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WELCOME. On. TELECOMMUNICATION. Presentation . JIND INSTITUTE OF ENGG. & TECH. TRAINING REPORT ON TELECOMMUNICATION. SUBMITTED TO, ECE DEPTT. SUBMITTED BY, PRAKASH KUMAR ARYA ROLL NO. 1608214 GROUP:- A BRANCH:- ECE YEAR:- 3 rd Yr.
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On TELECOMMUNICATION Presentation
JIND INSTITUTE OF ENGG. & TECH. TRAINING REPORT ON TELECOMMUNICATION • SUBMITTED TO, ECE DEPTT. • SUBMITTED BY, PRAKASH KUMAR ARYA ROLL NO. 1608214 GROUP:- A BRANCH:- ECE YEAR:- 3rd Yr.
BSNL: Bharat Sanchar Nigam Limited was formed in year 2000 and took over the service providers role from DoT. Today, BSNL has a customer base of over 9 crore and is the fourth largest integrated telecom operator in the country. BSNL is the market leader in Broadband, landline and national transmission network. BSNL is also the only operator covering over 5 lakh village with telecom connectivity. Area of operation of BSNL is all India except Delhi & Mumbai.
INTRODUCTION • Governments also need to intervene for ensuring fair competition and the best value for money for its citizens. • This handouts gives exposure on the Telecom Environment in India and also dwells on the role of international bodies in standardizing and promoting Telecom Growth in the world.
Institutional Framework • It is defined as the systems of formal laws, regulations, andprocedures, and informal conventions, customs, and norms, that broaden, mold, and restrainsocio-economic activity and behaviour. • country has been divided into units called Circles,Metro Districts, Secondary Switching Areas (SSA), Long Distance Charging Area (LDCA)and Short Distance Charging Area (SDCA).
Major changes in Telecommunications in India • Its began in the 1980s. • The initial phase of telecom reforms began in 1984 with the creation ofCenter for Department of Telematics (C-DOT) for developing indigenous technologies and private manufacturing of customer premise equipment. • Soon after, the Mahanagar TelephoneNigam Limited (MTNL) and Videsh Sanchar Nigam Limited (VSNL) were set up in 1986.
Major changes in Telecommunications in India • The Indian telecom sector was setting up of an independent regulatory body in1997 – the Telecom Regulatory Authority of India (TRAI), to assure investors that the sectorwould be regulated in a balanced and fair manner. • In 2000, DoT corporatized its serviceswing and created Bharat Sanchar Nigam Limited.
Major changes in Telecommunications in India • With the TRAI Act of 2000 that aimed at restoring functional clarity andimproving regulatory quality and a separate disputes settlement body was set up calledTelecom Disputes Settlement and Appellate Tribunal (TDSAT) to fairly adjudicate any dispute between licensor and licensee, between service provider, between service providerand a group of consumers.
Major changes in Telecommunications in India • In October 2003, Unified Access Service Licenses regime forbasic and cellular services was introduced. This regime enabled services providers to offerfixed and mobile services under one license. • Indian telecom has seenunprecedented customer growth crossing 600 million connections. India is the fourth largesttelecom market in Asia after China, Japan and South Korea. • The Indian telecom network isthe eighth largest in the world and the second largest among emerging economies.
Lesson Plan • Institutional Mechanism and role & Telecom Eco system • National DOT, TRAI,TDSAT, TEC,CDOT • International Standardization bodies- ITU,APT,ETSI etc. • Licensed Telecommunication services of DOT • Various Trade associations, Network Operators, Manufacturers, service providers,service provisioning and retailing, billing and OSSJob opportunities in telecom Market, government and statutory bodies.
INTRODUCTIONComputer network A communications, data exchange, and resource-sharing system created by linking two or more computers and establishing standards, or protocols, so that they can work togetherTelecommunication system -Enable the transmission of data over public or private networks (voice, data, graphics, video…)
TELECOMMUNICATIONS-VOICE • Voice Communications Require:- 1. A source device 2. A switching system 3. A data channel 4. A destination device • The line remains open for the duration of the call • Requires a dedicated connection
Telecommunications - data • Data communications – data traffic • Data traffic on the Internet doubles every 100 days. • Does not “grab the line” during transmission • Uses packet switching technology
Ways to describe a network… • Type of traffic (voice or data) • Type of signal (analog or digital) • Type of transmission mode (Simplex…) • Geographic area covered (LAN, WAN...) • Architecture - peer-to-peer, client/server • Physical topology (Bus, Star…) • Protocols - Ethernet, Transmission Control Protocol/Internet Protocol (TCP/IP) • Transmission medium (guided or unguided)
Types of Signals • Analog • Continuous sine wave over a certain frequency range • positive voltage = 1 • negative voltage = 0 • Digital • Discrete burst of electric energy • on = 1 • off = 0 • Most phone lines use analog signaling
Converting Signals • Computers can only process digital signals • If data is transmitted using analog signaling over a phone line, it must be converted into a digital signal before the computer can process it……
Modems • Modulation - converting digital signals into analog form • DEModulation - converting analog signals back into digital form
Transmission Modes • Performance can be measured by the mode of the connection. • Simplex transmission, messages can be carried in only one direction. • Half-duplex, messages can be carried in both directions just not simultaneously. • Full-duplex, messages can be carried in both directions simultaneously.
LOGICAL TOPOLOGIES (protocols) • Protocol - a standard that specifies the format of data as well as the rules to be followed during transmission • A communication protocolis essentially a set of codes or conventions used for facilitating communications between hardware and software. • Interoperability - the capability of two or more computer systems to share data and resources, even though they are made by different manufacturers
Protocol – how it works • common set of rules that allow different components in a network to talk to each other • handshaking protocol • identify each device • secure attention of other device • transmission protocol • verify correct receipt of message • send re-transmit message if necessary • recover error and re-transmit
Some Protocols • Ethernet -a physical and data layer technology for LAN networking • IP or Internet Protocol directs packets on the Internet. • TCP or Transmission control protocol puts the packets in their correct sequence. • HTTP or hyper text transfer protocol is used to transmit web pages over the Internet. • Mobile IP provides IP routing for mobile devices. • Voice over IP (VoIP) - uses TCP/IP technology to transmit voice calls over long-distance telephone lines
TRANSMITTING AND RECEIVING DEVICES THE HARDWARE: • Network adapters • Modems • Repeaters • Wiring concentrators, hubs, and switches • Bridges, routers, and gateways • Microwave transmitters • Infrared and laser transmitters • Cellular transmitters • Wireless LAN transmitters
NETWORKING BASICS • Bandwidth - indicates how much information can be carried in a given time period (usually a second) over a wired or wireless communications link. • Measured in megabits per second
Outline • cdma2000 network architecture • Call processing states and call flows • CDMA evolution • Essential elements in a CDMA system • Power Control • Mobility management • Handoffs • Registration • Roaming
Network Architecture Black Mountain Packet Network PSTN PDSN MSC BSC Ericsson UCSD
A CDMA Network architecture consists of the following components: • Mobile station • Radio Base Station (RBS) • Base Station Controller (BSC) • Mobile Switching Center (MSC) • Public Switch Telephone Network • PDSN as an IP Gateway
Call Processing - Pilot First MS monitors Pilot channel for • Initial acquisition • Channel estimation • Detection of multipaths for rake receiver • Handoffs Pilot Ch
Call Processing - Sync Pilot channel is transmitted at all times by the base station. MS uses it to lock to Synch Channel to • Synchronize to CDMA system time • Obtain configuration parameters such as • Protocol Revision (P-REV) • Network Identifier (NID) • Pilot PN offsetLong-code state • Paging channel data rate Sync Ch
Call Processing - Paging MS decodes the Paging Channel with the information received from the Sync Channel. Paging channel provides • Overhead messages: systems parameter, access parameter, neighbor list, channel list • Mobile directed messages: page request, SMS Paging Ch
Call Processing – Access MS uses Access channel to originate a call or to respond to a page request. Access Channel is used in a random access fashion. Access Ch
Call Processing - Traffic • Base station assigns a forward and reverse traffic channel to the mobile when it is in conversation • Traffic Channel conveys signaling and traffic information • When MS is on traffic channel it no longer listens to paging channel or uses the access channel
Power Up Call originationor page response Synchronization Initialization State IdleState AccessState Traffic State Paging Loss Page response completed End of call Mobile Station States
Initialization: • Acquire pilot channel of the selected CDMA system within 20 secs (not standardized) • Process synch channel for synchronization (long code and CDMA timing) • Idle: • Monitor paging channel for overhead and mobile directed messages • Move to access state to originate a call or respond to a page request
Access: • MS sends messages to the base station and gets responses in the paging channel • This can be a call origination or a page response • Traffic: • MS communicates with the base station using forward and reverse traffic channels • Paging and access channels are no longer monitored • Alert with info is used for order message
Mobile Originated Voice Call Flow MSC BSC MS Overhead Info Paging Ch. Access Ch. Origination Msg BS Ack Order Paging Ch. CM Service Request Null Frames Fwd Traffic Ch. SCCP Connection Cfm Paging Ch. Channel Assign Msg Rev Traffic Ch. Preamble Fwd Traffic Ch. BS Ack Order Assignment Request MS Ack Order Rev Traffic Ch. Service Connect Fwd Traffic Ch. Rev Traffic Ch. Service Conn Cmplt Assignment Complete
CDMA Evolution (1/3) • IS-95A (2G) • First CDMA protocol, published in May’99 • 14.4/9.6 kbps circuit/packet data • IS-95B (2.5G) • Most analog information is removed • Some technical corrections • New Capabilities, such as higher data rate • 64 kbps packet data
CDMA Evolution (2/3) • CDMA2000 1X • High speed data (144 kbps packet data with Mobile IP) • Coding (Turbo) and Modulation (Hybrid QPSK) • New dedicated and common channels • Enhanced Power Control • Reverse link detection • Forward link modulation
CDMA Evolution (3/3) • 1X EV-DO (1xRTT Evolution for high-speed integrated Data Only) • The objective is to provide the largest practical number of users to run high-speed packet data applications • 2.4 Mbps packet data • 1X EV-DV (1xRTT Evolution for high-speed integrated Data and Voice) • Voice and High Speed Data mixed on one carrier • Backward-compatible with CDMA2000 1X • 3.1 Mbps packet data
Dedicated band during entire call Each user transmits at the same time, at the same frequency with a unique code Certain frequency, time-slotted Multiple Access Methods
B E A A G C B A A A A G A A F D A A A A E F A A Frequency Re-use Patterns FDMA and TDMA vs. CDMA
Channelization • Channelization is provided by orthogonal Walsh codes • cdma2000 uses variable length Walsh codes for supplemental channel data services • Walsh codes can be of length 8, 16, 32, 64, and 128
Walsh Codes • Walsh codes are orthogonal to each other • The shorter the code the higher the data rate since the chip rate is kept constant
Use of Multipath sin CDMA Systems • FDMA/TDMA (narrow-band) • multipath hurts • equalizers are used to cancel multipath • CDMA (wide-band) • can discriminate between the multipath arrivals • Rake receivers are used to combine multipath signals to reduce error rate at the receiver
Power Control – Algorithm • Capacity is maximized • By having each user transmitting just sufficient SNR to maintain a target FER • Open Loop Estimate • Initial transmit power level for the mobile is determined by the received pilot strength • Closed Loop Power Control • Base station controls the power level on the mobile by the received quality information.