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  • 1. Internship Report1 | P a g e[PAKISTANTELECOMMUNICATIONCOMPANY LTD][INTERNSHIP REPORT]

2. Internship ReportIN THE NAME OF ALLAH, MOST GRACIOUS, MOST COMPANSSIONATE.2 | P a g e 3. Internship Report3 | P a g eINTERNSHIP REPORT ON PTCLPakistan Telecommunication Company Limited(PTCL)PREPARED BY:M. UMAR KHALID (09TL41)B.Sc. Telecommunication EngineeringUNIVERSITY COLLEGE OF ENGINEERING & TECHNOLOGYTHE ISLAMIA UNIVERSITY OF BAHAWALPUR, PAKISTAN 4. Internship Report4 | P a g eCONTENTSSr. No Name Page1 Who is who and what is what? 82Services provided by PTCL92.1Optical fiber services to the private sector92.2Services for corporate customers102.3Home and personal112.4Business services122.5Carrier services and wholesale1233.13.23.33.43.53.63.73. 8MDF( Main distribution frame)PTCL ArchitectureNetworksMDF (Main Distribution Frame) JPX-202/3219 (Huawei)Joint Cable ConnectorsFaults detection and checkingDSL Connection in ExchangeVoltages and currents in MDFDocuments for New Connection13131414151516171744.14.24.34.44.54.64.74.84.94.10DSL( 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 & DSL181818181819202021212155.15.25.35.45.55.65.75.85.9NGN( Next generation network)Block Diagram of NGN BWPOverviewSoft switchUMG (Universal Media Gateway)Hardware DivisionMSAN (Muti-Service Access Node)SS7 (signaling system. 7)E1Difference in Hub, Switch, Bridge, & Router222222232325252727 5. Internship Report5 | P a g e66.16.26.36.46.5AlcatelLocationBlock Diagram of Alcatel BWPMain Control Station (SMC)Auxiliary Equipment Control Station (SMA)Trunk Control Station (SMT)29293030343877.17.27.37.4TransmissionTypes of transmission MediaGuided mediaWireless (Unguided Media) TransmissionFactors to select media41414243478 Reference Page 48 6. Internship Report6 | P a g ePREFACEThis report is the practical part of the most vital practice of our B.ScEngineering program. The sole objective is to familiarize the student withthe practical manipulation of Engineering Sector. This report has beenwritten to know how big organizations like PTCL work with their teams toachieve their common goals.In the first phase of the report there is the general introductionabout the employers in the CTX Bahawalpur, then the mission regardingtechnical and operational network, different services and then there is somedetail of the hardware used in the Telecommunication sector by PTCL.M. Umar Khalid 7. Internship Report7 | P a g eACKNOWLEDGEMENTIn the name of Almighty Allah who is most merciful, and who give us strengthto write this internship report in a different way.We extend our heartiest thanks to our seniors, colleagues, and subordinates whoassist me on every occasion to enable me to write this report.I pay special homage to the following persons. Mr. Shahrukh Rafi Abbasi (Business Manager) Mr. Masood-ul-Rauf (Assistant Business Manager) Mr. Ubaid-Ur-Rehman Mr. Akram Mr .Nawaz Abbasi 8. Internship Report1. Who is who and what is what?There are technician and officers which deals the customers problems. Each person has its own work.8 | P a g e1) Mr. Sohail (BB Technical 1 BNCC): All orders of PTCL connections are enter in the computer here. Allot number, its cut off or restore the number according to the number.2) Mr. Ghulam Yaseen(Technical officer CMS( Complaint Management system)): Fault of the telephone and DSL are entered here.3) Mr. Munawar Rauf (POC (person of coordinator) coordinator): DSL documents are submitted here.4) Mr. Tariq: Tells informations 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. Muhammad Sajid Mahmood (Engineer Supervisor): OSP maintenance (Cabinet, DP, pole etc).6) Mr. Masood-ul-Rauf (Assistant Business Manager): Assign the technician of war room to deal the customer problems. Supervisor of MDF. 9. Internship Report2. Services Provided by PTCL2.1 Optical fiber services to the private sector:Pakistan Telecommunication Company Limited not only Provides Conventional telephonefacilities, it also offers optical fiber services to the private sector. We will briefly discussbelow the product lines being offered by the PTCL. Basically PTCL divide their services intotwo parts:-9 | P a g e Services for consumers Services for corporate customersI. Services for Consumers:These services are basically for the common users (Individual/home users) those use telephone intheir 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-linetelephony in the country. So whenever, any Private business concern or any individual needs a newtelephone connection for provision of telephone service.b) Value Added Services:CLI (Callers Line Identification) it allows customers to identify the caller before picking up thephone receiver. To subscribe to Customer needs a telephone set with display capability or a CLIdevice at phone. Advantages: Check on obnoxious callsComplete record of incoming / outgoing calls with timedate.i. PREPAID CALLING CARDS:PTCL calling card is the most popular choice of millions of customers all over the country. Itis now available with balance transfer facility and follow on call facility. Comes in easily affordable denominations ofRs. 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 customersPTCL launched a new billing service which is available through PTCL Calling Card . Thisservice is basically providing billing solutions for the users. Advantages: Customer can save his time by paying his bill onphone Customer can pay his bill whenever he wantsiii. 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 Dont Disturb 10. Internship ReportII. SERVICES FOR CORPORATE CUSTOMERS: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 ofCorporate Services is given as under. For more information regarding any of the following services,PTCL Corporate Customer Centers can be contacted.10 | P a g eIN BASED VALUED ADDEDSERVICESVALUED ADDED SERVICES 0800- Toll Free PTCL calling cards Domestic andinternational Premium Rate Service- 0900 Virtual Private Network Universal access Number (UAN) Universal internet number (UNI) ISDN PRI Teleplay (ISDN/BRI) LocalDomestic/ International LeasedBandwidth and point Leased Lines(DXX) Local Leased Circuits ( 2Wires/4wires) 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 orservices. Here is a list of business that can avail UAN Service. Banks Insurance Trading Companies Courier Services Newspapers Credit Card Companies Fast Food Outlets Utility Services Airlines Travel Consumer Products Stock Brokers Hotels Shipping LinesCompanies Voice Messaging Service (VMS): With PTCL Messaging Service, you can have all for (or Desired) calls recorded when you areabsent, busy on phone or do not want to attend the calls for any reason. You can, later on at yourconvenience, 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 bebeneficial. 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 inyour 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 havingproblems with managing telephone message. PTCL MESSAGING PLUS will definitely handle these problems for you. Advanced messagingfeatures save time, make you truly mobile and increase productivity. 11. Internship Report Essential for time-conscious executives, frequent travelers and Professional groups.Feature: Call answer Co- Location CentersPakistan Telecommunication Company has taken land mark decision to establish co location centersthroughout the country.Benefits: Easy access to local 11 | P a g einternational connectivity Quick deployment of services Higher reliability and quality of service Full connectivity under one roof Just plug in andstart businessTarget market: IT companiesTelecom data companies Virtual Private Network (VPN):Communication is the secret of success in todays highly competitive market. When it comes toenabling your enterprise, your communication got to be instant, fast and hassle free. The answer tothis corporate need is virtual private net work. ISDN BRI/PRI:It is a near broadband experience suitable for household and small/medium sizedorganizations.Features: Faster and clear voice Fax and data communicationon a single phone PRI provides thirty 64 kbpsuser channel plus two 16 kbpssignaling channel Cost effective BRI provides two 64 kbpsuser channel plus one 16 kbpssignaling channel2.3 Home and Personal: 3G EVO TabIntroducing Pakistans First 3G Enabled Smartphone Android Tablet3G EVO Tab. EVO 3G Wireless BroadbandEVO 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. LandlineProvide the facility of Landline to connect nationwide and international wide with thepeoples. BroadbandPTCL 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 ofa few countries across the globe that offers this state of the art interactive TV service to itssubscribers. Vfone:PTCL provides Pakistan Largest wireless network based on CDMA technology. 12. Internship Report12 | P a g e Dialup:Enjoy Phone-n-Net innovative service with nominal charges.2.4 Business Services: Business Connectivity:PTCLs business connectivity offers secure, reliable and integrated end to end domestic andglobal connectivity solutions to cater for the demands of corporate and enterprise users. Business Communication:PTCLs communication product portfolio is tailored to help business enterprises gainproductivity advantages by offering a suite of powerful convergence, presence-enabled applications. Managed Services:PTCLs Managed Network Services is a comprehensive solution for those corporatecustomers which are aimed at satisfying the essential needs of telephony/voice, data and securityneeds. Hosted Solutions:Get your e-business up and running quickly for competitive advantage. PTCL offers itsclients a combination of business acumen and technical expertise that your business can neverexhaust. With us, your infrastructure, applications and systems are maintained by certified expertswith experience to make your environment meet and exceed the... Business Security:Provide the services with business security.2.5 Carrier ServicesWholesale: Wholesale Services:PTCL customers can now provide services to their clients without undertaking large scaleinvestment in infrastructure or developing expertise in running their own networks. Telecom Operators:Extend the boundaries of your reach. 13. Internship Report13 | P a g e3. MDF (Main Distribution Frame):3.1 PTCL Architecture: PTCL ExchangeThe Exchange is the building where the local exchange switch resides. A COs switch may servetelephone 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 (2-300pairs) from DP to Distribution Frame. New building can be built and DPs are used to provide themconnection Instead to direct connection to Exchange. Distribution Frames (DF)Distribution fames surround the CO. They are high density copper cable (50-1500 pair) PrimaryCable. Usually all connection to a distribution frame are copper. It allows the telephone company touse High Density Copper Cabling. Main Distribution Frames (MDF)MDFs are distribution frames that have some smart switching in them. Usually, this equipment hasbeen placed to provide the facility of DSL for access to use Internet. With the help of DSLAMInternet is enabling in MDFs for particular user.3.2 NetworksThere are two types of networksi. 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. 14. Internship ReportCabinet Distribution Subscriber14 | P a g eCable system:There are three types of cables are use for the transmission and receiving of data transmissioni. Main Cable System (Primary Cable): It is having cables from exchange to maindistribution points, e.g. cabinets or subscribers distribution frame in multi-story buildings. Itis highly density copper cable. Primary cable has 300/400 pairs while Secondary cable has600/800 pairs.600 pairs Primary cablesExchange Cabinetii. Distribution Cables System (Secondary Cable): This is having cables from main distributionpoint (e.g. cabinets) to subscriber distribution points e.g. DP boxes.Secondary Cable Drop Wirepoint (DP)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 PTCLexchange is using cable having diameter of 0.4mm. It is low density copper cable. 0.4mmcable is used b/c it is easily joinable and is cheap. 0.6 mm cable is not b/c it is difficult to jointand costly.b. OFC (optical Fiber cable) is mostly used in Islamabad and Lahore. But it is not used mostlyin Pakistan b/c it need regular power supply but there is load shading issues so thats way it isnot. But OFC can transmit more data than copper cable. As 1 Fiber optics can support 7890channels. It transmits data with the speed of light.3.3 MDF (Main Distribution Frame) JPX-202/3219 (Hawaii):MDF has two sidesi. Insideii. OutsideInside connects the MDF to required switching Exchange NGN while outside connects the MDFto 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 boardcable). The connection b/w these wire is horizontally connected by punching tool. PG (permanentGlow) is inserted b/w the NEs to block or disconnection some subscriber from switching exchangeand cabinet.Outside of MDF:Outside of the MDF is consisted of the multiple racks of 15 tags having 100 fuses in onevertical. Fuses show the subscriber connections. Outside of the MDF is connected to the inside of theMDF by jumping wire. Outside of the MDF have two wires which have vertically connection. 15. Internship ReportMDF 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 PTCLexchange. I.e. switching room, Alcatel, MDF, officer telephones numbers, war room telephonenumber and optical fiber telephone numbers etc.Types of Exchanges in Bahawalpur:15 | P a g e1) NGN2) ALCATEL3) EWSDSNR 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 connectorU-Y connector:They enable connecting wires without the need of isolation stripping. They are filled with gel, whichprotects wires from corrosion. UY connectors should be used for wires with external coat up to1.52mm in diameter and 0.4-0.7 wire diameter. The Sealant used in the connector provides the mosteffective watermoisture 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 Fusei. 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 thenthere is no fault. If there is not dialing tone then the DP connection has fault. Then newconnection 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. 16. Internship Reportiv. The dialing tone is checked in cabinet if there is dialing tone then there is no fault. If there is noN.E Cabinet Distribution Frame16 | P a g edialing tone the fault may be in MDF.v. MDF required vertical cable pair connection is checked by dialing tone. If there is no dialing tonethen vertical cable pair is changed. If there is the dialing tone then there is no fault so the faultwill be in switching exchange.vi. Switching exchange power supply, cards etc. is checked and changed. Then card is sending to berepaired in required manufacturing company3.6 Connection in Exchange:HomeExchangeSwitchingroomDSLAM3.7 Voltage and Current at MDF:ON Hook Off Hook When bell is ringing When bell is not ringingVoltage 49 v 13.6 v 53.1 vDC /139 vAC 53.1 vDC /116.2 vACCurrent 0.130 mA 48mA 0.9 mA 0.9 mA3.8 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) 17. Internship Report17 | P a g e4. DSL (Digital Subscriber Line):4.1 DSL Introduction:DSL is a family of technologies that provides digital data transmission over the wires of a localtelephone network. DSL originally stood for digital subscriber loop. DSL service is deliveredsimultaneously with regular telephone on the same telephone line. This is possible because DSLuses 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 thedirection to the customer (downstream), depending on DSL technology, line conditions, and service-levelimplementation.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 technologiesDSL Type Max. Send Speed Max. Received Speed Max. DistanceADSL 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 atelephone circuit that has Digital Subscriber Line service configured. Like other modems, it is a type 18. Internship Reportof 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 formanagement purposes. A DSL modem modulates high-frequency tones for transmission to a DigitalSubscriber Line Access Multiplexer (DSLAM), and receives and demodulates them from theDSLAM. A single telephone line can be used for simultaneous voice and data with a DSL modemwhereas a voice-band modem precludes simultaneous voice traffic. Most DSL modems are external tothe computer and wired to the computer's Ethernet port, or occasionally its USB port. Internal DSLmodems with PCI interface are rare but available. DSL modems use frequencies from 25 kHz toabove 1MHz in order not to interfere with voice service. Voice-band modems use the same frequencyspectrum as ordinary telephones, and will interfere with voice service - it is usually impossible tomake a telephone call on a line which is being used by a voice-band modem.Used Equipment:On/offPowerLAN1 ADSL MODEMLAN2LAN3LAN418 | P a g eDSL ModemSN=E29EB6D14870Power= 12v= 500mADate=Jun 2011ZTE CorporationADSL CPEZXDSL 83IC11Made in chinaADSL SplitterSP-206Rosette has four cables blue,yellow, black and red.Connection:PhoneDSL ModemRosette ADSLsplitterPC1 PC2 PC3 PC44.6 DSLAM (Digital Subscriber Line Access Multiplexer):The Digital Subscriber Line Access Multiplexer or DSLAM is a mechanism at a phone companyscentral location that links many customer DSL connections to a single high speed ATM line. It takesconnections from many customers and aggregated them onto single high capacity connection to the 19. Internship Reportinternet. They are generally flexible and able to support multiple types of DSL in a single centraloffice and different varieties of protocol and modulation. It may provide additional functionsincluding routing or dynamic IP address assignment for customers.19 | P a g eDSLAM Architecture:DSLAM shelf contain card and each card contain 64 connections and so a complete shelf contain thatcontain 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 accessnetworks that serves as an aggregation point for subscriber traffic (IP, PPP and ATM) and providessession 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 DSLnetwork infrastructure and devices, modern B-RASs started to provide advanced services beyondtraffic aggregation 20. Internship Report20 | P a g e4.8 Relation b/w DSL modem, DSLAM and BRAS:4.9 LQT (Line Quality testing) meter reading for 2MB DSL:Uplink DownlinkDSL SNR 25.00 dB 42.30 dBLine Attenuation 0.00dB 1.00dBActual Rate 636kbps 2557kbpsMaximum Rating936kbps 28288kbps4.10 Difference b/w ADSLDSL:ADSL have different uplink and downlink rate while DSL have same uplink and downlink rate. 21. Internship Report5. NGN (Next Generation Network):NGN the Next Generation Network will be the future of all telecommunication Engineers. Theseswitches which are categorized as Networks can integrate and Handle networks of differenttechnologies. For example it can handle a land line Network, a data network, a VOIP network andeven a CDMA network at once. NGN is the next step in telecommunication technology. TheTelephone system started up with direct connections to all users. With the expansion new switchingtechniques 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 ControlBut the future is here today. Sri Lanka Telecom has taken the giant leap to bring the newesttechnology in to their system in parallel with the developed and powerful nations in the world. Withthis 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 isbecause it can function as a circuit switch, or a video interworking Gateway.21 | P a g e5.1 Block Diagram of NGN BWP:5.2 Overview:NGN is a service oriented network. It provides an independent service system by splitting the servicemodule from the call control and the call control from the bearer. That is the services provided to eachsubscriber are handled from a database at central control where as in a normal system the services aredefined from where it is connected. Control is merely a place where some information in processedand send back some Instructions. The access point to the user equipment is merely a packet creationpoint. In this way, it frees the service from the original network model. NGN employs open andintegrated network structure. With abundant service Models, NGN is able to provide a variety ofservices, such as voice, data and multimedia services, or integrated services. Like in the normaltelephone system the entire system can be divided in to four areas. Edge access Core switching Network control Service management 22. Internship Report5.3 Soft switch:A Soft switch is the centrally located device which is used in telecommunications for connecting thetelephone calls over the various phone lines totally under the supervision of computer softwarerunning on one system .physical switch board are used as the main hardware that acts for carryingcalls from one line to another line. These are the routes for the traveling of signals. If we talk aboutthe soft switch technology it is widely used in the field of networking and telecommunications in alllocal 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 asbilking, call routing, transferring signals, call service and the other minor functionalities. A call agentcan also control the functioning of the other part of Soft switch with the connections over the Transfercontrol 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 typesof digital streams that works collectively in the creation of end to end for the control of voice and callover the line. Many interfaces are involved in it which is used for connecting the media to the PSTNnetworks such as DS1, DS3 and sometimes E1 and US and No us networks. The call agent maycontrol the functioning of the media gate way for connecting the media streams and also for theinterfaces 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 this22 | P a g etechnology. Some of the advantages are listed below. Soft switch has higher scalability. They usually work very wickedly by just handling the controlpart of the server saving the rest of the switch for the other purposes. They can handle moreclients for the packet data switching. No specific hardware is required for the soft switch they are completely platform independentwhich is very attractive feature of these switches .they can act well in any computer serverenvironment. Soft switch can be extended by just purchasing the extension license and the controllingconnection over the IP. Sometimes PBX support or card is required for the expansion of the softswitches in the wide areas. Some of the soft switch vendors provide open source to be used by other developers and end userseven .this can help the developer and other programmers to enhance the existing code provide inthe open source. Its installation is very easy. It also allows remote installations for its user. Just remote access withthe system containing the installed software set up. Its management is also easy. No extramaintenance is required for the soft switches. Soft switches also provide the extra software based functionalities that no other networkingdevice 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. Inthe current implementation of the system in the country this is the main Access system that is beingused since it has multiple functions. It is the most economical solution when the telecom network ispart 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 Function as a Trunk gateway (TG) and as an Access gateway (AG) It has an embedded signaling gateway (SG). 23. Internship ReportUMG8900 can be divided into two parts according to its functionality. This help to understand thesystem 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 PSTNsystem with the NGN. This is what gives a subscriber in the NGN the chance to call one in PSTN orany other network even though they work in different ways. In the Absence of a connection with theswitch it can act as a switch in NGN. This gives it the standalone capability and intern morereliability. Service switching module (SSM) consists of 4 parts Main control frame Management and maintenance functions of the device and supports23 | P a g eservice 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 framedoes not support access and process functions of user Services, But provides connectionmanagement and control function.User access module (UAM):This is the access point currently provided by Hawaii for the users that are in the NGN. Theinstrument can be at the UMG itself or function as a RSU from a distant place. It provides integratedaccess function for both narrowband and broadband users. It can even function as an AG if an IPconnection is provided Card structure of the UMG89001. Sysyetm Management BoardsOMU- Operation Mintance unitMPU- Main Control unitCMF- Connection management unit frontNET- packet switch net boardCLK- clock boardCMB-connection management unit backPPB- protocol processing unit1. IP interface process BoardE8T-8xFEE1G-1xGHRB-High speed routing board2. Signalling BoardsSPF- signalling processing board3. TDM interface procesTNU- TDM switch Net UnitTCLU- TDM convergencelink unitE32- 32xE1S2L- 2xSTM-1 optical2. Voice Process BoardVPU- voice process unitSRU- signal resource unitCascading BoardFLU-front link unitBLU- back link unit 24. Internship Report5.5 Hardware Division:UMG8900 hardware system can be divided into the following subsystems according to their function.1. Operation and maintenance subsystem2. Gateway control subsystem3. 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 (althoughsometimes in a roadside serving area interface cabinet) which connects customers' telephone lines tothe 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 separateequipment including DSLAMs to provide the various types of services to customers. Integrating allservices on a single node, which typically backhauls all data streams over IP or AsynchronousTransfer 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 canprovide multiple types of services to a range of different customers. MSANs were originally designedto be placed in a small community to address all its communications requirements. Traditional designshad a range of slots to accommodate different types of line cards and dual busses to handle both TDMand data. Today the principle stays the same, but new technology deployed on products--such as theMarconi Access Hub--allow for any card in any slot; high-density combination DSL and POTS linecards; and media gateway functionality that allows seamless interworking with soft switches forpacketized voice delivery.5.7 SS7 (signaling system. 7):SS7 is a critical component of modern telecommunications systems. SS7 is a communicationsprotocol that provides signaling and control for various network services and capabilities. While theInternet, wireless data, and related technology have captured the attention of millions, many forget ordon't realize the importance of SS7. Every call in every network is dependent on SS7. Likewise, everymobile phone user is dependent on SS7 to allow inter-network roaming. SS7 is also the glue thatsticks 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 datapipes for transmission of information, packet switching dynamically assigns routes based onavailability and least cost algorithms. Another example of packet switching is TCP/IP, the protocolused for routing messages over the Internet. Unlike the Internet, which utilizes a vast public web ofinterconnecting facilities and routing equipment, SS7 networks are private and logically self-contained.24 | P a g eThe private nature of SS7 networks is critical for security and reliability.SS7 involves two different types of signaling: connection oriented signaling and connectionlessoriented signaling. Connection oriented signaling refers to the establishment of switch-to-switchfacilities call inter-office trunks. These trunks carry carriers of voice communications. The ISDN UserPart (ISUP) part of the SS7 protocol is utilized to establish trunks between switches. In contrast, the 25. Internship ReportTransaction Capability Application Part (TCAP) is utilized for connectionless signaling whichtypically entails switch-to-database or database-to-database communications. An example ofconnectionless signaling is TCAP signaling of HLR to VLR communications discussed in the mobilenetworking article.SS7 Networks:SS7 is comprised of a series of interconnected network elements such as switches, databases, androuting nodes. Each of these elements is interconnected with links, each of which has a specificpurpose. 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 SS7control logic. SSP switches are connected to the STPs via Access links (A links). STPs also connect todatabases called Service Control Points (SCP) via A links. The SCP is the network element thatcontains service control logic such as instructions for converting an 8XX (toll-free) number into aroutable number.STPs are always deployed in pairs, allowing a spare should one of the STPs have a problem. EachSTP of a mated pair are connected to each other via Cross links (C links). STP pairs connect toother STP pairs via Bridge or Diagonal links (B or D links). B links connect STP pairs that are at thesame level of hierarchy while D links connect STP pairs that are different hierarchical levels. Anexample would be STPs in a local network connecting with STPs of a long distance network. Being atdifferent 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 fullyassociated links (F links). An example of these links is those that are used in combination with voicetrunks between two mobile network SSPs. The F link is used to signal a hand-off message from oneSSP to the other, allowing the mobile phone user to travel from one area (served by one switch) toanother area (served by another switch).Extended links (E links) are used to connect an SSP to an alternative STP pair. In the event that theprimary STP pair is inoperable, the alternative pair establishes operations with the SSP over the Elinks.Business Issues:In today's modern telecommunications networks, SS7 is used for virtually every call to establish avoice connection between the callings and called party locations. SS7 is also the medium foradvanced capabilities and applications including mobile networking and services as well as wire lineapplications such as toll-free calling and automatic calling card identification5.8 E1:E1 basics:An E1 link runs over two sets of wires that are normally coaxial cable and the signal itself comprises anominal 2.4 volt signal. The signaling data rate is 2.048 Mbps full duplex and provides the full datarate in both directions. For E1, the signal is split into 32 channels each of 8 bits. These channels havetheir own time division multiplexed slots. These are transmitted sequentially and the completetransmission of the 32 slots makes up a frame. These Time Slots are nominated TS0 to TS31 and theyare 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 dataTime slot 0 is reserved for framing purposes, and alternately transmits a fixed pattern. This allows thereceiver to lock onto the start of each frame and match up each channel in turn. The standards allowfor a full Cyclic Redundancy Check to be performed across all bits transmitted in each frame.25 | P a g e 26. Internship ReportE1 signaling data is carried on TS16 is reserved for signaling, including control, call setup andteardown. 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 alsobe used and this is passed through on the voice circuits themselves. More recent systems use CommonChannel Signaling (CCS) such as ISDN or Signaling System 7 (SS7) which sends short encodedmessages containing call information such as the caller ID. Several options are specified in theoriginal CEPT standard for the physical transmission of data. However an option or standard knownas 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. Thisallows where groups of E1 circuits, each containing 30 circuits, to be combined to produce highercapacity. E1 to E5 are defined and they are carriers in increasing multiples of the E1 format. Howeverin reality only E3 is widely used and this can carry 480 circuits and has an overall capacity of 34.368Mbps.Physically E1 is transmitted as 32 timeslots and E3 has 512 timeslots. Unlike Internet data serviceswhich are IP based, E-carrier systems are circuit switched and permanently allocate capacity for avoice call for its entire duration. This ensures high call quality because the transmission arrives withthe same short delay (Latency) and capacity at all times. Nevertheless it does not allow the sameflexibility 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. E1circuits are widely used to connect to medium and large companies, to telephone exchanges. Theymay also be used to provide links between some exchanges. E3 lines are used where higher capacityis 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 througha hub as messages going into a mailing list. The mail is sent out to everyone and it is up to thereceiving party to decide if it is of interest. The biggest problem with hubs is their simplicity. Sinceevery packet is sent out to every computer on the network, there is a lot of wasted transmission. Thismeans that the network can easily become bogged down. Hubs are typically used on small networkswhere 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. Ifthe destination address is not on the other side of the bridge it will not transmit the data. A bridgeonly has one incoming and one outgoing port. To build on the email analogy above, the bridge isallowed to decide if the message should continue on. It reads the address [email protected] and decidesif there is a [email protected] on the other side. If there isnt, 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.Switch:A switch steps up on a bridge in that it has multiple ports. When a packet comes through a switch it is26 | P a g e 27. Internship Reportread to determine which computer to send the data to. This leads to increased efficiency in thatpackets are not going to computers that do not require them. Now the email analogy has multiplepeople able to send email to multiple users. The switch can decide where to send the mail based onthe address. Most large networks use switches rather than hubs to connect computers within the samesubnet.Router:A router is similar in a switch in that it forwards packets based on address. But, instead of the MACaddress that a switch uses, a router can use the IP address. This allows the network to go acrossdifferent protocols. The most common home use for routers is to share a broadband internetconnection. The router has a public IP address and that address is shared with the network. When datacomes through the router it is forwarded to the correct computer. This comparison to email gets a littleoff base. This would be similar to the router being able to receive a packet as email and sending it tothe user as a fax.Network Patch Panels:Patch panels are most commonly found in Ethernet networks. Cat5e patch panels and Cat 6 patchpanels are the most common but patch panels can be used in many other applications. A patch panelsometimes referred to as a patch bay or a jack field is a panel designed for the management of cableconnections. 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 HAVEconnections of longer and more permanent cables. The assembly of hardware is arranged so that anumber of circuits appear on jacks for monitoring, interconnecting, and testing in a convenient andflexible way. This offers the convenience of allowing techs to quickly change the circuit of selectsignals without the use of expensive dedicated switching equipment. Patch panels are typically rackmountable.27 | P a g e 28. Internship Report6. Alcatel6.1 LOCATION:Alcatel 1000 El0 is the digital switching system developed by Alcatel CIT. Multi-application, Alcatel1000 El0 could be used for the entire range of switch, from the smallest local exchanges to the largesttransit gateway switches. It adapts to every type of habitat, from dense urban environment, to sparselypopulated areas, and to every type of climate, from Polar Regions to the hot and humid climates ofEquatorial Africa and the tropics. System operation and maintenance can be local or common toseveral switches, or both at the same time.Alcatel 1000 El0 provides all modern communication services: Basic Telephony, ISDN (IntegratedServices Digital Network), Centrex, digital cellular radiotelephony and all the Intelligent Networkapplications. It handles all accepted signaling systems in a current total of over 80 countries and isbuilt in accordance with recognized international standards. Alcatel CIT actively contributes todefinition of those standards.SYSTEM APPLICATIONS (NON-EXHAUSTIVE LIST):28 | P a g e 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 networkS: Remote line unitL: Local subscriber exchangeTR: Transit exchangeCID: Outgoing international exchangeCIA: Incoming international exchangeCTI: International transit exchange 29. Internship Report29 | P a g e6.2 Block Diagram of Alcatel BWP: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 MainControl Stations (SMC) and with the SMM station, The Main Control Station Access Multiplexes (MAS): 1 to 4 they carry out interchanges ofinformation with the Auxiliary Equipment Control (SMA), Trunk Control Station (SMT) andMatrix Control Station (SMX) connected on those multiplexes The Alarm Multiplex (MAL): this transmits power alarms from the station to the SMM station. 30. Internship Report30 | P a g eRole (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 besupported by the same Main Control StationFunctional Architecture:General architecture of a multiprocessor station Philosophy of multiprocessor derived from Alcatel 8300 system concepts one or more than oneprocessor, one or more than one intelligent coupler, interconnected by a bus and interchangingdata through a common memory. Two-way communication between subassemblies coordinated by the basic system. 31. Internship Report31 | P a g eBSM = 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). 32. Internship ReportPhysical 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 the32 | P a g eInterstation Multiplex (MIS), and the BSM, four ACAJA are responsible with their associated ACAJB boards to manage interchangesbetween 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 forcollecting and transmitting power alarms of the Main Control Station. It is connected to the AlarmMultiplex (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 5V160W 33. Internship Report33 | P a g eLocation Assembly:6.4 Auxiliary Equipment Control Station (SMA):Role of SMA:The Auxiliary Equipment Control Station (auxiliaries multiprocessor station) supports the followingfunctions: 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 auxiliaryequipment manager software machine (ETA), a SS7 Protocol Handler Software Machine (PUPE), orboth.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 theauxiliary equipment control station receives basic time distributions from the STS, The Main Control Station Access Multiplex (MAS). It carries out interchanges of informationbetween the auxiliary equipment control station and the command components of the OCB283, Alarms Multiplex (MAL). 34. Internship ReportFunctional Architecture:The Auxiliary Equipment Control Station is connected to the Host Switching Matrix by 8 matrix linksequipment:The SMA may have the following boards:34 | P a g e 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. 35. Internship ReportPhysical Form of SMA:The Auxiliary Equipment Control Station is organized around a standardized Multiprocessor StationBus (BSM). This is a 16-bit bus. The different boards are connected to this bus, which is used by themas 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 the35 | P a g eMain 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 EquipmentControl 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 connectionmatrix and the auxiliary equipment control station, An ACALA board which is responsible for collecting and transmitting alarms appearing onauxiliary equipment control station.The structure chosen has the advantage of permitting a wide variety of configurations or, at the sametime, call-handling capacities (put into physical form by the number of ACUTR). The operationalcapacity (according to the number and the type of application boards) can be adjusted to a widevariety of needs. 36. Internship Report36 | P a g e9 types of boardsCMP coupler ACAJA/ACAJBMain processing unit, secondary processing unit ACUTRCommon memory ACMCSSpeech signal processing coupler ICTSHClock coupler ICHORAlarms coupler ACALABranch section function ICIDMultiprotocol processing coupler ACHILAuxiliary Equipment Control Station: (maximum of 20 boards + 2 CV)Maximum consumption on 5V120 WFunctions of ICTSH Board:ICTSH BOARD: It can generate 32 voice frequency signals/timings e.g. Ring tone, Busy tone etc. Signals aresequences of mono, bi, tri or quadric frequencies. A sequence consists of maximum eighttransmission/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 ICTSHICHOR board. 37. Internship Report37 | P a g eLocation and Rack Assembly:6.5 TRUNK CONTROL STATION (SMT):Role of SMT: It provides functional interface between PCMthe 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 POCMLRII. 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 LRPCM.Location of SMT:The Trunk Control Station is connected to:- CSND, CSED, digital announcement equipmentother 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). 38. Internship Report38 | P a g eGeneral 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 connectionmodule) or MRS (Satellite connection Module) All these eight modules are managed by logic: (LOGUR-0 or LOGUR-1) which is the pilotlogic.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 39. Internship Report39 | P a g eo Alarm Coupler ACALAo Branch selection function ICID Maximum outfitting 49 boards + 4 converters.Location and Rack Assembly: 40. Internship Report7. TRANSMISSION:Transmission is the action of conveying signals from one point to one or more other points whilemedia 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.40 | P a g e7.1 Types of transmission Media:7.2 Guided media: Conductive metalTwisted pairs, coaxial cable Glass or plasticFiber optics 41. Internship Report41 | P a g eElectromagnetic spectrum:The above picture shows the EM spectrum and indicates the frequencies at which various guidedmedia and transmission technique operate.a. Twisted pairs:Since straight copper wires tend to act as antennas and pick up extraneous signal. Thetwisting help reduce the amount of outside interferences. Twisted pairs often are bundled together andwrapped 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 10Mbps and 100Mbps respectively. B/c is lacks shielding, UTP is not good at blocking noise andinterference as STP.c. STP: 42. Internship ReportSTP can handle high speed transmissions. Cable itself is relatively expensive, can be quite bulky andheavy. STP is used in ARC net and token ring networks.42 | P a g ed. Coaxial cable:Coaxial cable is a popular for cable television transmission and for creating LAN such as BaseOperates 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 ohme. 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 longerdistance before the signal must be amplified. Data Transmission using optical fiber is many fasterthan electrical methods.7.3 Wireless (Unguided Media) Transmission: Microwave, satellite, Radioa. Microwave:Microwave links are widely used to provide communication links when it is impractical or tooexpensive to install physical transmission media. Two properties of microwave transmission placerestriction on its use. 1st microwave travels in straight line and will not follow the earth curvature. 2ndatmosphere conditions and solid objects interfere with microwaves. For example, they cannot travelthrough buildings. Typical microwave distances before repeaters are necessary:Frequency (GHz) Approx. distance (miles)2-6 3010-12 2018 723 5 43. Internship ReportSRAL:Microwave systems cover most of connectivity needs especially in the lower layers of thetransmission networks, consolidating their role of reliable, easy-to-install and cost-effective accesssolution. Siemens, used to be one of the frontrunners in this market segment, is ready to match theexpectations of the new incoming telecommunication era characterized by broadband and mobilityconvergence.Nowadays, the new challenge launched by operators aims to increase link density and capacity,leaving spectrum occupancy practically unchanged. Siemens, always ready to acknowledge marketindications and trends, adds to its extensive microwave portfolio the new line of point to point lowcapacity digital radio: SRAL XD.Siemens expertise covers most of the outstanding technologies which current applications are basedon: 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-houseproduct lines and a worldwide field proven experience, represent the unequaled Siemens businesscard.43 | P a g eUnits:SRAL has two units IDU (indoor Unit) and ODU (outdoor Unit). There functions areIDU Basic Functions:ODU Basic Functions:System interface to external world Modulation of baseband signalBaseband digital signal processing Up-conversion to RF signalIDU-ODU cable interface management Down-conversion of received RF signalSystem supervision and configuration Mngt. Demodulation to baseband signalEquipment power supply ODU supervision and config. MngtIDU-ODU cable interface MngtApplications: 44. Internship ReportSRAL XD line is primarily designed four ban networks, but is also suitable in regional networksmeeting all the requirements of access and trunk applications. Mobile Networks: in the 3G Mobile ATM based network, typically SRAL XD is used to collecttraffic conveying from Node B to Hub stations; in the 2G networks it is already implemented toprovide access to core networks. In the next future, the overlay of the two mobile networks willcertainly benefit from SRAL XD upgrading facilities, rewarding operators with flexible and versatileinfrastructures. Mobile Networks: in the 3G Mobile ATM based network, typically SRAL XD is used to collecttraffic conveying from Node B to Hub stations; in the2G networks it is already implemented toprovide access to core networks. In the next future, the overlay of the two mobile networks willcertainly benefit from SRAL XD upgrading facilities, rewarding operators with flexible and versatileinfrastructures. Fixed services Networks: SRAL XD supports ATM/IP networks, LAN and WAN.44 | P a g ea. Satellite:Satellite transmission is microwave transmission in which one of the stations is a satellite orbiting theearth. A microwave beam is transmitted to the satellite from the ground. This beam is received andretransmitted 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 significantnoise from natural sources, atmospheric noise, and noise from electronic devices. Above 10 GHZ, thesignal is attenuated by atmospheric absorption.Satellite bands:Freq. Bands Uplink Downlink Use4/6 C 5.925-6.425 3.7-4.2 Commercial7/8 X 7.9-8.4 7.9-8.4 Military11/14 Ku 14-14.5 11.7-12.2 Commercial20/30 Ka 27.5-30.5 17.7-21.2 Military20/44 Q 43.5-45.5 20.2-21.32 Military 45. Internship Report45 | P a g eb. Radio:A radio transmitter is placed at the fixed wired terminal point, providing a wireless link b/w eachterminal and central site. The coverage area of a base station is restricted by limiting its power o/p sothat it provides only sufficient channels to support the total load in that area. Wider coverage area isachieved by arraying multiple base stations in a cell structure.Each base station operates using different band of frequencies from its neighbors. Since the field ofcoverage of each base station is limited, it is possible to reuse its frequency band in other parts ofnetwork.DRS (Digital Radio system):Digital radio system is used to provide telecommunication, connection b /w destination point ofexchanges, sources and drops, nodes and terminating points of the PTCL network point to pointtransport of voice and data. In order commission and links the expansion of local telephone exchangesystem detailed engineering studies is made to determine the requirements of the transmission mediakeeping in view the existing system. Up gradation of the existing DRS links is too made for thereplacement 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) Antenna 46. Internship Report46 | P a g e7.4 Factors to select mediaCostData rate/ bandwidthDistanceTwisted pairs Coaxial Optical fiber MicrowaveData rate(Mbps)1-100 10 400-500 200-300Interference Electrical Electrical Immune Solid objectDistance( miles) Up to 1 2-3 20-30 20-308. References: Supervisors at Central exchange Bahawalpur www.google.com.pk www.wikipedia.com www.ptcl.com.pk