Time Hopping

The time hopping method or time hopping in English called Time Hopping Spread Spectrum ( THSS ) is a modulation method in which the individual bits of a user to be sent only in short periods of time. The distance of these time periods within a transmission period is varies. It is thus possible that several subscribers can transmit on the same frequency. Each participant varies its time slot, so that it can be collisions but who is rarely occur due to the constant change in the time window of the participants. In addition, suitable error correction method can be applied to higher protocol level, so that usually correct the errors easily or can at least recognize.

In the figure above, the schematic expiry of a time- hopping transmission is seen. The time frame is divided in this case, five time slots. The two participants share in that time frame and each occupy one time slot for transmission. This time slot is determined by a pseudo-random pattern. Thus, the receiver can receive all the associated bits, this must also know the random pattern, so that he can regain the signal. The random pattern may therefore be viewed as code, for anyone who wants to monitor the signal must also know the random pattern with which the time slots have been set for transmission.