TDMA in telephone circuit switching - isn't there delay in transmitting a particular user's speech?
The high-speed channel C can transmit two bits in the same time that X and A each produce one bit, so it can simply transmit both bits, one after the other. No bits get lost. Actually, in the PSTN, samples (bytes), rather than bits, are interleaved. In this way, a 1.544 Mbps T1 line can handle 24 conversations simultaneously. 8000 times a second, a complete 193-bit frame of data is transmitted, which contains one 8-bit audio sample for each of the 24 circuits (plus one bit of "overhead").

In wireless TDMA, FIFO buffers are used to bunch the bits from X and A into larger groups called "packets", and the packets are interleaved in the high-speed radio channel. Each packet is transmitted in much less time than it took to create it. At the other end, another buffer captures the packet and then the data is transferred to the DAC at the original sample rate.