WordNet (r) 3.0 (2006):

communication system
    n 1: a system for communicating
    2: facility consisting of the physical plants and equipment for
       disseminating information [syn: communication system,
       communication equipment]

The Free On-line Dictionary of Computing (30 December 2018):

communication system

    A system or facility for transfering data
   between persons and equipment.  The system usually consists of
   a collection of individual communication networks,
   transmission systems, relay stations, tributary stations and
   terminal equipment capable of interconnection and
   interoperation so as to form an integrated whole.  These
   individual components must serve a common purpose, be
   technically compatible, employ common procedures, respond to
   some form of control and generally operate in unison.

   ["Communications Standard Dictionary", 2nd Edition, Martin
   H. Weik].

   (1995-02-06)