PTCL

Internship Report

XpertSolver.com

1. INTRODUCTION --------------------------------------------------------------------------- 1

Wired Telecommunication Network -------------------------------------------------------- 1 Wireless Telecommunication Network ----------------------------------------------------- 2 Outside Plant/ Access Network --------------------------------------------------------------- 2

Main Distribution Frame ----------------------------------------------------------------------- 2 Base Transceiver Station (BTS) ---------------------------------------------------------------- 3

2. DISCUSSION Transmission/Optical Fiber Introduction ---------------------------------------------------------------------------------------- 3 Modulation Techniques ------------------------------------------------------------------------- 4 Multiplexing Techniques ------------------------------------------------------------------------ 4 Carries Standards --------------------------------------------------------------------------------- 7 Digital Hierarchies -------------------------------------------------------------------------------- 9 Optical Fiber Multiplexing ----------------------------------------------------------------------10

Switching Introduction --------------------------------------------------------------------------------------- 12 Types of Switching ------------------------------------------------------------------------------- 13 EWSD ----------------------------------------------------------------------------------------------- 14 Billing Procedure --------------------------------------------------------------------------------- 19

Few Developing Technologies DSLAM ---------------------------------------------------------------------------------------------- 19 DXX 19 NGN 20

Software Tools BNCC ------------------------------------------------------------------------------------------------ 21 CMS (Complaint Management System) ---------------------------------------------------- 21 BMML/ iManager -------------------------------------------------------------------------------- 21

XpertSolver.com

TABLE OF CONTENTS Power Management

Description LIST OF TABLES Table 1. T-Carrier and E-Carrier Data Rates ---------------------------------------------------- 4 Table 2. SDH and PDH Data Rates ---------------------------------------------------------------- 5 Table 3. SDH Multiplexing Structure for STM Frames --------------------------------------- 13

LIST OF FIGURES Figure 1.Wired Telecommunication Network ------------------------------------------------- 1 Figure 2.Wireless Telecommunication Network --------------------------------------------- 2 Figure 3.STM-1 Framework ------------------------------------------------------------------------ 11 Figure 4.Main Components of DLU -------------------------------------------------------------- 15 Figure 5. Interconnection of EWSD Parts ------------------------------------------------------ 18

XpertSolver.com

Telecommunication:

Telecommunication is the transmission of information from one place to another. The information can be in any form e.g. Speech, packet data etc .There are number of mediums used for telecommunication, most prominent of which are:

• Wired • Optical Fiber • Wireless (Through Air)

For the means of ease, the whole telecommunication network is divided into three parts:

1. Access Network 2. Transmission 3. Switching

Wired Telecommunication Network:

XpertSolver.com

Wireless Telecommunication Network:

Outside Plant/Access Network

An access network is that part of a telecommunications network which connects subscribers to their immediate service provider. It is different form the core network, (for example the Network Switching Subsystem) which connects local providers to each other. It refers to the series of wires, cables and equipment lying between a consumer/business telephone termination point (the point at which a telephone connection reaches the customer) and the local telephone exchange. Access network ends at Main Distribution Frame (MDF).

Main Distribution Frame:

In telephony, a main distribution frame (MDF or main frame) is a signal distribution frame for connecting equipment (inside plant) to cables and subscriber carrier equipment (outside plant). The MDF is a termination point within the local telephone exchange where exchange equipment and terminations of local loops are connected by jumper wires at the MDF. All cable copper pairs supplying services through user telephone lines are terminated at the MDF and distributed through the MDF to equipment within the local exchange e.g. repeaters and DSLAM. In MDF each user have his own wire pair which can be identified with the help of Equation Number (EQN #).

XpertSolver.com

Base Transceiver Station (BTS):

Most of the subscribers are connected to the exchange by means of wired medium. However in few cases the used of wired medium is not possible or not recommendable. If an area is located in some densely populated region where digging is not possible or far away in some remote region from where wired communication is not economically affordable. In such cases wireless communication is used to transmit the subscriber’s data from the remote location to the exchange. This part of transmission takes place with the help of Base Transceiver Station (BTS). BTS is also used for mobile communication.

A remote BTS is present at the remote location and another BTS is present at the exchange. Both BTS communicate with each other and Receive/Send the Data. BTS is controlled with the help of software. An Ethernet cable connects the computer to the BTS and Tx, Rx power, SNR and many other such factors are analyzed. During my internship I was shown and explained the Configuration of BTS.

Transmission

In telecommunication, Transmission is the process of sending and propagating an analogue or digital information signal over a physical transmission medium, either wired, optical or wireless.

Optical Fiber:

An optical fiber (or optical fiber) is a flexible, transparent fiber made of glass (silica) or plastic. In past decade’s optical fiber has emerged as a very effective medium for long distance signal transmission. It permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Optical fibers typically include a transparent core surrounded by a transparent cladding material with a lower index of refraction. Light is kept in the core by total internal reflection which is the basic principle of the working of optical fibers. This causes the fiber to act as a waveguide.

Another advantage of optical fiber is that multiple light beams can pass through single fiber at the same time. This principle is used in DWDM.

XpertSolver.com

Modulation Technique:

The signal voice signal coming through copper cable in the form of electric pulses is in analog form. Before it can be transmitted to other exchanges, it must be digitized. In order to digitize the analog signal some modulation technique is to be followed. The technique which is adopted to digitize the signal is known as Pulse Code Modulation (PCM).

Pulse Code Modulation (PCM):

Pulse Code Modulation is a technique for digitizing an analog signal. . The main steps of PCM are:

Sampling:

In general, the amplitude of the analog signal is sampled at regular intervals. The value of signal at other time than specified intervals is not stored.

Quantization:

The amplitude at the sampling time is mapped against a scale in a process called quantizing. Each level is assigned a certain discrete value.

Encoding:

This value is encoded in binary numbers and can then be stored or transmitted digitally.

PCM has been widely used for digitizing human voice in the public switched telephone network (PSTN). It is also used in computer-based digital audio, CDs, and the audio component of digital video .The PCM modulated signal can then be multiplexed and transmitted.

Multiplexing techniques:

There are three Basic Multiplexing techniques: • Space Division Multiplexing • Frequency Division Multiplexing • Time Division Multiplexing

XpertSolver.com

Space Division Multiplexing: Space division multiplexing (SDM) is nothing more than the provision of multiple fixed bandwidth channels by multiple physical paths (i.e., pairs of wires or optical fibers). A good example of SDM is the use of a 25-pair cable to carry the conversations of 25 individual users from the customer's premises to the local telephone company’s central office location.

SDM is not the most efficient technique from the standpoint of outside plant resources, but it does play a role in all carrier networks. A given copper or fiber facility has a finite capacity for information. When that capacity is completely utilized, SDM is the only alternative.

By some arguments, SDM is not a multiplexing scheme at all, since it does not support multiple communication channels on a single medium. However, the concept is an important one because it occurs both in the deployment of transmission facilities as well as the internal architecture of some switches. Given Below is the example of Space Division Multiplexing.

Frequency Division Multiplexing:

Frequency Division Multiplexing (FDM) refers to sharing a channel by dividing up the passband of the channel into multiple sub bands. Each sub band can carry a signal conveying data. The bandwidth (not the passband) allocated to a channel determines how much information the channel can carry; thus, sub bands of equal bandwidth can each carry the same amount of information.

XpertSolver.com

As long as the various input signals contain frequencies only in their designated sub band, all the inputs can be transmitted simultaneously without interfering. This is the principle applied in broadcast radio. Each station is assigned its own transmitting frequency. The FDM of 0-40Hz Channel is shown in the figure below.

Time Division Multiplexing:

Time division multiplexing (TDM) is the most effective way of multiplexing. It is commonly used to transport multiple digital signals over a single facility. Because the frequency spectrum of a digital signal cannot easily be confined (Theoretically infinite), such signals are amenable to multiplexing only in the time domain. In TDM, a single facility is split into multiple time slots of equal size. Each pair of users is assigned a time slot when the circuit is established; that time slot remains dedicated to them for the life of the circuit.

In TDM, the passband (Frequency Band) is not divided. Rather, each user gets the use of the entire passband, but only for a short time. Thus, rather than dividing up the use of the medium in frequency, it is divided in time. The users simply take turns. In ptcl the time delay for each time slot is 125ms.

Below is an example of 5-slot TDM.

XpertSolver.com

Carrier Standards:

In digital communication systems a single physical wire pair can be used to carry many simultaneous voice conversations by Time Division Multiplexing (TDM). Worldwide standards have been created and deployed for this purpose. The two standards which are currently being used for TDM are E-carrier and T-Carrier.

T-Carrier: In telecommunications, introduced in 1970, T-carrier, sometimes abbreviated as T-CXR, is the generic carrier system. It was originally developed by Bell Labs and used in North America, Japan, and South Korea. Other countries throughout the world use a modern carrier system named E-Carrier.

The basic unit of the T-carrier system is the DS0, which has a transmission rate of 64 kbit/s, and is commonly used for one voice circuit. The T-1 channel combines 24 x 64 kbit/s channels into one single channel, using a technique known as Channel Bonding. T-Carrier is successfully being used Frequency division multiplexing signals. In T-Carrier line data rate is 1.544 Mbps.

E-Carrier: E-Carrier is a new technology as compared to T-Carrier. An E1 link operates over two separate sets of wires, usually coaxial cable. A nominal 3 volt peak signal is encoded with pulses using a method avoiding long periods without polarity changes. The line data rate is 2.048 Mbit /s (full duplex, i.e. 2.048 Mbit /s downstream and 2.048 Mbit /s upstream) which is split into 32 timeslots, each being allocated 8bits in turn. Thus each timeslot sends and receives an 8-bit PCM sample. This is ideal for voice telephone calls where the voice is sampled at that data rate and reconstructed at the other end. The timeslots are numbered from 0 to 31. Unlike the earlier T-carrier systems developed in North America, all 8 bits of each sample are available for each call. This allows the E1 systems to be used equally well for circuit switched data calls, without risking the loss of any information.

Out of 32, two time slots (also termed as overhead bits) are used for special functions. One timeslot (TS0) is reserved for framing purposes. This allows the receiver to lock onto the start of each frame and match up each channel in turn. Another timeslot (TS16) is often reserved for signaling purposes, to control call setup according to one of many telecommunications protocols.

XpertSolver.com

arrier and E-Carrier, A Comparison:

T-carrier and E- carrier systems

North American

(T-Carrier)

Japanese

(T-Carrier)

European (CEPT)

(E-Carrier)

Level zero (channel data

rate)

64 kbit/s (DS0)

64 kbit/s

64 kbit/s

First level

1.544 Mbit/s (DS1) (24 user channels) (T1)

1.544 Mbit/s (24 user channels)

2.048 Mbit/s (32 user channels) (E1)

(Intermediate level, T- carrier hierarchy only)

3.152 Mbit/s (DS1C) (48 Ch.)

–

–

Second level

6.312 Mbit/s (DS2) (96 Ch.) (T2)

6.312 Mbit/s (96 Ch.), or 7.786 Mbit/s (120 Ch.)

8.448 Mbit/s (128 Ch.) (E2)

Third level

44.736 Mbit/s (DS3) (672 Ch.) (T3)

32.064 Mbit/s (480 Ch.)

34.368 Mbit/s (512 Ch.) (E3)

Fourth level

274.176 Mbit/s (DS4) (4032 Ch.)

97.728 Mbit/s (1440 Ch.)

139.264 Mbit/s (2048 Ch.) (E4)

Fifth level

400.352 Mbit/s (DS5) (5760 Ch.)

565.148 Mbit/s (8192 Ch.)

565.148 Mbit/s (8192 Ch.) (E5)

XpertSolver.com

Digital Hierarchies:

Currently two digital hierarchies are being used for transmission purposes.

1. Plesiochronous Digital Hierarchy (PDH) 2. Synchronous Digital Hierarchy (SDH)

Plesiochronous Digital Hierarchy (PDH): The Plesiochronous Digital Hierarchy (PDH) is a technology used in telecommunications networks to transport large quantities of data over digital transport equipment such as fiber and microwave radio systems. Basic Features of PDH hierarchy are illustrated below:

1. The systems in PDH are separately clocked. i.e. There may be variations in clock speed of two different exchanges.

2. Due to separately clocked system, PDH based systems cannot be monitored centrally (from one place).

3. Overhead bits in PDH are los as compared to SDH. 4. Due to separately clocked system the data rate of PDH is limited.

Synchronous Digital Hierarchy (SDH) : Synchronous Digital Hierarchy (SDH) is standardized multiplexing protocol that transfer multiple digital bit streams over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs). The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting large amounts of telephone calls and data traffic over the same fiber without synchronization problems. Basic Features of SDH are given below:

1. The SDH based systems are centrally clocked. Each system throughout the network works on

same clock frequency. 2. Due to synchronized system, it can be controlled centrally. 3. SDH has high overhead bits as compared to PDH. His is because more information is conveyed

along with the data. 4. SDH has high data rates as compared of PDH. 5. Add/drop of lines can easily be done with the help of add drop multiplexers.

XpertSolver.com

SDH Vs. PDH:

Date Rates:

Level E1 E3 STM-1 STM-4 STM-16 STM-64 SDH Line Rate

2 Mbps 155.5 Mbps 622 Mbps 2.5 Gbps 10 Gbps

PDH Line Rate

2 Mbps 34 Mbps 140 Mbps 565 Mbps NIL NIL

Add Drop Method:

SDH Frame :

The STM-1 (Synchronous Transport Module, level 1) frame is the basic transmission format for SDH—the first level of the synchronous digital hierarchy. The STM-1 frame is transmitted in exactly 125 µs. STM-1 is formed by combining 63 E-1s that are coming from the exchange (EWSD in case of Gujrat Exchange). The STM-1 frame consists of overhead and pointers plus information payload. The first nine columns of each frame make up the Section Overhead and Administrative Unit Pointers, and the last 261 columns

XpertSolver.com

make up the Information Payload. The pointers (H1, H2, H3 bytes) identify administrative units (AU) within the information payload.

Formation of STM-N from different Levels:

XpertSolver.com

Optical Fiber Multiplexing:

In optical fibers multiple optical carriers can be multiplexed to pass through a single optical fiber cable with the help of multiplexing.

Wavelength-division multiplexing:

In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e. colours) of laser light. This technique enables bidirectional communications over one strand of fiber, as well as multiplication of capacity. Different wavelengths of light are transmitted and received in the same way as distinguished wavelengths of light.

Dense Wavelength-division multiplexing (DWDM):

DWDM is same as WDM but is different in the way that optical signals are multiplexed within the 1550 nm band (Densely Multiplexed).

Switching

In its simplest form, a communication system can be established between two nodes (or stations) that are directly connected by some form of point-to-point transmission medium. This may, however, be impractical, if there are many dispersed nodes or the communication requires dynamic connection between different nodes at various times. An alternative method to a point-to-point connection is establishing a communication network. In a communication network, each communicating device (or station) is connected to a network node. The interconnected nodes are capable of transferring data between stations. Such a communication network is called switched network. In a switched network, the transmitted data is not passed on to the entire medium. Instead, data are transferred from source to destination through a series of intermediate nodes. Such nodes, often called switching nodes are only concerned about how to move the data from one node to another until the data reaches its destination node.

There are two categories of switching:

• Circuit Switching • Packet Switching

XpertSolver.com

Circuit Switching: Circuit switching is a switching method in which a communication way in physical form between two ways within a network is established, maintained and for each communication. It has three phases: establishment, data transfer and circuit disconnect. Though being replaced by packet switching, circuit switching is widely used throughout Pakistan by PTCL. Following types of exchanges are used by PTCL for circuit switching:

Exchange Manufacturer EWSD Germany AXE10 Sweden NEC Japan ZXD China Alcatel Germany Huawei China

Previously NEC and EWSD exchange was being used for circuit switching but now NEC has been abandoned. During in the detailed explanation on EWSD is presented in the report.

Packet Switching: In packet switching data networks, all user data to be transmitted is first divided into one or more units, called packets, by the source DTE. These packets are of varying lengths, and reach packet is assigned an address and the necessary control information. In each switching node, packets are received, stored briefly, and passed on to the text node. Packets include both the source and the destination DTE network addresses. On receipt of each packet, the switching node inspects the destination address contained in the packet. Each switching nodes contains a routing director specifying the outgoing links to be used for each network address. On the receipt of each packet, the switching node forwards the packet on the appropriate link at the maximum available bit rate, which is not possible in case of circuit switching.

Advantage of Packet Switching: In Packet switching, the data packet may pass through any of the paths to reach destination. This means that no specific line gets reserved for communication between two devices. However in Circuit switching, a specific path is reserved as long as the connection is established. i.e. Waste of resources and increase in cost.

At PTCL following packet switching-based exchanges are used:

NGN (Next Generation Networks *used for 3G communication) UMG (Universal Media Gateway) MGW (Media Gateway)

XpertSolver.com

EWSD

Overview: EWSD Digital switching system has been designed and manufactured by M/s Siemens, Germany. The name is the abbreviated form of German equivalent of Electronic Switching System Digital (Electronische Wheler Systeme Digitale).EWSD switch can support maximum 2,50,000 subscribers or 60,000 incoming, outgoing or both way trunks, when working as a pure tandem exchange.

Parts of EWSD:

1. DLU (Digital Line Unit): DLU is the Functional unit on which subscriber lines are terminated. It connects subscriber lines to LTG’s. One standard rack of DLU can accommodate 2 DLUs of 992 Subscribers each. For the reason of security, each DLU is connected to two LTGs via 4Mbps links.DLU Contain following major Subparts.

• SLMA Modules:

Within DLU SLMA (Subscriber Line Module Analog) Modules are present which provide the working of DLUs. Based on version SLMA Modules can support 8,16 or 32 Subscribers. Each module is programmed to control the traffic of certain Number. Digital (ISDN) Subscribers are connected to SLMD (Subscriber Line Module Digital) Modules.

• RDLUs (Remote DLUs):

The DLUs present within exchange are local DLUs. However DLUs can be situated remotely. In such case all the concerned subscribers are connected to RDLU which is in turn connected to the exchange. In case line between RDLU and main exchange gets broken, the subscribers connected to RDLU can still communicate with each other with the help of Stand Alone Service Cr. Card (SASCE).SASCE also provides functionality of connecting multiple RDLUs in a cluster (Maximum 6).

• ALEX (Alarm External) Alex is a module present in each DLU.It is used for forwarding Alarms.

• TU (Test Unit): All DLUs are provided with Test Units with test units which performs test and measurements on subscriber lines and telephones.

XpertSolver.com

Block Diagram of DLU components:

2. LTG (Line Trunk Group):

LTG forms the interface between digital environment of EWSD and SN (Switching Network).It is connected to other digital exchanges with the help of 2Mbps trunks .Given Below are basic functional units of LTGs.

• DIU30 (Digital Interface ): DIU30 is a module used to connect DLUs to the 2Mbps trunk which is in turn connected to LTG.

• CR ( Code Receivers): Code receivers are used for receiving multiple frequency codes from DTMF (Dual Tone Multiple Frequency) subscribers. Each DTMF tone represents are certain code.

• COUB and COUC (Conference Unit B or C ) Modules: As name suggests, conference unit modules are used for conference calls.

XpertSolver.com

• GS (Group Switch) : Group switch is a non-blocking time stage switch (512TS) which is controlled by GP (Group Processor).

• LIU (Link Interface Unit): LIU provides interconnectivity between LTGs and SN(Switching Network) with the help of two parallel 8Mbps SDCs.

• GP (Group Processor): Group Processor controls all functional units of LTG. The received signals from LTU,SU,GS and LIU are processed by Group processor.

Functions of LTG:

• Call Processing Functions:

Receiving and analyzing line and register signals, injecting audible tones, switching user channels from and to the switching network etc.

• Safeguarding functions:

Detecting errors in LTG and on the transmission paths within LTGs, analyzing the extent of errors and initiating counter measures like disabling lines or channels etc.

• Operation and Maintenance functions:

Acquiring traffic data, carrying out QOS (Quality of Service) measures etc.

3. SN (Switching Network):

Different peripheral units like LTGs and CCNC are connected to SN via 8Mbps highways called SDCs. Each SDC consists of 128 channels. The SN consists of several duplicated Time Stage Groups (TSGs) and Space Stage Groups (SSGs).Each TSG can support 63 SDCs. The switching network can be expanded by adding extra plug-in modules.

Function of SN:

• Speech Path Switching • Message path Switching • CC#7 signaling channels connection

XpertSolver.com

4. Co-Ordination Processor: The main units of CP and their functions are described below:

Base Processor is used for Operation/Maintenance and call processing.

Common Memory (CMY) -256 to 1024 MB in 4 memory banks consists of 4Mb DRAM chips.

Input/output Controllers (ION)-4 IONs are used to co-ordinate and supervise the access of CMY.

Input/output Processors(IOPs) are used for co-ordination and supervision if external subsystem or mass storage is connected to the CP. Central Clock Generator is used for the synchronization of Exchange and network.CCG is extremely accurate (up to 10-9 and can be extended to 10-9).

5. CCNC (Common Channel Signaling Network

Control): It provides Signaling System 7 (SS7) capability for Inter-Exchange as well as Intra-Exchange Signaling. For flexibility Signaling are divided into two parts Message Transfer Pert (MTP) and User Part (UP).A maximum of 254 signaling channels can be connected to the CCNC. The CCNC is connected to SN with the help of two 8Mbps Trunks.

Controlling of EWSD Exchange: BMML command manager is used to control the EWSD exchange. Specified commands are used for performing different operations. Apart from directly controlling by BMML command manager, BNCC can also be used to control specific services. Once executed by BNCC, the command automatically gets executed on BMML window.

XpertSolver.com

Interconnection of EWSD Parts:

EWSD System Data: • Maximum Number of Subscribers 250,000 • Supply Voltage -48 DC • Clock Accuracy 10-9 (Plesiochronous)

10-11(Synchronous) • Supported Signaling Systems All Conventional Systems: MF-R2 etc. • Call Charge Reg. Methods Periodic Pulse Metering

AMA Billing (CAMA, LAMA) IACHASTA

• Call Charge Reg. Specs Maximum 511 Zones. Maximum 5 Tariffs Per Zone.

• Environmental Conditions Ambient Temp. : 50C to 400C Relative Humidity: 10% TO 80%

XpertSolver.com

Billing Procedure: When a customer makes some call or uses network in some other way, billing is to be made. This process is completed in the respective exchange from which the subscriber is dialing which is EWSD in case of Gujrat exchange. Whenever subscriber uses the line, EWSD automatically records the bill according to the tariff. The recorded data is then sent to head office Islamabad from the respective General Manager Office (GM Office) after regular time period (i.e. two weeks).Previously the billing was recorded in electromagnetic tapes which were expensive as compared to optical disks and could be reused limited ties. However Electromagnetic tapes have been replaced with Optical disks which are small in size and can store more data (Approximately 4GB). Also through optical disks the online server can automatically pick up the billing data.

A few Developing Technologies:

DSLAM (Digital Subscriber Line Access Multiplexer):

A DSLAM is a network device often located in the telephone exchange. It connects multiple customer Digital Subscriber Line (DSL) to a high speed digital communication channel using multiplexing techniques.

By placing additional DSLAMS at locations remote form the telephone exchange, telephone companies now provide DSL service to locations previously beyond from effective range.

Hardware:

Customers connect to the DSLAM through ADSL Modems or DSL Routers which are connected to PSTN network via typical telephone line. Each DSLAM has multiple aggregation cards and each such cards have multiple points to which customer lines are connected. Typically a single DSLAM aggregation card has 24ports, but this number can vary with manufacturer.

DXX (Digital Cross Connect):

Just like DSLAM, DXX is a fast and reliable communication technology over optical fiber. Data rate can be provided from 64kbps to several Mbps.

The main difference between DXX and DSL is that in DSL subscribers are provided with a shared path from DSLAM. However DXX is a dedicated path used by a single customer. It is a node based network and PTCL has made nodes at different locations to provide DXX services to its customers. The most common example of DXX subscribers are banks.

XpertSolver.com

DXX has an E1-Card, U-Card and G-Card.

ard is used to provide service to the subscriber that demands a very high

bandwidth. DXX has following benefits:

• Efficient Utilization of transmission Bandwidth • Expandability • Manageability • Higher Service Quality • Flexibility for networking • Powerful NMS (Network Management Service) to manage large networks

NGN (Next Generation Networks): NGN is a broad term used to describe key architectural evolutions in telecommunication core and across networks. The general idea behind the NGN is that one network transports all information and services (voice, data and all sort of media such as video) by encapsulating these into packets similar to those used on the internet. NGNs are commonly built around the Internet Protocol and therefore the term IP- Based Communication is also used to describe NGN. It provides following services:

• Real time Conversation voice services • Instant Messaging (IM) • Push to talk over NGN (PoN) • Point to point multimedia services • Group messaging • Content Recovery Services • Push Based Services • Broadcast/Multicast Services • Hosted and transit services for enterprises • Information Services • Notification Services • 3GPP Release 6 and 3GPP2 Release A OSA based Services

XpertSolver.com

Software Tools

BNCC: BNCC is very vast online management and customer care software used throughout the Pakistan. It provides following features:

• Order Entry • Order Management • Customer Management • Product Management • Resource Management • System Management • Integrated Stat. Query • WLL Sales Management • Payphone Company Management • Franchise & Payphone Management

Each Employee is given a username and password and privileges are given to access only certain features according to the type of job of the employee. BNCC is the central management system which is linked with the exchanges as well. Any new feature updated on specific number automatically gets updated on the respective exchange. During my internship period I worked on BNCC in switching room as well as made new entries of Telephone numbers and DSL.

CMS (Complaint Management System): CMS Complaint Management System) is another management software which is as vast as BNCC. Its purpose is to manage complaints of PTCL customers throughout the country. The CMS is aimed at achieving customer satisfaction” , improving the MIS and centralizing the control and monitoring. Just like BNCC, CMS is also online system which can be accessed from anywhere hence providing centralization to the system. The complaints of customers are registered on CMS which is checked regularly by all employees. The concerned employee checks the complaints and resolves the issues.

BMML/ iManager: BMML is software used to control EWSD exchange and iManager controls the media gateway exchange. Specific commands are entered to perform a specific task.

XpertSolver.com

Power Management

Apart from Telecommunication System I also got chance to see the power management system of the exchange. All the exchanges where electricity is available are powered by rental electricity. However in hours of load shedding or in case of emergency Generators and UPS (Uninterruptible Power Supply) are present. At Gujrat exchange two 320KVA and one 100KVA generator is present. At power Supply cutoff UPS immediately restores the power supply without any time delay. Then workers manually start generator and switch the load to generator. Even if workers are unable to start generator due to some reason, UPS can run all the exchanges for 10 Hours. SE Switching Gujrat also controls the fuel supply and power management of Gujrat Division as well as Mandi Bahauldin Division. In case of any fault technicians are sent to the respective exchange to check and correct the fault.

XpertSolver.com