According to this link http://club.cdfreaks.com/showthread.php?s=&postid=433891
"It is a technique to monitor and maintain write quality throughout the recording session. The laser power is adjusted on-the-fly throughout the writing process to maintain this optimum condition."
But Philips preferred to used the term walking OPC "WOPC" applied on +/-R whereas running OPC "ROPC" on +/-rw disc. The algorithim, principle and objective are most likely the same. My question is: What is the main difference between those techniques? Or is it just a matter of naming and implementation of fw algorithm and depends on the developer how those things implemented?
Bottom line the purpose of techniques is used for monitoring and maintaining the quality of the disc writing and ensuring the accuracy of all marks and lands lengths across the disc.