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Rajeev GuptaEn no- 091094Ece final year

Summer training presentation

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AN Introduction Of Bsnl

Today, BSNL is the No. 1 telecommunication company and the largest public sector undertaking of India and its responsibilities includes improvement of the already impeccable quality of telecom services, expansion of telecom services in all villages and instilling confidence among its customers.

EXCHANGE:

Equipment which effects interconnected of telephones is known as switching equipment. The switching centre, which houses the terminating and switching equipment is called telephone exchange.

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Services provided by Bsnl:-

• BSNL provides almost every telecom service in India. Following are the main telecom services provided by BSNL:

• Universal Telecom Services:  Fixed wireline services and wireless in local loop (WLL) using CDMA Technology called bfone and Tarang respectively. As of June 30, 2010, BSNL had 75% marketshare of fixed lines.• Cellular Mobile Telephone Services: BSNL is major provider of Cellular Mobile Telephone services using GSM platform under the brand name Cellone & Excel (BSNL Mobile). As of June 30, 2010 BSNL has 13.50% share of mobile telephony in the country.

• Internet: BSNL provides internet services through dial-up connection (Sancharnet) as Prepaid, (NetOne) as Postpaid and ADSL broadband (BSNL Broadband). BSNL has around 50% market share in broadband in India. BSNL has planned aggressive rollout in broadband for current financial year.

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• Intelligent Network (IN): BSNL provides IN services like televoting, toll free calling, premium calling etc.

• 3G: BSNL offers the '3G' or the'3rd Generation' services which includes facilities like video calling etc.

• IPTV: BSNL also offers the 'Internet Protocol Television' facility which enables us to watch television through internet.

• FTTH: Fibre To The Home facility that offers a higher bandwidth for data transfer.This idea was proposed on post-December 2009.

• WiMax: BSNL has introduced India's first 4th Generation High-Speed Wireless Broadband Access Technology with the minimum speed of 256kbit/s. The focus of this service is mainly rural customer where the wired broadband

facility is not available.

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GSM frequencies

• 2G GSM networks operate in the 900 MHz or 1800 MHz bands• GSM-900 uses 890–915 MHz to send information from the mobile station to the base station (uplink)• 935–960 MHz for the other direction (downlink),• providing 125 RF channels (channel numbers 0 to 124) spaced at 200 kHz. Duplex spacing of 45 MHz is used

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NETWORK STRUCTURE

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Base Transceiver Station (BTS)

• The BTS handles the radio interface to the mobile station. The BTS is the radio equipment (transceivers and antennas) needed to service each cell in the network. A group of BTSs are controlled by a BSC.

BASE STATION CONTROLLER(BSC)

• The BSC provides all the control functions and physical links between the MSC and BTS. It is a high-capacity switch that provides functions such as handover, cell configuration data, and control of radio frequency (RF) power levels in base transceiver stations. A number of BSCs are served by an MSC.

 

MOBILE SWITCHING CENTER

(MSC)• The MSC performs the telephony switching functions of the system. It controls calls to and from other telephone and data systems. It also performs such functions as toll ticketing, network interfacing, common channel signaling, and others.

Gateway Mobile Switching Centre (GMSC)

• A gateway is a node used to interconnect two networks. The gateway is often implemented in an MSC. The MSC is then referred to as the GMSC.

HLR & VLR

• The HLR is a database used for storage and management of subscriptions. The HLR is considered the most important database, as it stores permanent data about subscribers, including a subscriber's service profile, location information, and activity status..,

• VLR is a database that contains a subset of the information located on the HLR

Equipment Identity Register (EIR) & Authentication Centre (Auc)

• The EIR is a database that contains information about the identity of mobile equipment that prevents calls from stolen, unauthorized, or defective mobile stations.

•A unit called the AUC provides authentication and encryption parameters that verify the user's identity and ensure the confidentiality of each call. The AUC protects network operators from different types of fraud found in today's cellular world.

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Incoming calls•Gateway MSC contact:-The first job of the Gateway MSC is to determine the current location of the mobile phone in order to connect the call. It does this by consulting the Home Location Register (HLR)

•Routing the call:- When the HLR receives this query message, it determines whether the call should be routed to another number (called a divert), or if it is to be routed directly to the mobile.

•Locating and ringing call:-When the call arrives at the Visiting MSC, the MSRN is used to determine which of the phones in this area is being called, that is the MSRN maps back to the SIM of the original phone number dialled. The MSC pages all the mobile phone masts in the area in order to inform the phone that there is an incoming call for it.

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Encoding of speech during call:- During a GSM call, speech is converted from analogue sound waves to digital data by the phone itself, and transmitted through the mobile phone network by digital means.

OUTGOING CALLS• Once a mobile phone has successfully attached

to a GSM network as described above, calls may be made from the phone to any other phone on the global PSTN.

• The user dials telephone no, presses the send or talk key, and the mobile phone sends a call setup request message to the mobile phone network via the nearest mobile phone base transceiver station (BTS).

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• The call setup request message is handled next by the mobile switching center, which checks the subscriber's record held in the visitor location register to see if the outgoing call is allowed. If so, the MSC then routes the call in the same way that a telephone exchange does in a fixed network

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EWSDINTRODUCTION

• EWSD is the abbreviated form of German equivalent of Electronic Switching System Digital (Electronische Wheler Systeme Digitale).

• EWSD switch can support maximum 2,50,000 subscribers or 60,000 incom ing, outgoing or both way trunks. It can carry 25,200 Erlang traffic.

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SYSTEM ARCHITECTURE

• Digital line unit (DLU)

• Line/Trunk Group (LTG)

• Switching Network (SN)

• Coordination Processor (CP)

• Common Channel Signalling Network Control (CCNC) Unit or Signalling System Network Control (SSNC)

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DLU

DLUCC

LTG

GP

LTG

GP

Common channel signalling/ Signalling System Network Control

CCNC/SSNC

Access

Coordination

CPSYPSYPC

MBMBC

CCG

EM

OMT SGC

Switching Network

Distributed controls in EWSD

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• Digital line unit (DLU) - functional unit on which subscriber lines are terminated.

• Line/Trunk Group (LTG) - Digital Trunks and DLUs are connected to LTGs.

• Switching Network (SN) - All the LTGs are connected to the SN which inter connects the line and trunks connected to the exchange in accordance with the call requirement of the subscrib ers. CCNC and CP are also connected to SN.

• Coordination Processor (CP) - It is used for system-wide coordination functions, such as, routing, zoning, etc. However each subsystem in EWSD carryout practically all the tasks arising in their area independently.

• Common Channel Signaling Network Control (CCNC) Unit or Signaling System Network Control (SSNC)- This unit functions as the Message Transfer Part (MTP) of CCS#7. The User Part (UP) is incorporated in the respective LTGs.

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BROADBAND SERVICE

BSNL offers Internet service with a speed range of 2 Mbps to 8 Mbps across 3,200 towns and cities. Out of the 612 district headquarters in the country, 585 have broadband connectivity.

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What is broadband?

• An ‘always-on’ data connection that is able to support interactive services including Internet access and has the capability of the minimum download speed of 256 kbps to an individual subscriber from the Point Of Presence (POP) of the service provider.

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Broadband Services Network Architecture

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DSL• Digital Subscriber Line (DSL) is a very high-speed

connection that uses the same wires as a regular telephone Line to connect to the Internet and transport high-bandwidth data, such as multimedia and video, to service subscribers.

• Despite its name, DSL does not refer to a physical line but to a modem—or rather a pair of modems.

• A DSL modem pair creates a digital subscriber line.

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• DSL modem transmits duplex (i.e., data in both directions simultaneously) at 160 kbps over copper lines of up to 18,000 feet.

• DSL modems use twisted-pair bandwidth from 0 to approximately 80 kHz which precludes the simultaneous use of analog telephone service in most cases

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ADSL• An ADSL circuit connects an ADSL modem on each

end of a twisted-pair telephone line, creating three information channels---

1. a high-speed downstream channel, 2. a medium-speed duplex channel, and 3. a basic telephone service channel.

• The basic telephone service channel is split off from the digital modem by filters, thus guaranteeing uninterrupted basic telephone service, even if ADSL fails.

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• The high-speed channel ranges from 1.5 to 6.1 Mbps, and duplex rates range from 16 to 640 kbps.• Each channel can be sub multiplexed to form

multiple lower-rate channels.

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DSLAM

• A digital subscriber line access multiplexer (DSLAM) delivers exceptionally high-speed data transmission over existing copper telephone lines.

• A DSLAM separates the voice-frequency signals from the high-speed data traffic and controls and routes digital subscriber line (xDSL) traffic between the subscriber's end-user equipment (router, modem, or network interface card [NIC]) and the network service provider's network

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• The DSLAM at the access provider is the equipment that really allows DSL to happen.

• A DSLAM takes connections from many customers and aggregates them onto a single, high-capacity connection to the Internet.

• DSLAMs are generally flexible and able to support multiple types of DSL in a single central office, and different varieties of protocol and modulation -- both CAP and DMT, for example -- in the same type of DSL.

• In addition, the DSLAM may provide additional functions including routing or dynamic IP address assignment for the customers.

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THANK YOU