1. Industrial Training Report
On
CDMA Network & E1 Troubleshooting
at
Tata Teleservices Ltd.
New Delhi
Presented by: Divyansh Gupta
Project Guide : Mr. J. B. Singh
Faculty Supervisor: Prof. Shashikant Patil
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2. Tata Teleservices Limited
Incorporated in 1996, Tata Teleservices Limited was the pioneer of the CDMA 1x technology in India.
Significant services:
CDMA services
market-defining wireless mobile broadband(Tata Photon)
2G and 3G Services
launched significant services CDMA mobile operations in January 2005 under the brand name Tata
Indicom,
Market-defining wireless mobile broadband services under the brand name Tata Photon in 2008
2G GSM services under the brand name Tata DOCOMO in 2009
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3. CDMA Network of TTSL
8 BSC of TTSL in Delhi and NCR region. BSC 1,2,6,7 are
grouped at Concorde and BSC 3,4,5,8 are grouped at VSB
(Videsh Sanchar Bhawan)
190-250 BTS are connected to each BSC
Each BTS covers an area of approx. 3-4 Km with a radiating
power of 3-5 W.
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4. Understanding CDMA
Code Division Multiple Access (CDMA) is a channel access method originally developed for
the battlefield.
CDMA bands used in telecom:
450 MHz
800 MHz
1900 MHz
In Code Division Multiple Access (CDMA), every communicator will be allocated the entire
spectrum all of the time.
Use of wide bandwidth: wider. Advantages including an increased immunity to Interference
or Jamming, and multiple user access.
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5. A few of the benefits of CDMA are
• Superior voice quality
• Better reception with less background noise,
• Fewer dropped calls,
• Enhanced security and greater reliability.
• Greater network capacity,
WHY IS CDMA BETTER---------?
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9. Basic Function of OMC(Operation And
Maintenance Centre)
1. Site Monitoring
2. Fault Management
3. Alarm Monitoring
4. Performance Analysis
5. Backups
6. Analysis Report On Network Outages
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10. Site Monitoring
BTS monitoring
Fault Management
Fault Management relates to the software as well as hardware faults
in the MSC,BSC and BTS
11. Alarm Monitoring
Continuously monitors the alarm reported by all BTSs, BSCs, MSC
and other elements.
Since it is not possible to man hundreds of fields locates sites for
these types of issues, so these alarms are also reported to at the
OMC from where again these are reported back to the site
engineers and technicians for suitable action to be taken to remove
them.
The following parameters are monitored –VSWR, RSSI difference,
CHPA, and other Sector Down alarms
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12. Types of alarm
Critical
Due to which BTS goes down or any
service (CDMA 1x or EV-DO) goes down.
Communication b/w BSC & BTS
Interrupted.
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Non-Critical
Due to which service on aparticular sector
goes down.
13. Alarm Management System
Used for live monitoring of the various components of the RAN.
Issues occurring in various entities are reported as alarms of
various levels (minor, major ,critical) , along with the date, time
,location and origination of the alarm.
Alarms are categorized as:-
Power System alarms
Environment System Alarms
Signalling System Alarms
Trunk System Alarms
Hardware System Alarms
Software System Alarms
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14. Some Important Alarms
PPP Link Fault
E1/T1 Loss of Signal (LOS)
E1/T1 Alarm Indication Signal
(AIS)
Communications Between BSC
and BTS Interrupted
E1/T1 BER(Bit error rate)
Threshold Exceeded
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Alarms
15. Parameters analyzed in KPI
It is a type of performance measurement.
Used to evaluate the working efficiency and success of a particular
technological service such as a telecom network.
Evaluating the performance of RAN. Separate KPI reports are
generated for both 1x & HSIA.
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• TCH CONGESTION RATIO (0.5%)
• CS Call Attempts (CS- Circuit Switched)
• CS Drop Call Rate 5(%)
• CS Call Setup Success Ratio (CSSR) &Access Fail Rate (AFR)(5%)
• Hard Block (0.5)
• RSSI Difference(Received signal strength indication)
KPI-Key Performance Indicator
17. Backups
Backups are basically taken for the purpose of redundancy. As the software
is loaded for all the hardware installed which is very much prone to errors
and bugs, also the network changes are being made continuously ,so it
becomes very essential to have a back up, a duplicate copy of all the
changes made and that even very up to date. There are two types of
Backups:
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18. Report On Outages
Covers the total number of sites down through out the day, the time
for which it was down and the main reason for the failure of site.
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19. E1 Troubleshooting
What is E1 ?
The E-carrier system enables the transmission of several (multiplexed) voice/data
channels simultaneously on the same transmission facility
A single physical wire pair can be used to carry many simultaneous voice conversations
by time-division multiplexing
The line data rate is 2.048 Mbit/s (full duplex, i.e. 2.048 Mbit/s downstream and
2.048 Mbit/s upstream) which is split into 32 timeslots, each being allocated 8 bits in
turn.
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