A UE performs up to a threshold number of attempts to transmit a default capability message to a base station, the default capability message representing a default set of CA combinations supported by the UE. If transmission is unsuccessful, the UE switches to a compact capability mode in which the UE attempts to transmit compacted UE capability messages representing successively smaller subsets of the default set of CA combinations until either a capability message is successfully received by the base station or a second threshold number of unsuccessful transmission attempts is performed. To facilitate configuration of an initial compacted capability message, the UE maintains a PC list that lists one or more cells that have been identified previously as incapable of receiving default-sized capability messages and that further identifies a representation of a limited subset of CA combinations to include in capability messages sent to a corresponding listed cell.

A UE performs up to a threshold number of attempts to transmit a default capability message to a base station, the default capability message representing a default set of CA combinations supported by the UE. If transmission is unsuccessful, the UE switches to a compact capability mode in which the UE attempts to transmit compacted UE capability messages representing successively smaller subsets of the default set of CA combinations until either a capability message is successfully received by the base station or a second threshold number of unsuccessful transmission attempts is performed. To facilitate configuration of an initial compacted capability message, the UE maintains a PC list that lists one or more cells that have been identified previously as incapable of receiving default-sized capability messages and that further identifies a representation of a limited subset of CA combinations to include in capability messages sent to a corresponding listed cell.

Aspects described herein relate to a base station for providing air-to-ground wireless communication over various altitudes. The base station includes a first antenna array comprising one or more antennas configured to form a first cell coverage area extending substantially from a horizon up to a first elevation angle away from the first antenna array to a predetermined distance from the first antenna array. The base station further includes a second antenna array configured at an uptilt elevation angle to form a second cell coverage area extending at least from the first elevation angle to a second elevation away from the second antenna array, wherein the first cell coverage area and the second cell coverage area are concentric to define the ATG cell at least to the predetermined distance and up to a predetermined elevation.

Aspects described herein relate to a base station for providing air-to-ground wireless communication over various altitudes. The base station includes a first antenna array comprising one or more antennas configured to form a first cell coverage area extending substantially from a horizon up to a first elevation angle away from the first antenna array to a predetermined distance from the first antenna array. The base station further includes a second antenna array configured at an uptilt elevation angle to form a second cell coverage area extending at least from the first elevation angle to a second elevation away from the second antenna array, wherein the first cell coverage area and the second cell coverage area are concentric to define the ATG cell at least to the predetermined distance and up to a predetermined elevation.

A knowledge base of cell information can be built and made available to one or more mobile devices. A mobile device with access to this cell information may proactively perform a radio signal scan at a frequency of an expected cell(s) that is/are indicated in the cell information (e.g., if the expected cell is associated with a serving cell and/or with a geolocation that corresponds to the current Global Positioning System (GPS) location of the mobile device). After performing the radio signal scan, the mobile device may store measurement information (e.g., signal strength) about the expected cell(s) in local memory of the mobile device, and, upon receiving an instruction from the serving cell, the mobile device may access the stored measurement information from its local memory, and may send the measurement information to the requesting serving cell.

A knowledge base of cell information can be built and made available to one or more mobile devices. A mobile device with access to this cell information may proactively perform a radio signal scan at a frequency of an expected cell(s) that is/are indicated in the cell information (e.g., if the expected cell is associated with a serving cell and/or with a geolocation that corresponds to the current Global Positioning System (GPS) location of the mobile device). After performing the radio signal scan, the mobile device may store measurement information (e.g., signal strength) about the expected cell(s) in local memory of the mobile device, and, upon receiving an instruction from the serving cell, the mobile device may access the stored measurement information from its local memory, and may send the measurement information to the requesting serving cell.

Disclosed is a wireless communication system using multiple transmission and reception points. In a wireless communication system having a first transmission and reception point and at least one second transmission and reception point belonging to the same cell, the first transmission and reception point has a wider transmission area than the at least one second transmission and reception point, and the first transmission and reception point and the at least one second transmission and reception point generate downlink transmission signals by using the same physical layer cell ID or virtual cell IDs allocated to each terminal, and then the terminals generate uplink transmission signals by using the allocated virtual cell IDs.

A radio terminal (3) can perform carrier aggregation using a first cell (10) of a first radio station (1) and a second cell (20) of a second radio station (2). The first radio station (1) performs, with the radio terminal (3), radio resource control for the first cell (10) and the second cell (20) in order to perform the carrier aggregation. At least one of the second radio station (2) and the radio terminal (3) is configured to transmit, to the first radio station (10), information about a problem occurring in a radio link in the second cell (20) between the second radio station (20) and the radio terminal (30) while the carrier aggregation of the first cell (10) and the second cell (20) is being performed.

A radio terminal (3) can perform carrier aggregation using a first cell (10) of a first radio station (1) and a second cell (20) of a second radio station (2). The first radio station (1) performs, with the radio terminal (3), radio resource control for the first cell (10) and the second cell (20) in order to perform the carrier aggregation. At least one of the second radio station (2) and the radio terminal (3) is configured to transmit, to the first radio station (10), information about a problem occurring in a radio link in the second cell (20) between the second radio station (20) and the radio terminal (30) while the carrier aggregation of the first cell (10) and the second cell (20) is being performed.

In order to perform location-specific services of a broadcasting unit, virtual cells for the location-specific services are set up so that cell data, which define a local cell area, are transmitted to a mobile receiving device via the broadcasting unit. The cell data are stored in the mobile receiving device. The mobile receiving device establishes its current position and determines whether it is located in the cell area. In the event the mobile receiving device is located in the cell area, the receiving device performs a service assigned to the cell data. The setting up of cells for local-specific services by the broadcasting unit in a multitude of mobile receiving devices in the service area of the broadcasting unit enables geographical areas inside and outside the service area to be slit up into smaller, interactive and virtual service cells and cell clusters in a dynamic and optimal manner according to need and geographical and/or service-specific parameter.