  Molecular communication (MC) engineering is inspired by the use of chemical
signals as information carriers in cell biology. The biological nature of
chemical signaling makes MC a promising methodology for interdisciplinary
applications requiring communication between cells and other microscale
devices. However, since the life sciences and communications engineering fields
have distinct approaches to formulating and solving research problems, the
mismatch between them can hinder the translation of research results and impede
the development and implementation of interdisciplinary solutions. To bridge
this gap, this survey proposes a novel communication hierarchy for MC signaling
in cell biology and maps phenomena, contributions, and problems to the
hierarchy. The hierarchy includes: 1) the Physical Signal Propagation level; 2)
the Physical and Chemical Signal Interaction level; 3) the Signal-Data
Interface level; 4) the Local Data Abstraction level; and 5) the Application
level. To further demonstrate the proposed hierarchy, it is applied to case
studies on quorum sensing, neuronal signaling, and communication via DNA.
Finally, several open problems are identified for each level and the
integration of multiple levels. The proposed hierarchy provides language for
communication engineers to study and interface with biological systems, and
also helps biologists to understand how communications engineering concepts can
be exploited to interpret, control, and manipulate signaling in cell biology.
