I analyzed the old IR boundary when adding a mag strip sensor to an older 9250 not equipped for mag strips. See http://www.robotreviews.com/chat/viewtopic.php?f=4&t=20181
A European owner was interested so we captured the IR signaling in use with old marker. They seemed poorly designed. A complicated exchange takes place where the boundary tower exchanges messages with the robot. The side proximity sensors on the robot also serve as IR signaling devices, being computer controlled instead of simple self-contained dedicated parts. These sensors also detect the IR spot projected on the floor with the remote for that follow-the-spot feature. Different coded messages allow identifying different components in the conversations with the robot.
Since the Virtual Wall IR tower detection is entirely in software, it is doubtful this code is continued in the models using mag strip detection.
A funny thing happened when analyzing the VW -- a peculiar software update occurred over the WiFi which changed the coding used in the IR signals, making the VW supplied with the robot unusable.
These Samsung VW's work entirely different from those by iRobot for Roomba robots. The Roomba VW projects a beam which acts like a wall, while the Samsung is an omnidirectional, 360 degree emitter which operates over a certain range in which it can be detected, and activated by receiving a coded signal from the robot's proximity detectors.
The Neato robots have gone beyond the mag strips to support "virtual boundaries" marked on a map of the floor in the smartphone app., with need for physical boundaries. It is not clear how well this works. Samsung has not yet matched this feature.
Incidentally, all the different brand robots with mag strip boundaries have the same detectors and work any brand boundary strip. Neato strips seem the best physically and have the widest availability. Such strips are more expensive than common magnetic stick-on material because they are magnetized in a different way for the detectors, with a single pole all across the top, compared to alternating poles in common materials.