A cellular repeater may be considered as a form of bi-directional amplifier. They will receive a signal from the local base-station and then re-broadcast it locally within the users premises - house, office, etc. The signal transmitted by the cellular handset or user equipment is packed up by the repeater and rebroadcast to the base-station. Typically a cellular repeater will utilise an external directional antenna to communicate with the base station. There will then be a downlead to the repeater unit itself which will contain the antenna for radiating the signal within the premises.

Many simple cellular repeaters only allow use by one cell phone, but others allow the use of multiple phones.

In order to reduce cellular interference and congestion, the cellular repeater will transmit and receive on the same frequency. While this does present some difficulties for the design, these can be overcome to enable this to be achieved.

Cellular repeaters of cell phone repeaters are sometimes also called wireless cellular signal boosters.

These cellular repeaters boost a cellular signal so that it can be received more easily. These cellular repeaters are often used to boost the cellular signal in areas where the signal may be weak, and they find particular usage in buildings such as homes and offices.

As poor coverage is often one of the key reasons for cellular subscriber churn, methods of improving coverage in localised areas represent a good method of overcoming some of the coverage problems. These can often be installed in homes and offices as personal cellular repeaters to overcome these coverage problems.

While personal repeaters offer good coverage solution for many operators, to date they have not been broadly deployed. Problems including device costs and the installation costs have been factors driving low adoption of cellular repeaters.

However with improvements in technology enabling the installation to be run by the cellular repeater itself, and requiring only a couple of cables such as power, etc to be made by the user - the installation of an external antenna would require additional installation - these cellular repeaters are now becoming more of a reality.