GSM Optimization
and TEMS
Includes Brief intro on
Cellular
Communication
Assigned By:
Sir Ahmed Sikander
HINA MANZOOR
AHMER MURTAZA
IQBAL UDDIN KHAN
Group Members
Special Thanks:
Mr Muhammad Kashan
RF Engineer ( Optimization and
Planning) in LCC Pakistan.
MAPINFO
• Introduction
o MapInfo Professional is the power of computer
mapping is at your complete disposal.
o You can display your data as points, as
thematically shaded regions, as pie or bar charts,
as districts, etc.
o You can perform geographic operations such as
redistricting, combining and splitting objects, and
buffering. You can also make queries against your
data and access your remote data directly from
MAPINFO
MapInfo Professional is a desktop software
product produced by Pitney Bowes Software,
formerly MapInfo. It is a Geographic
information system or GIS used for mapping
and location analysis. It allows users to
visualize, analyze, interpret, understand and
output data in ways that reveal relationships,
patterns, and trends.
MAPINFO
Use of MapInfo in Cellular Communication
To create map of each deployed region.
To have a working road map, for easy route selection.
To have elaborated details about each cell.
Which provide platform for optimization and error removal.
What is TEMS Investigation?
• TEMS Investigation – Complete name.
• TEMS stands for - TEst Mobile System.
• Firstly released by Ericsson.
• In June 2009 it came under ASCOM
proprietary.
• The latest release is 13.01.
Why to use TEMS Investigation?
• As it is a AIR INTERFACE TEST TOOL.
• Used for :
Optimization
Verification
Maintenance
Troubleshooting
• To maintain QoS.
Why to use TEMS Investigation?
Cont’dTEMS Investigation is the industry-leading solution
for troubleshooting, verification, optimization,
and maintenance of wireless networks. Designed
for in-vehicle, in-building, and pedestrian-area
testing, TEMS Investigation has powerful,
versatile, features that are essential throughout
the network’s lifecycle. Using TEMS Investigation,
operators can achieve improved voice quality,
increased accessibility, more successful call
attempts, and better service performance.
Before moving Further
Review of GSM and
Optimization
GSM
o Global System for Mobile (GSM) is a second
generation cellular standard developed to
cater voice services and data delivery using
digital modulation.
o GSM network consist of different cells and
each cell transmit signals and receive signals
from the multiple mobile stations.
GSM System Architecture
BSC BSC MSC MS MS BTS BTS BTS GMSC PSTN ISDN PDN EIR VLROptimization
Optimization
o Every alive Network needs to be under continues
control to maintain/improve the performance.
o Optimization is basically the only way to keep
track of the network by looking deep into
statistics and collecting/analyzing drive test data.
o It is keeping an eye on its growth and modifying it
for the future capacity enhancements. It also
helps operation and maintenance for
Optimization Process
Output
Soft Parameter Change -> Hard Parameter Change -> BSC / LAC Redimensioning
Optimization
Issue Identification Investigation Resolution Attempts
*1….n+ Benchmarking *1…n+ Reversion *1…n+
Input
Optimization
(Cont’d)Successful Optimization requires:
• Recognition and understanding of common
reasons for call failure
• Capture of RF and digital parameters of the
call prior to drop
• Analysis of call flow, checking messages on
both forward and reverse links to establish
“what happened”, where, and why.
Optimization
(Cont’d)Purpose and Scope of Optimization
o The optimization is to intend providing the
best network quality using available spectrum
as efficiently as possible.
o The scope will consist all following:
Finding and correcting any existing problems after site implementation and integration.
Optimization
(Cont’d)Meeting the network quality criteria agreed in the contract.
Optimization will be continuous and iterative process of improving overall network quality.
Optimization can not reduce the performance of the rest of the network.
Area of interest is divided in smaller areas called clusters to make optimization and follow up
Terms to Understand
• MS1 – MS3 • CGI • GPRS • Band • BCCH AFRCN • TCH AFRCN • BSIC • Channel Mode • Channel Type • Rx Level • C/I • MS Power Control • TA • RL Time out • C1 , C2Terms to Understand
Cont’d• MS1 – MS3
o Supports Up to three Mobile Stations for Data collection and Route analysis.
o Can be use as :
MS1 – Idle mode MS2 – Short Call MS3 – Long Call
Terms to Understand
Cont’d• CGI
o Cell Global Identity
o Each id is unique global wide.
o It consists of: CGI = MCC + MNC + LAC + CI.
MCC - Mobile Country Code 0 – 999. (410 – Pakistan)
MNC - Mobile Network (operator) Code 0 – 99. (06 Telenor)
LAC - Location Area Code 0 ‐65535. CI - Cell Identity 0 – 65535.
Terms to Understand
Cont’d• GPRS
o General packet radio service.
o Sector GPRS enable or not. (Yes / No).
• Band
o Freq. Band mobile is operating e.g. GSM 900/ 1800.
• AFRCN
o Allocated/Absolute Radio Frequency Channel.
o Usually Each ARFCN has a bandwidth of 270.833 kbps.
Terms to Understand
Cont’d• BCCH
o Broadcast Channel.• TCH
o Traffic Channel.• BSIC
o Base Station Identity Code.
Terms to Understand
Cont’d• BSIC
cont’dNCC = Network Color Code. It is a 3 bit ( 0 – 7 ) code, used
in GSM to uniquely identify a base station within a particular geographic area.
BCC = Base Station Color Code. It is also a 3 bit ( 0 – 7 )
code transmitted in the SB ( Synchronization Burst ) of GSM
system.
• Channel Mode
Terms to Understand
Cont’d• Channel Type
o Current channel type
o E.g. BCCH, SDCCH, CBCH, TCH, FACCH and SACCH.
SDCCH – Stand Alone Dedicated Control channel. CBCH – Cell Broadcast Channel.
FACCH – Fast Associate Control Channel. SACCH – Slow Associate Control Channel.
Terms to Understand
Cont’d• C / I
o Carrier to Interference Ratio
• MS Power Control
o Power Control Level ( 0 – 8 ) according to network
design.
• TA
o Timing Advance.
o Base Stain sends advance burst to MS as to compensate propagation delay .
Terms to Understand
Cont’d• RL – Time Out
o Radio Link, radio link counter expressed in SACCH blocks.
o If it is zero, call is dropped.
• C1 & C2
o Cell path loss parameter and cell selection parameter in idle mode.
Over View of TEMS’s GUI
• Definitions:
1. Time: It is system time of computer.
2. Cell name: It displays the name of the sector which is serving according to the cell file that is loaded in TEMS.
3. CGI : It stands for the Cell
Global Identity which is unique for every sector of the site. It consists of MCC,MNC,LAC,CI. MCC: Mobile Country Code 0 – 999 (e.g. 404), MNC: Mobile Network Code 0 – 99 (e.g. 98) LAC : Location Area Code 0 -65535 (e.g. 5101) CI: Cell
Over View of TEMS’s GUI
Cont’d• Cell GPRS Support: Tells sector is
having GPRS or not. Values are Yes or No.
• Band : It tells in which Freq. Band mobile is operating e.g. GSM 900/ 1800.
• BCCH ARFCN: It tells by which BCCH is the mobile station getting served.
• TCH ARFCN: On which Traffic Freq. call is going on.
• BSIC : Base Station Identity Code.
• Mode: It is shows in which state is mobile operating, Idle, Dedicated & Packet.
• Time slot: On which time slot of current TCH call is going on. Viz. time slot no. of TRX.
Over View of TEMS’s GUI
Cont’d• Channel Type: Type of channel
mobile is getting now. Like BCCH / SDCCH/8 + SACCH/C8 or.
• Channel Mode : Shows mode of coding like Speech Full Rate of Half Rate.
• Speech Codec: It shows FR for Full Rate, HR for Half Rate & EFR for Enhanced Full Rate.
• Ciphering Algorithm : It shows ciphering algorithm used by the system. E.g. Cipher by A5/2.
• Sub Channel Number: It is displayed at a time when mobile is on dedicated mode at time of call setup when it is getting SDCCH at that time it shows
Over View of TEMS’s GUI
Cont’d• Hopping Channel : It shows that current
sector is having hopping feature or not. Values are Yes or No.
• Hopping Frequencies: It displays no. of
freq. on which mobile is allowed to hop. viz. MA List for hopping of that sector.
• Mobile Allocation Index Offset (MAIO):
It is the number which tells from which freq. from given MA list for sector hopping has to be started. E.g. 0 means sector will start from first freq. to hop.
• Hopping Sequence Number (HSN) :
Indicates sequence in which frequencies are allowed to hop from the MA List. 0- 63. 0
Observations during Drive Test
• DT Order and Locating BTS.
Obtain BIC, Azimuth and Tilt of newly installed or complained BTS.
Now using Map-Info software to locate the BTS.
• On Air the Site
( Newly Installed).
Confirm the azimuth and tilt of antenna. As it will confirm the coverage area.
Observations during Drive Test
Cont’d• Starting The Drive Test
INTRA CELL
o During DT, observe the intra cell handover.
o DT should be Clock wise and Counter Clock wise.
INTER CELL
o Performs DT to check handover among cells. o Observe in both Idle and dedicated mode.
o Checking is done of SQI, Rx Level, call establishing , call dropping up to 9 km of each cell.
Observations during Drive Test
Cont’d• Starting The Drive Test
TRX ( Transceiver)
o During DT, observe the intra cell handover.
o DT should be Clock wise and Counter Clock wise.
GPRS
o Either service is enable or disable
Observations during Drive Test
Cont’d• Dropped Calls
There are wide possibilities of call drop, they can be observed by Call drop analysis.
o Elaborate the drop call ratio, use cell with more complains.
o Check the causes and factors of call drop in that cell. o Also check the ratio of fail handovers
Observations during Drive Test
Cont’d• Handover Performance
Hand over is a key function in Cellular communication.
Handover Performance can effect QoS.
