Method for efficient harq feedback using two levels of pucch reporting for multicast/broadcast users in nr

Abstract

Techniques of transmitting and receiving HARQ feedback for point to multipoint data packets include using two different PUCCHs for providing ACK/NACK feedback to a sequence of point-to-multipoint (PTM) data packets. For example, when a gNB sends PTM data packets (e.g., as part of a subscription) to subscriber UE's, each UE sends ACK/NACK messages in response over a first PUCCH which has a smaller bandwidth than a conventional PUCCH under which full uplink control information (UCI) may be sent. In some implementations, the ACK/NACK messages are a single bit. In response to a NACK message from a UE, the gNB allocates a second PUCCH to the UE. The UE then send additional details to explain the NACK message. In some implementations, the additional details include an identifier of a missing data (e.g., packet m of n).