In this section, we categorize the available literature on D2D
communication in cellular networks based on the spectrum in
which D2D communication occurs. In the following subsection we provide a formal definition for each category and sub-
category. Next, we provide a quick overview to advantages
and disadvantages of each D2D method.
Inband D2D:
The literature under this category, which
contains the majority of the available work, proposes to use
the cellular spectrum for both D2D and cellular links. The
motivation for choosing inband communication is usually
the high control over cellular (i.e., licensed) spectrum. Some
researchers (see e.g., [6], [39]) consider that the interference
in the unlicensed spectrum is uncontrollable which imposes
constraints for QoS provisioning. Inband communication can