  Joint radar and communication (JRC) technology has become important for civil
and military applications for decades. This paper introduces the concepts,
characteristics and advantages of JRC technology, presenting the typical
applications that have benefited from JRC technology currently and in the
future. This paper explores the state-of-the-art of JRC in the levels of
coexistence, cooperation, co-design and collaboration. Compared to previous
surveys, this paper reviews the entire trends that drive the development of
radar sensing and wireless communication using JRC. Specifically, we explore an
open research issue on radar and communication operating with mutual benefits
based on collaboration, which represents the fourth stage of JRC evolution.
This paper provides useful perspectives for future researches of JRC
technology.
