  Integrated sensing and communications (ISAC) has been visioned as a key
technique for B5G/6G networks. To support monostatic sensing, a full-duplex
radio is indispensable to extract echo signals from targets. Such a radio can
also greatly improve network capacity via full-duplex communications. However,
full-duplex radios in existing ISAC designs are mainly focused on wireless
sensing, while the ability of full-duplex communications is usually ignored. In
this article, we provide an overview of full-duplex ISAC (FD-ISAC), where a
full-duplex radio is used for both wireless sensing and full-duplex
communications in B5G/6G networks, with a focus on the fundamental interference
management problem in such networks. First, different ISAC architectures are
introduced, considering different full-duplex communication modes and wireless
sensing modes. Next, the challenging issues of link-level interference and
network-level interference are analyzed, illustrating a critical demand on
interference management for FD-ISAC. Potential solutions to interference
management are then reviewed from the perspective of radio architecture design,
beamforming, mode selection, and resource allocation. The corresponding open
problems are also highlighted.
