Abstract: The present invention relates to radio communications, and discloses a method and apparatus for feeding back and receiving acknowledgment (ACK) information of semi-persistent scheduling (SPS) data packets. The method for feeding back ACK information of SPS data packets includes: receiving an uplink downlink assignment index (UL DAI) from a base station (BS), where the value of the UL DAI indicates the number of downlink data packets (N); mapping ACKs/NAKs of k SPS data packets of the downlink data packets to positions from the (N?k+1)th ACK/NAK to the Nth ACK/NAK; and feeding back N ACKs/NAKs to the BS. This method can guarantee that N ACKs/NAKs are arranged correctly.

Abstract: A method and device for service time division multiplexing as well as a method and a device for transmitting service are disclosed. The method for service time division multiplexing includes: selecting a part or all of radio frames in one time unit as specific radio frames; and selecting a part or all of subframes in the specific radio frames as specific subframes for sending a specific service. The specific service is a multimedia broadcast multicast service, or a unicast service, or one or more than one kind of service transmitted in broadcast or multicast mode.