A communication system onboard an aircraft includes: a first multi-frequency transceiver coupled to a first antenna; a second multi-frequency transceiver coupled to a second antenna; and at least one processor communicatively coupled to a memory, the first multi-frequency transceiver, and the second multi-frequency transceiver. The at least one processor is configured to: establish a first air-to-ground data communication link with the first multi-frequency transceiver and a first ground station using a first frequency; determine that a handoff from the first frequency to a second frequency is needed, wherein the second frequency is different from the first frequency; and establish a second air-to-ground data communication link with the second multi-frequency transceiver and a second ground station using a second frequency, wherein the first air-to-ground data communication link is maintained until the second air-to-ground data communication link is successfully established.

An aviation connectivity gateway module for remote access to an aircraft's systems and remotely offloading its aircraft data. The module broadly comprises a CPU, a first set of communication elements, a second set of communication elements, a memory, a battery, an IMU, a GPS module, and a number of antennas. The module responds to remote prompts and offloads aircraft data when the aircraft is powered off. An aviation connectivity gateway module for complete BVLOS cellular network connectivity broadly comprises a CPU, a set of electronic connectors, a memory, an IMU, a GPS module, a first cellular connectivity element, a second cellular connectivity element, and a number of antennas. The module switches between the first cellular communication element and the second communication element based a status of the aircraft.

One disclosure of the specification provides a method performed by UE. The method comprises the steps of: receiving a synchronization signal from a network; on the basis of the UE being connected to a base station via an NTN satellite, receiving, from the network, system information related to an NTN; transmitting a RACH to the network; receiving a RA response message from the network; receiving measurement information from the network, wherein the measurement information includes information regarding a measurement point in time for measurement by the UE; determining, on the basis of orbit information of a target satellite, a measurable point in time when an elevation angle of the target satellite exceeds a threshold value; on the basis of the measurement point in time being earlier than the measurable point in time, transmitting a failure message to the network; and carrying out measurement at the measurable point in time.

Aspects described herein relate to a network for providing air-to-ground wireless communication in various cells. The network includes a first base station array, each base station of which includes a respective first antenna array defining a directional radiation pattern that is oriented in a first direction, wherein each base station of the first base station array is disposed spaced apart from another base station of the first base station array along the first direction by a first distance. The network also includes a similar second base station array where the second base station array extends substantially parallel to the first base station array and is spaced apart from the first base station array by a second distance to form continuous and at least partially overlapping cell coverage areas between respective base stations of the first and second base station arrays.

Various aspects of the disclosure relate to handoff of a user terminal in communication with a satellite network portal through a satellite. In some aspects, a satellite network portal and a user terminal use a satellite handoff information to determine when to handoff the user terminal from one cell to another and/or from one satellite to another. In some aspects, a user terminal sends capability information, location information, or other information to a satellite network portal whereby, based on this information, the satellite network portal generates the satellite handoff information and/or selects a handoff procedure for the user terminal. In some aspects, handoff of a user terminal to a different satellite involves the user terminal conducting satellite signal measurements and sending a measurement message to the satellite network portal. In some aspects, the satellite network portal generates new satellite handoff information as a result of receiving a measurement message.

A Distributed Unit (DU) (2) of a base station sends a first message to a Central Unit (1) of the base station in response to detecting initiation of a conditional mobility of a radio terminal (3) from a first cell served by the DU (2) to a second cell. It is thus for example possible to allow a Central Unit (CU) to be aware of satisfaction of an execution condition of a conditional mobility (or initiation of the conditional mobility).

A method and apparatus for receiving a broadcast configuration indicating when a change in a RAN function termination occurs is provided, for example, by a timer value. The broadcast configuration may be received from a satellite, blimp or other moving transmitter. A dedicated configuration may also be received from the serving cell. The dedicated configuration may include a preamble, a transient configuration and an indication of a layer 2 behavior. If a WTRU detects a change in RAN function termination, the WTRU may suspend any uplink data transmissions, apply the transient configuration and transmit the preamble to a target cell. The WTRU may synchronize with the target cell and apply the layer 2 behavior.

Embodiments provide efficient multicast handover for content delivery to client devices in multi-carrier communications systems. For example, client devices in a transport craft can consume a media channel offering via a first carrier during transport through the communications system. Embodiments can establish respective multicast groups for the media channel offering in at least the first carrier and a subsequent second carrier, and can notify the craft of the multicast groups prior to the craft being serviced by the second carrier. Such pre-notification can permit multicast handover of the media channel offering from the first carrier to the second carrier in a manner that avoids typical handover-related. For example, embodiments can direct multicast delivery of the media channel offering to the craft in accordance with the first multicast group while being serviced by the first carrier and in accordance with the second multicast group while being serviced by the second.

In an aspect, a communication control method is a communication control method in a mobile communication system. The communication control method includes a step of changing, by a user equipment, a frequency priority of a frequency to be used in a cell reselection procedure depending on an altitude of the user equipment.

A network node of a terrestrial cellular system provides telecommunications service to a user equipment (UE) in an airborne aircraft. Navigation information transmitted from the aircraft is periodically acquired, including aircraft identity, position, altitude, and a time of determining aircraft position. A link is maintained between the network node and the UE by transmitting beam steered, Doppler shift compensated downlink signals, and by performing beam steered reception of uplink signals. Beam steering is directed toward the aircraft based on the navigation information. Doppler shift compensation is adapted to compensate for a Doppler shift such that the UE experiences a nominal carrier frequency when receiving transmissions from the antenna nodes. Handover from a first to a second coverage area includes using a same cell identifier and a same frequency allocation in the second coverage area as are used in the first.