Abstract: A system includes a communications device and power supply units detachably installable thereon. On an outer surface of the communications device there is an aperture arranged to enable the insertion of different power supply units in different sections of the volume inside the communications device. The volume is continuous so that instead of separate power supply units it is possible to insert, through the aperture, in the volume a physically larger power supply unit which, when installed in the volume, extends into more than one section of the volume. The communications device can be flexibly equipped e.g. with power supply units functioning as back-ups for each other, each taking up part of the volume, or with a single power supply unit, larger than the above-mentioned, taking up the volume. Therefore the volume inside the communications device can be utilized in connection with power supply units of various types.

Abstract: A system includes a communications device and power supply units detachably installable thereon. On an outer surface of the communications device there is an aperture arranged to enable the insertion of different power supply units in different sections of the volume inside the communications device. The volume is continuous so that instead of separate power supply units it is possible to insert, through the aperture, in the volume a physically larger power supply unit which, when installed in the volume, extends into more than one section of the volume. The communications device can be flexibly equipped e.g. with power supply units functioning as back-ups for each other, each taking up part of the volume, or with a single power supply unit, larger than the above-mentioned, taking up the volume. Therefore the volume inside the communications device can be utilized in connection with power supply units of various types.