Embodiments describe a varied transmission time interval in wireless communication system. According to some embodiments is a method for assigning a transmission time interval. The method can include measuring a channel condition and/or a data rate of packet communicated by at least one wireless device. Based in part on the data rate and/or channel condition information, a determination can be made whether to schedule a long transmission time interval or a short transmission time interval to the packet. A long transmission time interval can be scheduled if the channel condition is poor and/or there is a low data rate. A short transmission time interval can be scheduled if the channel condition is good and/or the data rate is high or fast. The method can be repeated for multiple wireless devices. Also included is an alternative interlacing structure that supports both long transmission time intervals and short transmission time intervals.