Basic of Telecom System / NetworkCommunication means transportinginformation (Voice / Data / Video) from onepoint to other.Transmitter ReceiverSource DestinationOutputTransmission SystemTransmission Media
Communication SystemDuplex Communication LinkLocationBRXTXVoiceVoiceDataDataVideoVideoChannel (carries Information) LinkAny Communication System can be characterized by :• Source : Transmit Point (TX)• Destination : Receive Point (RX)• Communication Medium : Copper, Co-axial, MW, Satellite, Optical• Information Transfer Capacity : function (Channel, Link) = Bandwidth• Traffic : Flow of Information from one location to other
Basics of Telecom System / NetworkComparative Study of CoxialCable andOFCableCharacteristics Coaxial OFC1. Right of way Required Required2. Bandwidth Limited Very High3. Expansion /ScalabilityMedium Excellent4. Immunity toInterferenceProne Quite immune tointerferences
VSAT NetworkHBJ NetworkGREP NetworkJLPL NetworkMCPC NetworkSub Network-1 Sub Network -2Sub Network-3Sub Network -4Sub Network -5GAILnet(GAIL’s own dedicated integrated communication network)Sub Network-7Sub Network-6DVPL NetworkGAILTEL NetworkVSPL NetworkSub Network-8
Phase 1 Network Deployed in 2002, spans over 1650 Km, extends fromBareilly to Vijaipur via Delhi and from Palanpur toMumbai via Baroda It also provides the connectivity to major cities like:Ahmadabad, Baroda, Surat, Jaipur, Udaipur, Jodhpur,Agra, Meerut. In this network SDH & DWDM equipment of M/s Nortelhave been deployed. The equipped capacity of Phase-I network is 2.5 Gbps.
Phase 2A Network Deployed in 2003-04 and spans over 1700 Km. It consists of Links:a) from Baroda to Mumbai as a redundant link,b) from Bareilly to Kanpur,c) from Delhi to Chandigarhd) DVPL link from Vijapur to Dahej It also provides connectivity to major cities like:Lucknow, Bhopal, Indore, Nasik, Thane, Ambala, Karnal& Panipat In this network SDH & DWDM equipment of M/s Nortelhave been deployed. The equipped capacity of Phase-IIA network is 2.5 Gbps
Phase 2B Network Deployed in 2003-04 and spans over 1800 Km. It consists of Links:a) from Kanpur to Vijaipur,b) from Pune to Hyderabad,c) VSPL link from Hyderabad to Vizag It also provides connectivity to major cities like: Auraiya,Pata, Jhansi, Rae-Bareilly, Aligarh, Solapur, Sangareddy,Secunderabad, Vijayawada, Rajahmundry In this network SDH & DWDM equipment of M/s Fibcomhave been deployed. The equipped capacity of Phase-IIB network is 2.5 Gbps.
PDH (Plesiochronous Digital Hierarchy)• Plesiochronous is a Greek word meaning AlmostSynchronous , but not fully synchronous.• In Plesiochronous system every equipment isgenerating its own clock for synchronization.
Digitisation ProcessTelephony signals:• 4 Khz Voice signal is sampled at twice the frequency-8000 Hz• Samples are Quantized- Benchmarked to nearestpredefined levels• Quantized samples are encoded using 8 binary bits• Each Voice channel hence occupies8x8000 = 64000 Bits per Second = 64 Kbps000000010000001000000011....
Limitations There is insufficient provision for network management within the PDH frame format for them to be able to do this. No standard for synchronization Standard equipment from different vendors are not compatible Increase in number of equipments required. Theres no standardized definition of PDH bit rates greater than140 Mbit/s
SDH EquipmentTerminal Multiplexer• Path Termination equipment which acts asconcentrator of tributary signals like E1Regenerator• Regenerator is used to boost the signalsbetween multiplexers placed across a longdistanceAdd-Drop Multiplexer•Add Drop Multiplexer is used to access the signals to bedropped or inserted while allowing the other signals toflow through without processingSTM-4E 1E 3T 1Path TerminationEquipmentPath TerminationEquipmentRegeneratorSTM-4STM- 4STM- 4 STM- 4
SDH- Network Topologies Point to Point• Involves two terminal multiplexersconnected together with an opticalfiber with or without regenerators Point to Multipoint• This configuration necessarilyinvolves a Add Drop Multiplexerwhich connects to multiple sitesadding or dropping signals ateach sitePTE Regenerator PTEPTERegeneratorADM PTERegenerator
SDH- Network TopologiesMUXRegeneratorDCSRegeneratorRegeneratorMUXMUXMUXRegenerator Hub Configuration• Hub configuration involves a Digital Cross ConnectSystem at the centre of a mesh network, grooming thetraffic from various directions. Ring Configuration• Ring configuration involves multiple ADMs connectedalong the optical fiber ring either in bi-directional orUni-Directional connectivity.ADMADM ADMADM