Systems and methods for device-to-device communication in the absence of network coverage

A method for coupling a first mobile device with a second mobile device in a Proximity-based Services (ProSe) group communication session comprising:

• the first mobile device discovering the presence of the second mobile device;
• negotiating between the first mobile device and the second mobile device to determine which of the first mobile device and the second mobile device is to become a group owner of the communication session and which is to become a client of the communication session;
• initiating a certificate-based authentication procedure;
• establishing a device-to-device connection between the first mobile device and the second mobile device;
• and
• establishing a Push to Talk over Cellular (PoC) connection between the first mobile device and the second mobile device,
• wherein initiating a certificate-based authentication procedure comprises one of:
• a) the first mobile device asserting a D2D link layer identity and an application layer identity and receiving from the second mobile device an assertion of the D2D link layer identity and application layer identity;
• having the first mobile device assert its belonging to a group by providing an application layer identity belonging to the group and a link layer identity belonging to the group;
• having the first mobile device assert its knowledge of a group master key;
• deriving a group temporary key from the group master key;
• and
• using the group temporary key to protect multicast frames the first mobile device sends over the PoC connection,
• b) having the group owner receive a D2D link identifier for the client;
• having the group owner receive a pairwise master key that is shared with the client;
• and
• using the pairwise master key to transmit and receive data to and from the client, and
• c) having the client receive a D2D link identifier for the group owner;
• having the client receive a pairwise master key that is shared with the group owner;
• and
• using the pairwise master key to transmit and receive data with the group owner.

A mobile device for communicating in a Proximity-based Services (ProSe) one-to-one communication session comprising:

• a processor;
• a transceiver coupled to the processor and arranged to transmit and receive signals via an antenna assembly;
• wherein
• the processor is arranged to:
• discover the presence of a second mobile device;
• negotiate with the second mobile device to determine which of the mobile device and the second mobile device is to become a group owner of the communication session and which is to become a client of the communication session;
• and
• conduct a mutual authentication with the group owner, when the mobile device is a client of the communication session;
• wherein,
• the connection between the first mobile device and the second mobile device is via a device-to-device (D2D) link,
• to conduct mutual authentication the processor is arranged to:
• cause the transceiver to transmit a first certificate owned by the mobile device to the second mobile device to permit the second mobile device to verify the first certificate;
• and
• verify a second certificate owned by the second mobile device;
• and
• wherein:
• the first certificate includes a first link identifier that identifies the mobile device;
• the second certificate includes a second link identifier that identifies the second mobile device;
• the first certificate is arranged to confirm that the mobile device is authorized;
• and
• the second certificate is arranged to confirm that the second mobile device is authorized.

A non-transitory machine-readable medium including instructions for coupling a first computing device with a computing mobile device in a Proximity-based Services (ProSe) one-to-one communication session, which when executed by the first computing device, cause the first computing device to:

• discover the presence of a second computing device;
• negotiate between with the second computing device to determine which of the first computing device and the second computing device is to become a group owner of the communication session and which is to become a client of the communication session;
• and
• wherein when the first computing device is the client, initiate a mutual authentication with the second computing device;
• when the first computing device is the group owner, the instructions cause the first computing device to receive mutual authentication information from the second computing device;
• and
• the connection between the first computing device and the second computing device is via a device-to-device (D2D) link,
• wherein the instructions to initiate mutual authentication with the second computing device comprise instructions to:
• transmit a first certificate owned by the first computing device to the second computing device to permit the second computing device to verify the first certificate;
• and
• verify a second certificate owned by the second computing device;
• wherein:
• the first certificate includes a first link identifier that identifies the first computing device;
• the second certificate includes a second link identifier that identifies the second computing device;
• the first certificate is arranged to confirm that the first computing device is authorized;
• and
• the second certificate is arranged to confirm that the second computing device is authorized.