Using GNU Radio to transmit and receive audio channels

Hi guys,

I have recently discovered GNU Radio and got very interested, spending
many weeks studying and experimenting with GRC.

From what I’ve read so far, GNU Radio has potentially many different
applications, but you might need to have some deep technical knowledge
to go beyond the standard blocks and tune/tweak them for a specific
application. So, I was hoping that someone with wider and deeper
knowledge than me could point me out the right direction.

I want to implement a wireless transmitter/receiver system for audio
content. It would a consist of a transmitter and 4 receivers. 4 audio
channels are required, one for each receiver. I want to frame the data
and modulate it with GMSK. So, I would want to transmit 4 different
slots in each frame. The slot format would be something like: preamble
(2 Bytes)+SLOT Identifier(2 bits)+ Payload (640 Bytes)+ CRC16 (2 Bytes).

But to be honest, I am bit lost and dont really know which strategy
would be the best. Should I assign a channel for each slot before
framing and modulating and then listen to the “right” slot in each
receiver? Or should I multiplex the 4 channels into a byte stream and
pack the 4 “slots” into one frame payload? How would I retrieve the
correct data in each receiver?

I have tried to edit/modify the existing Packed Encoder/Decoder, but
found it impossible to adapt them to the frame format I want since the
decoder will no longer be able to correlate without access code.
Moreover, the encoder/decoder do not work alone in series, meaning that
can only be used in association with a Modulator/Demodulator.

So can you advise an hypothetical flow graph for what I want to
implement? Which blocks from the already available ones could I use or
try to adapt for my specific implementation?

Thanks in advance for your time.