Patent ID: 8908630

Claim:
A method in a user equipment (UE) in connection with a base station in a cellular communication system, for avoiding errors in a Hybrid Automatic Repeat reQuest (HARQ) process, wherein at least two scheduling modes are supported including a dynamic scheduling mode in which the UE receives scheduling messages from the base station indicating which resources have been allocated for uplink and downlink transmission, and a semi-persistent scheduling (SPS) mode in which new transmissions are performed on pre-assigned resources, and wherein a New Data Indicator (NDI) flag included in a scheduling message for SPS mode is interpreted as indicating either SPS activation or SPS retransmissions, and an NDI flag included in a scheduling message for dynamic scheduling mode is interpreted as indicating, by toggling of the flag, a new transmission in dynamic scheduling mode, the method comprising: receiving, in a scheduling message, an indication that dynamically scheduled transmission will take place for a first HARQ process; and if a previous transmission that occurred for the first HARQ process before the indication was received used a semi persistent resource, then considering the NDI flag to be toggled regardless of the value of the NDI flag, whereby the received indication is interpreted as an indication of a new transmission.