issues for a future 6G system. We provide
results on new candidate waveforms for monostatic sensing and finally highlight
important open issues and directions that deserve future in-depth research.
