Circular buffer

A circular buffer to store data continuously in a certain period and writes them after the elapse of a predetermined time again to release the memory space for new data. For graphical representation of this process we obtain necessarily a ring shape, where this technique has its name.

Use

This technique is preferably used in security systems, since this technology reduces the cost of the recording medium by a significant factor. Modern video-monitored buses are usually equipped for example with a surveillance camera system with a ring buffer that stores the last 30 minutes. In one incident can now disable the ring buffer deletion of the bus driver; the records of the last 30 minutes in the ring memory are thus retained and not overwritten and can thus be used as criminal evidence.

Due to recent events ( in early 2006 ) an increase in the storage ring period of 30 minutes was currently under discussion: an offender could escape undetected from a bus because the bus driver had failed to disable the ring buffer deletion.