== rx_tchf_fn(): TCH/FS, TCH/EFS, TCH/AFS, TCH/F2.4, and FACCH/F

  00  01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 4
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d |  Rx bid={0,1,2,3}, decode
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 4
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h |  Rx bid={0,1,2,3}, decode
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 4
                                                                |
                                                                |<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|  frame A
                                                                |               |<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|  frame B
                                                                @ decoding from here


== rx_tchf_fn(): TCH/F14.4, TCH/F9.6, TCH/F4.8

  00  01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 4
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d |  Rx bid={0,1,2,3}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 4
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h |  Rx bid={0,1,2,3}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 4
|   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h | i | j | k | l |  Rx bid={0,1,2,3}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 4
|   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p |  Rx bid={0,1,2,3}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 4
|   |   |   |   | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t |  Rx bid={0,1,2,3}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 4
| a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x |  Rx bid={0,1,2,3}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 4
|
|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|  frame A
|               |<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|  frame B
@ decoding from here


== rx_tchh_fn(): TCH/HS, TCH/AHS

  00  01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b |   |   |  Rx bid={0,1}, decode
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d |   |   |  Rx bid={0,1}, decode
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f |   |   |  Rx bid={0,1}, decode
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
                                                                |
                                                                |<~~~~~~~~~~~~~>|  frame A
                                                                |       |<~~~~~~~~~~~~~>|  frame B
                                                                @ decoding from here


== rx_tchh_fn(): FACCH/H

  00  01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b |   |   |  Rx bid={0,1}, decode
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d |   |   |  Rx bid={0,1}
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f |   |   |  Rx bid={0,1}, decode
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---|---+---+---+---+---+---+---+---+  << 2
                                                                |
                                                                |<~~~~~~~~~~~~~~~~~~~~~>|  frame A
                                                                |               |<~~~~~~~~~~~~~~~~~~~~~>|  frame B
                                                                @ decoding from here


== rx_tchh_fn(): TCH/H4.8, TCH/H2.4

  00  01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b |   |   |  Rx bid={0,1}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d |   |   |  Rx bid={0,1}
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f |   |   |  Rx bid={0,1}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h |   |   |  Rx bid={0,1}
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h | i | j |   |   |  Rx bid={0,1}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h | i | j | k | l |   |   |  Rx bid={0,1}
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   |   |   | a | b | c | d | e | f | g | h | i | j | k | l | m | n |   |   |  Rx bid={0,1}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   |   |   | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p |   |   |  Rx bid={0,1}
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   |   |   | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r |   |   |  Rx bid={0,1}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|   |   | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t |   |   |  Rx bid={0,1}
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
| a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v |   |   |  Rx bid={0,1}, decode
|---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+  << 2
|
|<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|  frame A
|               |<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|  frame B
@ decoding from here