Telecommunication switching system

Claim 2

An automatic telecommunications switching arrangement, in which the arrangement includes electronic switching means via which inlets to and outlets from the arrangement are interconnected, in which intelligence in digital form is handled within the switching arrangement using a redundant line code whose characteristics are such that spare code combinations are available, which spare combinations are used to provide auxiliary data channels, which auxiliary data channels are used to transmit data through the switching means, in which the data transmitted through the switching means via a said auxiliary channel includes for each inlet-outlet connection which is established the inlet port number for the inlet involved in that connection, and in which at an outlet involved in the connection the inlet port number as received via a said auxiliary channel is extracted and compared with the expected inlet port number, the result of said comparison being indicative of the correct or incorrect operation of the switching means, whereby the operation of the arrangement is checked while the arrangement is handling traffic.

Claim 3

An arrangement as claimed in claim l, in which the inlets to and outlets from the arrangement are connected to trunks over which the code used differs from that used within the switching means, in which the intelligence as it arrives over a said trunk is converted by a code converter to the redundant line code used in the switching means, the inlet port member being applied to the auxiliary channel provided by the spare combinations by the code converter, in which the intelligence as it leaves the switching means is converted by a further code converter to the code used on the trunks, and in which the inlet port member is extracted from the auxiliary data channel by the further code converter.

Claim 4

An arrangement as claimed in claim l, and in which the redundant line code used within the switching means is of the 3B6B type, each code combination of which has six binary bits, three of which are l bits and three of which are 0 bits.

Claim 5

An arrangement as claimed in claim l, in which the switching means is a three-stage network each stage of which consists of a number of co-ordinate matrices of integrated circuit type.

Claim 6

An automatic telecommunications switching arrangement, for interconnecting a number of incoming PCM/TDM trunks and a number of outgoing PCM/TDM trunks with the incoming trunks forming inlets to the arrangement and the outgoing trunks forming outlets from the arrangement, wherein : (a) the arrangement includes a plural stage electronic switching network via which the inlets to the arrangement and the outlets therefrom are interconnected, each said inlet being connected to an inlet port of the network and each said outlet being connected to an outlet port of the network; (b) the intelligence to be conveyed, which is in digital form, is converted by conversion means associated with each said inlet port into a redundant line code in which that intelligence is handled within the switch, the redundant line code characterics being such that spare code combinations are available; (c) the intelligence in said redundant line code is converted by further conversion means associated with each said outlet port into the digital format appropriate to the said outgoing trunks; (d) the spare code combinations provided by the redundant line code used within the switch are used to provide auxiliary data channels through the switching network; (e) the data transmitted through the switching network over a said auxiliary data channel includes for each inlet - outlet connection which is set up the inlet port number for the inlet involved in that connection, which number is inserted into said auxiliary data channel during the conversion by the first-mentioned conversion means and extracted from the auxiliary data channel during the conversion by said further conversion means; and (f) the outlet ports each includes means whereby when an outlet port is involved in a connection the inlet port number as received via a said auxiliary data channel is extracted and compared with the expected inlet port number, the result of said comparison indicating whether the switching network is operating correctly or incorrectly, whereby the operation of the switching arrangement is checked while that arrangement is actually handling traffic.

Claim 7

An automatic telecommunications switching arrangement, for interconnecting a number of incoming PCM/TDM trunks and a number of outgoing PCM/TDM trunks with the incoming trunks forming inlets to the arrangement and the outgoing trunks forming outlets from the arrangement, wherein : (a) the arrangement includes a plural stage electronic switching network via which the inlets to the arrangement and the outlets therefrom are interconnected, each said inlet being connected to an inlet port of the network and each said outlet being connected to an outlet port of the network; (b) the intelligence to be conveyed, which is in digital form, is converted by conversion means associated with each said inlet port into a redundant line code in which that intelligence is handled within the switch, the redundant line code characterics being such that spare code combinations are available; (c) the intelligence in said redundant line code is converted by further conversion means associated with each said outlet port into the digital format appropriate to the said outgoing trunks; (d) the spare code combinations provided by the redundant line code used within the switch are used to provide auxiliary data channels through the switching network; (e) the data transmitted through the switching network over a said auxiliary data channel includes for each inlet - outlet connection which is set up the inlet port number for the inlet involved in that connection, which number is inserted into said auxiliary data channel during the conversion by the first-mentioned conversion means and extracted from the auxiliary data channel during the conversion by said further conversion means; and (f) the outlet ports each includes means whereby when an outlet port is involved in a connection the inlet port number as received via a said auxiliary data channel is extracted and compared with the expected inlet port number, the result of said comparison indicating whether the switching network is operating correctly or incorrectly, whereby the operation of the switching arrangement is checked while that arrangement is actually handling traffic.

Claim 8

An arrangement as claimed in claim 5, wherein the trunks to be interconnected are bidirectional trunks each of which has separate GO and RETURN physical transmission paths, and wherein the switching network is duplicated, separate switching networks being used to interconnect the GO and RETURN highways of the trunks.