Operating states for D2D discovery

A first device capable of device-to-device (D2D) communication in a wireless communication network in accordance with a Long Term Evolution (LTE) standard, the first device comprising:

• a non-transitory memory storage comprising instructions;
• and
• one or more processors in communication with the memory storage, wherein the one or more processors execute the instructions to:
• receive, from the network, an allocation of a D2D identifier (ID) for D2D discovery operation;
• enter a radio resource control-idle (RRC-Idle) state or a radio resource control-connected (RRC-Connected) state, in a cell of the network in which the first device is located;
• transmit, while in the RRC-Idle state or the RRC-Connected state, on a first set of discovery resources, without requesting authorization from an enhanced node B (eNB) of the cell, a first D2D discovery signal for reception by a second device in the RRC-Idle state or the RRC-Connected state in the network;
• and
• receive, while in the RRC-Idle state or the RRC-Connected state, on a second set of discovery resources, a second D2D discovery signal transmitted by a third device in the RRC-Idle state or the RRC-Connected state in the network, the first and second sets of discovery resources being allocated on a non-device-specific basis.

A system for device-to-device (D2D) communication in a wireless communication network in accordance with a Long Term Evolution (LTE) standard, the system comprising:

• a first D2D device in the network;
• a second D2D device in the network, and
• a third D2D device in the network,
• wherein the first D2D device is configured to:
• receive, from the network, an allocation of a D2D identifier (ID) for D2D discovery operation;
• enter a radio resource control-idle (RRC-Idle)state or a radio resource control-connected (RRC-Connected) state, in a cell of the network in which the first D2D device is located;
• transmit, while in the RRC-Idle state or the RRC-Connected state, on a first set of discovery resources, without requesting authorization from an enhanced node B (eNB) of the cell, a first D2D discovery signal for reception by the second D2D device in the RRC-Idle state or the RRC-Connected state;
• and
• receive, while in the RRC-Idle state or the RRC-Connected state, on a second set of discovery resources, a second discovery signal transmitted by the third D2D device in the RRC-Idle state or the RRC-Connected state, the first and second sets of discovery resources being allocated on a non-device-specific basis.