s-72.3270 coverage planning mika

7/30/2019 S-72.3270 Coverage Planning Mika

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Coverage planning exercise

M.Sc. Mika Husso

16.2.2007


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Last time we discussed

Capacity planning

How much traffic offered and how many BSs and

channels/BS do we need to serve it with the given

blocking probability (e.g. 1 %)?

Micro and macro cells

When designed an area with multiple regions (e.g. A,

B, C and D), traffic already served by some region

should not be served again by the next one planned

Traffic given in Erlangs [E]


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Coverage planning problem (FDMA/TDMA)

1. Where to put the cell

border to fulfill the

coverage probability

target with given radio

link parameters?

2. How to choose the radiolink parameters to fulfill

the coverage probability

target for a given cell

size?

1 2 3 4 5 6 7 9 10

1

2

3

4

5

6

7

8

9

10

80

rxP S

rxP S


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Coverage planning

Starting points- QoS requirements

Required SINR (signal-to-interference-and-noise-ratio)

Coverage propability (e.g. 90 %)

- Link budget (Prx = Ptx+ Gi - Li)

Gi = Sum of all gains (antennas, mast-top-amplifier, ) Li= Sum of all losses (radio path, cables, connectors, )

- Pathloss models to determine radio path loss (examples)

Okumura-Hata MACROCELLS

Walfisch-Ikegami MICROCELLS COST231 Lhteenmki INDOOR

- Propagation environment (indoor, city, rural, )


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Coverage planning process

1. Choose a suitable path loss model depending on the

propagation environment (rural, )2. Calculate SFM based on the given values

- cov. prob. target, path.loss.exp. and SF std.

3. Calculate how large the cell radius can be so that user

can have coverage with the given coverage probabilitytarget (e.g. 80 %)- Link bugdet + SFM

4. Choose the smaller of the capacity and coveragebased cell radiuses

5. If radius is coverage limited recalculate the traffic in thecell with the new radius and determine the new numberof BSs on the are and traffic channels per BS


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Calculation of SFMExample

Values that you already have:

Coverage probability target Fu = 0.9

Shadow fade standard deviation SM = 6 dB

Path loss exponent n = 3.2

-> SM / n = 1.875

Now, there are two ways to proceed

1. Reading from a graph

SFM / SM 0.58 (from the graph on the next slide)

-> SMF = SM* a = 0.58 * 6 dB 3.5 dB

2. Calculating using the Q-functionPb 0.72 (from the graph on Slide 10)

Pb = 1 Q(a) is the coverage prob. at the cell border

Q(a) 0.28 -> Q-1(0.28) = 0.583 = a

- >SFM = SM * a = 0.583 * 6 dB = 3.5 dB


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Calculation of SFM

1.0

0.8Fu 0.95

Fu 0.90

Fu 0.85

Fu 0.80

SF

/n1 1.5 2 2.5

0

0.6

0.4

0.2

0.2

0.4

1.2

SFM/SF


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Border coverage prob. from cell cov. prob.

0.4 0.6 0.8 10.6

0.65

0.7

0.75

0.8

0.85

0.9

0.95

1/n = 1.0

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

2.1

2.2

2.3

2.4

2.5 /n

Fu

1 Pob

Relationship between average cell coverage probability andcell border coverage probability

coverage_prob.dsf


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Calculation of the link budget

To make sure that the received power for both

MS and BS does not go below sensitivity (e.g. -

102 dBm) more often than what is defined by

coverage probability target (e.g. 90 %)

Shadow Fade Margin (SFM) is later introducedto take into account random additional

attenuation on the connection caused by fading

Bigger SFM is needed, if

Coverage probability target increases (e.g.Fu = 80 % -> 90 %)

Shadow fade standard deviation increases (e.g. 4 dB -> 6 dB)

Path loss exponent decreases (e.g. n = 4 -> 3)


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Calculation of the link budget

Example (Downlink link budget)

Receiver (MS) sensitivity: -101 dBm

BS transmit power: 30 dBm

MS antenna gain: 0 dB

BS antenna gain: 10 dB

BS cable + connectors losses: 2 dB BS other losses: 2 dB (duplexer etc.)

MS other losses: 1 dB

Radio path loss = 130 dB (depends on the cell radius!)

Prx,MS = 30 + 0 + 10 2 2 1 130= -95 dBm > -101 dBm

We have a 6 dB Fade Margin!


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Coverage planning in the assignment

You already performed preliminary capacityplanning and now you check if coverage can begranted

1. Excel sheet: Link budget + SFM- Defining the maximum cell radius

- If radius is capacity limited, the parameter values (antennaheigth etc.) in the link budget should be minimized

2. Modifiying the preliminary capacity plan forthose regions whose cells have coverage

limited radiuses- naturally this may also affect traffic served by thesecells in other regions


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Assignment: Link budget calculation (Macrocells)

Maximum cell size in Region A

DL frequency fDL 1900 UL frequency fUL 1800

BS tx power level Pbs_tx 44 MS tx power level Pms_tx 30BS feeder loss MS tx feeder loss Lf_ms_rx 0

combiner filter Lcomb 4.0 MS tx antenna gain Gms_tx -3

connectors Lconn 1.5 EIRP 27

jumpers Ljump 2.5 macrocell path loss

cable length l 105 path length R 2.55

cable char. loss 0.0393 BS antenna height hbs 100

total feeder loss Lf 12.127 MS antenna height hms 1.50BS tx antenna gain Gbs_tx 18 MS ant. correction

EIRP 49.87 dense city >400 M -0.03

macrocell path loss city 0.04

path length R 2.55 suburban 11.98

BS antenna height hbs 100 rural 32.02

MS antenna height hms 1.50 actual correction Ahms -0.82MS ant. correction average path loss r400 M -0.03 Slow fade margin as in DL

city 0.05 SFM 6.05

suburban 12.15 FFM 0


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rural 32.33 total path loss 148.85

actual correction Ahms -0.03 BS tx antenna gain Gbs_tx 18

average path loss r


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Assignment: Link budget calculation (Microcells)

DL frequency fDL 1900 UL frequency fUL 1800

BS tx power level Pbs_tx 44 MS tx power level Pms_tx 30

BS feeder loss MS tx feeder loss Lf_ms_rx

0

combiner filter Lcomb 4.0 MS tx antenna gain Gms_tx -3

connectors Lconn 1.5 EIRP 27

jumpers Ljump 2.5 microcell path loss

cable length l 15 path length R 0.559

cable char. loss 0.0393 BS antenna height hbs 10

total feeder loss Lf 8.59 MS antenna height hms 1.60

BS tx antenna gain Gbs_tx 12 roof height hr 20.00

EIRP 47.41 street width w 25.00

microcell path loss building distance b 200.00

path length R 0.559 free space loss 92.55

BS antenna height hbs 10.00 street diffr.loss 26.97

MS antenna height hms 1.60 multi screen diffr 26.45

roof height hr 20.00 average path loss r>0.5 km 145.97

street width w 25.00 SFM as in DL

building distance b 200.00 SFM -0.75

free space loss 93.02 FFM 0street diffr.loss 27.20 total path loss 145.22

multi screen diffr 26.92 BS tx antenna gain Gbs_tx 12

average path loss r>0.5 km 147.15 BS feeder loss

Slow fade margin SFM connectors Lconn 1.5

PLE 4.55 umpers Ljump 2.5


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free space loss 93.02 FFM 0

street diffr.loss 27.20 total path loss 145.22

multi screen diffr 26.92 BS tx antenna gain Gbs_tx 12average path loss r>0.5 km 147.15 BS feeder loss

Slow fade margin SFM connectors Lconn 1.5

PLE 4.55 jumpers Ljump 2.5

S 6.00 cable length l 15

SF/n 1.319 cable char. loss 0.0383

Fu 0.80 total feeder loss Lf 4.57

SFM -0.75 BS diversity gain 5

FFM 0 BS rx level -105.80

total path loss 146.40 mast top amplifier

MS rx antenna gain Gms_rx -3 mta gain 10

MS rx feeder loss 0 mta noise figure 2

MS rx level -101.99 bs rx noise figure 8

MS sensitivity -102 mta effective gain 7.40DL_margin 0.01 BS rx level with mta -98.40

BS sensitivity -104

DL_UL power balance 1.81 UL_margin -1.80

DL_UL pwr bal with mta -5.59 UL_margin with mta 5.60


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Observations from the calculation of maximum cell size due

to coverage requirements

Region A

microcells

Region A

macrocells

Region B

macrocells

Region C

macrocells

Region D

macrocells

Capacity

based cell

radius1.004 km 2.96 km 1.59 km 3.73 km 28.28 km

Coverage

based cellradius

0.559 km 2.55 km 2.56 km 6.16 km 24.33 km

Used cell

radius 0.5 km* 1.59 km** 1.59 km 3.73 km 21.21 km**

* The sites must can be matched to block size and full coverage

** This value is fitted to not give coverage outside Regions A and D

Despite of using maximum equipment parameters, the macro cell size in

Region A and D and microcell size in Region A must be reduced.

This leads to a revision of the ca acit lans for these Re ions


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Modified cell plan to meet cov. requirements

(Region A)

B1 B2 B3 B4 B5 B6 B7

B8 B9 B10 B11 B12 B13 B14

B15 B16 B17 B18 B19 B20 B21

B22 B23 B24 B25 B27 B28B26

B29 B30 B31 B32 B33 B34 B35

B36 B37 B38 B39B40

B41 B42 B43 B44 B45

0.48 km

0.48 km = 5 - 2x2.26 km

0.82 km

0.82 km =7x2.2615 km15x15 km

2

A1 A2

A3 A4


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Modified cell plan

Region A is now covered with four omnidirectional macrocells. Taking the

total offered traffic determined in the capacity planning phase, the offeredtraffic in each cell will be 38.8 4 9.7 Erlang/cellT 16 TRXs in the FDMA-system giving a capacity of 9.83 ErlangThe cell size is the same as in Region B 1.59AR km


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Summary of modified capacity planning results

Region T Ncell NBS R/km NTCH Timpl

Amacro

47.538.8* 1.93 4 1.59

416=64 39.3A

micro

250.0 12.41 60 0.742 403+202=160 337.0B 792.0 39.31 45 1.59 3228+1224+120=1204 857.5C 919.9

903.0* 44.81 55 3.734028+1420+112=1412 997.1

D 153.9

151.4* 7.51 15 21.211220+116+212=280 181.2

Total 1913.3

+250.0

119

+91

2960+640, 740+160 TRX 2412.1

* Traffic originated from overlapping coverage from cells in adjacent

Regions has been subtracted

The lower right corner is uncovered, but can be served from macrocells

Equipment parameters in Region A macrocell base stations (TDMA)


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Summary of coverage planning

Coverage planning results for the TDMA-system

Subregionand type

R/km GBS/dBi feed/" hBS/m PBS/dBm

PMS/dBm

mast-top

amp.

pwrbal.

P/dBA, macro 1.59 18.0 1 1/4 30.0 41.81 29.92 no 0.01B 1.59 18.0 1 1/4 30.0 41.74 29.85 no +0.01

C 3.73 18.0 7/8 30.0 43.42 23.65 yes 0.01D 21.21 18.0 1 5/8 65.0 44.00 24.20 yes 0.01A, micro 0.500 9.0 7/8 10.0 42.12 29.92 no 0.00


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Coverage planning summarized

1. Based on preliminary capacity plan and QoS

requirements

2. Calculation of SFM and link budget based on coverage

probability target and other given parameters

3. Modifiying the values obtained from the capacity

planning process if necessary (coverage based cellradius < capacity based cell radius)

-> More cells (BSs) to cover the area

4. Optimizing the parameter values (antenna height,

antenna gain, feeder type etc.)


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About the assignment

Assignment will be published after the last

exercise Introduction to the assignment

Will be done in 1-2 persons teams

There will be two deadlines, one of which you

have to choose depending on when you wish toget your grade

First DL at the end of the 4. study period

Second DL somewhere in August

Grades will come a few weeks after the DL

s-72.3270 coverage planning mika

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