By using the average delay of CoAP message derived above, we can calculate the total handover latency of CoMP. The handoff latency at mCSN is the time interval during which a mCSN cannot send or receive any packets during handover operation. The total handover latency consists of the link switching time (tL2) which is caused by L2 handover between new ER and mCSN, the movement detection delay (tMD) at mCSN, the IP configuration delay and duplicate address detection by DHCP (tDHCP), and location update latency (tBU). tBU is the sum of 2t(mCSN, IMMS) and 2t(IMMS, CWC), which are transmission delay of bind messages between mCSN and IMMS, and between IMMS and CWC, respectively. The total handover delay TCoMP is then calculated as follows: