Abstract: A communications assembly, comprising a first device (130) operable for a public mobile radio network (168) such as a cellular telephony network, a second device (102) operable for a private mobile radio network (166) such as a TETRA network and a communications interface module (170) configured to provide a communications conduit between said first (130) and second (102) devices over a local communications medium is disclosed. The communications interface module (170) is configured to route a communication originating at said first device (130) through said communications interface module (170) to said second device (130) for transmission over said private mobile radio network (166). Optionally or additionally a communication initiated at said communications interface module (170) is routed to said first device (130) for transmission over said public mobile radio network (168).