System Architecture AN-RAX
The C-DOT 256P AN-RAX has been designed by reconfiguring the basic building block used in higher capacity systems of the C-DOT DSS family. The system is highly modular, and flexible to the changing technology. The software is structured and clear interfaces exist between hardware and software. The redundancy of critical circuitry and exhaustive set of diagnostic schemes ensure high system reliability.
- SYSTEM HARDWARE BLOCKS (REFER FIG. 3.1 & 3.2)
All subscriber lines are interfaced to the system through the Terminal Interface cards (LCC, CCM). Each terminal interface card caters to 8 terminations. Four such cards form a Terminal Group. There are 32 such terminal interface cards; sixteen in each frame (C-DOT 256P AN-RAX has a two frame implementation. The top frame is called ‘Slave Frame’ and bottom frame is called ‘Master Frame’).
- Terminal Group (TG)
Analog information from the terminations is first changed to digital PCM form at a bit rate of 64 Kbps. Thirty two such PCM (Pulse Code Modulation) channels from four Terminal Interface cards are time division multiplexed to generate one 32 channel, 2.048 Mbps PCM link. Thus from 32 terminal interface cards, eight such PCM links are obtained, which are terminated on ARC (AN-RAX controller card).
- SYSTEM ENGINEERING
Complete hardware of AN-RAX including PDP apart from the main card assembly are all housed in AN-RAX cabinet.
The distribution is as follows :
AN-RAX Controller Card (ARC) = 2 Nos.
AN-RAX Interface Card (ARI) = 2 Nos.
Signalling Processor Card (SPC/ISP) = 4 Nos.
RAX Terminal Tester Card (RTC) = 1 No.
Subscriber Line Card LCC/CCM/CCB = 31 Nos.
Power Supply Card (PSU-1) = 4 Nos.
System Overview AN- RAX | System Architecture AN-RAX
- AN-RAX Controller Card (ARC)
The ARC card is the main controller card which performs all administrative functions of AN-RAX. Towards the line cards, it gives card select, subscriber select, clock and sync signals. It has an interface towards SPC/ISP card providing Signaling Interface to the line cards. It has an interface towards the ARI (AN-RAX Interface Card) used in slave frame for providing voice and Signaling Interface for the line cards in the slave frame.
There are two ARC cards (copy 0 & copy 1) in Master frame. ARC communicates with the duplicate ARC through HDLC link. One more HDLC link is used to communicate with the RTC cards.
There are two ACIA links. One of the link is used for (VDU) and other link is used for Debugging terminal.
Two Digital trunks of 2.048 Mbps are provided on ARC card which are to be used in Common Channel Signalling mode (CCS). These Digital trunks are used for V5.2 interface towards the Local Exchange (LE).
- AN-RAX Interface Card (ARI)
The ARI Card acts as an extension of ARC for the cards in slave unit. The copy 0 ARI card interfaces with the copy 0 ARC card and other cards in slave frame. Similarly, copy 1 ARI card interfaces with the copy 1 ARC card and other cards in slave frame. The signals between ARI card and the corresponding ARC card are exchanged through both front end cables as well as through interframe cables on the back plane.
- Signalling Processor Card (SPC)/ Integrated Signalling Processor Card (ISP)
Signalling information related to terminations such as dialled digits, ring trip etc., are separated at the Terminal Interface cards and carried to the Signalling Processor (SPC/ISP) on a time multiplexed link. The SPC/ISP passes on this information to the ARC.
- Power and Ringing
A DC-DC converter generates the various voltages required for the system operation and also provides ringing for the subscriber loops. System Architecture AN-RAX