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INDUSTRIAL TRAINING
Presented By:- Vishal Balana
Roll no:- 02104041
Date:- 15th july 2005
Hutchison Essar South Ltd.
(punjab)
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IntroductionHutchison Max Telecom Pvt. Ltd. is a joint promotion byMax and Hutchison Whampoa Ltd. (HWL) of Hong Kong.
The Company holds licenses to provide cellular services inMumbai, Gujrat, Kolkata, Chennai, Andhra Pradesh, NewDelhi and Karnatka. The services are provided in the city ofMumbai under the brand name ofORANGE
Today with a subscriber base of 5.8 lacs
subscribers ORANGE covers whole of Mumbai and NaviMumbai. ORANGE has a superior coverage spread throughvarious cell Sites across Mumbai. The company hasInternational tie-ups for roaming customers as well as allIndia roaming. The inherent strength of the Network lies in
the fact that ORANGE Mumbai has its own networkbackbone to carry its signal, thus, making the Companytotally self dependent. As per the figures released by COAI(Cellular Operators Association of India), HutchisonTelecom is 2nd largest cellular service provider in India.
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The Chaos That Existed
Before GSM networks, there were public mobile radio
networks. They normally used analog technologies, which
varied from country to country and from one
manufacturer to another. These analog networks did notcomply with any uniform standard. There was no way to
use a single mobile phone from one country to another.
The speech quality in most networks was not satisfactory.
Due to increasing use of radio communications
throughout Europe, the frequency band was also getting
congested.
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The Birth of GSM
In 1982, the Conference of European Posts &
Telecommunications Administrations (CEPT) established
a committee called Groupe Special Mobile (GSM). This
committee was set up to specify a unique radio
communication system for Europe. This system came tobe known as GSM.
In 1992, to avoid confusion between the GSM system and
the GSM committee, the GSM system was renamed as
Global System for Mobileand the committee was now
called Special Mobile Group (SMG).
In 1988, the European Telecommunications Standards
Institute (ETSI) was created to specify the standards forGSM.
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GSM- Architecture
MS
BTS
BTS
BTS
BTSBTS
BTS
BTS
BTS
BSC
BSC
PSTN
VLR
TRAUHLR
EIR
OMC
SMSC
AUC
VMSC
MSC
A
OML
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GSMSystem Architecture
A typical GSM system is made up of the
following components:
Mobile Switching Centre (MSC)
Base Station Controller (BSC)
Base Transceiver Station (BTS)
Transcoder (XCDR)
Messaging System
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GSMCell Architecture
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Features of GSM
Flexibility & increased capacity.
Compatibility Support for international
roaming.
Security Distinction between user and
device identification.
Noise Robust Excellent speech quality.
Wide range of services.
Inter-working (e.g. with ISDN, DECT).
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Feature: Flexibility
In analogue air interface, every connection
between a mobile subscriber and a cell site
requires a separate RF carrier.
In GSM, 8 simultaneous conversations can be
carried out on one RF carrier.
The system is more versatile and it is possibleto move capacity from one part of the network to
another just by reconfiguring the system
database.
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Feature: Compatibility & Security
Compatibility:
ISDN is a new & advanced standard intelecommunications
GSM is compatible with ISDN
GSM phones are ISDN compatible
Security:
In analogue systems, anyone can eavesdrop if
equipped with an appropriate receiver.
GSM offers high speech & data security.
In GSM, the calls are digitized, encoded and then
ciphered (encrypted) before transmission. This makeslistening to calls virtually impossible.
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GSMAir Interface
Frequency Band Used
Logical Channels Frequency Hopping
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Air Interface: Freq Band
GSM 900:
Uplink: 890 - 915 MHz (MS to base station)
Downlink: 935 - 960 MHz (base station to MS)
124 RF carriers.
200 KHz bandgap.
GSM 1800 (previously DCS-1800):
Uplink: 1710 - 1785 MHz
Downlink: 1805 - 1880 MHz
GSM 1900 (previously PCS-1900):
Uplink: 1850 - 1910 MHz
Downlink: 1930 - 1990 MHz
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Air Interface: Logical Channels
Traffic Channels
Signalling Channels
Dedicated Channels
Broadcast Channels
Common Control Channels
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Air Interface: Freq. Hopping
Provide Diversity.
Reduce Interference.
Mobile transmits on one frequency during
one TS.
Switches to different frequency to transmitduring next TS.
Broadcast channel does not support hopping.
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Sequence of Learning
Projects
Transmission
RF maintenance
OMC-R (Operations
and Maintenance-Radio)
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Functions of OMC-R
The OMC-R performs the following functions:
Direct management of BSS and RXCDR and the linksbetween them.
Management of the NE devices associated with thelinks (on the RXCDR side) between the MSC, the BSSsand RXCDRs. This is all done using the O&M data
packets sent to/from the NE.
Monitoring of events and alarms, performing fault
handling, NE re-configuration, NE software uploadingand downloading, and performance data collection andreporting for all the NE under its control.
Provides a centralized facility for network managementof up to 120 NEs with up to 45,000 traffic channels forthe OMC-R.
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OMC-R N/W Management
Fault Management
Event/Alarm Management
Performance Management
Configuration Management
Load management
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Fault Management
Fault management provides the facility to changethe status of any device using fault handling
procedures. From the OMC-R, the GSM networkoperator can react to changes in the network andre-configure the site by taking devices in or out ofservice as required, thus maintaining continuity of
service to mobile phone users. Fault managementtasks can be performed from the map, the alarmwindow, Navigation Tree and through containeddevices
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Event/Alarm Management
A primary function of an OMC-R is to maintain the qualityof service to customers/users of the GSM network bymonitoring the state of Motorola equipment in the network.Event or alarm messages containing information on the stateof the network, devices and links in the system are sent, via
the X.25 network, to the OMC-R.There is the optionalAlarm notification via Paging feature which automaticallynotifies key personnel of certain alarm or state changes.Operators can filter and select the way in which alarms aredisplayed and handled; for example, alarms which have been
handled, but not yet cleared, can be deferred.An optionalNetwork Health Analyst (NHA) provides a means by whichoperators can move from being purely reactive to a more
proactive role by observing a combination of events,statistical information and configuration data that notifiesthem of network problems before any faults are raised.
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Performance Management
Performance management provides collection and
reporting of network performance statistics. The
OMC-R collects, processes and storesperformance statistics on the different NEs in the
network, and provides reporting facilities for the
presentation and printing of the processed
statistics. These statistics can be then used toanalyse network performance and aid long term
planning.
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Configuration Management
The OMC-R provides the configuration managementfacilities for a system that can cater for an expandingGSM network. The System Processor can beconfigured for a variety of expandable traffic channelcapacities on the same basic platform. The OMC-Rsystem allows customers to expand their networkoperations and maintenance support in line with their
business growth and provide orderly migration for
existing users and rapid deployment for new users.TheOMC-R also includes the Call Trace function.Optional tools may also include the IntelligentOptimization Product (IOP) and the MotorolaAnalysis and Reporting System (MARS).
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Load management
Load Management forms part of the
Configuration Management and provides
the operator with a central location toremotely load all the NEs with the latest
compatible version of operating software.
New software loads are installed at theOMC-R and later downloaded to the NEs
under the OMC-Rs control
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Connectivity dig.
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Types of Links
Physical Links
Logical Links
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Physical Links
Path:
A PATH device defines the connectivity between
a BSC site and BTS sites under its control. It is alogical representation of a 2 Mbit/s route betweenthe BSC and a destination BTS. This connectivityspecifies the physical route from the BSC, through
intermediary BTSs to the destination BTS. APATH may contain a route through a maximum of10 BTS sites. The connection information betweenany two sites consists of an MSI (NIU for M-Cell)/MMS device at each end of the link.
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Logical Links
Operation and Maintenance Link (OML)
Message Transfer Link (MTL)
Radio Signaling Link (RSL)
XCDR to BSC Link (XBL)
Cell Broadcast Link (CBL)
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Operation & Maintenance Link
(OML)
The purpose of the OML is to provide
communication between an OMC-R and a BSC orRXCDR for transferring network management
(O&M) data. Up to four OML links can be
configured between an OMC-R and BSC or
RXCDR; one OML is used at any one time, the
other three OMLs exist for redundancy purposes.
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Message Transfer Link (MTL)
The purpose of the MTL is to provide a link forsignalling information between the BSC and the MSC.In the Motorola system, when local transcoding isused, this is a physical connection between the BSC
and the MSC. When a Remote Transcoder is used, thelogical MTL is made up of two physical parts; theconnection between the BSC and the RXCDR and theconnection between the RXCDR and the MSC. When
more than one MTL is configured between the BSCand MSC, both load sharing and redundancy arepresent. Up to 16 MTLs may be configured between a
BSC and MSC.
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Radio Signaling Link (RSL)
A signalling link between a BSC and a remote BTS iscalled a Radio System Link (RSL). The purpose of anRSL is to provide signalling information between a BSCand a remote BTS. The Motorola software chooses the
timeslots used, automatically. This is to ensure that newBTSs, added to the network, can be communicated withon default timeslots. Each RSL link is associated with aPATH. It is possible to have multiple (up to eight) RSLs
between a BSC and a remote BTS. There are two RSLs
between BTS2 and the BSC. This is possible because ofthe daisy chain connection in the BSS. The two RSLsprovide both load sharing and redundancy functions forthe signalling link.
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XCDR to BSC Link (XBL)
An XBL link may be configured between the BSC
and the RXCDR for exchanging internal FaultManagement (FM) data between them. An
Enhanced XBL (EXBL) will allow generic
messaging between the RXCDR and BSC in
support of current and future operator needs.
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Cell Broadcast Link (CBL)
A CBL link can be configured between the BSC
or RXCDR and the Cell Broadcast Centre (CBC).
This is used for downloading messages to
broadcast along with other necessary information
such as repetition rate and number of broadcasts.
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Site Containment
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Information flow b/w OMC & NE
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Thank You
