Telecommunications system

A telecommunications system for transmitting and receiving radio signals between one or more portable units and at least one system base unit, each of said portable units comprising:

• a signal receiving and transmitting device for receiving and transmitting radio signals;
• a system identification device connected to said signal receiving and transmitting device for determining whether a received signal is a valid signal transmitted by one of the system base units;
• a recipient identification device for determining whether the received signal is intended for a respective said portable unit;
• a timing device connected to said recipient identification device for monitoring a time lapse since a signal intended for the respective said portable unit was received;
• and
• an automatic registration request generator connected to said timing device for generating a registration request when a received signal is a valid signal not intended for the respective said portable unit and the time lapse is greater than a predetermined period.

A method of automatic registration of a portable unit in a telecommunications system comprising:

• monitoring radio signals received by the portable unit;
• determining whether a received signal is a valid signal from a base unit of the telecommunications system;
• determining whether the received signal is intended for the portable unit;
• monitoring a time lapse since receipt of the last valid signal intended for the portable unit and determining whether the time lapse is greater than a predetermined period;
• and
• generating an automatic registration request when a valid signal not intended for the portable unit is received and the time lapse is greater than the predetermined period.