While receiving a stream of framed data, frame synchronization is the process by which incoming frame alignment signals, i.e., distinctive bit sequences (a syncword), are identified, i.e., distinguished from data bits, permitting the data bits within the frame to be extracted for decoding or retransmission. This is sometimes referred to as "framing".
If the transmission is temporarily interrupted, or a bit slip event occurs, the receiver must re-synchronize.
The transmitter and the receiver must agree ahead of time on which frame synchronization scheme they will use. The most common frame synchronization schemes are:
- Framing bit. A common practice in telecommunications, for example in T-carrier, is to insert, in a dedicated time slot within the frame, a noninformation bit or framing bit that is used for synchronization of the incoming data with the receiver. In a bit stream, framing bits indicate the beginning or end of a frame. They occur at specified positions in the frame, do not carry information, and are usually repetitive.
- Syncword framing. Some systems use a special syncword at the beginning of every frame.
- CRC-based framing. Some telecommunications hardware uses CRC-based framing.
Contents |
References
This article incorporates public domain material from the General Services Administration document "Federal Standard 1037C" (in support of MIL-STD-188).
Scientific Articles
J. L. Massey. "Optimum frame synchronization ". IEEE trans. comm., com-20(2):115-119, April 1972.
R Scholtz. "Frame synchronization techniques", IEEE Transactions on Communications, 1980
P. Robertson. "Optimal Frame Synchronization for Continuous and Packet Data Transmission", PhD Dissertation, 1995, Fortschrittberichte VDI Reihe 10, Nr. 376 PDF
External links
See also
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
