ymbol) Frame Duration (ms) Peak Spectral PEAKTHR =NDATANsNbFECRATE Efficiency Peak DL Throughput 161.28 347.44 (Mbps) Peak UL Throughput 92.16 188.01 (Mbps) DL Peak Spectral 16.13 17.37 Efficiency (bits/s/Hz) UL Peak Spectral Efficiency (bits/s/Hz) CHAPTER 12 Performance of IEEE 802. 16m and 3GPP LTE-Advanced 12.9.5 User-Plane/Control-Plane Latency and Handover Interruption Time The user-plane latency, alternatively known as transport delay, is defined as the one-way transit time between the availability of a packet at the IP layer at the source (user terminal/base station), and the availability of this packet at the IP layer at the destination (base station/user terminal). User-plane packet delay includes delay introduced by associated protocols and control signaling, assuming the user terminal is in the active state. The IMT-Advanced systems are required to have a user-plane latency of less than 10 ms in unloaded conditions (i.e., a single user with a single data stream) for small IP packets (e.g., 0 byte payload + IP header) in the downlink and uplink directions. To calculate the user-plane and control-plane latencies, it is assumed that each 5 ms radio frame consists of eight subframes of 0.617 ms length, and the Transmission Time Interval (TTI) is equal to one subframe. The mobile station and base station processing times are assumed to take three subframes (3 X TTI). This analysis further assumes an intra-ASN handover mechanism where the serving and target base stations belong to the same ASN entity. Typical values of HARQ re-trans- mission probability or air-link error rate prior to HARQ processing range from 10% to 30%. The HARQ Round-Trip Time (RTT) or the time interval between two consecutive downlink or uplink data transmissions (or re-transmissions) is assumed to be one radio frame (8 X TTI) for the FDD mode. The HARQ RTT for the TDD mode, assuming a DL:UL ratio of 5:3 and one DL/UL switching point per radio frame, is 8 X TTI. Using the user-plane latency calculation model shown in Figure 12-9, the us