Reframing method for a carrier system having a serial digital data bit stream
AssigneeTRW Inc.
InventorDieter A. Susset
Life of this patent
Estimating the term…
Abstract
A reframing method for a T1 carrier type pulse code modulation digital data system utilizes the combination of the terminal frame code and the signalling code wherein four consecutive framing bits provide a unique four bit code indicating any one frame of a 12 frame. The method includes the steps of searching for the terminal frame code, synchronizing the framing code generator with the unique 4 bit code, and thereafter checking the three subsequent frames to insure proper reframing.
Claims3
In a reframing method for a carrier system having a serial digital data bit stream having frames and multiframes which consist of a predetermined number of frames each frame having an additional frame bit used as a terminal frame code which is an alternating pattern of 1 and 0 bits every other frame and used as a signalling frame code for signalling frame detection which is a pattern of three 0 bits followed by three 1 bits every other frame said frame bit codes repeating themselves every multiframe said carrier system including a frame code generator for generating said frame bit codes said method comprising the following steps:
- storing a plurality of corresponding bits from each of at least four consecutive frames;
- searching for a valid terminal frame code in a group of four bits consisting of 1 corresponding bit from each of said four frame, said 4 bits, if valid, representing a unique frame of said multiframe;
- comparing said group of 4 bits in which a valid terminal frame code was found to 4 consecutive bits generated by said frame code generator;
- and synchronizing said generator to generate said multiframe code corresponding to said 4 valid bits.
Dependencies are inferred from the claim text.