  With the extremely large-scale array XL-array deployed in future wireless
systems, wireless communication and sensing are expected to operate in the
radiative near-field region, which needs to be characterized by the spherical
rather than planar wavefronts. Unlike most existing works that considered
far-field integrated sensing and communication (ISAC), we study in this article
the new near-field ISAC, which integrates both functions of sensing and
communication in the near-field region. To this end, we first discuss the
appealing advantages of near-field communication and sensing over their
far-field counterparts, respectively. Then, we introduce three approaches for
near-field ISAC, including joint near-field communication and sensing,
sensing-assisted near-field communication, and communication-assisted
near-field sensing. We discuss their individual research opportunities, new
design issues, as well as propose promising solutions. Finally, several
important directions in near-field ISAC are also highlighted to motivate future
work.
