Multiplex communications – Wide area network – Packet switching
Patent
1989-07-24
1990-05-08
Orsino, Joseph A.
Multiplex communications
Wide area network
Packet switching
375114, H04J 306
Patent
active
049244639
ABSTRACT:
A data coding method for digital communication systems is disclosed. In two embodiments, every four bits of data in a first data channel are mapped to a five bit code symbol. The five bit code symbols are chosen to have a duty cycle of 40 to 60 percent. In the first embodiment, a second channel of data is optionally interleaved with the encoded first channel data by placing single bits from the second channel every sixth bit in the data stream between each five bit code symbol. A plurality of synchronizing words are each formed from other pairs of five bit code symbols, and, in the two channel embodiment, the optional two bits of data from the second channel. The synchronizing words also have a duty cycle of 40 to 60 percent, and further have the characteristic that their bit patterns can only occur where they are placed in a stream of encoded data. This enables them to be easily recognized in a data stream for both synchronization of a communication element with the encoded data stream, and conveyance of control information between elements in the system. The second channel can also be utilized for conveyance of control information, as a separate data channel, or in a third embodiment, to provide an exact 50 percent duty cycle for a "balanced" code in which every four bits of data are mapped to a six bit code symbol. The maximum run length of this code is limited to five if the second channel is used, and four if it is not used.
REFERENCES:
patent: 3985967 (1976-10-01), Colton et al.
patent: 4161719 (1979-07-01), Parikh et al.
patent: 4530088 (1985-07-01), Hamstra et al.
patent: 4606056 (1986-08-01), Perloff
Cooper Jeffrey L.
Simcoe Robert J.
Thomas Robert E.
Digital Equipment Corporation
Orsino Joseph A.
Scutch III Frank M.
LandOfFree
Data coding method for use in digital communication systems does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Data coding method for use in digital communication systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data coding method for use in digital communication systems will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2355138