Planning for Radio Coverage & Capacity 2.0

7/28/2019 Planning for Radio Coverage & Capacity 2.0

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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confidential

Security Level:2013/4/19

Planning for RadioCoverage

&Capacity


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Content

Coverage planning

Three terms

Tool and case

Capacity planning

Three terms

Method and case

Relationship


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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential Page 3

EIRP

BTS Set-top power

Balance of Uplink and Downlink

UL DL


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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

Propagation Model

Propagation model of free space (Lp=32.4+20logf+20logd)

Okumura-Hata model (Applying to forecast of 900M macro cell)

COST231-Hata model (Applying to forecast of 1800M macro cell)

COST231 Walfish Ikegami model

(Applying to forecast of 900M and 1800M micro cells)

Keenan-Motley model

(Indoor propagation model, applying to 900M and 1800M cells)

Common propagation model

Path Loss = f (frequency, distance)


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Communication Probability

Concept of communication probability

Success call rate of MS on the radio coverage border or in the cell

Category of communication probability

Edge coverage probability

Area coverage probability

margin

ProbabilityDistribution


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Tool


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Case

To construct a 900MHz Network in the suburb that requires about

100 square kilometer coverage acreage, -94dBm minimum

receiving level, and 91% edge coverage probability, forecast the

coverage distance and calculate the required quantity of BTSs.

Useful input information

Band: 900MHz

Network environment: suburb

Coverage acreage: 100km2

Efficient receiving level: -94dBm

Edge coverage probability: 91


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Traffic -Traffic Load

)(3600

TimeHoldingCallAvg.BHCABH@LoadTrafficAvg. Erlang

BHCA: Busy Hour Call Attempt

Definition:

Call exchange volume of a subscriber in a particular time

Unit:

Erlang

If traffic in 15 min is 0.2 Erl, then traffic in one hour is also about 0.2 Erl

when distribution of traffic is even

If traffic in 15 min is 0.2 Erl, then traffic in one hour is 0.240.8Erl


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GoS - Grade of Service

It is the probability of a call in a circuit group being blocked or

delayed for more than a specified interval.

Erlang-B equation of GoS

GOS=2% Urban GOS=5% Suburb

N

0K

K

N

K!A

N!A

ServiceofGrade

A = Expected traffic intensity in Erlangs N = Number of circuits in group


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Erlang-B

GOSElang

TRXNumber

1. The relation between

number of TCH and

expected traffic is not linear

2. Because the channel is

shared

3. This share condition

happed in cell.

So the number of channel is in

one cell and correspond to the

traffic load of per cell.


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Capacity Planning

Coverage

estimationNumber of site

Traffic model

Subscribers

Distribution

Traffic Load ofsystem

Channel

Configuration

Traffic Load

per site

Traffic Load

per cell

Erlang-BTRX

Configuration


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Case

A local network will be constructed. After two years, the number

of subscribers may attain 100,000. Provide that the traffic per

subscriber is 0.02Erl, 120 BTSs are required, and the call loss

rate is 2%.

Useful information

Subscriber quantity: 100,000

Call loss rate: 2%

Traffic model: 0.015Erl

Number of BTSs: 120


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Case Roaming factor (traffic and developing trend): 10%; dynamic factor

(burst traffic): 15%

Network capacity: 100,000(1+10%+15%)=125,000 In terms of congestion, use 85% to calculate the bearer capability for

traffic. Thus, the design capacity of network is: 125,000/(85%)=147100,

that is 150,000 approximately.

According to the provided traffic model, that is average 0.015Erl traffic,forecast the busy-hour traffic of the whole network: 150000

0.015=2250Erl. The average traffic per BTS is: 2250/120=18.75Erl, average traffic per cell:

18.75/3=6.25Erl.

Based on 2% call loss rate, query the Erlang-B to find the number ofvoice channels: 12channels/every cell

The number of control channels: 14 channels/every cell, 2TRX/every cell


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Relation

Pay attention to both coverage and capacity:

Coverage

Dimensioning

Coverage

area per Site

Traffic model

Subscribers

Distribution

Traffic Load

pre Site

TRX/Channel/

Configuration

Limitation

Judgment

Figure out the

max. configuration

Frequency

Planning

ChannelConfiguration

END

Traffic Load

per Site

Coverage

area per Site

Coverage

limitation

BTS Quantity

Capacity

limitation


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Thank youwww.huawei.com


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Method to enhance coverage

Increase the transmission power of BTS

Reduce the loss of combiner

Reduce the loss of feeder

Increase the gain of antenna

Add TMA

Improve Rx. sensitivity


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No balance

Allowed loss is greateron

downlink than on uplink Cannot access

Allowed loss is greater on

uplink than on downlink.

No signal to

MS

when uplink and downlink are not on balance,

Coverage areais equivalent tothe worse one.

Coverage of downlink

Coverage of uplink


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Channel Configuration 8 channels (i.e. time slots) per TRX

BCCH Configuration Only 1 BCCH per cell; TS0 of TRX0

TCH Configuration

No.SDCCH-No.BCCH8TCHofNo. n

SDCCH configuration suggestion

TRX No.Without CBCH With CBCH

Normal cell Inner cell Edge cell Normal cell Inner cell Edge cell

1 SDCCH/4 SDCCH/8

2 SDCCH/8 SD/8 + SD/4

3 SDCCH/8 + SDCCH/4

4 2*SDCCH/8 SD/8 + SD/4 2*SDCCH/8

5 2*SDCCH/8 2*SDCCH/8 + SDCCH/4

6 2*SDCCH/8 + SDCCH/4 2*SDCCH/8 2*SDCCH/8 + SDCCH/4

7 2*SDCCH/8 + SDCCH/4 3*SDCCH/8 2*SDCCH/8 + SDCCH/4 3*SDCCH/8

8 3*SDCCH/8 3*SDCCH/8 + SDCCH/4

Simply calculating:1 SDCCH/8 per 2 TRXs

Documents

Planning for Radio Coverage & Capacity 2.0