A signal measurement method and apparatus, and a communication device and a storage medium are provided. The method includes that a first communication device receives, via a first type of network, a measurement result, sent by a second communication device, for a second type of network.

Aspects of the present disclosure relate to wireless communications, and more particularly, to cell recovery techniques. One example method generally includes receiving, at a user-equipment (UE), at least one pilot signal via a secondary cell, receive, via a primary cell, a first message triggering reporting of at least one preferred beam for communication via the secondary cell, determining the preferred beam based on the at least one pilot signal, transmitting, via the primary cell, a report indicating the at least one preferred beam, and communicating data via the secondary cell and via the preferred beam.

Apparatuses, methods, and systems are disclosed for discarding data corresponding to a conditional handover. One apparatus includes a transmitter that transmits information corresponding to a conditional handover to multiple candidate cells. The information indicates to one or more candidate cells of the multiple candidate cells a time to discard data or to discard the data.

Apparatuses, methods, and systems are disclosed for discarding data corresponding to a conditional handover. One apparatus includes a transmitter that transmits information corresponding to a conditional handover to multiple candidate cells. The information indicates to one or more candidate cells of the multiple candidate cells a time to discard data or to discard the data.

A system for converging fifth generation (5G) communication systems for supporting higher data rates beyond fourth generation (4G) systems with a technology for Internet of things (IoT) is provided. The communication method and system may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A system is provided for determining system information validity by acquiring and storing a first system information block and other system information, including information on a public land mobile network (PLMN) identity and a value tag, and determining whether the stored system information is valid for the cell. As another example, a terminal and base station are provided for performing beam failure detection and a recovery procedure using first and second configuration information for beam failure recovery (BFR) and if failure is detected, initiating a first random access (RA) procedure and if second configuration information is received while the first RA procedure is ongoing, terminating the first RA procedure and initiating a second RA procedure based on the second configuration information.

A system for converging fifth generation (5G) communication systems for supporting higher data rates beyond fourth generation (4G) systems with a technology for Internet of things (IoT) is provided. The communication method and system may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. A system is provided for determining system information validity by acquiring and storing a first system information block and other system information, including information on a public land mobile network (PLMN) identity and a value tag, and determining whether the stored system information is valid for the cell. As another example, a terminal and base station are provided for performing beam failure detection and a recovery procedure using first and second configuration information for beam failure recovery (BFR) and if failure is detected, initiating a first random access (RA) procedure and if second configuration information is received while the first RA procedure is ongoing, terminating the first RA procedure and initiating a second RA procedure based on the second configuration information.

An embodiment of the present disclosure may provide an inter-MeNB handover method in a small cell system, including: making, by a source MeNB and/or target MeNB, a determination as to whether to maintain a SeNB when handover is performed; and triggering different handover processes according to a result of the determination as to whether to maintain the SeNB. Another embodiment of the present disclosure may further provide an inter-MeNB handover device in a small cell system. With the inter-MeNB handover method and device in a small cell system provided by the present disclosure, unnecessary deletion and re-establishment of the bearers at the SeNB for the UE may be reduced. False bearer deletion may be avoided and data forwarding may be reduced. Furthermore, the SeNB may be maintained according to network deployment and SGW re-selection may be supported. Therefore, system capacity and transmission speed of the data may be improved.

An embodiment of the present disclosure may provide an inter-MeNB handover method in a small cell system, including: making, by a source MeNB and/or target MeNB, a determination as to whether to maintain a SeNB when handover is performed; and triggering different handover processes according to a result of the determination as to whether to maintain the SeNB. Another embodiment of the present disclosure may further provide an inter-MeNB handover device in a small cell system. With the inter-MeNB handover method and device in a small cell system provided by the present disclosure, unnecessary deletion and re-establishment of the bearers at the SeNB for the UE may be reduced. False bearer deletion may be avoided and data forwarding may be reduced. Furthermore, the SeNB may be maintained according to network deployment and SGW re-selection may be supported. Therefore, system capacity and transmission speed of the data may be improved.

Method, apparatus and systems are provided for key derivation. A target base station receives multiple keys derived by a source base station, where the keys correspond to cells of the target base station. The target base station selects a key corresponding to the target cell after obtaining information regarding a target cell that a user equipment (UE) is to access. An apparatus for key derivation and a communications system are also provided.

Method, apparatus and systems are provided for key derivation. A target base station receives multiple keys derived by a source base station, where the keys correspond to cells of the target base station. The target base station selects a key corresponding to the target cell after obtaining information regarding a target cell that a user equipment (UE) is to access. An apparatus for key derivation and a communications system are also provided.