A PRESENTATION ON LANDLINE SWITCHING TECHNOLOGY

INTRODUCTION A telephone exchange is a telecommunications system used in the public switched telephone network or in large enterprises. An exchange consists of electronic components and in older system also human operators that interconnect (switch) telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers.

EXCHANGE LAYOUT Typical exchange consist of:- 1.Switch Room 2.Operation Maintainanace Room(OMR) 3.Input Output Processor Room 4.Battery Room 5.Power Plant Room 6.Main Distribution Room

MAIN SECTIONS OF EXCHANGE There are three components of exchange:- 1.MDF 2.Power Plant 3.Switching Room POWER PLANT MDF SWITCHING ROOM

MAIN DISTRIBUTION FRAME The Switching Equipment common to all the subscriber of the area is located in an exchange To make possible for a subscriber to communicate with remaining subscriber must be connected to the exchange From OCB through PCM connected to various sections like WLL,TAX, etc.

ORGANISATION OF THE MDF Vertical side Horizontal side > The primary function of MDF is to remove fault. It is also known as Fault Remove Section. > The telephone numbers are also disconnected in the MDF because of some specific reason. ORGANISATION OF THE MDF Vertical side Horizontal side

VERTICAL SIDE RACK: -On the rack, the tags are situated. One rack is having eight tags. The counting is done from up (0) to down (7). TAGS: -Each rack consists of eight tags. 1 tag = 4 core 1 core = 4 bunch 1 bunch = 2 line N.E.:-The word NE stands for the ‘NUMBER OF EQUIPMENT’. It is used for testing number and WEDGE: Wedge is used as a device for checking the ring. Wedge is placed in jack strips, which is connected to telephone for checking.

HORIZONTAL SIDE The horizontal side connected to the underground cable. This cable is having 100 pairs. These pair is distributed when we allot the telephone number to the subscriber. Horizontal side is again subdivided in two parts: Another with the subscriber line by using 100 pair underground cable. One part is connected with the vertical side.

DIFFERENT TYPES OF FAULTS LOOP FAULT:-If two wires are joined together because of improper connection, storming air etc. EARTH FAULT:-If two wires get scrape at some places and if this wire comes in contact with tree, pillar or any metal objects then this type of fault occurs. CABLE FAULT:-For outdoor connections, jelly filled wires are used which are affected by natural causes such as rain, earthquake etc. At such time this fault occurs. DISCONNECT FAULT:-This type of fault occurs due to the breaking of wires between the vertical side & LEN side.

POWER PLANT T he main parts of the Power Room are:- 1.Batteries 2.UPS(Uninterrupted Power Supply) 3.Charging Discharging Unit 4.Inverter and Convertor Unit

OCB-283 EXCHANGE OCB-283(orgando commando B -type 2nd Generation 8300 microprocessor exchange) is digital switching system which supports a variety of communication needs like basic telephony, ISDN, etc. This system has been developed by CIT ALCATEL of France and therefore has many similarities to its predecessor E-10B (also known as OCB-181 in France).

Connection & Control Units SMC :Main Control Station SMA :Auxiliary Equipment Control Station SMT :Trunk Control Station SMX :Matrix Control Station STS :Synchronization and Time Base Station

FEATURES OF OCB-283 1.It is a digital switching with single‘T’ stage switch. A maximum of 2048 PCM’s can be connected. 2. It supports both analog and digital subscribers. 3. It provides telephony, ISDN, Data communication, cellular radio, and other value added services. 4.The traffic handling capacity of the system is huge.

OCB FUNCTIONAL UNIT The OCB283 system is made up of three independent functional units : - "Subscriber Access Subsystem" which carries out connection of analogue and digital subscriber lines. - "Connection and Control" which carries out connections and processing of calls - "Operation and Maintenance" which is responsible for all functions needed by the network operating authority.

OCB-283 SWITCHING SYSTEM Any Automatic Switching System comprises in general of  following distinct Subsystems:- • Subscriber Access Subsystem Connection & Control  Subsystem which  comprises of (a) Switching Network Units (b) Circuit Connection  Units (c) Common Control function units

GENERAL ARCHITECTURE OF OCB-283 • OCB-283 is the latest Electronics Digital ISDN type Switching technology being imported in INDIA. • THIS IS MANUFACTURED BY M/S ALCATEL OF FRANCE. • This Exchanage works on Stored Programme Control Principle. • Exchange can work with all types of Circuit & Subscriber Signallings & also provides for lot of novel facilities to the subscribers.   

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