Multiple Access Techniques

There are three techniques to various stations that can communicate simultaneously with the same satellite:

1. Division Multiple Access by the Frequency (FDMA) In this type of access, it is possible that all stations use the satellite simultaneously, but each uses a different band of frequencies. Such access is usually used in analog transmission.
2. By Division Multiple Access in Time (TDMA) This type of access is only allowed to broadcast stations one at a time on a given range of frequencies, using the "slot" time allocated. This type of access is typically used in digital transmission.
3. Division Multiple Access for in the Code (CDMA) In this type of access, it is possible that several stations broadcast simultaneously in the same frequency signals scattered by the spectrum, encoding the signals ortogonalmente. To recover a given signal is necessary to have knowledge of the code that was used to disperse the signal in the spectrum.