How does time division multiple access $($TDMA$)$ increase a channel's efficiency?

Increases the signal's transmission rate, allowing up to three senders$/$receivers to use the same channel simultaneously.

The technology allows three different senders$/$receivers to use part of the channel at all times.

The technology divides time slots and assigns three different senders$/$receivers some time slots.

The technology codifies three signals into a single one on one end and decodes it on the other.