CPC H04W 36/38 (2013.01) [H04L 5/001 (2013.01); H04W 16/28 (2013.01); H04W 36/0016 (2013.01); H04W 36/0044 (2013.01); H04W 36/06 (2013.01); H04W 80/02 (2013.01); H04W 88/085 (2013.01)] | 6 Claims |
1. A communication system, comprising:
a communication terminal device; and
a base station device that performs radio communication with the communication terminal device via a radio beam,
wherein a cell configured by the base station device is spatially separated by a plurality of radio beams being served by the base station device, and
the base station device changes a radio resource control (RRC) parameter to be applied to the communication terminal device from a first RRC parameter for a first radio beam to a second RRC parameter for a second radio beam, without requiring a random access procedure, when the communication terminal device moves from a range of the first radio beam to a range of the second radio beam,
wherein the base station device includes processing circuitry configured to implement:
at least one distributed unit (DU) that outputs the plurality of radio beams; and
a central unit (CU) that controls the at least one DU,
the at least one DU has a medium access control (MAC) function, and
the CU makes:
a notification of the second RRC parameter in advance to the communication terminal device with RRC signaling,
a notification of a switching instruction from a first RRC parameter for a first radio beam to the second RRC parameter for a second radio beam to the communication terminal device with an L1/L2 signaling or a MAC signaling,
wherein the RRC parameter relates to at least one of a scheduling request (SR), acknowledgement (Ack)/negative acknowledgement (Nack) repetitions, a Sounding Reference Signal (SRS), and channel quality indicator (CQI)/channel state information (CSI).
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