GSM network planning
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Transcript of GSM network planning
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RF SurveyP o in t s To be Con s ide red i n Su rvey Most populated areas.
Business Centers.
Developing areas.
W ha t To P l an No. of Sectors required. Type of Antenna & Height.
Capacity Required.
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Planning a Fill In Site.
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After Integration of the Site.
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Frequency Planning.
Frequency Reuse Concept.
Use of same frequency at differentplaces.
Co Channel Interference.
Adjacent Channel Interference.
Use of Map Info.
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Frequency Planning Using
MAP INFO.
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BSIC Planning.
BSIC = NCC + BCC.Base station Identity Code.
NCC.(NETWORK Color Code).
BCC.(Base Station Color Code).Values Range From 0..7.
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Importance of BSIC.
Identify the BTS.
Used to reduce DROP Calls during Co ChannelInterference.
Mobile cant understand co channel & identifyno difference between same frequency signal
coming from two sites & so DROP Call. BSICis the parameter that helps the mobile toidentify the different BTS.
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Drive Test.On Field Optimization
Include four tests
Verification
Drive in dedicated mode
Foot print
Hand over test
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Verification
MOC Test
MTC Test SMS Test
GPRS Test
Drive in dedicated mode
Checking signal strength in the entirecoverage area.
Checking C/I, C/A.
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Foot print
Checking the shooting distance of each
sector. Results of footprints are used in predicting
interference in neighboring cell due toovershoot or similar problems.
Hand over test
Intra cell hand over
Inter cell hand over
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Current Channel
Definitions:
1. Time: It is system time of computer.
2. Cell name: It displays the name ofthe sector which is serving according
to the cellfile that is loaded in TEMS.3. CGI : It stands for the Cell Global
Identity which is unique for everysector of the site. It consists ofMCC,MNC,LAC,CI.
MCC: Mobile Country Code 0 999(e.g. 404 in India), MNC: Mobile
Network Code 0 99 (e.g. 98 forAirtel in Gujarat) LAC : LocationArea Code 0 -65535 (e.g. 5101 inGujarat) CI: Cell Identity 0 65535(e.g. 11001)
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Current Channel
Cell GPRS Support: Tells sector is
having GPRS or not. Values are Yes orNo .
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) : It is
combination of Network Color Code
(NCC) (0 7) & Base Station Color Code
(BCC) (0 7). e.g. 62. It is decoded by
mobile on every Sync. Channel Message.
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.
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Current Channel
Channel Type: Type of channel mobile isgetting now. Like BCCH / SDCCH/8 +SACCH/C8 or CBCH / TCH/F+FACCH/F +SACCH/F.
Channel Mode : Shows mode of codinglike 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 to protectdata for privacy. E.g. Cipher by A5/2.
Sub Channel Number: It is displayed ata time when mobile is on dedicated modeat time of call setup when it is getting
SDCCH at that time it shows whichSDCCH it is getting out of 8 available.E.g. 2.
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Current Channel
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 for Cyclic Hopping, 1 63 randomhopping sequences.
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Radio Parameters
RxLev : Receiving level in terms of dBmthat mobile is receiving from the site.
Range of -30 dBm to -110dBm. RxQual : Quality of voice which is
measured on basis of BER. Range ofRxQual 0 -7.
FER : Frame Erasure Rate it representsthe percentage of frames being droppeddue to high number of non-corrected biterrors in the frame. It is indication of voicequality in network.
BER Actual : Ratio of the number of biterrors to the total number of bitstransmitted in a given time interval. BERis a measure for the voice quality innetwork.. Depending on BER RxQual ismeasured. E,g, BER 0 to 0.2 %corresponds to RxQual 0. Max. BERcountable and useful is up to 12.8 % whichcorresponds to RxQual of max. 7.
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Radio Parameters
SQI : SQI is a more sophisticated measure
which is dedicated to reflecting the qualityof the speech (as opposed to radio
environment conditions). This means that
when optimizing the speech quality in
your network, SQI is the best criterion to
use. SQI is updated at 0.5 s intervals. It is
computed on basis of BER and FER. For
EFR 30, FR 21 & HR 17 arerespectively ideal values.
C/I : The carrier-over-interference ratio is
the ratio between the signal strength of the
current serving cell and the signal strength
of undesired (interfering) signal
components. It should be atleast > 9 . MS Power Control Level : Displays
range of power control from 0 to 8
depending upon network design. E.g. 0
means no power control and 1 means
level that is defined by operator viz. 2
dBm less acc. To airtel.
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Radio Parameters
DTX :Discontinuous transmission (DTX)
is a mechanism allowing the radiotransmitter to be switched off during
speech pauses. This feature reduces the
power consumption of the transmitter,
which is important for MSs, and decreases
the overall interference level on the radio
channels affecting the capacity of the
network..
TA : Value that the base station calculates
from access bursts and sends to the mobile
station (MS) enabling the MS to advance
the timing of its transmissions to the BS so
as to compensate for propagation delay.
Value of 0 means MS in radius of 550mt.From BS.
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Radio Parameters
RL Timeout Counter (Cur) : This
parameter define the maximum value ofthe radio link counter expressed in
SACCH blocks. Range of 4 64 in step
size of 4. it shows current value of RLT.
Decrease by 1 but increase by 2. When it
reaches zero it results in normal DROP
Call.
RL Timeout Counter (MAX) : This
parameter define the maximum value of
the radio link counter expressed in
SACCH blocks. Range of 4 64 in step
size of 4. it shows current value of RLT.
Normally 16, 20, 24.
MS Behavior Modified : This windowshows current settings for the mobile
station, for instance whether handover is
disabled or multiband reporting enabled.
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Serving + Neighbor
Cell Name :Name that describes the neighboring cell as per the cellfile.
ARFCN : Channel number mobile receives as neighbor.
BSIC : BSIC of the neighboring cell.
RxLev : Receiving Level in dBm of neighboring cell.
C1 & C2 : These are the cell path loss criterion and cell reselection criteria. Valid during idle modeof mobile station.
C31 & C32 : GPRS signal strength threshold criterion C31 and GPRS cell ranking criterion C32.Valid both in packet idle and packet dedicated mode.
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Other Useful Parameters.
Adjacent ChannelSignal Strength.
Carrier to InterferenceRatio.
Value of C/I range from -5..25. It should be more than 9.
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C/I Values
C/I Values Shown using line chart.
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Rx. Level, SQI, FER.
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Example
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Drive in Dedicated Mode.
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Foot Print.
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Signal Quality.
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In Building Solution.
NECESSITIES:
Low in building coverage.
More No. of users in a Business
Center having less coverage.
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Planning an IBS.
Check for the Coverage in the building.
Make Floor plan.
Plan different type of antennas according toneed.
Prepare Routing Diagram.
Prepare Link Budget. Accordingly plan Ultra or Metro Site.
After Integration do Walk Test.
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Floor Plan.
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Cable Routing.
This Diagram showsthe length of the cables& Splitter or Couplerthat is used forPreparing Link Budget.
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Link Budget.
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Walk Test.
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THANK YOU
By- Toshniwal Enterprises Controls Pvt.Ltd.