Abstract: An erroneous synchronization preventing device includes a pattern detector detecting a sync pattern from received data with a broader sync window to output a sync detection notice and a sync timing. On receipt of the notice, a packet header detector checks an error in a header field of the received data, and, if detecting no error, outputs a header-normally-received notice, on receipt of which the timing corrector makes the inner timing synchronous with the sync timing to output a timing correction end notice. The mode manager in turn outputs a change notice. The pattern detector then detects the sync pattern with a narrower sync window. Unless the end notice is received within a predetermined period as from receipt of the change notice, a detection period monitor outputs an out-of-synchronism notice. The mode manager then outputs a restoration command for instructing detection of the sync pattern with the broader sync window.

Abstract: With radio-transmission apparatus, in order to control the rate of packet data transmitted between a master and slaves adaptively to the quality of an RF channel, a slave controls, when having received packet data, error detection to detect a reception error in the packet data. On the basis of the reception error detected, the quality of the packet data transmitted is determined. In response to the resultant quality thus determined, the slave generates a command instructing the master, sending out packet data, to alter a sort of packets to transmit the command to the master. The master alters the sort of packets as instructed by the command.

Abstract: Synchronization errors in a received pulse train are detected by detecting rising or falling transitions in the pulse train, generating numbers in a repeating cycle having a length corresponding to the pulse rate, selecting the number generated when each transition is detected, and performing a predetermined operation on the selected numbers. The predetermined operation may include, for example, comparing the average values of the selected numbers in successive groups of transitions. Alternatively, the predetermined operation may include taking a difference between consecutively selected numbers to measure pulse widths in the pulse train. Synchronization error detection can be used to supplement data error detection and correction methods such as forward error correction and cyclic redundancy checks.

Abstract: An erroneous synchronization preventing device includes a pattern detector detecting a sync pattern from received data with a broader sync window to output a sync detection notice and a sync timing. On receipt of the notice, a packet header detector checks an error in a header field of the received data, and, if detecting no error, outputs a header-normally-received notice, on receipt of which the timing corrector makes the inner timing synchronous with the sync timing to output a timing correction end notice. The mode manager in turn outputs a change notice. The pattern detector then detects the sync pattern with a narrower sync window. Unless the end notice is received within a predetermined period as from receipt of the change notice, a detection period monitor outputs an out-of-synchronism notice. The mode manager then outputs a restoration command for instructing detection of the sync pattern with the broader sync window.

Abstract: With radio-transmission apparatus, in order to control the rate of packet data transmitted between a master and slaves adaptively to the quality of an RF channel, a slave controls, when having received packet data, error detection to detect a reception error in the packet data. On the basis of the reception error detected, the quality of the packet data transmitted is determined. In response to the resultant quality thus determined, the slave generates a command instructing the master, sending out packet data, to alter a sort of packets to transmit the command to the master. The master alters the sort of packets as instructed by the command.

Abstract: Disclosed is an IP (Internet Protocol) phone system that performs communication through packet exchange by VoIP (Voice over IP) and ensures the use of child terminal devices which are cordless telephone terminals. In the IP phone system, a computer device having an H.323 gate keeper function, a plurality of computer devices having a protocol conversion function and IP phones are connected to an IP network, identifiers of child terminal devices are respectively registered in the latter computer devices. When a Piconet of a communication link among the computer devices and the child terminal devices is formed, one of the child terminal devices makes a call to a desired terminal and executes voice communication over an IP network.

Abstract: Synchronization errors in a received pulse train are detected by detecting rising or falling transitions in the pulse train, generating numbers in a repeating cycle having a length corresponding to the pulse rate, selecting the number generated when each transition is detected, and performing a predetermined operation on the selected numbers. The predetermined operation may include, for example, comparing the average values of the selected numbers in successive groups of transitions. Alternatively, the predetermined operation may include taking a difference between consecutively selected numbers to measure pulse widths in the pulse train. Synchronization error detection can be used to supplement data error detection and correction methods such as forward error correction and cyclic redundancy checks.