Subscriber loop terminal equipment-resident mechanism for determining bit rate of high-level data link control communication channel
AssigneeAdtran, Inc.
InventorKyle A. Farnsworth
Life of this patent
Estimating the term…
Abstract
An automated data rate detection mechanism examines bit contents of a data frame to identify the number of idle bytes (0111 1110). When no data is transmitted, an all ‘1’s bit pattern (1111 1111) occupies other time slots unused by the customer's device. The number of subscribed DS0 (64 kbps) increments is determined by looking for the first idle byte following all ‘1’s bytes, and counting the number of zero bits until further unused (all ‘1’s) DS0s are encountered. Dividing the total number of zeros counted by two represents the number ‘n’ of assigned DS0 increments. Multiplying this number ‘n’ by the bit rate per DS0 channel (64 kbps) yields the bit rate.
Claims15
A method for automatically enabling a digital communication device to conduct digital communications over a telecommunication link with a network device at a bit rate established by said network device, said method comprising the steps of:
- (a) monitoring digital communication signals conveyed over said telecommunication link from said network device to identify the presence of at least one prescribed digital code therein;
- and
- (b) determining said bit rate in accordance with contents of said least one prescribed digital code identified in step (a), wherein
- said telecommunication link comprises a T1 digital communication link, and said network device is operative, during idle mode, to transmit an idle byte over said T1 digital communication link during each DS0 time slot of a T1 frame used by said digital communications device, and an all ‘1’s bit pattern in every other time slot of said T1 frame unused by said digital communication device, and wherein step (a) comprises monitoring said telecommunication link from said network device to identify said all ‘1’s bit pattern as a precursor to detecting said at least one prescribed digital code.
A method for automatically changing the bit rate employed by a customer premises site installable digital communication device, that is configured to conduct digital communications over a telecommunication link with a network device at a first bit rate, and thereby enable said digital communication device to conduct digital communications at a second bit rate, different from said first bit rate, said method comprising the steps of:
- (a) monitoring digital communication signals conveyed over said telecommunication link from said network device to identify the presence of at least one prescribed digital code therein;
- (b) determining said second bit rate in accordance with contents of said least one prescribed digital code identified in step (a);
- and
- (c) changing the bit rate, employed by said digital communication device to conduct digital communications over said telecommunication link with said network device, from said first bit rate to said second bit rate determined in step (b);
- and wherein
- said telecommunication link comprises a T1 digital communication link, and said network device is operative, during idle mode, to transmit an idle byte over said T1 digital communication link during each DS0 time slot of a T1 frame used by said digital communications device, and an all ‘1’s bit pattern in every other time slot of said T1 frame unused by said digital communication device, and wherein step (a) comprises monitoring said telecommunication link from said network device to identify said all ‘1’s bit pattern as a precursor to detecting said at least one prescribed digital code.
A digital communication device comprising:
- a digital communications transceiver that is configurable to conduct digital communications over a telecommunication link with a network device at a bit rate established by said network device;
- and
- a communications controller, coupled to said digital communications transceiver, and being operative to process digital communication signals conveyed over said telecommunication link from said network device and received by said digital communications transceiver, so as to identify the presence of at least one prescribed digital code therein, and to configure said digital communications transceiver to operate at a bit rate that is based upon contents of said least one prescribed digital code identified in said digital communication signals received by said transceiver, and wherein
- said telecommunication link comprises a T1 digital communication link, and said network device is operative, during idle mode, to transmit an idle byte over said T1 digital communication link during each DS0 time slot of a T1 frame used by said digital communications device, and an all ‘1’s bit pattern in every other time slot of said T1 frame unused by said digital communication device, and wherein said communications controller is operative to examine said digital communication signals conveyed over said telecommunication link from said network device and received by said transceiver, to identify said all ‘1’s bit pattern as a precursor to detecting said at least one prescribed digital code.
Dependencies are inferred from the claim text.