SUMMER TRAINING ATThe Institute of Telecom Technology & Management NAME: ASHRAY SAWHNEY ROLL NO. : 05070102811 B.TECH(ECE) VII SEMESTER SWITCHING CONTENT ABOUT ITTM INTRODUCTION BASIC TERMINOLOGY OCB-283 DIGITAL SWITCHING ABOUT ITTM The Institute of Telecom Technology & Management, IITM (formerly DTTC), Shadipur is a state of the art training center of MTNL, Delhi engaged in imparting induction training and short duration trainings to its officers and employees in the field of Telecom, IT, Computer systems and Management. The students are imparted classroom lectures on the latest in Telecom Technologies and IT (4 weeks) followed by intensive field training and exposure to the latest in Telecom Technology(2 weeks). Classroom topics include Introduction to Telephony, Switching Technology, MDF and Protective Devices, Overview of External plant, Transmission basics, Optical fibre systems (SDH & FTTH), Data Communication & IP networks, Broadband concepts, Technology & service aspects, GSM, CDMA & 3G Overview and also HRD topics such as Communication skills, Stress Management & Time Management. Students are offered field training at any location / Exchange based on their preferences and the desired field. Students get the opportunity to visit & have hands on training on the latest in Telecom Technology & IT. INTRODUCTION Switch: Control consisting of a mechanical or electrical or electronic device for making or breaking or changing the connections in a circuit. And the process is called SWITCHING. WHY SWITCHING IS REQIRED?? Whenever the number of customers are more than resources available, switching is required. SIGNALLING CONTROL SWITCHING Control 1 2 3 N 1 2 3 N Connection of inputs to outputs … … TECHNOLOGIES USED IN MTNL 5ESS (ALCATEL) EWSD (Siemens) AXE-10 (Ericsson) OCB-283 (ALCATEL) OCB 283 O-------- ORGAN C-------- COMMAND OR CONTROL B-------- BHERSION 2--------- IIND GENERATION 83------ 8300 Motorolla MICRO PROCESSOR UNIT OCB 283 is digital switching system which supports a variety of communication needs like basic telephony, ISDN, interface to mobile communication, data communication. Developed by CIT ALKATEL, France . •First OCB 283 exchange of R11 version were commissioned in Brest (France) and Beijing (China) in 1991. •First OCB-283 exchange came to India in 1993. OM MQ GX MR TX TR PC COM ETA PU PE SMT URM MCX CSNL CKTS LR (4MB / S) DT LR LR COMMUNICATION MULTIPLEX TMN 2 MB/S PCM CSND BT OCB-283 FUNCTIONAL DIAGRAM SMA SMX SUBSCRIBER ACCESS SYSTEM CONNECTION AND CONTROL OPERATION AND MAINTENANCE CCITT #7 SIGNALLING NETWORK TELEPHONE NETWORK DATA NETWORK VALUE ADDED NETWORK O&M NETWORK DISK MAGTAPE PABX • SUBSCRIBER ACCESS SUBSYSTEM • CONTROL & CONNECTION SUBSYSTEM • OPERATION & MAINTENANCE SUBSYSTEM OCB-283 ARCHITECTURE OCB-283 COMPRISES OF FOLLOWING 3 SUBSYSTEMS Subscriber Access Subsystem • Subscribers in ocb-283 are connected on digital subscriber center (CSN) • CSN can be local or distant • Local CSN is called CSNL • Distant CSN is called CSND • Subscribers can also be connected via a CSED OM MQ GX MR TX TR PC COM ETA PU PE SMT URM MCX CSNL CKTS LR (4MB / S) DT LR LR COMMUNICATION MULTIPLEX TMN 2 MB/S PCM CSND BT SMA SMX SUBSCRIBER ACCESS SUBSYSTEM Control subsystem • Control subsystem supports all the common control functions of exchange which setup & release a call • Common control functions are :- MR, TR, TX, MQ, GX & PC • In software form they are called logical machines • Hardware component is called main control station [SMC] COMMUNICATION MULTIPLEX OM MQ GX MR TX TR PC COM ETA PU PE SMT URM MCX CSNL CKTS LR (4MB / S) DT LR LR TMN 2 MB/S PCM CSND BT OCB-283 FUNCTIONAL DIAGRAM SMA SMX CONTROL SUBSYSTEM Connection Subsystem It comprises of Switching Matrix Station(SMX), Trunk multiplex Station(SMT), Auxiliary Equipment Station(SMA) & all associative LR links. It consists of connection equipment for connecting PCM junctions, auxiliary equipment for tones and signaling, switching equipment for performing digital time switching. OM MQ GX MR TX TR PC COM ETA PU PE SMT URM MCX CSNL CKTS LR (4MB / S) DT LR LR COMMUNICATION MULTIPLEX TMN 2 MB/S PCM CSND BT SMA SMX CONNECTION SUBSYSTEM Operation and Maintenance Subsystem IN OCB-283 all the operation and maintenance activities are performed by O&M unit. This provides access for man machine dialogues for the human operators to interact and command the working of exchange instruments. OM MQ GX MR TX TR PC COM ETA PU PE SMT URM MCX CSNL CKTS LR (4MB / S) DT LR LR COMMUNICATION MULTIPLEX TMN 2 MB/S PCM CSND BT OCB-283 FUNCTIONAL DIAGRAM SMA SMX O & M SUBSYSTEM CALL PROCESSING CKTS OM TR MR MQ GX PC ETA TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC VC SC SMT PU/PE SC: Signaling channel VC: Voice channel NEW CALL MESSAGE COMES ON SIG.CHANNEL SC TO PU/PE WHICH DETECTS ERRORS CKTS OM TR MR MQ GX PC TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC VC SC SMT ETA SC: Signaling channel VC: Voice channel ‘A’ ‘B’ PU/PE NEW CALL MESSAGE IS SENT TO MR BY PU/PE. tr provides subs data to mr. mq provides address of vc on smx to mr. CKTS OM TR MR MQ GX PC TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC VC SC SMT ETA SC: Signaling channel VC: Voice channel ‘A’ ‘B’ PU/PE MR ORDERS SMX FOR CONNECTING DIAL TONE TO CALLING SUBS CKTS OM TR MR MQ GX PC TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC VC SC SMT ETA SC: Signaling channel VC: Voice channel ‘A’ ‘B’ PU/PE FIRST DIGIT IS RECEIVED VIA VOICE CHANNEL VC IN ETA ETA SENDS IT TO MR ON MAS DIAL TONE IS CUT OFF ON ORDERS OF MR CKTS OM TR MR MQ GX PC TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC VC SC SMT ETA SC: Signaling channel VC: Voice channel ‘A’ ‘B’ PU/PE ROUTING OF CALL - MR ORDERS CSN-B TO TEST ‘B’ & GIVE VC FOR ‘B’ CSN-B TESTS ‘B’ AND GIVES RINGING TO ‘B’ SMX GIVES RBT TO ‘A’ SC: Signaling channel VC: Voice channel ‘A’ ‘B’ CKTS OM TR MR MQ GX PC A B TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC SC SMT PU/PE CALLED PARTY B GOES OFF HOOK CALLED PARTY’S CSN SENDS LOOP CONDITION & VC- B GIVES INFORMATION TO MR OVER SC VIA PU/PE RINGING CURRENT & RBT ARE STOPPED ‘A’ ‘B’ CKTS OM TR MR MQ GX PC TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC-A SC SMT SC: Signaling channel VC: Voice channel PU/PE VC-B ‘A’ ‘B CKTS OM TR MR MQ GX PC TX MAS MIS SC SC SC SMX COM CSNL CSND CSNL VC-A RGF SC STM SC: Signaling channel VC: Voice channel PU/PE VC-B TWO UNIDIRECTIONAL CONNECTIONS ARE ESTABLISHED IN SMX ON ORDER OF MR VIA GX ‘A’ & ‘ B ‘ CAN NOW CONVERSE CHARGING IS STARTED BY TX - MR RELEASED Happy talking!! OCB-283 EXCH AND YOUR METER IS RUNNING HERE!!! Facilities Provided by OCB-283 A line can be made only incoming or outgoing. Immediate hot line Delayed hot line Abbreviated Dialing Call Forwarding Call Waiting Conference call THANK YOU!