Internship Report

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[PAKISTAN TELECOMMUNICATION COMPANY LTD]

[INTERNSHIP REPORT]

Internship Report

IN THE NAME OF ALLAH, MOST GRACIOUS, MOST COMPANSSIONATE.

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Internship Report

INTERNSHIP REPORT ON PTCL

Pakistan Telecommunication Company Limit

(PTCL)

PREPARED BY:

USAMA KHALID (K11-2419)B.Sc. Electrical Engineering

National University of Computer and Emerging Sciences

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CONTENTS

Sr. No Name Page

1 Who is who and what is what? 822.12.22.32.42.5

Services provided by PTCLOptical fiber services to the private sector Services for corporate customers Home and personalBusiness services Carrier services and wholesale

9910111212

33.13.23.33.43.53.63.73. 8

MDF( Main distribution frame)PTCL Architecture NetworksMDF (Main Distribution Frame) JPX-202/3219 (Huawei)Joint Cable Connectors Faults detection and checkingDSL Connection in ExchangeVoltages and currents in MDFDocuments for New Connection

131314141515161717

44.14.24.34.44.54.64.74.84.94.10

DSL( digital line subscriber)DSL IntroductionTypes of DSLDSL Technologies Speed and distance ChartADSL Basic ArchitectureDSL ModemDSLAM (Digital Subscriber Line Access Multiplexer)BRAS (Broadband Remote Access Server)RelationsLQT measurements for 2mb DSLDifference b/w ADSL & DSL

1818181818192020212121

55.15.25.35.45.55.65.75.85.9

NGN( Next generation network)Block Diagram of NGN Ahmadpur EastOverview Soft switch UMG (Universal Media Gateway)Hardware DivisionMSAN (Muti-Service Access Node)SS7 (signaling system. 7)E1Difference in Hub, Switch, Bridge, & Router

2222222323

25252727

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66.16.26.36.46.5

Alcatel Location Block Diagram of Alcatel Ahmadpur EastMain Control Station (SMC)Auxiliary Equipment Control Station (SMA)Trunk Control Station (SMT)

292930303438

77.17.27.37.4

TransmissionTypes of transmission Media Guided media Wireless (Unguided Media) TransmissionFactors to select media

4141424347

8 Reference Page 48

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PREFACE

This report is the practical part of the most vital practice of our B.Sc Engineering program. The sole objective is to familiarize the student with the practical manipulation of Engineering Sector. This report has been written to know how big organizations like PTCL work with their teams to achieve their common goals.

In the first phase of the report there is the general introduction about the employers in the CTX Ahmadpur East, then the mission regarding technical and operational network, different services and then there is some detail of the hardware used in the Telecommunication sector by PTCL.

Usama Khalid

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ACKNOWLEDGEMENT

In the name of Almighty Allah who is most merciful, and who give us strength to write this internship report in a different way.

We extend our heartiest thanks to our seniors, colleagues, and subordinates who assist me on every occasion to enable me to write this report.

I pay special homage to the following persons.

Mr. Sajid Mehmood

Mr. Wahid Razaq

Mr. Shahbaz Bhutta

Syed Hassan bukhari

Mr. Mosheer Shahib

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1. Who is who and what is what?There are technician and officers which deals the customers problems. Each person has its own work.

1) Mr. Wahid Razaq:

Allot number, its cut off or restore the number according to the number.

Fault of the telephone and DSL are entered here.

2) Mr. Shahbaz Bhutta:

Deals problem with optical fiber

3) Mr. Muhammad Sajid Mahmood:

All orders of PTCL connections are enter in the computer here.

4) Mr. Syed Hassan Bukhari:

Tells information’s about problems in DSL.

Detect the faults in DSL.

Faults are checked and correct here in this war room.

NPC (Network phone connection new version of NTC) is here.

5) Mr. Mausheer

Assign the technician of war room to deal the customer problems.

Supervisor of MDF.

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2. Services Provided by PTCL

2.1 Optical fiber services to the private sector:Pakistan Telecommunication Company Limited not only Provides Conventional telephone facilities, it also offers optical fiber services to the private sector. We will briefly discuss below the product lines being offered by the PTCL. Basically PTCL divide their services into two parts:-

Services for consumers Services for corporate customers

I. Services for Consumers:These services are basically for the common users (Individual/home users) those use telephone in their home/work place and they are basically non business users.

a) New Telephone Connections:

As mentioned earlier, PTCL is presently the only telecom company, who provided fixed-line telephony in the country. So whenever, any Private business concern or any individual needs a new telephone connection for provision of telephone service.

b) Value Added Services:

CLI (Caller’s Line Identification) it allows customers to identify the caller before picking up the phone receiver. To subscribe to Customer needs a telephone set with display capability or a CLI device at phone.

Advantages:

Check on obnoxious calls Complete record of incoming / outgoing calls with time & date.i. PREPAID CALLING CARDS:

PTCL calling card is the most popular choice of millions of customers all over the country. It is now available with balance transfer facility and follow on call facility. Comes in easily affordable denominations of

Rs. 100, 250, 500, 1000 and 2000. Easy to use from any PTCL digital phone

(Dial 1010)

Fast and easy, nationwide and international access 24 hours customer services through toll free number

(0800-80800)

ii. E-BILL PAYMENT:Billing system is a part of customer services so providing connivance to its valuable customers PTCL launched a new billing service which is available through “ PTCL Calling Card” . This service is basically providing billing solutions for the users.

Advantages:

Customer can save his time by paying his bill on phone

Customer can pay his bill whenever he wants

iii. DIGITAL FACILITIES:

PTCL offers a variety of features to digital exchange customers like Call Transfer on (a) Busy (b) No Reply

(c) Immediate Abbreviated Dialing Wake up call

Call Waiting Don’t Disturb

II. SERVICES FOR CORPORATE CUSTOMERS:

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PTCL is striving hard to facilitate its valued corporate customers at each level of service. PTCL offers a host of unmatched services to suit the needs of the Corporate Customers. The list of Corporate Services is given as under. For more information regarding any of the following services, PTCL Corporate Customer Centers can be contacted.

IN BASED VALUED ADDED SERVICES VALUED ADDED SERVICES 0800- Toll Free PTCL calling cards Domestic and

international Premium Rate Service- 0900 Virtual Private Network

Universal access Number (UAN) Universal internet number (UNI) ISDN PRI Teleplay (ISDN/BRI) Local

Domestic/ International Leased Bandwidth and point Leased Lines (DXX)

Local Leased Circuits ( 2Wires/4 wires) DXX

Digital facilities Digital subscriber loop (DSL) Co location Call centers (new)

Universal Access Number (UAN):

UAN (Universal Access Number) service is ideal for organizations Engaged marketing of products or services. Here is a list of business that can avail UAN Service. Banks Newspapers Airlines Hotels

Insurance Credit Card Companies Travel Shipping Lines

Trading Companies Fast Food Outlets Consumer Products

Companies

Courier Services Utility Services Stock Brokers

Voice Messaging Service (VMS):

With PTCL Messaging Service, you can have all for (or Desired) calls recorded when you are absent, busy on phone or do not want to attend the calls for any reason. You can, later on at your convenience, retrieve all recorded messages from any telephone anywhere in the country.

Security of message is ensured against eavesdropping through subscriber controlled password. PTCL VMS is designed for those who do not want to miss a call or Fax because that can be

beneficial. Great for anyone owning a telephone or Fax, at home or business. Much more powerful and flexible than answering machine due to Message options available in

your voice mail system.Features: Call answer Fax

Messaging Notification

Capacity 10 messages

PTCL Messaging Plus

PTCL MESSAGING PLUS is designed for small and medium business enterprises having problems with managing telephone message.

PTCL MESSAGING PLUS will definitely handle these problems for you. Advanced messaging features save time, make you truly mobile and increase productivity.

Essential for time-conscious executives, frequent travelers and Professional groups.

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Feature: Call answer Co- Location Centers Pakistan Telecommunication Company has taken land mark decision to establish co location centers throughout the country. Benefits:

Easy access to local & international connectivity

Quick deployment of services

Higher reliability and quality of service Full connectivity under one roof

Just plug in and start business

Target market:

IT companies Telecom data companies Virtual Private Network (VPN):Communication is the secret of success in today’s highly competitive market. When it comes to enabling your enterprise, your communication got to be instant, fast and hassle free. The answer to this corporate need is virtual private net work. ISDN BRI/PRI:

It is a near broadband experience suitable for household and small/medium sized organizations. Features:

Faster and clear voice Fax and data communication

on a single phone

PRI provides thirty 64 kbps user channel plus two 16 kbps signaling channel

Cost effective

BRI provides two 64 kbps user channel plus one 16 kbps signaling channel

2.3 Home and Personal: 3G EVO Tab

Introducing Pakistan’s First 3G Enabled Smartphone Android Tablet—3G EVO Tab.

EVO 3G Wireless Broadband EVO 3G Wireless broadband is the pioneer of 3G Wireless Broadband service in Pakistan. Launched in June 2009 - EVO has started the revolution of the internet evolution in Pakistan.

Landline Provide the facility of Landline to connect nationwide and international wide with the peoples.

Broadband PTCL Broadband is the largest and the fastest growing Broadband service in Pakistan.

Smart TV: Employing the IPTV (Internet Protocol TV) technology, PTCL brought Pakistan in the list of a few countries across the globe that offers this state of the art interactive TV service to its subscribers.

Vfone: PTCL provides Pakistan Largest wireless network based on CDMA technology.

Dialup:

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Enjoy Phone-n-Net innovative service with nominal charges.

2.4 Business Services:

Business Connectivity:PTCL’s business connectivity offers secure, reliable and

integrated end to end domestic and global connectivity solutions to cater for the demands of corporate and enterprise users.

Business Communication:PTCL’s communication product portfolio is tailored to help business enterprises gain

productivity advantages by offering a suite of powerful convergence, presence-enabled applications.

Managed Services:PTCL’s Managed Network Services is a comprehensive solution for those corporate

customers which are aimed at satisfying the essential needs of telephony/voice, data and security needs.

Hosted Solutions:Get your e-business up and running quickly for competitive advantage. PTCL offers its

clients a combination of business acumen and technical expertise that your business can never exhaust. With us, your infrastructure, applications and systems are maintained by certified experts with experience to make your environment meet and exceed the...

Business Security:Provide the services with business security.

2.5 Carrier Services & Wholesale:

Wholesale Services:PTCL customers can now provide services to their clients without undertaking large scale

investment in infrastructure or developing expertise in running their own networks.

Telecom Operators:Extend the boundaries of your reach.

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3. MDF (Main Distribution Frame):3.1 PTCL Architecture:

PTCL ExchangeThe Exchange is the building where the local exchange switch resides. A CO’s switch may serve telephone service subscriber in a very narrow geographic area such as a single large building.

Distribution Point (DP)From user to Distribution Point Drop Wire is used. And low- medium density copper cable (2-300 pairs) from DP to Distribution Frame. New building can be built and DPs are used to provide them connection Instead to direct connection to Exchange.

Distribution Frames (DF)Distribution fames surround the CO. They are high density copper cable (50-1500 pair) Primary Cable. Usually all connection to a distribution frame are copper. It allows the telephone company to use High Density Copper Cabling.

Main Distribution Frames (MDF)MDFs are distribution frames that have some smart switching in them. Usually, this equipment has been placed to provide the facility of DSL for access to use Internet. With the help of DSLAM Internet is enabling in MDFs for particular user.

3.2 NetworksThere are two types of networks

i. Internal network: It is consisted of connections of Exchange to MDF and MDF to cabinet.ii. External network: It is consisted of connections of cabinet to DP and Drop line to subscriber.

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Cable system:There are three types of cables are use for the transmission and receiving of data transmission

i. Main Cable System (Primary Cable): It is having cables from exchange to main distribution points, e.g. cabinets or subscriber’s distribution frame in multi-story buildings. It is highly density copper cable. Primary cable has 300/400 pairs while Secondary cable has 600/800 pairs.

600 pair’s Primary cables

ii. Distribution Cables System (Secondary Cable): This is having cables from main distribution point (e.g. cabinets) to subscriber distribution points e.g. DP boxes.

Secondary Cable Drop Wire

Two types of cables are used in the distribution cable system.

a. Polyethylene insulated copper cable having diameter of 0.4mm or 0.6mm but this PTCL exchange is using cable having diameter of 0.4mm. It is low density copper cable. 0.4mm cable is used b/c it is easily joinable and is cheap. 0.6 mm cable is not b/c it is difficult to joint and costly.

b. OFC (optical Fiber cable) is mostly used in Islamabad and Lahore. But it is not used mostly in Pakistan b/c it need regular power supply but there is load shading issues so that’s way it is not. But OFC can transmit more data than copper cable. As 1 Fiber optics can support 7890 channels. It transmits data with the speed of light.

3.3 MDF (Main Distribution Frame) JPX-202/3219 (Hawaii):MDF has two sides

i. Inside ii. Outside

Inside connects the MDF to required switching Exchange NGN while outside connects the MDF to the cabinet. And inside and outside of the MDF are connected to each other through jumper wire. Inside of MDF:

Inside of the MDF is consisted of NEs which has one pair of jumping wire (Switching board cable). The connection b/w these wire is horizontally connected by punching tool. PG (permanent Glow) is inserted b/w the NEs to block or disconnection some subscriber from switching exchange and cabinet.

Outside of MDF:Outside of the MDF is consisted of the multiple racks of 15 tags having 100 fuses in one

vertical. Fuses show the subscriber connections. Outside of the MDF is connected to the inside of the MDF by jumping wire. Outside of the MDF have two wires which have vertically connection.

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Exchange Cabinet

Cabinet SubscriberDistribution point (DP)

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MDF belonging to which switching room:This MDF belongs to switching exchange of NGN Exchange.

Local Exchange:MDF room has its own local exchange which handles the telephone numbers within this PTCL exchange. I.e. switching room, Alcatel, MDF, officer telephones numbers, war room telephone number and optical fiber telephone numbers etc.

Types of Exchanges in Ahmadpur East:1) NGN2) ALCATEL3) EWSD

SNR of Cable:

S/N is mostly used to measure how much a signal has been corrupted by noise. Mostly SNR is checked before providing DSL connection. SNR should be b/w 1 to 9 for telephone and DSL. No of joints in a cable should be less. The higher the ratio, the greater the resulting clarity.

3.4 Joint Cable Connectors: 1. U-Y connector

U-Y connector:They enable connecting wires without the need of isolation stripping. They are filled with gel, which protects wires from corrosion. UY connectors should be used for wires with external coat up to 1.52mm in diameter and 0.4-0.7 wire diameter. The Sealant used in the connector provides the most effective water & moisture protection. It connects more than 25 pair of solid copper wires at one time.

3.5 MDF Faults, Detection and Checking:

Faults occurring in primary/ secondary cable are due to following reasons:-1. Jumper Loosing2. Jumper Break3. Contact Fault4. Faulty DSL Port5. Switch room Fault6. Fault in Fuse

i. Drop line cable is checked by fault locator if there is no fault. Then fault may be in DP.ii. DP connection is checked by checking dialing tone on the telephone. If there is dialing tone then

there is no fault. If there is not dialing tone then the DP connection has fault. Then new connection in DP is assigned by punching tool. If still now the telephone is not in working state. Then fault may be cabinet.

iii. Secondary cable is checked by fault locator if there is no fault then cabinet connection has fault. Then fault may in cabinet.

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iv. The dialing tone is checked in cabinet if there is dialing tone then there is no fault. If there is no dialing tone the fault may be in MDF.

v. MDF required vertical cable pair connection is checked by dialing tone. If there is no dialing tone then vertical cable pair is changed. If there is the dialing tone then there is no fault so the fault will be in switching exchange.

vi. Switching exchange power supply, cards etc. is checked and changed. Then card is sending to be repaired in required manufacturing company

3.6 Connection in Exchange:

Home

3.7 Voltage and Current at MDF:

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Exchange

Switching room

N.E (MDF)

Cabinet Distribution Frame

DSLAM

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ON Hook Off Hook When bell is ringing When bell is not ringing

Voltage 49 v 13.6 v 53.1 vDC /139 vAC 53.1 vDC /116.2 vAC

Current 0.130 mA 48mA 0.9 mA 0.9 mA

3.8 New Telephone Connection:Document required for new connection:

i. NIC Copyii. Property Deal (Rent Agreement+ NIC of House owner if a person is living on Rent)

iii. Demand Notice(With 3 Months line rent in Advance)

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4. DSL (Digital Subscriber Line):

4.1 DSL Introduction:

DSL is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. DSL service is delivered simultaneously with regular telephone on the same telephone line. This is possible because DSL uses a higher frequency. These frequency bands are subsequently separated by filtering.The data throughput of consumer DSL services typically ranges from 256 Kbit/s to 40 Mbit/s in the direction to the customer (downstream), depending on DSL technology, line conditions, and service-level implementation.

4.2 Types of DSL: ADSL ( Asymmetric digital subscriber Line (Most popular)) HDSL (High Bit rate digital subscriber Line0 IDSL (ISDN based digital subscriber Line) VDSL( Very High Speed digital subscriber Line)

4.3 DSL Technologies Speed and distance Chart:The chart below provides a comparison of the various DSL technologies

DSL Type Max. Send Speed Max. Received Speed Max. Distance

ADSL 800 kbps 8 Mbps 18,000 ft (5,500 m)

HDSL 1.54 Mbps 1.54 Mbps 12,000 ft (3,650 m)

IDSL 144 kbps 144 kbps 35,000 ft (10,700 m)

VDSL 16 Mbps 52 Mbps 4,000 ft (1,200 m)

4.4 ADSL Basic Architecture:

4.5 DSL Modem:

A Digital Subscriber Line (DSL) modem is a device used to connect a computer or router to a telephone circuit that has Digital Subscriber Line service configured. Like other modems, it is a type

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of transceiver. It is also called a DSL Transceiver or ATU-R (for ADSL Transceiver Unit-Remote). DSL modem working as a bridge does not need an IP address; it may have one assigned for management purposes. A DSL modem modulates high-frequency tones for transmission to a Digital Subscriber Line Access Multiplexer (DSLAM), and receives and demodulates them from the DSLAM. A single telephone line can be used for simultaneous voice and data with a DSL modem whereas a voice-band modem precludes simultaneous voice traffic. Most DSL modems are external to the computer and wired to the computer's Ethernet port, or occasionally its USB port. Internal DSL modems with PCI interface are rare but available. DSL modems use frequencies from 25 kHz to above 1MHz in order not to interfere with voice service. Voice-band modems use the same frequency spectrum as ordinary telephones, and will interfere with voice service - it is usually impossible to make a telephone call on a line which is being used by a voice-band modem.

Used Equipment:

DSL Modem

SN=E29EB6D14870Power= 12v= 500mADate=Jun 2011ZTE CorporationADSL CPEZXDSL 83IC11Made in china

ADSL Splitter

SP-206

Rosette has four cables blue, yellow, black and red.

Connection:

Phone

DSL Modem

PC1 PC2 PC3 PC4

4.6 DSLAM (Digital Subscriber Line Access Multiplexer):

The Digital Subscriber Line Access Multiplexer or DSLAM is a mechanism at a phone company’s central location that links many customer DSL connections to a single high speed ATM line. It takes connections from many customers and aggregated them onto single high capacity connection to the

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Rosette ADSL splitter

On/offPowerLAN1 ADSL MODEMLAN2 LAN3LAN4

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internet. They are generally flexible and able to support multiple types of DSL in a single central office and different varieties of protocol and modulation. It may provide additional functions including routing or dynamic IP address assignment for customers.

DSLAM Architecture:

DSLAM shelf contain card and each card contain 64 connections and so a complete shelf contain that contain 14 cards would have 896 connections/subscribers.4.7 BRAS (Broadband Remote Access Server):

The Broadband Remote Access Server (B-RAS) is a key component of DSL broadband access networks that serves as an aggregation point for subscriber traffic (IP, PPP and ATM) and provides session termination (PPPoX, RFC 1483) and subscriber management functions such as authentication, authorization, accounting (AAA), and IP address assignment.Triggered by the new functional requirements that Triple-Play service delivery imposed on the DSL network infrastructure and devices, modern B-RASs started to provide advanced services beyond traffic aggregation

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4.8 Relation b/w DSL modem, DSLAM and BRAS:

4.9 LQT (Line Quality testing) meter reading for 2MB DSL:

Uplink Downlink

DSL SNR 25.00 dB 42.30 dB

Line Attenuation 0.00dB 1.00dB

Actual Rate 636kbps 2557kbps

Maximum Rating 936kbps 28288kbps

4.10 Difference b/w ADSL & DSL:

ADSL have different uplink and downlink rate while DSL have same uplink and downlink rate.

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5. NGN (Next Generation Network):NGN the Next Generation Network will be the future of all telecommunication Engineers. These switches which are categorized as Networks can integrate and Handle networks of different technologies. For example it can handle a land line Network, a data network, a VOIP network and even a CDMA network at once. NGN is the next step in telecommunication technology. The Telephone system started up with direct connections to all users. With the expansion new switching techniques were required. In theory normally we learn as “Switching developed in 4 stages.1. Manual switching2. Mechanical switching3. Semi Electronic Switching4. Electronic Switching- Stored Program Control”But the future is here today. Sri Lanka Telecom has taken the giant leap to bring the newest technology in to their system in parallel with the developed and powerful nations in the world. With this we can say there are five systems.5. Packet switching using Routers.The new system can be called as an information transfer system rather than telephone System. That is because it can function as a circuit switch, or a video interworking Gateway.

5.1 Block Diagram of NGN Ahmadpur East:

5.2 Overview: NGN is a service oriented network. It provides an independent service system by splitting the service module from the call control and the call control from the bearer. That is the services provided to each subscriber are handled from a database at central control where as in a normal system the services are defined from where it is connected. Control is merely a place where some information in processed and send back some Instructions. The access point to the user equipment is merely a packet creation point. In this way, it frees the service from the original network model. NGN employs open and integrated network structure. With abundant service Models, NGN is able to provide a variety of services, such as voice, data and multimedia services, or integrated services. Like in the normal telephone system the entire system can be divided in to four areas.

Edge access Core switching

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Network control Service management

5.3 Soft switch: A Soft switch is the centrally located device which is used in telecommunications for connecting the telephone calls over the various phone lines totally under the supervision of computer software running on one system .physical switch board are used as the main hardware that acts for carrying calls from one line to another line. These are the routes for the traveling of signals. If we talk about the soft switch technology it is widely used in the field of networking and telecommunications in all local and broad systems.Call Agent: The call agent is the first part of the soft switch; this part takes care of the sequential functions such as bilking, call routing, transferring signals, call service and the other minor functionalities. A call agent can also control the functioning of the other part of Soft switch with the connections over the Transfer control Protocol (TCP) and internet protocol (IP) some times.Media Gateway: The second part of the soft switch is called media gate way which is responsible for the different types of digital streams that works collectively in the creation of end to end for the control of voice and call over the line. Many interfaces are involved in it which is used for connecting the media to the PSTN networks such as DS1, DS3 and sometimes E1 and US and No us networks. The call agent may control the functioning of the media gate way for connecting the media streams and also for the interfaces in keeping them transparent to the end users of the phone lines.

Benefits of Soft switch: Unlike he point devices soft switch has remarkable benefits for the users who are using this

technology. Some of the advantages are listed below. Soft switch has higher scalability. They usually work very wickedly by just handling the control

part of the server saving the rest of the switch for the other purposes. They can handle more clients for the packet data switching.

No specific hardware is required for the soft switch they are completely platform independent which is very attractive feature of these switches .they can act well in any computer server environment.

Soft switch can be extended by just purchasing the extension license and the controlling connection over the IP. Sometimes PBX support or card is required for the expansion of the soft switches in the wide areas.

Some of the soft switch vendors provide open source to be used by other developers and end users even .this can help the developer and other programmers to enhance the existing code provide in the open source.

Its installation is very easy. It also allows remote installations for its user. Just remote access with the system containing the installed software set up. Its management is also easy. No extra maintenance is required for the soft switches.

Soft switches also provide the extra software based functionalities that no other networking device provides such as voice mails, call record, call billing etc., all this happens via software.

5.4 UMG (Universal Media Gateway):The Universal Media Gateway is one of the main equipment in the Access subsystem of the NGN. In the current implementation of the system in the country this is the main Access system that is being used since it has multiple functions. It is the most economical solution when the telecom network is part PSTN and part NGN. Some of the main features of the UMG It supports interworking between different networks It provides conversion function between different formats of traffic

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Function as a Trunk gateway (TG) and as an Access gateway (AG) It has an embedded signaling gateway (SG). UMG8900 can be divided into two parts according to its functionality. This help to understand the system better.

Types of UMG:i. Service switching module (SSM)

ii. User access module (UAM)

Service switching module (SSM):It processes the formats of various types of traffic flow. It functions as a TG connecting the PSTN system with the NGN. This is what gives a subscriber in the NGN the chance to call one in PSTN or any other network even though they work in different ways. In the Absence of a connection with the switch it can act as a switch in NGN. This gives it the standalone capability and intern more reliability. Service switching module (SSM) consists of 4 parts

Main control frame – Management and maintenance functions of the device and supports service access and process simultaneously.

Service frame – Process services requested by user Central switching frame – Handles Multi-frame cascading function Extended control frame – When the device is at maximum capacity. The Extended frame

does not support access and process functions of user Services, But provides connection management and control function.

User access module (UAM):This is the access point currently provided by Hawaii for the users that are in the NGN. The instrument can be at the UMG itself or function as a RSU from a distant place. It provides integrated access function for both narrowband and broadband users. It can even function as an AG if an IP connection is provided Card structure of the UMG8900

1. Sysyetm Management BoardsOMU- Operation Mintance unitMPU- Main Control unitCMF- Connection management unit frontNET- packet switch net boardCLK- clock boardCMB-connection management unit back PPB- protocol processing unit1. IP interface process BoardE8T-8xFEE1G-1xGHRB-High speed routing board

2. Signalling BoardsSPF- signalling processing board3. TDM interface procesTNU- TDM switch Net UnitTCLU- TDM convergence & link unitE32- 32xE1S2L- 2xSTM-1 optical2. Voice Process BoardVPU- voice process unitSRU- signal resource unit Cascading BoardFLU-front link unitBLU- back link unit

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5.5 Hardware Division:UMG8900 hardware system can be divided into the following subsystems according to their function.1. Operation and maintenance subsystem2. Gateway control subsystem 3. TDM access and switching subsystem4. Packet processing subsystem5. Service resource processing subsystem6. Subscriber access subsystem7. Signaling forwarding subsystem8. Clock subsystem9. Cascading subsystem.

5.6 MSAN (Multi-Service Access Node):A multiservice access node (MSAN) is a device typically installed in a telephone exchange (although sometimes in a roadside serving area interface cabinet) which connects customers' telephone lines to the core network, to provide telephony, ISDN, and broadband such as DSL all from a single platform.Prior to the deployment of MSANs, telecom providers typically had a multitude of separate equipment including DSLAMs to provide the various types of services to customers. Integrating all services on a single node, which typically backhauls all data streams over IP or Asynchronous Transfer Mode can be more cost effective and may more quickly provide new services to customers. Typical outdoor MSAN cabinet consists of Narrowband (POTS), Broadband (XDSL) services, batteries with rectifiers, optical transmission unit and copper distribution frame.

MSAN concept:A MSAN (multi-service access network) can be defined as a single piece of access equipment that can provide multiple types of services to a range of different customers. MSANs were originally designed to be placed in a small community to address all its communications requirements. Traditional designs had a range of slots to accommodate different types of line cards and dual busses to handle both TDM and data. Today the principle stays the same, but new technology deployed on products--such as the Marconi Access Hub--allow for any card in any slot; high-density combination DSL and POTS line cards; and media gateway functionality that allows seamless interworking with soft switches for packetized voice delivery.

5.7 SS7 (signaling system. 7):SS7 is a critical component of modern telecommunications systems. SS7 is a communications protocol that provides signaling and control for various network services and capabilities. While the Internet, wireless data, and related technology have captured the attention of millions, many forget or don't realize the importance of SS7. Every call in every network is dependent on SS7. Likewise, every mobile phone user is dependent on SS7 to allow inter-network roaming. SS7 is also the "glue" that sticks together circuit switched (traditional) networks with Internet protocol based networks.

SS7 Technology:SS7 signaling is a form of packet switching. Unlike circuit switching, which utilizes dedicated data "pipes" for transmission of information, packet switching dynamically assigns "routes" based on availability and "least cost" algorithms. Another example of packet switching is TCP/IP, the protocol used for routing messages over the Internet. Unlike the Internet, which utilizes a vast public "web" of interconnecting facilities and routing equipment, SS7 networks are private and logically self-contained. The private nature of SS7 networks is critical for security and reliability.SS7 involves two different types of signaling: connection oriented signaling and connectionless oriented signaling. Connection oriented signaling refers to the establishment of switch-to-switch facilities call inter-office trunks. These trunks carry carriers of voice communications. The ISDN User

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Part (ISUP) part of the SS7 protocol is utilized to establish trunks between switches. In contrast, the Transaction Capability Application Part (TCAP) is utilized for connectionless signaling which typically entails switch-to-database or database-to-database communications. An example of connectionless signaling is TCAP signaling of HLR to VLR communications discussed in the mobile networking article.

SS7 Networks:SS7 is comprised of a series of interconnected network elements such as switches, databases, and routing nodes. Each of these elements is interconnected with links, each of which has a specific purpose. The routing nodes are the heart of the SS7 network and are called a Signal Transfer Point (STP). STPs are connected to Service Switching Points (SSP) that are switches equipped with SS7 control logic. SSP switches are connected to the STPs via Access links (A links). STPs also connect to databases called Service Control Points (SCP) via A links. The SCP is the network element that contains service control logic such as instructions for converting an 8XX (toll-free) number into a routable number.STPs are always deployed in pairs, allowing a spare should one of the STPs have a problem. Each STP of a "mated pair" are connected to each other via Cross links (C links). STP pairs connect to other STP pairs via Bridge or Diagonal links (B or D links). B links connect STP pairs that are at the same level of hierarchy while D links connect STP pairs that are different hierarchical levels. An example would be STPs in a local network connecting with STPs of a long distance network. Being at different hierarchies, the local-to-long distance links would be considered D links.Links used for SS7 communication directly between SSPs (no STP involved) are called fully associated links (F links). An example of these links is those that are used in combination with voice trunks between two mobile network SSPs. The F link is used to signal a hand-off message from one SSP to the other, allowing the mobile phone user to travel from one area (served by one switch) to another area (served by another switch).Extended links (E links) are used to connect an SSP to an alternative STP pair. In the event that the primary STP pair is inoperable, the alternative pair establishes operations with the SSP over the E links.

Business Issues:In today's modern telecommunications networks, SS7 is used for virtually every call to establish a voice connection between the callings and called party locations. SS7 is also the medium for advanced capabilities and applications including mobile networking and services as well as wire line applications such as toll-free calling and automatic calling card identification

5.8 E1:E1 basics:An E1 link runs over two sets of wires that are normally coaxial cable and the signal itself comprises a nominal 2.4 volt signal. The signaling data rate is 2.048 Mbps full duplex and provides the full data rate in both directions. For E1, the signal is split into 32 channels each of 8 bits. These channels have their own time division multiplexed slots. These are transmitted sequentially and the complete transmission of the 32 slots makes up a frame. These Time Slots are nominated TS0 to TS31 and they are allocated to different purposes:TS0 is used for synchronization, alarms and messagesTS1 - TS 15 used for user dataTS 16 is used for signaling, but it may also carry user dataTS17 - TS31 are used for carrying user data

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Time slot 0 is reserved for framing purposes, and alternately transmits a fixed pattern. This allows the receiver to lock onto the start of each frame and match up each channel in turn. The standards allow for a full Cyclic Redundancy Check to be performed across all bits transmitted in each frame.E1 signaling data is carried on TS16 is reserved for signaling, including control, call setup and teardown. These are accomplished using standard protocols including Channel Associated Signaling (CAS) where a set of bits is used to replicate opening and closing the circuit. Tone signaling may also be used and this is passed through on the voice circuits themselves. More recent systems use Common Channel Signaling (CCS) such as ISDN or Signaling System 7 (SS7) which sends short encoded messages containing call information such as the caller ID. Several options are specified in the original CEPT standard for the physical transmission of data. However an option or standard known as HDB3 (High-Density Bipolar-3 zeros) is used almost exclusively.

E1 Applications and standards:The E-carrier standards form part of the overall Synchronous Digital Hierarchy (SDH) scheme. This allows where groups of E1 circuits, each containing 30 circuits, to be combined to produce higher capacity. E1 to E5 are defined and they are carriers in increasing multiples of the E1 format. However in reality only E3 is widely used and this can carry 480 circuits and has an overall capacity of 34.368 Mbps.Physically E1 is transmitted as 32 timeslots and E3 has 512 timeslots. Unlike Internet data services which are IP based, E-carrier systems are circuit switched and permanently allocate capacity for a voice call for its entire duration. This ensures high call quality because the transmission arrives with the same short delay (Latency) and capacity at all times. Nevertheless it does not allow the same flexibility and efficiency to be obtained as that of an IP based system.In view of the different capacities of E1 and E3 links they are used for different applications. E1 circuits are widely used to connect to medium and large companies, to telephone exchanges. They may also be used to provide links between some exchanges. E3 lines are used where higher capacity is needed. They are often installed between exchanges, and to provide connectivity between countries.

5.9 Difference in Hub, Switch, Bridge, & RouterIn an Ethernet network there are 4 devices that from the outside look very similar.HubsSwitchesBridgesRoutersHub: A hub is the simplest of these devices. Any data packet coming from one port is sent to all other ports. It is then up to the receiving computer to decide if the packet is for it. Imagine packets going through a hub as messages going into a mailing list. The mail is sent out to everyone and it is up to the receiving party to decide if it is of interest. The biggest problem with hubs is their simplicity. Since every packet is sent out to every computer on the network, there is a lot of wasted transmission. This means that the network can easily become bogged down. Hubs are typically used on small networks where the amount of data going across the network is never very high.Bridge: A bridge goes one step up on a hub in that it looks at the destination of the packet before sending. If the destination address is not on the other side of the bridge it will not transmit the data. A bridge only has one incoming and one outgoing port. To build on the email analogy above, the bridge is allowed to decide if the message should continue on. It reads the address bob@smith.com and decides if there is a bob@smith.com on the other side. If there isn’t, the message will not be transmitted. Bridges are typically used to separate parts of a network that do not need to communicate regularly, but still need to be connected.

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Switch: A switch steps up on a bridge in that it has multiple ports. When a packet comes through a switch it is read to determine which computer to send the data to. This leads to increased efficiency in that packets are not going to computers that do not require them. Now the email analogy has multiple people able to send email to multiple users. The switch can decide where to send the mail based on the address. Most large networks use switches rather than hubs to connect computers within the same subnet.Router:A router is similar in a switch in that it forwards packets based on address. But, instead of the MAC address that a switch uses, a router can use the IP address. This allows the network to go across different protocols. The most common home use for routers is to share a broadband internet connection. The router has a public IP address and that address is shared with the network. When data comes through the router it is forwarded to the correct computer. This comparison to email gets a little off base. This would be similar to the router being able to receive a packet as email and sending it to the user as a fax.Network Patch Panels:Patch panels are most commonly found in Ethernet networks. Cat5e patch panels and Cat 6 patch panels are the most common but patch panels can be used in many other applications. A patch panel sometimes referred to as a patch bay or a jack field is a panel designed for the management of cable connections. On the front side of a patch panel there are jacks designed to receive short patch cables (RJ45), while on the back of the panel there are either jacks or punch down blocks THAT HAVE connections of longer and more permanent cables. The assembly of hardware is arranged so that a number of circuits appear on jacks for monitoring, interconnecting, and testing in a convenient and flexible way. This offers the convenience of allowing techs to quickly change the circuit of select signals without the use of expensive dedicated switching equipment. Patch panels are typically rack mountable.

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6. Alcatel 6.1 LOCATION:Alcatel 1000 El0 is the digital switching system developed by Alcatel CIT. Multi-application, Alcatel 1000 El0 could be used for the entire range of switch, from the smallest local exchanges to the largest transit gateway switches. It adapts to every type of habitat, from dense urban environment, to sparsely populated areas, and to every type of climate, from Polar Regions to the hot and humid climates of Equatorial Africa and the tropics. System operation and maintenance can be local or common to several switches, or both at the same time.Alcatel 1000 El0 provides all modern communication services: Basic Telephony, ISDN (Integrated Services Digital Network), Centrex, digital cellular radiotelephony and all the Intelligent Network applications. It handles all accepted signaling systems in a current total of over 80 countries and is built in accordance with recognized international standards. Alcatel CIT actively contributes to definition of those standards.SYSTEM APPLICATIONS (NON-EXHAUSTIVE LIST):

Remote subscribers unit. Local subscribers exchange Transit exchange (local, trunk or international gateway). Hybrid local/transit exchange. Tandem exchange. Centrex (private or public).

Fig: 1 Alcatel 1000 E10 location in the telephone network

S: Remote line unitL: Local subscriber exchangeTR: Transit exchangeCID: Outgoing international exchangeCIA: Incoming international exchangeCTI: International transit exchange

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6.2 Block Diagram of Alcatel Ahmadpur East:

6.3 MAIN CONTROL STATION (SMC):Location:The Main Control Station is linked to the following communication media The Interstation Multiplex (MIS): it carries out interchanges of information with the other Main

Control Stations (SMC) and with the SMM station, The Main Control Station Access Multiplexes (MAS): 1 to 4 they carry out interchanges of

information with the Auxiliary Equipment Control (SMA), Trunk Control Station (SMT) and Matrix Control Station (SMX) connected on those multiplexes

The Alarm Multiplex (MAL): this transmits power alarms from the station to the SMM station.

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Role (Function) of SMC: The Main Control Station (SMC) supports the following functions

MR (Call handler): call processing, CC (Communication Control): processing of the SSP application, TR (Translator): database, TX (Charging): charging for communications, MQ (Message Distributor): message distribution, GX (Matrix System Handler): management of connections, GS (Services management): SSP application, PC (SS7 Controller): signaling network management.

According to the configuration and the traffic to be handled, one or more of these functions may be supported by the same Main Control Station

Functional Architecture:General architecture of a multiprocessor station Philosophy of multiprocessor derived from Alcatel 8300 system concepts one or more than one

processor, one or more than one intelligent coupler, interconnected by a bus and interchanging data through a common memory.

Two-way communication between subassemblies coordinated by the basic system.

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BSM = Multiprocessor Station BusA multiprocessor station can include: one or more than one multiplex coupler, one or more than one processor unit, a common memory, Specific couplers for switching functions or data processing inputs/outputs.

SMC Architecture:

The Main Control Station includes: a main multiplex coupler (CMP), a main processor unit (PUP), a common memory (MC), 1 to 4 secondary processor units (PUS), 1 to 4 secondary multiplex couplers (CMS).

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Physical Form of SMC:

The Main Control Station (SMC) is organized around a standardized Multiprocessor Station Bus (BSM). The size of this bus is 16 bits.The different boards are connected to this bus and it is used by them as a means of communication.Thirteen boards can be connected onto the Multiprocessor Station Bus within a Main Control Station: an ACAJA board is responsible with its associated ACAJB to manage interchanges between the

Interstation Multiplex (MIS), and the BSM, four ACAJA are responsible with their associated ACAJB boards to manage interchanges

between the MAS and the BSM, three ACMCQ boards which carry out the Common Memory function, or only one ACMCS(1) an ACUTR board which carries out the Main Processor function (PUP), four ACUTR boards which carry out the Secondary Processor functions (PUS),The ACALA board, which is not connected on Multiprocessor Station Bus, is responsible for collecting and transmitting power alarms of the Main Control Station. It is connected to the Alarm Multiplex (MAL).

5 types of cards:UC 68020 or 68030 ACUTR16 MB memory ACMCQMIS/MAS coupling module ACAJA/ACAJBAlarms coupling module ACALA

SMC station (max. 17 cards + 2 converters). Estimated maximum consummation at 5V < 160W

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Location Assembly:

1.4 Auxiliary Equipment Control Station (SMA):

Role of SMA:The Auxiliary Equipment Control Station (auxiliaries’ multiprocessor station) supports the following functions:

ETA: Auxiliary Equipment Manager: Management of tone and of auxiliary equipments, PUPE: SS7 Protocol Handler: Processing of CCITT No. 7 Protocols.

According to the configuration and the traffic to be handled, one SMA can support an auxiliary equipment manager software machine (ETA), a SS7 Protocol Handler Software Machine (PUPE), or both.The auxiliary equipment control station contains auxiliaries of the OCB 283 exchange. These are:

Frequency receivers/generators, Conference circuits, Tone generators, Clock management, CCITT No. 7 signaling receivers/transmitters.

Location of SMA:The Auxiliary Equipment Control Station is linked to:

The connection network by a set of 8 matrix links. It is via the connection system that the auxiliary equipment control station receives basic time distributions from the STS,

The Main Control Station Access Multiplex (MAS). It carries out interchanges of information between the auxiliary equipment control station and the command components of the OCB 283,

Alarms Multiplex (MAL).

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Functional Architecture:The Auxiliary Equipment Control Station is connected to the Host Switching Matrix by 8 matrix links equipment:The SMA may have the following boards:

A main multiplex coupler (CMP), According to call-handling capacity power necessary:

A main processor unit (PUP),A secondary processor unit (PUS),A common memory (MC),

1 to 12 couplers:Processing of speech signals (CTSV),Multiprotocol signaling (CSMP),Clock management (CLOCK)

The CTSV can process functions of the following types: Frequency receiving generation, Conference, Tone generation, Testing of sundry modulations, psophometer.

The CSMP can process protocols such as No. 7 signaling or other HDLC protocols.

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Physical Form of SMA:The Auxiliary Equipment Control Station is organized around a standardized Multiprocessor Station Bus (BSM). This is a 16-bit bus. The different boards are connected to this bus, which is used by them as a means of communication. Sixteen boards can be connected to the multiprocessor station bus:

an ACAJA board is responsible with associated ACAJB board to manage interchanges via the Main Control Station Access Multiplex (MAS),

an ACMCQ or ACMCS board which supports the bulk memory of the station, an ACUTR board: main processor function (PUP), an ACUTR board which carries out the secondary processor functions (PUS), At most 12 boards which carry out the specific operations for which the. Auxiliary Equipment

Control Station is responsible:o one or more ICTSH board, o one or more ACHIL board, o An ICHOR board.

The following are inserted within the station but not connected to the multiprocessor station bus: A pair of ICID boards. These are the SAB interface between the branches of the connection

matrix and the auxiliary equipment control station, An ACALA board which is responsible for collecting and transmitting alarms appearing on

auxiliary equipment control station.The structure chosen has the advantage of permitting a wide variety of configurations or, at the same time, call-handling capacities (put into physical form by the number of ACUTR). The operational capacity (according to the number and the type of application boards) can be adjusted to a wide variety of needs.

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9 types of boardsCMP coupler ACAJA/ACAJBMain processing unit, secondary processing unit ACUTRCommon memory ACMCS Speech signal processing coupler ICTSHClock coupler ICHORAlarms coupler ACALABranch section function ICIDMultiprotocol processing coupler ACHIL

Auxiliary Equipment Control Station: (maximum of 20 boards + 2 CV)Maximum consumption on 5V < 120 W

Functions of ICTSH Board:

ICTSH BOARD: It can generate 32 voice frequency signals/timings e.g. Ring tone, Busy tone etc. Signals are

sequences of mono, bi, tri or quadric frequencies. A sequence consists of maximum eight “transmission/silence” sequences.

Can manage 8 RGF terminals. Can provide 8 conf. Circuits 4 subs on each. Supervise the process of recorded announcements.

Functions of MLETA:1) Call processing: Reception of frequency dialing Transmission of frequencies according to instructions. Management of ICTSH boards Provision of conf. Circuits. Provision of tones Indication of call waiting.2) Observations (load of ICTSH resources)3) Clock Management4) Maintenance LA continuity check To check the modulation of announcements. On line test of ICTSH & ICHOR board.

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Location and Rack Assembly:

6.5 TRUNK CONTROL STATION (SMT):

Role of SMT:

It provides functional interface between PCM & the switching centre. These PCM come from:- Other switching centers. A Remote subscriber Digital Access Unit (CSND). A Remote Electronic Satellite concentrator (CSED). The digital recorded announcement equipment.

To control the PCM, MLURM is implemented on SMT which performs: I. In PCM to switching centre direction:

HDB-3 conversion to binary Extraction of CAS signaling. Management of C7 signaling. Cross-connection of channels between POCM & LR

II. In Switching centre to PCM direction: Binary to HDB-3 conversion Transmission (injection) of CAS in T.S. 16 Management of C7 signaling. Cross connection of channels between LR & PCM.

Location of SMT:

The Trunk Control Station is connected to:- CSND, CSED, digital announcement equipment & other switching centers by max. 32 PCM. SMX through up to 32 LR (4GLR)

MAS is used to communicate with other stations Stations alarm ring (MA2).

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General Architecture: 32 PCM are divided in 8 groups of 4 PCM each. Each group of 4 PCM is processed by a software module MRM (multiplex connection

module) or MRS (Satellite connection Module) All these eight modules are managed by logic: (LOGUR-0 or LOGUR-1) which is the pilot

logic.

Physical Form of SMT:

2 Sub-racks for 1 complete SMT. 12 types of boards.

o Main Multiplex coupler ACAJ A, ACAJ B.o 6 types of board for PCM controller ICPRO, ICD1M, ICMEC, ICCTM, ICSDT,

ICCLA.o Acquisition logic ICMOD.o PCM termination ICTR1

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o Alarm Coupler ACALAo Branch selection function ICID

Maximum outfitting 49 boards + 4 converters.

Location and Rack Assembly:

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2. TRANSMISSION:Transmission is the action of conveying signals from one point to one or more other points while media describes the cabling and various media used to send data b/w multiple points of a network. Transmission media is the physical path between transmitter and receiver.

7.1 Types of transmission Media:

7.2 Guided media: Conductive metal

Twisted pairs, coaxial cable Glass or plastic

Fiber optics

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Electromagnetic spectrum:

The above picture shows the EM spectrum and indicates the frequencies at which various guided media and transmission technique operate.

a. Twisted pairs:

Since straight copper wires tend to act as antennas and pick up extraneous signal. The twisting help reduce the amount of outside interferences. Twisted pairs often are bundled together and wrapped in a protective coating. Each pair has twist length, reducing the interference b/w them (crosstalk).

b. UTP:

UTP is a primary choice for a 10 Base T and 100BaseT Ethernet network that use UTP cabling at 10 Mbps and 100Mbps respectively. B/c is lacks shielding, UTP is not good at blocking noise and interference as STP.

c. STP:

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STP can handle high speed transmissions. Cable itself is relatively expensive, can be quite bulky and heavy. STP is used in ARC net and token ring networks.

d. Coaxial cable:

Coaxial cable is a popular for cable television transmission and for creating LAN such as Base Operates at 10Mbps.RG-6: Drop cable for CATV, 75 ohm impedanceRG-8: Thick Ethernet LAN (10 Base 5), 50 ohmRG-11: Main CATV truck, 75 ohm impedanceRG-58: Thin Ethernet LAN (10 Base 2), 50 ohmRG-59: ARC net, 75 ohm

e. Optical fiber:Fiber optic cable or optical fiber provides a medium for signals using light rather than electricity. Light waves are immune to EM interference and crosstalk. Optical fiber can be used for much longer distance before the signal must be amplified. Data Transmission using optical fiber is many faster than electrical methods.7.3 Wireless (Unguided Media) Transmission: Microwave, satellite, Radio

a. Microwave:

Microwave links are widely used to provide communication links when it is impractical or too expensive to install physical transmission media. Two properties of microwave transmission place restriction on its use. 1st microwave travels in straight line and will not follow the earth curvature. 2nd

atmosphere conditions and solid objects interfere with microwaves. For example, they cannot travel through buildings. Typical microwave distances before repeaters are necessary:

Frequency (GHz) Approx. distance (miles)

2-6 30

10-12 20

18 7

23 5

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SRAL: Microwave systems cover most of connectivity needs especially in the lower layers of the transmission networks, consolidating their role of reliable, easy-to-install and cost-effective access solution. Siemens, used to be one of the frontrunners in this market segment, is ready to match the expectations of the new incoming telecommunication era characterized by broadband and mobility convergence. Nowadays, the new challenge launched by operator’s aims to increase link density and capacity, leaving spectrum occupancy practically unchanged. Siemens, always ready to acknowledge market indications and trends, adds to its extensive microwave portfolio the new line of point to point low capacity digital radio: SRAL XD.Siemens expertise covers most of the outstanding technologies which current applications are based on: switching, cellular technology, radio and networking, voice and data over IP and ATM. An outstanding turnkey project management capability, the ownership of a so wide range of in-house product lines and a worldwide field proven experience, represent the unequaled Siemens business card.

Units:SRAL has two units IDU (indoor Unit) and ODU (outdoor Unit). There functions are

IDU Basic Functions: ODU Basic Functions:

System interface to external world Modulation of baseband signal

Baseband digital signal processing Up-conversion to RF signal

IDU-ODU cable interface management Down-conversion of received RF signal

System supervision and configuration Mngt. Demodulation to baseband signalEquipment power supply ODU supervision and config. Mngt

IDU-ODU cable interface Mngt

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Applications:SRAL XD line is primarily designed four ban networks, but is also suitable in regional networks meeting all the requirements of access and trunk applications.• Mobile Networks: in the 3G Mobile ATM based network, typically SRAL XD is used to collect traffic conveying from Node B to Hub stations; in the 2G networks it is already implemented to provide access to core networks. In the next future, the overlay of the two mobile networks will certainly benefit from SRAL XD upgrading facilities, rewarding operators with flexible and versatile infrastructures.• Mobile Networks: in the 3G Mobile ATM based network, typically SRAL XD is used to collect traffic conveying from Node B to Hub stations; in the2G networks it is already implemented to provide access to core networks. In the next future, the overlay of the two mobile networks will certainly benefit from SRAL XD upgrading facilities, rewarding operators with flexible and versatile infrastructures. • Fixed services Networks: SRAL XD supports ATM/IP networks, LAN and WAN.

a. Satellite:

Satellite transmission is microwave transmission in which one of the stations is a satellite orbiting the earth. A microwave beam is transmitted to the satellite from the ground. This beam is received and retransmitted to predetermined destination. Receiver and transmitter are known as transponder.The optimum frequency range for satellite is the range 1 to 10 GHz. Below 1GHz, there is significant noise from natural sources, atmospheric noise, and noise from electronic devices. Above 10 GHZ, the signal is attenuated by atmospheric absorption.Satellite bands:

Freq. Bands Uplink Downlink Use 4/6 C 5.925-6.425 3.7-4.2 Commercial 7/8 X 7.9-8.4 7.9-8.4 Military 11/14 Ku 14-14.5 11.7-12.2 Commercial20/30 Ka 27.5-30.5 17.7-21.2 Military 20/44 Q 43.5-45.5 20.2-21.32 Military

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b. Radio:

A radio transmitter is placed at the fixed wired terminal point, providing a wireless link b/w each terminal and central site. The coverage area of a base station is restricted by limiting its power o/p so that it provides only sufficient channels to support the total load in that area. Wider coverage area is achieved by arraying multiple base stations in a cell structure.Each base station operates using different band of frequencies from its neighbors. Since the field of coverage of each base station is limited, it is possible to reuse its frequency band in other parts of network.

DRS (Digital Radio system):Digital radio system is used to provide telecommunication, connection b /w destination point of exchanges, sources and drops, nodes and terminating points of the PTCL network point to point transport of voice and data. In order commission and links the expansion of local telephone exchange system detailed engineering studies is made to determine the requirements of the transmission media keeping in view the existing system. Up gradation of the existing DRS links is too made for the

replacement with high capacity links.

Transmission developing work: Establishment of new Digital Radio Links to connect new exchanges. Up-gradation of Digital Radio Links for enhanced requirement. Towers at new exchanges / repeaters for DRS links. Power plant including rectifiers, batteries, solar modules and diesel engine generators. Construction of building for repeater stations.  

Equipment Architectures: Indoor unit (ODU) Coaxial cable Outdoor unit (ODU)

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Antenna

7.4 Factors to select mediaCost Data rate/ bandwidthDistance

Twisted pairs Coaxial Optical fiber MicrowaveData rate (Mbps)

1-100 10 400-500 200-300

Interference Electrical Electrical Immune Solid objectDistance( miles) Up to 1 2-3 20-30 20-30

3. References: Supervisors at Central exchange Ahmadpur East www.google.com.pk www.wikipedia.com www.ptcl.com.pk

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