  With the proliferation of wireless applications, the electromagnetic (EM)
space is becoming more and more crowded and complex. This makes it a
challenging task to accommodate the growing number of radio systems with
limited radio resources. In this paper, by considering the EM space as a radio
ecosystem, and leveraging the analogy to the natural ecosystem in biology, a
novel symbiotic communication (SC) paradigm is proposed through which the
relevant radio systems, called symbiotic radios (SRs), in a radio ecosystem
form a symbiotic relationship (e.g., mutualistic symbiosis) through intelligent
resource/service exchange. Radio resources include, e.g., spectrum, energy, and
infrastructure, while typical radio services are communicating, relaying, and
computing. The symbiotic relationship can be realized via either symbiotic
coevolution or symbiotic synthesis. In symbiotic coevolution, each SR is
empowered with an evolutionary cycle alongside the multi-agent learning, while
in symbiotic synthesis, the SRs ingeniously optimize their operating parameters
and transmission protocols by solving a multi-objective optimization problem.
Promisingly, the proposed SC paradigm breaks the boundary of radio systems,
thus providing us a fresh perspective on radio resource management and new
guidelines to design future wireless communication systems.
