A method of transition encoding including: receiving a data packet having a packet size; identifying one or more forbidden patterns in the data packet; segmenting the data packet into a plurality of segments based on a location of the one or more forbidden patterns in the data packet; and encoding the plurality of segments by removing the one or more forbidden patterns, and appending position indicator bits according to positions of the segments in the data packet.

A method includes: scheduling transmission of a first synchronization signal by a first node; and scheduling transmission of a second synchronization signal by a second node. The method also includes, after transmission of the first synchronization signal: receiving, from the first node, a first phase reference associated with the first synchronization signal; and receiving, from the second node, a first phase-of-arrival of the first synchronization signal at the second node. The method additionally includes, after transmission of the second synchronization signal: receiving, from the second node, a second phase reference associated with the second synchronization signal; and receiving, from the first node, a second phase-of-arrival of the second synchronization signal at the first node. The method further includes calculating a propagation delay between the first node and the second node based on the first phase reference, the second phase reference, the first phase-of-arrival, and the second phase-of-arrival.

[Problem to be Solved] Optimizing a route of time synchronization in a network including apparatuses with different types of precision classes. [Solution to the Problem] A time transmission system includes BC nodes 200 with different types of apparatus performances, and multiple routes of PTP packets from GM nodes 101 and 102 to a BC node 220 via the BC node 200 are present. Each BC node 200 located upstream on a route performs notification of performance information indicating its apparatus performance to the BC node 200 located downstream with respect thereto. The BC node 220 includes a determination index calculation unit 11 that calculates a determination index for each route by referencing the performance information notified from the BC nodes 200 located upstream on each route, and a route selection unit 12 that selects a route for transmitting and receiving PTP packets from multiple routes of PTP packets to the BC node 220, based on the calculated determination index for each route.

There is provided a communication device comprising: a communication control section configured to calculate a distance measurement value based on time stamp information received from another communication device during distance measurement that is based on wireless communication that is performed between the communication device and the another communication device different from the communication device, and conforms to specified communication standards, wherein, when the time stamp information is an eigenvalue specified in advance, the communication control section does not calculate the distance measurement value.

A digital clock data recovery circuit including: a first vote circuit connected at an output of a first deserializer and configured to generate an even up/down signal based on even deserialized signals from the first deserializer; a first digital to analog converter (DAC) connected at an output of the first vote circuit and configured to control a voltage and/or frequency of a voltage controlled oscillator (VCO) based on the even up/down signal from the first vote circuit; a second vote circuit connected at an output of a second deserializer and configured to generate an odd up/down signal based on odd deserialized signals from the second deserializer; and a second DAC connected at an output of the second vote circuit and configured to control the voltage and/or frequency of the VCO based on the odd up/down signal from the second vote circuit.

A method applicable to a receiver circuit, including: performing a cross-correlation operation upon at least one time-domain signal on at least one receiver path of the receiver circuit according to a local sequence signal, to estimate at least one time offset amount of the at least one time-domain signal as at least one time offset compensation amount; and, performing time offset compensation upon the at least one time-domain signal on the at least one receiver path according to the at least one time offset compensation amount.

Logic to receive a first set of two or more timing management frames wherein one or more of the two or more timing management frames in the first set comprise a first adjusted follower clock value. Logic to calculate a second adjusted clock value. Logic to cause transmission of a second set of two or more timing management frames, wherein one or more of the two or more timing management frames in the second set comprise the second adjusted clock value. Logic to cause transmission of a first set of two or more acknowledgement frames. Logic to receive a second set of two or more acknowledgement frames. And logic to calculate a difference between the first adjusted follower clock value and the second adjusted clock value to determine a synchronization error, the synchronization error to represent a performance of the time synchronization.

A system includes a plurality of in-vehicle devices and having a function of determining abnormality of communication in the devices by authenticating a message including data, a first counter counted each time a power source is turned on, and a second counter incremented over time. The system includes an authentication unit for performing, when a message including control data to be exchanged between the devices is authenticated, authentication on a message sent and received between the devices and including at least the control data and the first counter by using at least the control data and the first counter, in which when it is confirmed whether synchronization is achieved between the devices, the authentication unit is for performing authentication on a message sent and received between the devices and not including the first counter but including the second counter by using the second counter without using the first counter.

Provided are a method and an apparatus for optimizing the performance of an optical transceiver, and the gist is as follows: receiving an optical input and converting the optical input into electrical signals; receiving a performance value and a reference clock of the electrical signals from a DSP part; generating a plurality of clocks by using the reference clock; determining ADC sampling timings of a plurality of ADCs on the basis of phases of the plurality of clocks applied to the plurality of ADCs; and compensating, on the basis of the determined ADC sampling timings, for differences in physical length between output signals of the plurality of ADCs.

Included are a demodulation unit 20 that demodulates a received OFDM modulation signal to acquire a demodulated constellation signal, an ideal constellation signal generation unit 312 that generates an ideal constellation signal from the demodulated constellation signal, a data extraction unit 313 that extracts signal data corresponding to subcarriers included in a part of an intermediate frequency section among all frequency sections, from the demodulated constellation signal and the ideal constellation signal, a phase error calculation unit 314 that calculates the phase error of the demodulated constellation signal for the ideal constellation signal, with respect to the extracted signal data, a phase error characteristic estimation unit 315 that estimates the frequency characteristic of the phase error, and a phase error correction unit 316 that corrects the phase error of the demodulated constellation signal, based on the frequency characteristic of the phase error.