GPI-311/E is designed and manufacture for developing capabilities of the BAT-311/E telephone set. This system can be used without operator in the zones where two individual BAT-311/E networks are needed for extending the under coverage area and or communication between the BAT-311/E subscriber and battlefield switchboard, radio networks, and PSTN telephone sets is needed. Benefitting from the GPI-311/E, PSTN subscriber can establish communication with a radio network.