Avago Technologies General IP (singapore) Pte. Ltd.

Nokia Corporation

Shanghai Research Center for Wireless Communications

Jinling Du

Haifeng Wang

Jing Xu

Zhenhong Li

Ting Zhou

Wei Zou

Kari Rikkinen

From a plurality of messages provided by at least a first license-exempt access node which give usage information for the at least one channel in license-exempt radio spectrum, there is derived channel-specific statistical traffic information. This information for the channel is then provided to a second access node that controls licensed radio spectrum. Or in another embodiment the second access node can get this information by sensing and measuring the channel itself. The second access node retrieves this information from its local memory and sends on the licensed radio spectrum a downlink message having contents, determined from the channel-specific statistical traffic information, for aiding a user equipment UE to access the channel with a probability defined by the contents. The UE receives this message, extracts the contents, and attempts to access that channel in the license-exempt radio spectrum utilizing the defined probability.

Apparatus and method for accessing unlicensed band with network assistance

A method and an apparatus for switching D2D data communications between a licensed and a license-exempt band are disclosed. A D2D device receives from a cellular network a pre-switch notification to prepare for a switch of its D2D communications, and in response adopts a temporary strategy for conducting its D2D transmissions prior to the switch. After the switch the D2D device discontinues the temporary strategy. In one embodiment the temporary strategy and its duration are indicated in the pre-switch notification. Two example temporary strategies are presented: 'no-new-data' where new data transmissions are suspended and data re-transmissions are sent with high reliability; and 'no-feedback' where new data is sent with high reliability and data re-transmissions are suspended. Different embodiments have the cellular network access node or D2D device contending for the radio resource in the license-exempt frequency band.

Switching between cellular and license-exempt (shared) bands

The present invention discloses a cluster head assisted method for converting a user terminal from device-to-device (D2D) communication to cellular communication. When quality of a D2D link between a user terminal and a cluster head is lower than a predetermined threshold, if the user terminal has to leave the cluster but still expects to continue an original the service, the user terminal performs cell search and random access, and establishes a radio resource control (RRC) connection with a target base station of a cellular network. Switching from D2D communication to cellular communication is implemented with the assistance of the cluster head, and a communication manner after the switching is provided. The present invention implements mobile switching from D2D communication in distributed cluster communication to cellular communication, which can reduce route search delay and save wireless resources.

Cluster head assisted method for converting user terminal from D2D communication to cellular communication

A method can include receiving at a cluster head, a multicast/broadcast packet from a base station. The method can also include monitoring, at the cluster head, to detect whether any members of a cluster of the cluster head responds to the multicast/broadcast packet with a negative acknowledgment directed to the cluster head. The method can further include, when a result of the monitoring is no detection of any negative acknowledgments, and the cluster head successfully received the multicast/broadcast packet, sending, by the cluster head, a general acknowledgment of the multicast/broadcast packet to the base station.

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Shanghai, China

Jinling Du