Dimensioning of WCDMA radio network subsystem for ...• Impact of site solutions SRC and MHA*, and also ROCs are examined • Generally single layer macro cellular network the

1 © NOKIA Config_dim_in_WCDMA_RNS.ppt / 12.2.2002 / Jarno Toivonen

Dimensioning of WCDMA radio network subsystem for determining optimal configurations

Master’s Thesis, Jarno ToivonenNokia Networks

Supervisor: Prof. Sven-Gustav Häggman


Agenda

• Background

• Research problem

• Definitions

• Review of prior research

• Simulations

• Conclusions


Background

• Strategic intent to rationalise and limit the number of configurations to the optimum

• Gained benefits• in supply logistics• shorter lead times in delivery• reduced inventories and obsolescence risk• reduced costs during the network life cycle in O&M, spares, etc.⇒ higher margin for the supplier, lower OPEX for the operator

• However, by limiting the variety of HW elements of different properties, the risk of impoverishing the offerings portfolio increases and the cost-performance ratio of the overall network is compromised resulting in less competitive solutions


Research problem

• Triangular framework where the configurations are interconnected with the achievable network performance and resulting cost

• The challenge is to find limited number of cost efficient configurations that meet the defined performance requirements

Configuration

Network performance:Coverage, capacity & quality

Cost effectsin the rollout


Definitions

• The scope of research includes base station configurations and access network transmission

• The number and configuration of base stations drive both the performance and cost of the overall network

• Configuration refers to an assembly of base station structural elements, antenna system, and transmission equipment

• Costs are considered as configurations’ characteristic impact on the required CAPEX in the rollout


Review of prior research (1/2)• BTS site sectorisation increases offered capacity and coverage

probability, also lower transmit powers are possible. However, for a cluster of cells increasing other to own cell interference i and SHO overhead limit the optimal sectorisation

⇒ Best performing site types in macro cellular environment*:• 3-sector 65° 3dB antenna beam width• 6-sector 33° 3dB antenna beam width

• In addition comparisons include• 2-sector site (in particular for highway coverage)• 4-sector site

• Impact of site solutions SRC** and MHA***, and also ROCs are examined• Generally single layer macro cellular network the most cost efficient

for rollout* Source: Wacker et al.: The Impact of Base Station Sectorisation on WCDMA Radio Network Performance, IEEE VTC 1999** Source: Holma, Tölli: Simulated and Measured Performance of 4-branch Uplink Reception in WCDMA, Paper for IEEE VTC 2001*** Source: Cooreman: Masthead Amplifier (MHA) Benefit, Network Planning Belgium, February 2001, Nokia Networks


Review of prior research (2/2)

• Currently two-thirds of access network transmission implemented with microwave radio*

• Fast and cost-efficient rollout

• Depending on link length and how competitive prices are locally, also copper/leased lines may be the underlying media

• Fibre practically only in core, although the share of fibre expected to grow along with data traffic increase and all-IP

• Tree and chain topologies most common in GSM, loops for high capacity and important links**

• GSM CT TDM-based, whereas ATM specified as WCDMA transport technology

• Operator decision between IMA/fractional E1 and ATM network

* Source: Whitepaper: Microwave Radio Network Planning in 3G, 2001, Nokia Networks** Source: Törmä: Cellular Access Network, Planning Aspects of 3G Networks, Merito Forum Seminar, April 2001


Simulations


Formulation of simulation cases

• The performance of each configuration measured by the required number of sites in the three network scenarios

• Reference for morphology classes and demographics is Helsinki/Espoo

45

53

448

5326

263

53

211

0%10%20%30%40%50%60%70%80%90%

100%

NRT dataRT dataSpeech

Low asymmetry speech oriented trafficwith low penetration

Low asymmetry speech oriented trafficwith high penetration

Medium asymmetry data oriented trafficwith high penetration

Subs./km2

Higher cell loading (network maturity)

Dense urban20%

Urban30%

Suburban10%

Rural35%

Road5%

300km2 service area: 1.1 1.2 2


• MHA has great importance against thermal noise in AWGN channel

• SRC & MHA together ensure high performance for 3-sector site

• Triple-mode GSM/EDGE/WCDMA cost efficient config

• 6-sector not recommended in low loading scenario (uplink load less than 10%)

• Configs UL load limited, thus low TX powers

Traffic scenario 1.1Low asymmetry speech oriented traffic with low penetration

+46%

+125%

0

5

10

15

20

25

30

35

40

45

50

55

60

Req

uire

d nu

mbe

r of

site

s3-

secto

r SRC

ul +

MHA

basic

3-se

ctor +

MHA

GSM

/EDG

E co

-site

5W +

MHA

GSM

/EDG

E co

-site

8W +

MHA

basic

3-se

ctor (

50%

) & 3-

secto

r SRC

ul +

MHA

(50%

)

GSM

/EDG

E co

-site

5W (5

0%) &

1+1 R

OC 20

W (5

0%)

6-se

ctor 2

0W

2*(1

+1) R

OC 20

W

2*(1

+1) R

OC 40

W

3*(1

+1) R

OC 20

W

3*(1

+1) R

OC 40

W

basic

3-se

ctor (

60%

) & 1+

1 ROC

20W

(40%

)3-

secto

r SRC

ul1-

omni

5W

basic

3-se

ctor (

30%

) & 6-

secto

r 20W

(70%

)

basic

3-se

ctor (

30%

) & 3*

(1+1

) ROC

20W

(70%

)

basic

3-se

ctor (

50%

) & ba

sic 3-

secto

r + M

HA (5

0%)

basic

3-se

ctor (

50%

) & 2*

(1+1

) ROC

20W

(50%

)

GSM

/EDG

E co

-site

5W (5

0%) &

3-se

ctor S

RC ul

(50%

)1+

1 ROC

20W

1+1+

1 ROC

20W

1+1+

1 ROC

40W

basic

3-se

ctor 2

0W2+

2+2 R

OC 20

W

basic

3-se

ctor (

50%

) & G

SM/E

DGE

co-si

te 5W

(50%

)

GSM

/EDG

E co

-site

5W

GSM

/EDG

E co

-site

8W

basic

3-se

ctor (

80%

) & om

ni fi

ll-in

site

5W (2

0%)


• 3-sector site with SRC & MHA clearly the best alternative

• Top four configs utilise two or three carriers per sector→ impact of available bandwidth on the operator’s business case

• ROCs run out of capability to meet rising loads, uplink load at around 30-40%

Traffic scenario 1.2Low asymmetry speech oriented traffic with high penetration

+48%

+104%

+519%

0102030405060708090

100110120130140150160170180

Req

uire

d nu

mbe

r of

site

s3-

secto

r SRC

ul +

MHA

basic

3-se

ctor +

MHA

6-se

ctor 2

0W3-

secto

r SRC

ul

basic

3-se

ctor (

50%

) & 3-

secto

r SRC

ul +

MHA

(50%

)

basic

3-se

ctor (

30%

) & 6-

secto

r 20W

(70%

)

basic

3-se

ctor (

60%

) & 1+

1 ROC

20W

(40%

)

basic

3-se

ctor (

50%

) & ba

sic 3-

secto

r + M

HA (5

0%)

GSM

/EDG

E co

-site

5W (5

0%) &

3-se

ctor S

RC ul

(50%

)

GSM

/EDG

E co

-site

8W (5

0%) &

3-se

ctor S

RC ul

(50%

)

basic

3-se

ctor (

30%

) & 3*

(1+1

) ROC

20W

(70%

)

basic

3-se

ctor (

50%

) & 2*

(1+1

) ROC

20W

(50%

)2-

omni

40W

basic

3-se

ctor 2

0W

basic

3-se

ctor (

50%

) & G

SM/E

DGE

co-si

te 5W

(50%

)

GSM

/EDG

E co

-site

5W

GSM

/EDG

E co

-site

8W

basic

3-se

ctor (

80%

) & om

ni fi

ll-in

site

5W (2

0%)

GSM

/EDG

E co

-site

8W +

MHA

2+2+

2 ROC

20W

GSM

/EDG

E co

-site

5W +

MHA

GSM

/EDG

E co

-site

5W (5

0%) &

1+1 R

OC 20

W (5

0%)

3*(1

+1) R

OC 40

W

2*(1

+1) R

OC 40

W

1+1+

1 ROC

40W

1+1 R

OC 20

W

2*(1

+1) R

OC 20

W

1+1+

1 ROC

20W

3*(1

+1) R

OC 20

W


• Configs TX power limited

• Transmit diversity, i.e. SRC dl, would drive the site count even lower

• 6-sector config’s capacity assets fully used and therefore it is a valid alternative

• in targeted urban and suburban areas,• where traffic is expected to concentrate and grow rapidly, or• as a mirco cellular layer for hot spots

Traffic scenario 2Medium asymmetry data oriented traffic with high penetration

+45%

+100%

+824%

0

20

40

60

80

100

120

140

160

180

200

220

240

260

280

300

Req

uire

d nu

mbe

r of

site

s3-

secto

r SRC

ul +

MHA

basic

3-se

ctor +

MHA

basic

3-se

ctor (

50%

) & 3-

secto

r SRC

ul +

MHA

(50%

)3-

secto

r SRC

ul6-

secto

r 20W

basic

3-se

ctor (

60%

) & 1+

1 ROC

20W

(40%

)

basic

3-se

ctor (

30%

) & 6-

secto

r 20W

(70%

)

basic

3-se

ctor (

50%

) & ba

sic 3-

secto

r + M

HA (5

0%)

basic

3-se

ctor (

50%

) & 2*

(1+1

) ROC

20W

(50%

)

GSM

/EDG

E co

-site

5W (5

0%) &

3-se

ctor S

RC ul

(50%

)

GSM

/EDG

E co

-site

8W (5

0%) &

3-se

ctor S

RC ul

(50%

)

basic

3-se

ctor 2

0W

basic

3-se

ctor (

50%

) & G

SM/E

DGE

co-si

te 5W

(50%

)3-

omni

40W

basic

3-se

ctor (

30%

) & 3*

(1+1

) ROC

20W

(70%

)

basic

3-se

ctor (

80%

) & om

ni fi

ll-in

site

5W (2

0%)

GSM

/EDG

E co

-site

8W

GSM

/EDG

E co

-site

5W

GSM

/EDG

E co

-site

8W +

MHA

2+2+

2 ROC

20W

GSM

/EDG

E co

-site

5W +

MHA

GSM

/EDG

E co

-site

5W (5

0%) &

1+1 R

OC 20

W (5

0%)

2*(1

+1) R

OC 40

W

3*(1

+1) R

OC 40

W

1+1+

1 ROC

40W

1+1 R

OC 20

W

2*(1

+1) R

OC 20

W

1+1+

1 ROC

20W

3*(1

+1) R

OC 20

W


• Site count × cost per site

Cost-performance analysis

Traffic scenario 1.1Configuration Number of sites

Overall RAN cost impact

1. 3-sector triple-mode 5W + MHA 32 0.0%

2. 3-sector SRC ul + MHA 24 +10.9%

3. 3-sector 1+1+1 ROC 46 +22.9%

4. Basic 3-sector + MHA 33 +29.3%

5. 3-sector SRC ul 35 +32.4%

6. 3-sector triple-mode 5W 49 +32.6%

7. Basic 3-sector 46 +61.0%

8. 6-sector 34 +140.0%

Traffic scenario 1.2Configuration Number of sites

Overall RAN cost impact

1. 3-sector SRC ul 40 0.0%

2. 3-sector triple-mode 5W 65 +1.4%

3. Basic 3-sector + MHA 40 +2.7%

4. Basic 3-sector 56 +13.0%

5. 3-sector SRC ul + MHA 27 +15.9%

6. 6-sector 40 +62.9%

7. 3-sector 1+1+1 ROC 166 +155.9%


• In the likely rollout scenario 1.1 relatively low capacities per BTS

• Co-siting possible upon an existing topology and TDM-based CT network• 2×2M medium adequate

• Scenario 2 represents transmission capacity peak

• Based on the analysis 58GHz short haul MWR not in demand

Transmission capacity development

0

1

2

3

4

5

6

7

8

9

10

11

12

13

Traffic scenario 1.1 Traffic scenario 1.2 Traffic scenario 2T

rans

mis

sion

cap

acity

/BT

S [M

bps]

0

50

100

150

200

250

Sim

ulta

neou

sly

serv

ed su

bs./B

TS

at b

usy

hour

6-sector3-sector SRC ul + MHA3-sector GSM/EDGE/WCDMA + MHA3-sector 1+1+1 ROC2-sector 1+1 ROC


Conclusions


NetDim results, general

• Selection of service mix has paramount effect on the required number of sites for given capacity, coverage, and QoS targets

• The site count can be minimised with diversity techniques, by adding carriers, and increasing transmit power

• In conservative loading scenario cost for capacity is high in WCDMA compared to GSM→GPRS→EDGE evolution path, because technological discontinuity to 3G demands higher investments regardless of theprojected subscribers

• Optimal sectorisation for macro cellular environment is 3-sector site both from performance point of view and in terms of co-siting


NetAct results, general

• With low additional investment into transmission capacity the capability to serve simultaneous subscribers increases considerably

• As data traffic share breaks to 40%, transmission capacities per base station as high as 12Mbps at busy hour

• Despite of reuse of legacy equipment and existing media, dedicated WCDMA transmission is needed from the beginning

• Higher capacities compared to max. of 1-2Mbps per GSM site• Higher site density• ATM transport


Optimal configurationsLow asymmetry speech

oriented traffic withhigh penetration

Medium asymmetrydata oriented traffic with

high penetration

Low asymmetry speechoriented traffic with

low penetration6-sector @ 20W per carrier,Antenna system: 33°/18dBi

Config: 1+1+1+1+1+1TRS capacity: 7×2M

TRS media: SDH radio, leased lines, fibre

3-sector @ 20W per carrier,Antenna system: 65°/18dBi,SRC ul and MHA

Config: 2+2+2TRS capacity: 5×2M


TRS media: PDH (SDH) radio, leased lines, fibre

2-sector ROC @ 20W per carrier,Antenna system: 120°/18dBi

Config: 1+1TRS capacity: 3×2M


TRS media: PDH radio

3-sector triple-modeGSM/EDGE/WCDMA@ 5W per carrier,Antenna system: 65°/18dBi,MHA

TRS media: PDH radio, leased lines








high penetration

Medium asymmetrydata oriented traffic with

high penetration


low penetration6-sector @ 20W per carrier,Antenna system: 33°/18dBi

Config: 1+1+1+1+1+1TRS capacity: 7×2M

TRS media: SDH radio, leased lines, fibre

3-sector @ 20W per carrier,Antenna system: 65°/18dBi,SRC ul and MHA



TRS media: PDH (SDH) radio, leased lines, fibre




TRS media: PDH radio

3-sector triple-modeGSM/EDGE/WCDMA@ 5W per carrier,Antenna system: 65°/18dBi,MHA









Support slides


Impact of DL code orthogonality

0,0

20,0

40,0

60,0

80,0

100,0

0 10 20 30 40 50 60

UL Load [%]

DL

Load

[%]

DL Load, 40% OrthogonalityDL Load, 50% OrthogonalityDL Load, 60% Orthogonality

145

150

155

160

0 10 20 30 40 50 60

UL Load

Path

loss

NRT Data 144k UL PathlossNRT Data 384k UL PathlossDL Pathloss, 40% OrthogonalityDL Pathloss, 45% OrthogonalityDL Pathloss, 45% OrthogonalityDL Pathloss, 55% OrthogonalityDL Pathloss, 60% Orthogonality

For a given maximum UL load, the greater orthogonality allows for higher DL load, i.e. more capacity

For a given maximum UL load,the greater orthogonality allows for higher tolerable path loss, meaning more coverage


Hardware assembly in 1.1

• GSM/EDGE/WCDMA 5W and 1+1+1 ROC 20W are light configs in terms of WPAs, also small power consumption

• The general rules1 WAM per 1 WTR1 WAM per 3 WSPsare not necessarily true with low loading, so even fewer WAMs may be adequate

Required number of sites increases

3-se

ctor S

RC ul

+ M

HA

basic

3-se

ctor +

MHA

GSM

/EDG

E co

-site

5W +

MHA

GSM

/EDG

E co

-site

8W +

MHA

6-se

ctor 2

0W2*

(1+1

) ROC

20W

2*(1

+1) R

OC 40

W

3*(1

+1) R

OC 20

W

3*(1

+1) R

OC 40

W3-

secto

r SRC

ul1-

omni

5W1+

1 ROC

20W

1+1+

1 ROC

20W

1+1+

1 ROC

40W

basic

3-se

ctor 2

0W2+

2+2 R

OC 20

W

GSM

/EDG

E co

-site

5W

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+ M

HA

basic

3-se

ctor +

MHA

GSM

/EDG

E co

-site

5W +

MHA

GSM

/EDG

E co

-site

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MHA

6-se

ctor 2

0W2*

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20W

2*(1

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OC 20

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Hardware assembly in 1.2

• Growing demand for capacity shows as increase in the number of WTRs, and thus also in CEs


3-se

ctor S

RC ul

+ M

HA

basic

3-se

ctor +

MHA

6-se

ctor 2

0W3-

secto

r SRC

ul

basic

3-se

ctor 2

0W2-

omni

40W

GSM

/EDG

E co

-site

5W

GSM

/EDG

E co

-site

8W2+

2+2 R

OC 20

W

GSM

/EDG

E co

-site

5W +

MHA

2*(1

+1) R

OC 40

W1+

1+1 R

OC 40

W3*

(1+1

) ROC

40W

1+1 R

OC 20

W

2*(1

+1) R

OC 20

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1+1 R

OC 20

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(1+1

) ROC

20W

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basic

3-se

ctor 2

0W2-

omni

40W

GSM

/EDG

E co

-site

5W

GSM

/EDG

E co

-site

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2+2 R

OC 20

W

GSM

/EDG

E co

-site

5W +

MHA

2*(1

+1) R

OC 40

W1+

1+1 R

OC 40

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(1+1

) ROC

40W

1+1 R

OC 20

W

2*(1

+1) R

OC 20

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Hardware assembly in 2

• Although the difference in HW setup per BTS is in favour of e.g. ROCs, the difference in required number of sites is equally remarkable

• Figure shows the required changes in site configurations once asymmetric data oriented traffic with high penetration becomes reality


3-se

ctor S

RC ul

+ M

HA

basic

3-se

ctor +

MHA

6-se

ctor 2

0W3-

secto

r SRC

ul

basic

3-se

ctor 2

0W3-

omni

40W

GSM

/EDG

E co

-site

8W

GSM

/EDG

E co

-site

5W2+

2+2 R

OC 20

W

GSM

/EDG

E co

-site

5W +

MHA

1+1+

1 ROC

40W

3*(1

+1) R

OC 40

W1+

1 ROC

20W

2*(1

+1) R

OC 20

W2*

(1+1

) ROC

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1 ROC

20W

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OC 20

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ctor +

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ul

basic

3-se

ctor 2

0W3-

omni

40W

GSM

/EDG

E co

-site

8W

GSM

/EDG

E co

-site

5W2+

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OC 20

W

GSM

/EDG

E co

-site

5W +

MHA

1+1+

1 ROC

40W

3*(1

+1) R

OC 40

W1+

1 ROC

20W

2*(1

+1) R

OC 20

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(1+1

) ROC

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OC 20

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Dimensioning of WCDMA radio network subsystem for ...• Impact of site solutions SRC** and MHA***, and also ROCs are examined • Generally single layer macro cellular network the

Documents

Dimensioning of WCDMA radio network subsystem for ...• Impact of site solutions SRC and MHA*, and also ROCs are examined • Generally single layer macro cellular network the