2. INTRODUCTION TO COMPANY
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ďąMTNL stands for Mahanagar Telephone Nigam Limited .It is
state -owned telecommunication service provider in the metro
cities of Mumbai & New-Delhi in India.
ďąâTransparency makes us differentâ is the motto of the company.
ďąMTNL was set up on 1 April 1986 by the Government of India
with the aim of upgrading the quality of telecom services,
expanding the telecom network, introducing new services &
raising revenue for the telecom development.
ďą Its main goal is to remain market leader in providing world class
telecom & IT related services at affordable prices & be a global
player.
ďą It also aims at venturing into other areas in India and abroad on
strengthening to compete with core companies.
3. TRAINING PROFILE
While undergoing training at ITTM the following topics were explained and
Labs were imparted on them :-
ďśSWITCHING
ďśSIGNALLING
ďśBROADBAND
ďśTRANSMISSION
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4. SWITCHING OVERVIEW
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SWITCHING is a process which involves the control consisting of a mechanical
or electrical or electronic device for making or breaking or changing the
connections in a circuit.
control
1
23
N
1
23
N
Connection
of inputs
to outputs
âŚ
âŚ
The switching centers receives the control signals,
messages or conversations & forwards to the required
Destination, after necessary modification (link
amplifications) if necessary. A switching system is a
collection of switching elements arranged &
controlled in such a way as to setup a communication
path between any two distant points.
5. SIGNALLING OVERVIEW
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Signalling system in a data communication network exchanges signalling
information effectively between subscribers. The signalling systems are
essential building blocks in providing the ultimate objective of a
worldwide automatic telephone services standardized. Signalling provides
the interface between different national systems. The introduction of
signalling system was the big step in improving the PSTN.
The consultative committe on international telegraphy and telephony
(CCITT) based in Geneva, recommended seven formats related to
signalling. The first five formats related to Inband signalling and the last
two in the category of common channel signalling. In In-band signalling,
voice information and signalling information travel on common paths,
where as in common channel signalling, they travel on separate paths.
6. DIFFERENCE IN TYPES OF SIGNALLING
COMMON CHANNEL
SIGNALLING (CCS)
CHANNEL ASSOCIATED
SIGNALLING (CAS)
ď Special hardware and software is
required
ď No multi-frequency analyzer are
required to
send and receive MFC tones.
⢠Only a few signalling channels are
required.
⢠Very fast signalling
⢠CCS can be used for other types of
information e.g. maintenance.
⢠Failures have major impact on system.
ď No special hardware and software is
required.
ď Special multi-frequency analyzer are
required
during call setup.
⢠Line signalling is required.
⢠Slow signalling
⢠CAS can only be used for call handling
information.
⢠Failures have limited impact.
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7. BROADBAND OVERVIEW
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An âalways âonâ data connection that is able to support
Interactive services including internet access. Broadband
Technology refers to a telecommunication device, lines or
technology that allow communication over a wide band of
frequency .Broadband system allow voice, data & video
to be broadcast over same medium at the same time.
Frequency spectrum used in broadband:-
ADSL Bandwidth
UPSTREAM DOWNSTREAM
4 KHz 26 KHz 138 KHz 1 . 1 MHz
8. TRANSMISSION OVERVIEW
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Transmission medium is the physical path by which a message travels from sender
to receiver.
Computer and telecommunication devices used signals to represent data.
These signals are transmitted from one device to another in the form of
electromagnetic energy.
10. QOS in cellular network
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Quality of service in cellular networks is defined as the capability of the cellular
service providers to provide a satisfactory service which includes voice quality,
signal strength , low call blocking and dropping probability , high data rates for
multimedia and data applications . For network based services QOS depends on
the following factors:-
â˘Throughput :- The rate at which the packets go through the network. Maximum rate is
always preferred.
â˘Delay :- This is the time which a packet takes to travel from one end to the other.
Minimum delay is always preferred.
â˘Packet Loss Rate :-The rate at which a packet is lost. This should also be as minimum
as possible.
â˘Packet Error Rate :- This is the errors which are present in a packet due to corrupted
bits. This should be as minimum as possible.
â˘Reliability :- The availability of a connection. (Links going up/down).
It is for these reasons that providing QOS has been a great challenge in the past and it
continues to be a hot topic as there is still a lot of scope to provide better service
standards.
11. NEED OF QOS
ďTo provide high quality service.
ďVoice should be given higher priority over data traffic as voice is the most
important service.
ďPreference should be given to customers who pay more to get better service
without affecting the remaining customers who pay normal amount.
CHALLENGES OF QOS
ď§Good transmission quality
ď§Service availability
ď§Minimum delay
ď§Handoff support
ď§Efficient usage of spectrum
ACHIEVEMENTS OF QOS
In 1g and 2g networks providing quality of speech was the major concern but
now in 3g network QOS can provide voice as well as data.
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13. The architecture of QOS being explained as follows :-
⢠End- to- End service &UMTS Bearer service
End - to - End service layer is the topmost layer of the QOS architecture. It makes communication possible from
one TE to the other. It is shown that a TE is connected to the UMTS network by means of a Mobile Termination
(MT). The End - to - End services used by a TE will be realized by the below layers namely TE/MT local bearer
service, a UMTS bearer service and external bearer service. The UMTS operator offers services provided by the
UMTS bearer service. Thus UMTS bearer service provides the UMTS QOS.
â˘The Radio Access Bearer Service and the Core Network Bearer Service
The UMTS Bearer service is comprised of two parts which are the Radio Access Bearer Service and the Core Network Bearer
Service. Both these services take care of the Bearer service over the network topology taking into consideration attributes such as
mobility and mobile subscriber profiles. The Radio Access Bearer Service makes provision for the transport of signaling and user
date between MT and CN Edge Node with QOS adequate to the negotiated UMTS bearer service or with default QOS for signaling.
Radio Bearer Services provides the unequal error protection if that feature has to be supported. The Core Network Bearer Service
of the UMTS core network connects the UMTS CN Edge Node with the CN Gateway to the external network. This service controls
and utilizes the backbone network efficiently in order to provide the contracted UMTS bearer service.
â˘The Radio Bearer Service and the RAN Access Bearer Service
The Radio Access Bearer Service is realized by a Radio Bearer Service and an RAN Access - Bearer Service. The Radio Bearer Service
covers all the aspects of the radio interface transport. To support unequal error protection, RAN and MT has the ability to
segment/reassemble the user flows into the different sub flows requested by the Radio Access Bearer Service. The
segmentation/reassemble is given by the Service Data Unit (SDU) payload format signaled at Radio Access Bearer establishment.
â˘The Backbone Network Service
The core Network Bearer Service uses a generic Backbone Network Service. The Backbone Network Service covers the
layer 1/layer 2 functionality and is selected according to the operator's choice in order to fulfill the QOS requirements of
the CN Bearer Service 13
14. STEPS TO IMPROVE QUALITY OF SERVICE
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1. Check E1 status between Node b & RNC.
36. 8. Use a trace of a particular MSISDN number in RNC as well as
Node B level.
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37. 9.Check RF parameters (including scrambling codes, power level of
Node b , cell coverage area ,antenna LAT/LONG position
& polarization etc.
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38. FIELD TRAINING
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ITTM provided us the opportunity of working with the professionals by
giving us hand on experience on sharing work space with them.
The Department with which I got the opportunity to work are as under and
brief summary of my work is provided alongside.
A. INDUSTRIAL TRAINING AT OMCR ,Karol Bagh Exchange
B. INDUSTRIAL TRAINING AT RF, Lodhi Road Exchange
39. OMC-R (Operation & Maintenance centre
Radio)
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For management and operation of all centre's and cells remotely MTNL used a software of MOTOROLA
Known as OMC-S/T. Name of the software used for the OMCR is SUN SOLARIS. Motorola system and
equipment provide security parameters that the operator configures based on their particular working
environment.
It deals with following network equipment operation:-
â˘Getting started
You can know the operation GUI of the OMC-S/T client, how to log in to, log out of, lock, and unlock the client, how to set the broadcasting message, and how to modify the user password
and customize the display style of the client.
â˘Network Monitoring
On the OMC-S/T client, you can monitor the alarms on the network, real-time NE performances, the RAN network, and operational status of the OMC-S/T. In this way, you can detect
network faults in time and then perform the related operations.
â˘Topology Management
Topology management offers the function of constructing and managing the topology structure of the whole network to display the networking situation and running status of the equipment.
You can query and monitor the entire network operation in real time through the topology view.
⢠Security Management
This describes how to guarantee the security of the OMC-S/T. The OMC-S/T security management manages the user and the user's rights. Through the security management, the security of
the OMC- S/T is guaranteed.
â˘Log Management
Log management involves the management of user logs, NE logs, and system logs. This function enables you to query logs and collect statistics of logs, thus helps monitoring and analyzing
operational status of the system and troubleshooting.
â˘Performance Management
Through the performance measurement, you can measure and observe the security, running status and signaling connection status of the equipment, also you can measure and observe the
utilization of the user and system resources. This function provides reliable data support for the measurement, designing and operation management of the communication network. OMCS/ T
can measure the performance of multiple NEs. When an NE is successfully set up and communicates normally with OMC-S/T, the NE automatically reports the measurement results of key
performance counters to OMC-S/T for data query and analysis based on a certain period.
â˘Performance Report Management
The OMC-S/T provides the function of performance report management. You can set the query conditions of system reports and custom reports on the GUI. The OMC-S/T can display the
queried performance report on the report query interface. By analyzing the report data, you can obtain the information about the performance of each NE. You can also manage KPIs, such as
create, modify, and delete KPIs on the KPI management interface
40. ALARM NAME HANDLING PROCEDURE
ď VSWR ALARM
ď NODE B clock source
abnormal
ď Loss of frame alarm
ď Loss of signal alarm
ď Signalling link
unavailable
ď Loose RF connector
ď DSP E1TI (Links 0&1 are
normal )
ď E1/T1 cables are faulty
ď Physical transmission
link fault
ď Run DSP MTP3BLNK to
check link is in
deactivation mode or
not.
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41. OMC-U
The Motorola OMC-U is a centralized mobile network management platform of Motorola. OMC-U provides the functionality of
managing the RNC and Node-Bs remotely. OMC-U server is Solaris OS based platform with OMC-U application software loaded
on it.. OMC-U client is a desktop PC with OMCU client software loaded on it.
The OMCU is available with a selection of capacity options to meet service providers needs.
Functions of OMC-U
â˘Centralized Fault Management
â˘Centralized Performance Management
â˘Centralized Configuration Management
â˘Centralized Software Management
â˘Centralized Topology Management
â˘Centralized Security Management
â˘Signaling Tracing
â˘System Management
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42. RF OPTIMIZATION
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OPTIMIZATION is the activity of achieving and maintaining the required
quality as designed.
Need of OPTIMIZATION is that there are deviations between plan and reality.
Optimization needs to be done because of the following reasons given below:
⢠Inaccuracy of radio planning
- Statistical variations in the path loss characteristics
- Finite terrain database resolution
⢠Implementation
- Antenna radiation pattern and effective radiated power
- Antenna pattern distortion
⢠Environment
- Seasonal environmental changes, e.g. trees leaves,
trees having thick leaves & trees with very thin leaves
- Environmental changes such as new highways, new buildings
43. DRIVE TEST THE SIGNAL DEFICIT AREAS
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Drive testing is done in the area where there is less or no signal. Also drive test needs to be done in the area where
there are customer complaints. Drive testing is done using the drive test tool. It is known as TEMS Investigation 5.0.
Drive-testing remains an essential part of the network life cycle, as an effective means for continually optimizing
network performance to maintain customer satisfaction and reduce subscriber migration to others.
â˘Drive Test Data Collection
- CELL ID including BSIC (Base station identification code), LAC (Location area code), and time slot.
- RXLEVEL for the serving and neighbor cells.
- RXQUALITY for the serving cell.
- BCCH, BSIC for the serving and the neighbor cells.
- TIMING ADVANCE.
- TRANSMIT POWER.
- GPS POSITION DATA
- TIME matching.
â˘Drive Test Route Planning
â˘Primary route:-
Includes all major roads, highways and wide thorough fares
â˘Secondary route:-
Includes all streets, subdivisions and compounds when accessible
â˘Miscellaneous routes (in-building and special locations) :-
Includes golf courses, beach resorts, shopping malls, department stores, convention centers, hotels and resorts and
inside of buildings and houses
44. DRIVE TEST TOOLS
Drive test equipments are as follows:-
ďąTest Mobile phone
ďąAntennas
ďąGPS
ďąLaptop computer
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46. Steps involved in implementation of drive test are as under :-
1. Starting TEMS investigation
2. Connecting the MS to the PC:- TEMS Investigation now scans the COM ports for external devices
and
enables these devices automatically. A Port Configuration window is opened, showing the progress of the
scan
3.Starting the recording
4.Replaying the log file
5.Connecting external
devices and equipments.
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