Test apparatus and process for digital data service system

Claim 1

Apparatus for testing loop circuits lacking byte alignment from a network operating at a frequency F1 and using test equipment operating at a frequency of F1/2 comprising: a) a test unit for transmitting test signals at the rate of F1/2 and wherein said test signals are framed into Y bit frames of X bytes of L bit length and wherein the same X bytes are transmitted X times per frame and wherein a consecutive series of n bits, each n bit occupying an n bit position in a byte are data bits; and b) a channel unit for receiving said test signals and selecting M successive bytes from each said frame for transmission of said data bits of said successive bytes over the loop circuit for testing the loop circuit and return of said data bits to said channel unit; c) reformatting means for reformatting the data bits returned from the loop circuit and compensating for any bit rotation caused by lack of byte alignment in the loop, comprising: (i) selecting means for selecting at least M+1 successive bytes from the returned data bits; and (ii) comparing means for comparing bits from a predetermined one of said bit positions of each of the M+1 successive bytes and determining which bytes of the M+1 bytes has identical bits in the predetermined bit position; (iii) transmitting means for repeatedly transmitting one of the M+1 bytes with an identical bit in the predetermined bit position and wherein L, Y and M are integer numbers.

Claim 7

A method for testing loop circuits lacking byte alignment from a network operating at a frequency F using test signals at a frequency F/2 comprising the steps of: a) transmitting test signals at said frequency F/2 and wherein said test signals are framed into Y bit frames of X bytes of L bit length and wherein the same X bytes are transmitted X times per frame and wherein a consecutive series of n bits occupy respective n bit positions in a byte and are data bits; and b) receiving said test signals and selecting M successive bytes from each said frame for transmission of said data bits of said M successive bytes over the loop circuit for testing the loop circuit and return of said data bits to said channel unit; c) reformatting the data bits returned from the loop circuit and compensating for any bit rotation caused by lack of byte alignment in the loop by selecting at least M+1 successive bytes from the returned data bits; and comparing bits from a predetermined one of said bit positions of each of the M+1 successive bytes and determining which bytes of the M+1 bytes has identical bits in the predetermined bit position; and transmitting one of the bytes with identical bits in the predetermined bit position X times.

Claim 8

A method for testing loop circuits lacking byte alignment from a network operating at a frequency F using test signals at a frequency F/2 comprising the steps of: a) transmitting test signals at said frequency F/2 and wherein said test signals are framed into Y bit frames of X bytes of L bit length and wherein the same X bytes are transmitted X times per frame and wherein a consecutive series of n bits occupy respective n bit positions in a byte and are data bits; and b) receiving said test signals and selecting M successive bytes from each said frame for transmission of said data bits of said M successive bytes over the loop circuit for testing the loop circuit and return of said data bits to said channel unit; c) reformatting the data bits returned from the loop circuit and compensating for any bit rotation caused by lack of byte alignment in the loop by selecting at least M+1 successive bytes from the returned data bits; and comparing bits from a predetermined one of said bit positions of each of the M+1 successive bytes and determining which bytes of the M+1 bytes has identical bits in the predetermined bit position; and transmitting one of the bytes with identical bits in the predetermined bit position X times.