Terminal for common channel signaling system

Claim 2

In a data signaling channel system having transmitter and receiver means at a terminal at each end of said channel, the combination comprising: means for causing the transmitter means at each said terminal independently to transmit a first synchronizing word to the other terminal, means at one terminal for recognizing the receipt by said receiving means thereat of a first synchronizing word transmitted from the remote terminal, means controlled by said recognizing means for thereafter causing said one terminal to transmit a second type of synchronizing word to said remote terminal, means responsive to the receipt of said second type of synchronizing word from said remote terminal for allowing said one terminal to transmit data words to said remote terminal, means responsive to the receipt of a group of data words from said remote terminal for formulating an error control information word regarding said received group of data words and for forwarding said error control information word to said transmitter means at said one terminal, means for controlling said transmitter means to normally insert said error control information word after a predetermined number of data words have been transmitted, and means operative when said predetermined number of data words has been transmitted and said error control information word has not been provided for causing said transmitter means to transmit one of said types of synchronizing words.

Claim 3

A data signaling channel system according to claim 1 wherein said transmitter means at said one terminal transmits an idle word when no data word is available, and wherein register means are provided for storing an indication of a predetermined number of said idle words having been transmitted by said transmitter means.

Claim 4

A signaling channel system according to claim 2 wherein said receiving means at said one terminal includes means for recognizing the receipt of an error control information word from said remote terminal and means responsive to the receipt of said error control information word for accessing said register means, and means responsive to said indication being read out of said register means for causing said error control information word received from said remote terminal to be disregarded.

Claim 5

A data transmission system comprising a pair of terminals connected by a common signaling channel, each said terminal having a receiver and a transmitter, a transmitter buffer at each said terminal for holding data words to be transmitted over said channel, word register means at each said terminal having stored therein a SYNC word, a RESYNC word, and an IDLE word, means for initially transferring said RESYNC word from said word register means to said transmitter, means responsive to said receiver receiving a RESYNC word from the distant one of said terminals for causing at least one of said SYNC words to be transferred to said transmitter, means for thereafter sequentially transferring data words from said transmitter buffer to said transmitter, means controlled by said receiver for normally formulating a BLOCK word and for transferring said BLOCK word to said transmitter after a predetermined number of said data words have been transferred to said transmitter, means for inserting one of said IDLE words among said predetermined number of words whenever there is no data word in said transmitter buffer, and means for inserting said SYNC word following said BLOCK word when said receiver has not formulated said BLOCK word after said predetermined number of data words or IDLE words have been transferred to said transmitter.

Claim 6

A data transmission system comprising a pair of terminals connected by a common signaling channel, each said terminal having a receiver and a transmitter, a transmitter buffer at each said terminal for holding data words to be transmitted over said channel, word register means at each said terminal having stored therein a SYNC word, a RESYNC word, and an IDLE word, means for initially transferring said RESYNC word from said word register means to said transmitter, means responsive to said receiver receiving a RESYNC word from the distant one of said terminals for causing at least one of said SYNC words to be transferred to said transmitter, means for thereafter sequentially transferring data words from said transmitter buffer to said transmitter, means controlled by said receiver for normally formulating a BLOCK word and for transferring said BLOCK word to said transmitter after a predetermined number of said data words have been transferred to said transmitter, means for inserting one of said IDLE words among said predetermined number of words whenever there is no data word in said transmitter buffer, and means for inserting said SYNC word following said BLOCK word when said receiver has not formulated said BLOCK word after said predetermined number of data words or IDLE words have been transferred to said transmitter.

Claim 7

In a data signaling channel system having transmitter and receiver means at the terminal at each end of said channel, the combination comprising: means for causing the transmitter means at one terminal to transmit a first synchronizing word to the remote terminal, means at said one terminal for recognizing the receipt by said receiving means of said synchronizing word from said remote terminal, means controlled by said recognizing means for thereafter causing said one terminal to transmit a second type of synchronizing word to said remote terminal, means responsive to the receipt of said second type of synchronizing word from said remote terminal for allowing said one terminal to transmit data words to said remote terminal, means for controlling said transmitter means to transmit an idle word when no data word is available to be transmitted, means responsive to the receipt of a group of data words from said remote terminal for formulating an error control information word regarding said received group of data words and for forwarding said error control information word to said transmitter means at said one terminal, means for controlling said transmitter means to normally insert said error control information word after a predetermined number of data words have been transmitted, means for storing an indication when a consecutive number of said idle words equal to said aforementioned predetermined number of data words normally dictating the insertion of an error control information word has been transmitted, means for counting each error control information word received by said receiver means from said remote terminal, means for accessing said indication storing means in accordance with the count of said received error control information word, and means operative subsequent to said accessing for thereafter disregarding said error control information word when said indication storing means accessed by said error control information word indicates that said error control information word pertains to a group of said predetermined number of idle words.

Claim 8

In a data signaling channel system having transmitter and receiver means at the terminal at each end of said channel, the combination comprising: means for causing the transmitter means at one terminal to transmit a first synchronizing word to the remote terminal, means at said one terminal for recognizing the receipt by said receiving means of said synchronizing word from said remote terminal, means controlled by said recognizing means for thereafter causing said one terminal to transmit a second type of synchronizing word to said remote terminal, means responsive to the receipt of said second type of synchronizing word from said remote terminal for allowing said one terminal to transmit data words to said remote terminal, means for controlling said transmitter means to transmit an idle word when no data word is available to be transmitted, means responsive to the receipt of a group of data words from said remote terminal for formulating an error control information word regarding said received group of data words and for forwarding said error control information word to said transmitter means at said one terminal, means for controlling said transmitter means to normally insert said error control information word after a predetermined number of data words have been transmitted, means for storing an indication when a consecutive number of said idle words equal to said aforementioned predetermined number of data words normally dictating the insertion of an error control information word has been transmitted, means for counting each error control information word received by said receiver means from said remote terminal, means for accessing said indication storing means in accordance with the count of said received error control information word, and means operative subsequent to said accessing for thereafter disregarding said error control information word when said indication storing means accessed by said error control information word indicates that said error control information word pertains to a group of said predetermined number of idle words.

Claim 9

In a channel signaling system having a pair of terminals each including means for normally inserting an idle word in the block transmitted by said terminal when there is no data word to be transmitted, means for formulating an error control word relating to a group of words received over said channel, said error control word normally being inserted in the next one of said blocks to be transmitted over said channel to the terminal originally sending said group of words, means for maintaining the effective rate of data transmission in one direction over said channel substantially equal to the effective rate of data transmission in the other direction comprising transmitter clock timing means for defining the interval during which said error control word is to be transmitted in said one of said blocks, means for inserting said error control word in said position defined by said defining means, and means for inserting an extra word in said one transmitted block following said error control word when said formulating means does not have said error control word available within a predetermined time interval before said interval defined by said defining means.

Claim 10

In a channel signaling system having a pair of terminals each including means for normally inserting an idle word in the block transmitted by said terminal when there is no data word to be transmitted, means for formulating an error control word relating to a group of words received over said channel, said error control word normally being inserted in the next one of said blocks to be transmitted over said channel to the terminal originally sending said group of words, means for maintaining the effective rate of data transmission in one direction over said channel substantially equal to the effective rate of data transmission in the other direction comprising transmitter clock timing means for defining the interval during which said error control word is to be transmitted in said one of said blocks, means for inserting said error control word in said position defined by said defining means, and means for inserting an extra word in said one transmitted block following said error control word when said formulating means does not have said error control word available within a predetermined time interval before said interval defined by said defining means.

Claim 11

In a channel signaling system according to claim 6 the combination wherein each said terminal normally transmits a synchronizing word to the remote terminal until the synchronizing word transmitted by said remote terminal is received over said signaling channel and wherein said additional word inserted after said error control word is an additional one of said synchronizing words.