User-detectable sequences for the collision channel without feedback

Protocol sequences are used for distributed multiple accessing in the collision channel without feedback. In this paper we consider user-detectable sequences with the property that each active user can be detected by looking at the channel activity only, within some bounded delay. It is important in some applications such as ad hoc networks. Some lower and upper bounds of its minimum period are investigated in this paper. In addition, we display some interconnections with some other sequence designs.