Subscriber line (or loop) interface circuitry (SLIC) may be found in or near a central office exchange of a telecommunications network.
One SLIC provides a communications interface between a digital switching network for a central office exchange and an analog subscriber line. The analog subscriber line connects to subscriber equipment, such as a subscriber station or telephonic instrument for example, at a location remote from the central office exchange. The analog subscriber line and subscriber equipment form a subscriber loop.
The SLIC detects and transforms voiceband communications transmitted from the subscriber equipment in the form of low voltage analog signals on the subscriber loop into corresponding digital data for transmission to the digital switching network. For bidirectional communication, the SLIC also transforms digital data received from the digital switching network into corresponding low voltage analog signals for transmission on the subscriber loop to the subscriber equipment.
One dual SLIC provides a dual-channel analog telephone interface and supports a General Circuit Interface (GCI) for the transmission and reception of both control and data information onto a GCI bus coupled to a digital switching network. The GCI interface provides a Signaling and Control (SC) channel for communicating limited, predetermined status information about each analog telephone channel to the digital switching network.
One disclosed method comprises maintaining by an integrated circuit status information for a communications channel, selecting by the integrated circuit a portion of the status information maintained for the communications channel, and repeatedly transmitting by the integrated circuit the selected portion of status information over a time-division multiplexed channel to a host.
One disclosed apparatus comprises circuitry to maintain status information for a communications channel, circuitry to select a portion of the status information maintained for the communications channel, and circuitry to transmit repeatedly the selected portion of status information over a time-division multiplexed channel to a host.
One disclosed system comprises a subscriber line interface circuitry integrated circuit for coupling to a host and comprises a plurality of linefeed interface integrated circuits for coupling to the subscriber line interface circuitry integrated circuit and to a plurality of subscriber loops. The subscriber line interface circuitry integrated circuit comprises circuitry to maintain status information for one or more of the subscriber loops, circuitry to select a portion of the maintained status information, and circuitry to transmit repeatedly the selected portion of status information over a time-division multiplexed channel to the host.
One or more described embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
Integrated circuit 110 for one or more embodiments may comprise any suitable circuitry to help provide any suitable status information for one or more communications channels to host 102 in a selective manner. Integrated circuit 110 for one or more embodiments may therefore help host 102 monitor the status of one or more communications channels as desired.
Integrated circuit 110 for one or more embodiments may help provide selective status information for one or more communications channels to host 102 in accordance with a flow diagram 200 of
For block 202 of
Integrated circuit 110 for one or more embodiments, as illustrated in
Integrated circuit 110 for one or more embodiments, as illustrated in
For block 204 of
Integrated circuit 110 for one or more embodiments, as illustrated in
For block 206 of
Integrated circuit 110 for one or more embodiments, as illustrated in
Repeatedly transmitting the selected portion of maintained status information over a time-division multiplexed channel to host 102 for one or more embodiments may help host 102 monitor the status of one or more communications channels in real-time or in substantially real-time while host 102 communicates with integrated circuit 110 over one or more other time-division multiplexed channels to communicate with, for example, device(s) 104 and/or device(s) 106.
Host interface 118 for one or more embodiments may be a General Circuit Interface (GCI) for integrated circuit 110 to communicate with host 102 over a GCI bus coupled to host interface 118 and host 102. Host interface 118 for one or more embodiments may transmit the selected portion of status information over a Signaling and Control (SC) channel for the GCI interface.
Integrated circuit 110 may perform operations for blocks 202-206 in any suitable order and may or may not overlap in time the performance of any suitable operation with any other suitable operation. Integrated circuit 110 for one or more embodiments may, for example, continue to maintain status information for block 202 as integrated circuit 110 performs operations for blocks 204 and 206. Integrated circuit 110 for one or more embodiments may overlap in time the performance of operations for blocks 202-206 for multiple communications channels.
Integrated circuit 110 for one or more embodiments may receive from host 102 one or more commands identifying the portion of status information to be selected for block 204. For one or more embodiments, as illustrated in
Enabling host 102 and/or integrated circuit 110 to help select a portion of status information for transmission to host 102 helps allow a user to have host 102 monitor the status of one or more communications channels as desired. Integrated circuit 110 for one or more embodiments may comprise any suitable circuitry, including any suitable hardware, software, and/or firmware, to enable host 102 and/or integrated circuit 110 to help select a portion of status information dynamically for transmission to host 102 to help increase the amount of status information available for monitoring by host 102.
Status information selector 116 for one or more embodiments, as illustrated in
Status information selector 116 for one or more embodiments, as illustrated in
Status information selector 116 for one or more embodiments may comprise a plurality of multiplexers two or more of which are coupled to receive different sets of status bits for a communications channel from status information maintainer 114. Such multiplexers for one or more embodiments may each selectively output one of its received status bits to host interface 118.
Status information selector 116 for one or more embodiments, as illustrated in
Although described and illustrated as comprising multiplexer(s) to help select a portion of status information for one communications channel, status information selector 116 for one or more embodiments may also comprise suitable circuitry, such as one or more multiplexers for example, to help select a portion of status information for one or more other communications channels.
SLIC Integrated Circuit
SLIC integrated circuit 410 for one or more embodiments may be coupled to control one or more linefeed interface integrated circuits, such as linefeed interface integrated circuits 430 and 440 for example, to help provide a communications interface between host 402 and one or more subscriber loops, such as subscriber loops 470 and 480 for example. SLIC integrated circuit 410 and linefeed interface integrated circuits 430 and 440, for example, may be used for any suitable application such as, for example, digital loop carriers; Central Office telephony; pair gain remote terminals; wireless local loop (WLL); digital subscriber line (DSL), coder/decoder (codec), and/or wireless voice-over-broadband systems; cable telephony; private branch exchange (PBX), Internet protocol PBX (IP-PBX), and/or key telephone systems; Integrated Services Digital Network (ISDN), Ethernet, and/or Universal Serial Bus (USB) terminal adapters; and/or Integrated Voice and Data (IVD) systems.
Subscriber loop 470 for one embodiment, as illustrated in
SLIC integrated circuit 410 and linefeed interface integrated circuit 430 for one embodiment may be coupled to receive signals on subscriber loop 470 from subscriber equipment 473 and forward the received signals or transform and transmit the received signals to switching network 401. SLIC integrated circuit 410 and linefeed interface integrated circuit 430 for one embodiment may be coupled to receive signals from switching network 401 and forward the received signals or transform and transmit the received signals on subscriber loop 470 to subscriber equipment 473. For one embodiment where SLIC integrated circuit 410 and linefeed interface integrated circuit 430 provide an analog telephone interface to subscriber loop 470 and where switching network 401 is a digital switching network, SLIC integrated circuit 410 and linefeed interface integrated circuit 430 may receive voiceband communications transmitted from subscriber equipment 473 in the form of low voltage analog signals on subscriber loop 470 and transform them into corresponding digital data signals for transmission to switching network 401. SLIC integrated circuit 410 and linefeed interface integrated circuit 430 for one embodiment may also transform digital data signals received from switching network 401 into corresponding low voltage analog signals for transmission on subscriber loop 470 to subscriber equipment 473.
Subscriber loop 480 for one embodiment, as illustrated in
SLIC integrated circuit 410 and linefeed interface integrated circuit 440 for one embodiment may be coupled to receive signals on subscriber loop 480 from subscriber equipment 483 and forward the received signals or transform and transmit the received signals to switching network 401. SLIC integrated circuit 410 and linefeed interface integrated circuit 440 for one embodiment may be coupled to receive signals from switching network 401 and forward the received signals or transform and transmit the received signals on subscriber loop 480 to subscriber equipment 483. For one embodiment where SLIC integrated circuit 410 and linefeed interface integrated circuit 440 provide an analog telephone interface to subscriber loop 480 and where switching network 401 is a digital switching network, SLIC integrated circuit 410 and linefeed interface integrated circuit 440 may receive voiceband communications transmitted from subscriber equipment 483 in the form of low voltage analog signals on subscriber loop 480 and transform them into corresponding digital data signals for transmission to switching network 401. SLIC integrated circuit 410 and linefeed interface integrated circuit 440 for one embodiment may also transform digital data signals received from switching network 401 into corresponding low voltage analog signals for transmission on subscriber loop 480 to subscriber equipment 483.
SLIC integrated circuit 410 for one or more embodiments may be a relatively low voltage device and may be coupled to control linefeed interface integrated circuit 430 and/or 440 to help control relatively higher voltages to operate subscriber equipment 473 and/or 483, respectively. SLIC integrated circuit 410 for one embodiment may comprise any suitable circuitry, including any suitable hardware, software, and/or firmware, to perform any suitable one or more BORSCHT functions and/or any other suitable one or more functions. BORSCHT is an acronym for battery feed, overvoltage protection, ring, supervision, coder/decoder (codec), hybrid, and test.
SLIC integrated circuit 410 for one or more embodiments, as illustrated in
SLIC integrated circuit 410 for one or more embodiments, as illustrated in
Processor 420 executes instructions stored in memory 421 and interfaces with host interface 418 through register(s) 422 and with linefeed controller and monitor 427 and/or 428 to help forward or transform and transmit signals received from switching network 401 onto subscriber loop 470 and/or 480, respectively, and/or to help forward or transform and transmit signals received from subscriber loop 470 and/or 480, respectively, to switching network 401.
At least a portion of processor 420, at least a portion of memory 421, at least a portion of register(s) 422, linefeed controller and monitor 427, and linefeed controller and monitor 428 generally correspond to channel(s) interface 112 of
SLIC integrated circuit 410 for one or more embodiments may comprise any suitable circuitry to help provide any suitable status information for one or more subscriber loops, such as subscriber loops 470 and 480 for example, to host 402 in a selective manner. SLIC integrated circuit 410 for one or more embodiments may therefore help host 402 monitor the status of one or more subscriber loops as desired.
SLIC integrated circuit 410 for one or more embodiments may help provide selective status information for one or more subscriber loops to host 402 in accordance with a flow diagram 500 of
For block 502 of
For block 504, SLIC integrated circuit 410 maintains status bits for one or more subscriber loops. SLIC integrated circuit 410 for one or more embodiments, as illustrated in
For block 506, SLIC integrated circuit 410 selects one or more status bits identified by one or more commands from host 402. SLIC integrated circuit 410 for one or more embodiments, as illustrated in
For block 508, SLIC integrated circuit 410 repeatedly transmits the selected status bit(s) over a Signaling and Control (SC) channel for a General Circuit Interface (GCI) to host 402. For one or more embodiments, as illustrated in
SLIC integrated circuit 410 for one or more embodiments repeatedly transmits the selected status bit(s) over a Signaling and Control (SC) channel as illustrated in an example General Circuit Interface (GCI) frame structure 600 of
As illustrated in
The SC channel has Command/Indicate (C/I) bits which may be used to carry selected status bits for subscriber loop 470 (SELECT STATUS A) and/or to carry selected status bits for subscriber loop 480 (SELECT STATUS B). The SC channel for one or more embodiments has three Command/Indicate (C/I) bits for subscriber loop 470 (SELECT STATUS A) and three Command/Indicate (C/I) bits for subscriber loop 480 (SELECT STATUS B). The SC channel also has Monitor Receive (MR) and Monitor Transmit (MX) handshaking bits to help exchange data in the Monitor (M) channel.
SLIC integrated circuit 410 for one or more embodiments for block 502 of
SLIC integrated circuit 410 may perform operations for blocks 502-508 in any suitable order and may or may not overlap in time the performance of any suitable operation with any other suitable operation. SLIC integrated circuit 410 for one or more embodiments may, for example, continue to maintain status information for block 504 as SLIC integrated circuit 410 performs operations for blocks 502, 506, and 508.
Although described in connection with selecting one or more status bits identified by one or more commands from host 402 for blocks 502 and 506, SLIC integrated circuit 410 for one or more embodiments may use processor 420 to help identify to status information selector 116 the one or more status bits to be selected for transmission to host 402. Processor 420 may execute one or more instructions stored in memory 421 to transmit data identifying one or more status bits to be selected to status information selector 116 through register(s) 422. SLIC integrated circuit 410 may use processor 420 to help identify the one or more status bits to be selected in addition to or in lieu of using commands from host 402 for blocks 502 and 506.
In the foregoing description, one or more embodiments of the present invention have been described. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit or scope of the present invention as defined in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.