Method and apparatus of providing bit count integrity and synchronous data transfer over a channel which does not preserve synchronization

Synchronization and bit count integrity of a synchronous data stream is preserved end to end even as it is transmitted via a medium which does not preserve the synchronous nature of the synchronous data stream. A terminal equipment unit produces a constant rate bit stream which is provided to a communications unit. The communications unit produces first, second, and third data frames comprising, respectively, first, second, and third set of bits from the constant rate bit stream and first, second, and third length fields. The first, second, and third data frames are transmitted to a base unit which places the first set of bits from the first frame into a queue. A set of fill bits equal to the maximum number of bits contained in any frame is then placed into the queue. The base unit then determines the number of bits in the second set of bits of the third data frame, based on the first length field value and the third length field value. The base unit overwrites excess fill bits in the queue with the third set of bits. The number of excess fill bits is equal to the difference between the maximum possible number of bits which may be contained in any frame and the number of bits in the second set of bits.