Ericsson- Multi Band Cell

MBC-Single BCCHg

Trần Việt Dũng-P.KTKTg

- May 2011 -

ContentsContents

IntroductionIntroduction

PreparationsPreparationsPreparationsPreparations

Trial projectTrial project

DiscussionDiscussion

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Some solutions for reducing TCH congestion

What is traditional dual site?

What is MBC-Single BCCH?g

Why MBC-Single BCCH?

Summary of Adv./Disadv. of MBC.

3

Introduction

• Hard solutions: More HW

TCH congestion: Some solutions

– Add TRXs.– Add BTSs.

• Soft solutions: No more HW.RNO– RNO.

• Coverage.• Channel.• Service.

– Activate features supported by BSS.• Dynamic Half Rate Allocation.• Dynamic FR/HR Mode Adaptation .• Assignment to Another CellAssignment to Another Cell.• Cell Load Sharing.• Multi-Band Cell (Single-BCCH).

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Introduction

Introduction ofMBC – Multi Band Cell

5

Introduction

Tranditional Dualband Site: Dual BCCH.

Multi-band Operation (D-BCCH) allows configuring two different frequencybands in the same or different site location using dual BCCH. It allowsreselection, assignment and handovers between different bands.

Cell DCS 1800 carries BCCH, SDCCH, PDCH & TCH

Cell GSM 900 carries BCCH, SDCCH, PDCH & TCH.

6

Introduction

What is Single-BCCH?

Single-BCCH: Common BCCH Cell, also called GSM900&DCS1800, g , ,Multi-band cell;

Two layers in a cell: UL (900M) and OL (1800M);

The UL covers the whole cell area, The OL may not match the UL coverage area;

UL manages BCCH, SDCCH,PDCH and TCH channels, while OL only g , , , ymanages the TCH channels.

OL(DCS 1800) contains only TCH, For Traffic Load

UL(GSM 900) carries BCCH, SDCCH, PDCH & TCH, For Coverage7

Introduction

Multi Band Cell Configurations

Conf. Subcell 1 Subcell 2

1 GSM800 GSM900

2 GSM800 GSM18002 GSM800 GSM1800

3 GSM800 GSM1900

4 GSM900 GSM1800

5 GSM900 GSM19005 GSM900 GSM1900

6 GSM800 AND GSM900 GSM800


8 GSM800 AND GSM900 GSM800 AND GSM9008 GSM800 AND GSM900 GSM800 AND GSM900



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Introduction

Why Single-BCCH?

1. Improve radio performance: There are several restrictions on the usage of

features Dynamic BTS Power Control, Discontinuous Transmission and

Frequency Hopping on the BCCH frequency. By omitting the BCCH from one

of the frequency bands in a multi band cell, these restrictions are removed forq y ,

that band.

.

9

Introduction

Why Single-BCCH (cont.)?

2. Improve capability: UL and OL share the BCCH, SDCCH, PDCH, and

the TCH channels will be increased accordingly.

OL(DCS 1800) contains only TCH, For Traffic Load

UL(GSM 900) carries BCCH, SDCCH, PDCH & TCH, For Coverage

10

Introduction

Traditional Dual-Band Cell

Example of theoretical capacity gain…

900TCHs

SDCCHRequired

Erlang B (2% GOS)

1800TCHs

SDCCH Required

Erlang B (2% GOS)

900 + 1800 Erlang B (2% GOS)

6 1 2.3 29 2 21.0 23.314 1 8.2 29 2 21.0 29.221 2 14.0 29 2 21.0 35.029 2 21.0 29 2 21.0 42.0

900 TCHs 1800 TCHs Multi-Band TCH T t l

SDCCHR i d Erlang B (2% GOS)

Multi Band Cell

TCH Total Required g ( )

4 32 36 3 27.312 32 44 3 34.719 32 51 4 41.227 32 59 4 48.7

11

Introduction

Why Single-BCCH (cont.)?

3. Simplify network structure:

Reduce number of cells in the network BSC capacity

Reduce number of Location Area Codes

Reduce number of neighboring cells

Simplify multi-layer network into one layer network.

12

Introduction

Multiband Cell -Multiband Operation –A-BA-CA-DA E

A-BA-CB-AB C

Common BCCH cellsDual BCCH cells

A A

A-EA-FB-CB-DB E

B-CC-AC-B

F

DB-EB-F......C D

EC B C B

C-DC-EC-FD-ED FD-FE-F

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Summary ofSummary ofAdv./Disadv. of Dual-BCCH and Single-BCCH

14

Introduction

Adv./Disadv. of Dual-BCCH

Adv :Adv.:• Dual Band mobiles can camp on either band.• 1800 MHz can provide additional capacity in high density areas.• 1800 MHz single band mobiles can still be served on the 1800MHz layer.• The network optimization becomes easier.

Disadv.:• Extra cells have to be defined. A dual band sector needs definition of 2 cells: one Extra cells have to be defined. A dual band sector needs definition of 2 cells: one cell for each band.• Significant increase in neighbor relations since handovers will be permitted between cells with the same band and between the different bands. This could b bl if th BSC i hb l ti li it i h d d ld ff tbecome a problem if the BSC neighbor relations limit is reached and could affect the accuracy of measurement reports sent by the MS.• Spectrum to be allocated for BCCH in the two bands. Can be a problem in spectrum-limited markets.p

15

Introduction

Ad /Di d f S BCCHAdv./Disadv. of S-BCCH

Adv.:• Improve capacity.• Improve radio performance by DTX, BTSPC and FH,• The number of defined cells and neighbor relations in a BSC isreduced. Reduction in the number of neighbor relations contributes tothe accuracy or measurement reports sent by the MSthe accuracy or measurement reports sent by the MS.• Signaling load on the system eased: No reselection of 900M/1800Mcells, less inter-cell HO.• Easy O&M.

Disadv.:• Non-BCCH band single-band mobiles will have no coverage.• The network optimization becomes more difficult.e et o opt at o beco es o e d cu t

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ContentsContents



Trial ProjectTrial Project


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Preparations

Transceiver Group Synchronization

Dynamic Overlaid/Underlaid Subcells

Multiband Cell DT

Planning Considerations

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PreparationsPreparations

Transceiver Group Synchronization

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Transceiver Group SynchronizationIn order to be able to configure a Multi Band Cell,transceivers for different bands have to be synchronized bytransceivers for different bands have to be synchronized, byeither being located in the same RBS cabinet and/or byusing the feature Transceiver Group Synchronizations if thetransceivers are located in different RBS cabinets.

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ESB cable between two RBS 2216 (length 1.6m) – Product Number RPM 119 0158/01600

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TT ESB Cable Type Description Product Number

1 DB9 ‐ RJ45 RBS2206 ‐ RBS2216 RPM 119 0476/15000

2 DB9 ‐ DB9 RBS2206 ‐ RBS2206 RPM 513 1104/15000

3 DB9 TerminatorTerminator at ESB port of RBS2206 RPT 403 805/01

4 RJ45 TerminatorTerminator at ESB port of RBS2216 RNV 899 066/14 RJ45 Terminator RBS2216 RNV 899 066/1

5 ESB cable 2206ESB Cable connect from DXU to ESB port RPM 513 904/1+

For more details, refer this documentTG

synchronization-User Guide

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Dynamic Overlaid/Underlaid SubcellsDynamic Overlaid/Underlaid Subcells

DCS1800Overlay

GSM900 Underlay

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Dynamic Overlaid/Underlaid SubcellsIn multi band networks it can often be assumed that onefrequency band has generally "better" coverage than the other.When combining two such frequency bands into one cell it isnaturally suitable to re-use the subcell structure concept fromthe feature Dynamic Overlaid/Underlaid Subcells. The featureDynamic Overlaid/Underlaid Subcells is a prerequisite for theM lti B d C ll Th f b d ith "b tt "Multi Band Cell. The frequency band with "better" coveragecan be configured in the UL subcell and the other frequencyband with "worse" coverage in the OL subcell. The parameterBAND defines the frequency band used within a channelBAND defines the frequency band used within a channelgroup in a subcell. The parameter CSYSTYPE has a differentmeaning in multi band cells, as it defines the BCCH frequencyband used in the cellband used in the cell.

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Dynamic Overlaid/Underlaid Subcells (cont.)The pathloss, TA and DTCB (Distance-To-Cell-Border)criteria are re-used to define the coverage limit of thecriteria are re-used to define the coverage limit of thefrequency band used in the OL subcell in order to securecontinuous service within the cell

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Dynamic Overlaid/Underlaid Subcells (cont.)The traffic load distribution between the two differentfrequency bands is handled by the Subcell LoadDistribution function, allowing the frequency band in thepreferred subcell (UL or OL as selected by the parameterSCLDSC) t b fill d fi t d ft t i t fSCLDSC) to be filled first, and after a certain amount oftraffic has been reached, the frequency band in the othersubcell.

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Dynamic Overlaid/Underlaid Subcells (cont.)It is also possible to configure the BCCH in the OverlaidSubcell which may be the frequency band with the "worse"Subcell which may be the frequency band with the worsecoverage, but this is not advisable as this frequency bandmay experience greater attenuation leading to MS’s notbeing able to re-select the network (especially insidebe g ab e to e se ect t e et o (espec a y s debuildings, or in basements, etc.)

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Multiband Cell DT Multiband Cell DT.doc

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Planning Considerations

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• SynchronizationIf 900 and 1800 cabinets are combined, their synchronization

t b k t E f S hmust be kept: Error of Synch…

• SDCCH Capacity LimitationsDue to the fact that SDCCHs should not be configured in theGSM-1800 Overlaid Subcells, it is possible that the defaultlimitation of 1 SDCCH/8 per TRX in each channel group willprove to be a problem. Activate feature IncreaseSDCCH/8.

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• Selection of the BCCH frequency bandAssuming that all MSs are multi band other issuesAssuming that all MSs are multi band, other issuesshould be considered: Coverage and frequencyplanning.

• The preferred subcell: UL or OL

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• Azimuth of the antenna.To ensure the success rate of service accessTo ensure the success rate of service access,the coverage direction of 900M and 1800Mshould be identical whenever possible. Theswapped antenna is big problem.pp g p

• Backup Power.

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ContentsContents

Basic PrinciplesBasic Principles




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Preparationscompleted P.KT: PA trien khai va CDD

Dai VT: HW, cable, bus

BTS configuration

, ,

Dai VT: HW đấu nối

Data configurationTrial Project

Dai VT: HW đấu nốiĐài ĐHKT: Khai báo CDD

ParameterTuning

DT andTraffic analysis

P.KT: DT, Tối ưu tham sốReport

Trial completedand Report

ContentsContents

Basic PrinciplesBasic Principles


Trial and ImplementationTrial and Implementation


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Ericsson- Multi Band Cell

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