BSNL Training Report - Sarthak Gupta - Read online. work conducted in the industry. This report is thus prepared for the training done at Bharat Sanchar Nigam Limited (B.S.N.L). .. summer training report on bsnl -ocb naini exchange allahabad. Uploaded by . wm-greece.info Uploaded by. Bsnl Training Report - Download as PDF File .pdf), Text File .txt) or read online. summer training report on bsnl -ocb naini exchange allahabad. Uploaded by. BSNL Training Report for wm-greece.info ECE final yr students. 1 Summer Training Report On Basic Telecom Submitted in partial fulfillment of the.
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A PRACTICAL TRAINING SEMINAR REPORT ON BHARAT SANCHAR NIGAM If people require IRS as well, here's a wm-greece.info In view of such benefits, imparting of vocational training has been made an. Training Report oF BSNL. Acknowledgement I acknowledge my gratitude and thank to all the well knowledge persons for giving me opportunity. 4 INTRODUCTION Today, BSNL is the No. 1 telecommunication company and the largest public sector undertaking of India and its responsibilities includes.
It mainly consists of the servers that are providing the different services.
The main servers of this room are: CERS are provided by the exchange to avoid the problems that the users are facing in repairing of telephone. The server present in the main computer room provides this service. In this type of service makes enquiry using the internet, which gets connected to the main server at the internet room in the exchange and further to the main server in the computer room.
All new technology switching systems are based on Stored Program Control concept. Handling or processing call means to ultimately establish a connection in a switch between incoming line and outgoing line. Depending on the name and architecture of control units and switch may change but criterion for switching remains more or less the same. There are two types telephone exchange. They are: Manual exchange.
Automatic exchange. Manual exchange: With manual service , the customer lifts the receiver off-hook and asks the operator to connect the call to a requested number. Provided that the number is in the same central office, the operator connects the call by plugging into the jack on the switchboard corresponding to the called customer's line. If the call is to another central office, the operator plugs into the trunk for the other office and asks the operator answering known as the "inward" operator to connect the call.
In these exchanges there are two types of switch boards used: Cordless type switch board: It is used for small Private Exchange, where number of telephone lines is less than Cord type switch board: It is used when number of telephone lines exceeds 12 telephone lines. Automatic exchange: All telephone subscribers are served by automatic exchanges. One , running the program that provides services. Second, monitoring the operation of the first, ready to take over in a.
There are two types of Automatic exchanges: Electromechanical Switching system: I Strowger Type Switching system. II Crossbar Type Switching system.
Electronic Switching system: Various exchanges present in BSNL are: I Strowger Type Switching system: Almon B.
Strowger was an undertaker in Kansas city, USA, the story goes that there was a competing undertaker locally whose wife was an operator at the local telephone exchange.
Whenever a caller asked to be put through to Strowger, calls were deliberately put through to his competitor. With the help of his nephew W. Strowger he produced a working model in II Crossbar Type Switching system: A crossbar switch is one of the principle architecture used to construct switches of many types. The other principle switch architectures are that of memory switches or crossover switch banyan switch.
C — DOT Exchange. Shyam Petroda of Gujarat The scientific advisor in the ministry of Mrs. Indira Gandhi to suit the Indian climatic conditions. The exchange works satisfactorily up to 35 degree Celsius. Exchange layout: The exchange can be divided into the following rooms.
Switch Room. Power Plant Room. Battery Room. In C — DOT exchange ,mainly 3 kinds of cards are used: Card Frames: From written material. Base Module cabinet.
Central Module Cabinet. Input Output Cabinet. Diagram given in written material. Base module BM. Central module CM. Administrative module AM. Base Module. Each BM can interface up to terminations.
Central module. Administrative module. It communicates with the BM via the CM. It supports the IOM for providing man machine interface. In order to realize a RSU, the normal BM can be modified for communication with the host exchange via 2Mbps digital links. As far as call processing is concerned, RSU is an autonomous exchange capable of local call completion. ISDN services are the most widely used carriers to transport the bulk volume of data. It integrates computer on telephone on single access.
Hardware crosslink planned in such a way that even failure 2 dissimilar processors do not affect the system performance. In the event of failure of 1 unit, other units will share its load preventing the disruption of services. Time Switch Unit. Alarm Display Panel. Power Supply Arrangement. Peripheral Processor Subsystem. Call Processing Subsystem. Maintenance Subsystem. Administrative Subsystem. Data Base Subsystem.
Input Output Processor Subsystem. From Written material. OCB Exchange. It supports both analog and digital subscribers. When a serious fault occurs in a control unit, it gives a message to SMM.
The SMM puts this unit out of service and loads the software of this unit in a back up unit and brings it into service.
Diagnostic programs run on the faulty unit and the diagnostics is printed on a terminal. It has a double remote facility. Subscriber access unit can be placed at a remote place and connected to the main exchange through PCM links.
Various units of OCB system are connected over token rings. This enables fast exchange of information and avoids complicated links and wiring between various units. The charge accounts of subscribers are automatically saved in the disc, once in a day.
This avoids loss of revenue in case of battery failure. The traffic handling capacity of the system is huge. All the control units are implemented on the same type of hardware. This is called a station. The system is made up of only 35 types of cards.
This excludes the cards required for CSN. Due to this, the number of spare cards to be kept for maintenance is drastically reduced. The system has modular structure. The expansion can be very easily carried out by adding necessary hardware and software. The SMMs are duplicated with one active other standby. In case of faults, switch over takes place automatically. The hard disc is very small in size, compact and maintenance free. It has a very huge memory capacity of 1.
The space requirement is very small. There is no fixed or rigid rack and suite configuration in the system. Facilities to analogue subscribers: A line can be made only outgoing or incoming. Immediate hot line facility - The subscriber is connected to another predetermined subscriber on lifting the handset without dialing any number.
Delayed hot line facility -When subscriber lifts the handset, dial tone is provided he can dial any number. If he does not dial a number, within a predetermined time, he is connected to predetermined number. Abbreviated dialing -The subscriber can record a short code and its corresponding full number in the memory.
Later he dial this number, he has to only dial short code. Call forwarding -When activated, incoming calls to the subscriber gets transferred to the number mentioned by the subscriber while activating the facility.
Conference between four subscribers -Two subscribers while in conversation can include two more subscribers by pressing button and dialing their numbers. Call waiting indication -When a subscriber is engaged in conversation and if he gets an incoming call, an indication is given in the form of tone.
Hearing this, the subscriber has option, either to hold the subscriber in conversation and attend the waiting call or to disconnect this subscriber and attend the waiting call. Automatic call back on busy- If this facility is activated and if the called subscriber is found busy, the calling subscriber simply replaces the receiver. The system keeps watch on the called subscriber and when it becomes free, a ring is given to both the subscribers. All telephone subscribers are served by automatic exchanges.
Todays automatic exchanges uses a pair of computers. One, running the program that provides services. Second, monitoring the operation of the first, ready to take over in a few seconds in the event of equipment failure. These cabinets are fastened to a switch Room and interconnected by cables. Main Distribution Frame is a signal distribution frame or a cable rack used in telephony to interconnect and manage telecommunication between itself and any number of intermediate distribution frame and cabling from the telephone network it supports Vertical side Horizontal 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. The channel data rate is GSM has used a variety of voice codecs to squeeze 3.
Originally, two codecs, named after the types of data channel they were allocated, were used, called Half Rate 5. These used a system based upon linear predictive coding LPC. In addition to being efficient with bit rates, these codecs also made it easier to identify more important parts of the audio, allowing the air interface layer to prioritize and better protect these parts of the signal.
Finally, with the development of UMTS, EFR was refactored into a variable-rate codec called AMR-Narrowband, which is high quality and robust against interference when used on full rate channels, and less robust but still relatively high quality when used in good radio conditions on half-rate channels. There are five different cell sizes in a GSM networkmacro, micro, pico, femto and umbrella cells. The coverage area of each cell varies according to the implementation environment.
Macro cells can be regarded as cells where the base station antenna is installed on a mast or a building above average roof top level. Micro cells are cells whose antenna height is under average roof top level; they are typically used in urban areas. Picocells are small cells whose coverage diameter is a few dozen meters; they are mainly used indoors. Femtocells are cells designed for use in residential or small business environments and connect to the service providers network via a broadband internet connection.
Umbrella cells are used to cover shadowed regions of smaller cells and fill in gaps in coverage between those cells. Cell horizontal radius varies depending on antenna height, antenna gain and propagation conditions from a couple of hundred meters to several tens of kilometers.
The longest distance the GSM specification supports in practical use is 35 kilometers 22 mi. There are also several implementations of the concept of an extended cell, where the cell radius could be double or even more, depending on the antenna system, the type of terrain and the timing advance.
Indoor coverage is also supported by GSM and may be achieved by using an indoor picocell base station, or an indoor repeater with distributed indoor antennas fed through power splitters, to deliver the radio signals from an antenna outdoors to the separate indoor distributed antenna system.
These are typically deployed when a lot of call capacity is needed indoors, for example in shopping centers or airports. However, this is not a prerequisite, since indoor coverage is also provided by in-building penetration of the radio signals from nearby cells.
In GMSK, the signal to be modulated onto the carrier is first smoothed with a Gaussian low-pass filter prior to being fed to a frequency modulator, which greatly reduces the interference to neighboring channels adjacent channel interference. Network structure The network behind the GSM system seen by the customer is large and complicated in order to provide all of the services which are required.
It is divided into a number of sections and these are each covered in separate articles. The Base Station Subsystem the base stations and their controllers. The Network and Switching Subsystem the part of the network most similar to a fixed network.
This is sometimes also just called the core network. The SIM is a detachable smart card containing the user's subscription information and phone book. This allows the user to retain his or her information after switching handsets.
Alternatively, the user can also change operators while retaining the handset simply by changing the SIM. Some operators will block this by allowing the phone to use only a single SIM, or only a SIM issued by them; this practice is known as SIM locking, and is illegal in some countries. Many operators lock the mobiles they sell. This is done because the price of the mobile phone is typically subsidized with revenue from subscriptions, and operators want to try to avoid subsidizing competitor's mobiles.
In some countries such as India, all phones are sold unlocked. The system was designed to authenticate the subscriber using a pre-shared key and challenge-response. Communications between the subscriber and the base station can be encrypted.