Time jump procedure
The time hopping ( English time-hopping ), in English as Time Hopping Spread Spectrum designated (THSS) is a modulation method in which the individual bits of a subscriber are transmitted only in short periods of time. The distance between these time segments within a transmission period is varied. This makes it possible for several participants to be able to transmit on the same frequency . Each participant varies his time window, so that although collisions can occur, these rarely occur due to the constant change in the participants' time window. In addition, suitable error correction methods can be used at a higher protocol level, so that the errors can usually be easily corrected or at least recognized.
The diagram above shows the schematic sequence of a time-hopping transmission. In this case, the time frame is divided into five time slots. The two participants share this time frame and each occupy a time slot for the transmission. This time slot is determined by a pseudo-random pattern. So that the receiver can receive all bits that belong together, it must also know the random pattern so that it can regain the signal. The random pattern can accordingly also be viewed as a code, because everyone who wants to listen to the signal must also know the random pattern with which the time slots for the transmission were determined.