3 carrier + femto layer management strategies - 03182010

8/11/2019 3 Carrier + Femto Layer Management Strategies - 03182010

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2009 AT&T Intellectual Property. All rights reserved. AT&T, the AT&Tlogo and all other marks contained herein are trademarks of AT&TIntellectual Property and/or AT&T affiliated companies. All othermarks contained herein are the property of their respective owners.

3rdCarrier + Femto Layer Management

Strategies for Ericsson UMTS

Emerging Technologies, NP&E

Performance, NP&E

A&PEricsson

Mar. 18, 2010


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AT&T Proprietary (Restricted)

Only for use by authorized individuals or any above-designated team(s) within the AT&T companies and not for general distribution.2

Table of Contents

Problem Statement

The Multi-Carrier Guiding Principles

The 3rdCarrier Layer Management Options

Recommendations

HSPA+ Readiness and the 4thCarrier

Backup Slides: Detailed Assessment of the LM Options


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Problem Statement

Challenge:

UE shall be able to complete both:1. In the connected mode (cell_DCH), directly fallback to the UMTS coverage layer (SHO)

from the capacity layer (non SHO) to maintain the connection

2. In the non DCH mode, move directly to Femto from macro once in the Femto footprint

Problem:

3gpp specification states that 2 non-used frequencies shall be measured by

the UEs. When macro network consists of 1x850 + 2x1900, particularly in

the 1 SHO + 2 HHO scenario, meeting both challenges stated above incur

compromises in the macro/Femto performance or capacity efficiency.

Desired solution:

Provide best method to meet the challenge as much as possible with

minimal negative impact to the overall macro and Femto network traffic


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The Multi-Carrier LM Principles

To keep UMTS devices on 3G network and moving to GSM network

when there is no other alternative

To provide the best possible 3G service to the customers with the

installed capacity.

UE devices are able to re-select from UMTS Macro to Femto cell in the

Femto footprint


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3rdcarrier Layer Management Option Summary3rd Carrier + Femto LayerManagement Options

3G Devices

on 3Gnetwork UMTS Macro Performance UMTS Macro Capacity Efficiency Femto User Experience

HW

deploymentconstrains

Are 3G

devices on3G?

Impact on Call ACCand RET

Interference Throughput

Resource

Balancing

BetweenLayers

Capacity EfficiencyFemto access within its

footprint and Femtoperformance

OBIF

and/or 2Cabinets

1. Round Robin & Femto co-

channel with GSM

- all Ucell neighbors to Femto cells

YesRisk in call drops

During transitionF3->F1 through F2

No impact expectedNo degradation

expectedOptimal Optimal Yes

The 1900 60W

RRUW with

OBIF can

reduce the riskof call drops

2a. Remove F3->Femto & Femto

co-channel with GSM-- Fallback F3 ->F1

Yes No No impact expectedNo degradationexpected

Optimal OptimalUEs on F3 wont reselectto Femto

Norestrictions

2b. Remove F3->Femto, restrict

UEs camping on F1 and F2 only

& Femto co-channel with GSM- Fallback F3 ->F1

-Push UEs from F3 to F2 in idle mode

using Qoffset

- F3 takes the traffic from F1 via IFLS

YesCS & PS call setup

delay (IFLS fromF1 to F3)

No impact expectedThroughput

degradation onF1

F2 and F3 is

expected to be

much lessloaded than F1

Overall efficiency

degradation .Yes

OBIF only

before Inter-

RBS IFLS isavailable

3a. Remove F3->Femto,

FemtoBandOverlap & closed

access to Femto- Femto band overlaps with F3 , offset

by100-2000khz- Fall fack F3 -> F1

Yes

Impact on non-White

List users on F3 in

vicinity of femto

Possible increase

for Cell_DCH trafficon F3 in vicinity ofFemto cells

Possible

degradation fordata traffic on F3

in vicinity ofFemto cells

Optimal

Efficiency degradation

on F3. High IFHO onF3. It gets severe with

dense Femtodeployment

Throughput degradation

due to interference, butalternative data access is

likely available at Femtolocations

Norestrictions

3b. Remove F3->Femto,

FemtoBandOverlap & open

access to Femto-- Fallback F3->F1

- Femto band overlaps with F3 band,offset by100-2000khz

Yes

Potential drops for

calls originated on

macro F3 & then

moving close tofemto

Possible increase

for Cell_DCH traffic

on F3 in vicinity ofFemto cells

SlightDegradation

Optimal


on F3 can be offset by

the capacity providedby Femto

Possible degradation for

resource sharing. but

alternative data access is


Norestrictions

4a. FEMTO co-channel with

UMTS & "closed" access to

Femto- fallback F3->F1

Yes

Pot. call drops

when close to

Femto for activecalls on F3.

Non-WL users on

F3; Possible

increase for

Cell_DCH traffic on

F3 in vicinity ofFemto cells

Possible

degradation for

data traffic on F3

in vicinity ofFemto cells

Optimal


on F3. It gets severe

with dense Femtodeployment

Throughput degradation

due to interference, but



Norestrictions

4b. FEMTO co-channel with

UMTS & open access to

Femto-- fallback F3->F1

Yes

Potential for drops for

calls originated on

macro F3 & thenmoving close to femto

Possible increase

for Cell_DCH traffic

on F3 in vicinity ofFemto cells

SlightDegradation

Optimal

Efficiency degradation in

voice and data on F3 can

be offset by the capacityprovided by Femto

Possible degradation for

resource sharing. but



Norestrictions

5. F3->GSM & Femto co-channel

with GSM- SHO or HHO_IR for F3 cells

More UEs

going toGSM

Possible on GSMafter IRAT

No impact expectedCustomer

experiencedegradation

Optimal

More signaling between

GSM and UMTS, and

resources consumed for

registration

YesNorestrictions

6. HS Service Separation &

Femto co-channel with GSM-neighbor to Femto from all three

layers

- Fallback F3->F1- F1 R99/HS, F2 R99, F3 HS

Yes

Potential

congestion on F1

and F2 for R99traffic. HS call

setup delay F3through F2

No impact expected

MultiRAB on F2

is limited toCS+PSR99

No, layers will

have different

utilization andbalancing willbe difficult

Degradation due to

concentration of R99traffic on one layerand HS on another

Yes Norestrictions

Closed access is the marketing

requirements based on theircustomer survey


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3rdcarrier Layer Management Option Summary (contd)

3rd Carrier + Femto Layer

Management Options-- GSM

Network consideration3G Devices on

3G network GSM Macro Performance GSM Macro Capacity Efficiency

Femto User

Experience

HW deployment

constrains

Are 3G devices

on 3G?

Impact on Call

ACC and RET Interference Throughput

Resource

Balancing

Between Layers

Capacity

Efficiency

Femto access

within its

footprint and

Femto

performance RBS and T1s

7. F3 on 850

- impact to GSM if 2x850 used

for UMTS in mkt with single

850 MHz

Yes

850 MHz GSM

may no longer

possible

C/N impact will

appear as C/I

impact to user

EDGE

degradation N/A

Offered Erlang

reduction due to

reduced

coverage Yes

Massive EDGE

DS0 migration

from 850 to

1900 cabinets

No or negligible impact

Minor impact on the overall traffic of the cell

considerable impact on the overall traffic of the cell

severe impact, can potentially get the option removed off the candidate list

Legend:


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Option 4a: Femto co-channel with UMTS & closed access Without Femto as the 4thcarrier, the LM strategy is essentially the same as the 2ndcarrier.

The LM has been tested in both Ericsson (SFL) and ALU (Philly) markets with successful results

The main concern of this option is the capacity and performance impact on macro due to the Femto

interference

Preparing the trial in Atlanta to evaluate the impact when the network is loaded up with Femto traffic

The load should be aligned with the Femto forecast. It is logistically challenging, buy any

workaround will be documented if the desired load can not be achieved in the trial.

1.557 million Femto devices by Dec.11. On average, well have 15 devices/cell(=1.577 m/(34,664 sites * 3 sectors/site)

3.221 million by Dec.12, which means 30 devices/cell.

If the impact is concluded to be acceptable, we can immediately roll out option 4a

Dipesh to provide the operational process (summary) to retune Femto

As an interim approach, Were collecting data from San Francisco, one of the co-UMTS markets

2 Femto cells co-channel with F2 UMTS located inside of a large residence

Experiencing drop calls on UMTS when approaching Femto cells

The calls are not dropping when only one Femto is present Further tests conducted 3/16, awaiting for results

Gaps: The incapability of the macro to Femto handover. The function is not on

the technology roadmap for the consumer femto cells. This results in potential call drops at F3 (the co-channeled layer) in the vicinity of a Femto.

In the trial, we will test a workaround solution which forces the call to IFHO from F3 to other layers

by removing the Femto neighbors from SIB 11

Recommended Option

-- Femto Co-Channel with UMTS


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Option 1: Round Robin & Femto co-channel with GSM The concern is the failed IFHOs from F3 to F1 through F2.

The performance impact is related to the % IFHO attempt. Currently based on the stats of CHI, DFW

and LA, we see 513% of the 1900 traffic IFHO to 850.

Most of them take place in the cells with HHO_IF_B designation. The chance is >3 times higher

due to the more aggressive IFHO settings at the carrier border.

Minimize the IFHO attempts from the 2nd1900 carrier by maximizing the SHO cells at F3 Consider the cluster-wise deployment (~10,000 sites projected to be on air by year end in the Ericsson markets)

The 1900 60W RRUW coming with the OBIF solution will improve the F3 coverage For the cells in F3 core, increase minpwrmax to sustain the ongoing call (until it makes to the neighboring cells)

By maximizing the SHO cells, we can also mitigate CM and fully leverage the additional capacity from F3

For the HHO cells, such as those at the F3 border, the relatively aggressive IFHO trigger is expected

to reduce the risk of drop calls.

This option will be tested in Boston (Ericsson) starting the week of 3/22

The ALU 3rdcarrier LM is less challenged as ALU supports separate neighbor lists for

dedicated and idle mode, which is tested and confirmed in the lab. Femto neighbors can be defined only in the idle mode list to ensure the Femto reselection

In the dedicated mode, without the Femto frequency, we can still keep the two way neighbors

between the 3 macro layers.

The strategy will be validated in Philly starting the week of 3/22

Recommended Option

Femto Co-Channel with GSM


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HSPA+ requires Option 6: HS Service Separation To provide 15 codes for the HSPA+ traffic, we need a dedicated HS layer

In Option 6, we use layer 1 for HS/R99, layer 2 for R99 only, and layer 3 HS only.

HSPA+ speed can be achieved if the HS call is at layer 3

The main concern about the Service Separation Option is its capacity efficiency The R99 congestions in F1 and F2 can not be relieved by the additional F3

This strategy is more suitable for the cells where the additional carrier is essentially triggered by data

The option will be tested in Boston (as part of the 3rdcarrier trial) and SFL (along with the

4thcarrier deployment)

4thcarrier LM development Regardless the Femto spectrum strategy, well face the inter-frequency neighbor limitation

with the 4thcarrier.

The LM task force (NP&E, A&P and the vendor) will provide the option assessment and

recommendations by end of March

Feature Development: separate neighbor lists for the dedicated and the idle mode A parity feature for Ericsson

In contact with A&P and Ericsson

HSPA+ Readiness and 4thCarrier


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2009 AT&T Intellectual Property. All rights reserved. AT&T, the AT&Tlogo and all other marks contained herein are trademarks of AT&TIntellectual Property and/or AT&T affiliated companies. All othermarks contained herein are the property of their respective owners.

Backup Slides

Detailed Assessment of the LM Options

O i 1 R d R bi i h All U ll i hb F ll


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Option1: Round Robin with All Ucell neighbors to Femto cells,Femto band does not overlap with UMTS band

Layer F3

LayerF2

Layer F1

Femto Layer F4

IFLS

IFHO

Re-Selection

IFHOoptional depending

on cell designation

IFLS if all carriers in the same cabinet

UE devices can camp on all 3 UMTS Layers. Reselection to

Femto from all UMTS cells. No IFHO from F3->F1

Pros3G UEs stay on 3G network as long as possible

Access to Femto from all UMTS layers

Traffic can be moved efficiently between all layers in idle mode to balance

radio resource utilization

Efficient utilization of spectrum and radio resources

Simplicity of implementation. LM Strategy can be applied consistently to

all network configurations (band, cell designations and hardware)

All layers accessible for Voice and Data services

ConsNo direct relation from F3 to F1 which can impact performance if F3 and

F2 are having the same e2d trigger thresholds (same hho_if_b or c

designation).

More aggressive e2d and cell selection settings required for F3 cells to

avoid risk of drop calls after IFHO and give enough time to IFHO from F2to F1 if needed. Settings will need to be tested for 850/1900/1900

configurations

One way inter-frequency neighbor definitions

IFLS limited to the direction of the neighbor relation definitions.


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Option1: Round Robin with All Ucell neighbors to Femto cells

(contd)

The IFHO stats from three 2ndcarrier markets show that

There overall IFHO attempts from 1900 to 850 is between 513%. Most of them take place in the cells with

HHO_IF_B designation, where the 2d trigger is much more aggressive than in the HHO_IF_C cells.

Inter Frequency Performance on 1900Mhz cells in 850/1900 Mhz markets2 Carrier

BandConfiguratio

n

Cell

Designations on

1900Mhz

IFHO_CS_S

uccfrom

1900Mhz

IFHO_PS_Succfrom 1900Mhz

# of IFHO_CS

per 100 CS_RabEst

from 1900Mhz

# of IFHO_PS

per 100 PS_RabEst from1900Mhz

Chicago 1900/850HHO_IF_B 98.8% 99.5% 28.20 1.42

HHO_IF_C 98.8% 99.3% 7.21 0.25

Dallas 1900/850HHO_IF_B 98.8% 99.2% 23.07 0.97

HHO_IF_C 98.5% 99.1% 3.62 0.09

LA 1900/850HHO_IF_B 99.2% 99.5% 31.71 3.45

HHO_IF_C 98.8% 99.3% 10.68 0.87

Distribution of the cell designations in 850/1900 Mhz marketsChicago Dallas Los Angeles

1900Mhz 850Mhz 1900Mhz 850Mhz 1900Mhz 850Mhz

HHO_IF_C 78.5% 1.6% 25.6% 0.1% 93.5% 0.8%

HHO_IF_B 4.1% 3.1% 11.1% 0.1% 2.9% 0.0%

SHO 6.6% 92.1% 62.0% 87.5% 2.0% 95.3%

HHO_IR 10.8% 3.2% 1.4% 12.4% 1.8% 4.0%


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Option2a: Remove F3->Femto, Femto Co-channel with GSM

Layer F3

LayerF2

Layer F1

Femto Layer F4

IFLS

IFHO

Re-Selection


on cell designation


UE devices can camp on all 3 UMTS Layers. Reselection

to Femto only from F1 and F2. IFHO from F3 and F2 to F1


F2 and F3 can IFHO directly to F1

Traffic can be moved efficiently between layers in idle mode to

balance radio resource utilization between layers


Simplicity of implementation. LM Strategy can be applied consistentlyto all network configurations (band, cell designations and hardware)

No need to change IFHO thresholds for F3 cells. F3 has always

contingency to fall back to F1


ConsUEs can re-select to Femto cells only from F1 and F2. UEs on F3 will

not be able to re-select to Femto even if within the proximity of the

Femto cell

LM strategy can impact Femto customers as they cannot re-select

from F3 cells to Femto cell


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Option2b: UE camping on F1 and F2, Remove F3->Femto, FemtoCo-channel with GSM

Layer F3

LayerF2

Layer F1

Femto Layer F4

IFLS

IFHO

Re-Selection


on cell designation


UE camp on F1 and F2 only and transition to F3 by

triggering Inter Frequency Load Sharing. UEs on F3 re-

selected to F1 or F2 as soon as they get to idle mode

(using qOffset2sn). Reselection to Femto cells only fromF1 or F2

ProsF2 and F3 can IFHO directly to F1

Traffic can be moved between layers in idle mode, but under limited

control.

No impact on Femto customers. They will be able to camp on Femtocell from either F1 or F2. UEs will not camp in idle mode on F3

ConsF1 and F3 must be in the same RBS

Possible large disproportions in TxPwr utilization and traffic between

layersIFLS to F3 only when F1 has over 50% nonHS power utilization

no idle model balancing from F1 to F2.

Risk of congestion on F1 while F3 is lightly loaded.

Risk of prolonged call establishment time

Possible poor spectrum efficiency and radio resource utilization. Max

allowed nonHS pwr usage on F3 is reduced to70%

Increase load on mMp due to additional RRC triggers for IFLS.


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UE devices can camp on all 3 UMTS Layers. Reselection to

Femto only from F1 and F2. IFHO from F3 and F2 to F1

If UEs close to Femto it will be pushed off to upper layers due to

degradation in EcIo. Femto access restricted to White List users



No need to change IFHO thresholds for F3 border cells. F3 has relations

to all upper layers.

Traffic can be moved easily between layers in idle mode to balanceefficiently radio resource utilization between layers

Simplicity of implementation. LM Strategy can be applied consistently to

all HW RBS configurations.

No need to define F3->Femto relations.


Cons

Possible loss in F3 capacity caused by higher power requirements fornon-WL UEs close to Femto cellshigher power usage and CM triggers.

Possible loss of spectral efficiency on F3

Possible performance degradation on F3 cells for non-WL UEs close to

Femto cells, e.g. high BLER, low throughput, hard handover, dropped

calls.

Possible traffic imbalance and resource usage between layers if Femto

cells are densely deployed.

Option3a: Remove F3->Femto, FemtoBandOverlap & close accessto Femto

Layer F3

LayerF2

Layer F1

Femto Layer F3+Offset

IFLS

IFHO

Re-Selection


on cell designation


i b d l


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Option3b: Remove F3->Femto, FemtoBandOverlap & Open accessto Femto

Layer F3

LayerF2

Layer F1

Femto Layer F3+Offset

IFLS

IFHO

Re-Selection


on cell designation


UE devices can camp on all 3 UMTS Layers.

Reselection to Femto only from F1 and F2. IFHO

from F3 and F2 to F1.

UE on f3 and close to Femto will be pushed off to

upper layers due to degradation in EcIo.

Femto access open to all users at all locations.

UE in connected mode can directly handover

from f3 to f2 and f1.

O i 3b R F3 F F B dO l & O


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Pros

3G UEs stay on 3G network as long as possible

No negative impact on macro network capacity, it would actually increase the total networkcapacity.


No need to change IFHO thresholds for F3 border cells. F3 has relations to all upper layers.


Traffic can be moved easily between layers in idle mode to balance efficiently radio resourceutilization between layers


Simplicity of implementation. LM Strategy can be applied consistently to all HW RBSconfigurations

Users will re-select to Femto at any place providing better spectrum efficiency for F3 band.


Cons

Femto users will have to re-select from F3 to F1 or F2 in order to camp on Femto cell.

Since we don't support macro to femto handover (at least one year away), the users withactive calls on f3 would experience high BLER and then, hard handover to f1 or f2.

Option3b: Remove F3->Femto, FemtoBandOverlap & Open accessto Femto

O ti 4 FEMTO h l ith UMTS & l t


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UE devices can camp on all 3 UMTS Layers and re-select from all

UMTS cells to Femto cells .

If UE is in dedicated mode and close to Femto it will be pushed

off to upper layers due to degradation in EcIo.

If UE is in idle mode and Femto restricts that UE from camping,

the UE might be forced to re-select to F1 or F2 due to degradation

in radio quality.

Pros 3G UEs stay on 3G network as long as possible


No need to change IFHO thresholds for F3 border cells

All UEs can re-select to Femto cell from any UMTS cellTraffic can be moved between layers in idle mode to balance

efficiently radio resource utilization between layers

All Inter- relations are mutual

LM Strategy can be applied consistently to all network configurations

(band, cell designations and hardware)


ConsPossible loss in F3 capacity caused by higher power requirements

for non-WL UEs close to Femto cellshigher power usage and CM

triggers.

Possible loss of spectral efficiency on F3

Call drops on F3 cells for non-WL UEs close to Femto cells

Possible traffic imbalance and resource usage between layers if

Femto cells are densely deployed.

Option 4a: FEMTO co-channel with UMTS & close access toFemto

Layer F3

LayerF2

Layer F1

Femto Layer F3

IFLS

IFHO

Re-Selection


on cell designation


O ti 4b FEMTO h l ith UMTS & t


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UE devices can camp on all 3 UMTS Layers

and re-select from all UMTS cells to Femtocells .

If UE is in dedicated mode on f3 and close to

Femto it will be pushed off to upper layers due

to degradation in EcIo.

Femto access open to all users at all locations.

UE in connected mode can directly handover

from f3 to f2 and f1.

Option 4b: FEMTO co-channel with UMTS & open access toFemto

Layer F3

LayerF2

Layer F1

Femto Layer F3

IFLS

IFHO

Re-Selection


on cell designation


O ti 4b FEMTO h l ith UMTS & t


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Pros

3G UEs stay on 3G network as long as possible

No negative impact on macro network capacity, it would actually increase the total network capacity.

F2 and F3 can IFHO directly to F1 No need to change IFHO thresholds for F3 border cells


All UEs can re-select to Femto cell from any UMTS cell

Traffic can be moved between layers in idle mode to balance efficiently radio resource utilization between layers


All Inter- relations are mutual

Users will re-select to Femto at any place providing better spectrum efficiency for F3 band.

Optional to configure six femto neighbors on f3 (the reselection to femto would occur as the UE camping on f3would experience interference from femto, do reselection to f1/f2 and then to femto)

Femto users can directly reselect to femto from any of the three macro carriers so long as the six femto neighborsare configured on f3 (which is optional in this case)

Simplicity of implementation. LM Strategy can be applied consistently to all network configurations (band, celldesignations and hardware)


Cons Since we don't support macro to femto handover, the users with active calls on f3 can experience drop calls if they

are close to Femto cells.

Option 4b: FEMTO co-channel with UMTS & open access toFemto


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Option5: F3->GSM & Femto co-channel with GSM

Layer F3

LayerF2

Layer F1

Femto Layer F4

IFLS

IFHO

Re-Selection


on cell designation


UE devices can camp on all 3 UMTS Layers. Reselection to Femto

from all UMTS cells. No IFHO from F3->F1. IRAT from F3 to GSM in

order to maintain the call when radio performance degrades on F3.

F3 cells are designated either SHO or HHO_IR

ProsAll UEs can re-select to Femto cell from any UMTS cell

Traffic can be moved between layers in idle mode to balance efficiently

radio resource utilization between layers

LM strategy is not limited by RBS HW configuration. LM strategy

targets only 850/1900/1900 carrier band configurations

UEs go to GSM layer to maintain call instead of risking drop calls after

IFHO to F2 in poor radio conditions

Possibility to use this strategy only on cells where calls can drop when

transitioning from F3 to F2 and F2 cannot provide good radio quality to

maintain the call or trigger another successful IFHO from F2 to F1.

ConsLM Strategy not in-line with multicarier LM strategy (keeping UMTS

devices on 3G network). Will cause increase traffic of 3G UEs on 2Gsystem

Possible negative impact on customer perceptionthrottling of data

throughput when changing from 3G to 2G

F3 traffic will go to GSM when fulfilling hho_if thresholds

No transition in dedicated mode from F3 to F2 or F1. F3 cells will have

HHO_IR or SHO cells designation.IRAT

GSM


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Option6: HS Service Separation, UEs camping on F1 and F2

Layer F3

HSDPAPreferred

Layer - F2Voice and R99 Data

Layer F1Voice and HS Data

FEMTO

1900F3

1900F2

850F1

IFLS

IFHO

Re-Selection

IFHOoptional dependingon cell designation


Coverage relation for HSDPA Rabs


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Option 6: HS Service Separation, UEs camping on F1 and F2 (contd)

Pros Cons

Access to FEMTO from all layers.

HS Performance improvement due todedicated HS carriers.

UMTS 1900 layers have a fallback

UMTS 850 coverage layer. Keep UEs on

3G.

Additional HS resources can be provided

for Dedicated HS Carrier by creating

additional HS Resource IDs.

60W RRUWs on 1900 can be used forHSPA layer with OBIF solutionAdditional

power for HS users.

Impact of HS on R99 traffic is minimized.

F3 Layer used exclusively for HS / MultiRAB. May not be utilized if low

HS traffic. We lose the F3 capacity for the R99 traffic.Not able to balanceresource utilization across layers. In-efficient use of spectrum / PA

utilization.

Use of IFLS for load balancing between F1 (850) and F2 (1900) bands

=> Call setup delays. Also IFLS may fail due to coverage differences

between 850/1900.

Complicated Implementation. And the Cell_Fach timer may need to be

increased.

Is not a solution for Non-HS Power depletion. MultiRAB UEs on F2 will not utilize HS if Speech call is originated first

followed by the Packet session.

Potentially increased RRC signaling due to HS Redirection.

Delays in HSDPA RAB establishment due to blind redirection from F2-

F3.

850 UMTS carrier will carry both HS / R99 traffic. Impact on R99

performance due to HS.

Some HS UEs may be stuck on F2 due to failed blind handovers.Need to optimize hspathlossthreshold.

HS UEs on F3 will have to downswitch to DCH to trigger compressed

mode. (HS CPM available in P7).

EUL will be supported only on 3x2 sector carriers.

More RAB establishments in F2 (1900 band) => higher IFHO where

coverage limited.


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Option7: Deploy 850/1900/850 instead of 850/1900/1900

As documented in ND-00321, Spectrum Mangement/Planning-UMTS Carrier Addition

If we assume that 4.2 MHz spacing is sufficient for the two adjacent 850 UMTS carriers,this provides 400 kHz on each of the far ends, and utilizes essentially all of the contiguous

spectrum within the B-band. Therefore, only the expanded spectrum channels of 240

thru 251 are available for GSM (plus a couple of channels from the 400 kHz that could be

used as GSM hoppers).

The primary 12 Frequencies for GSM 850 band

- Very tight (N=4) BCCH planning- challenge on Edge and Voice performance

- insufficient C/I for currently acceptable EDGE throughput performance

- Insufficient capacity for many EDGE sites current demand

- To improve EDGE capacity & perf needs, the EDGE would need to be moved

to 1900 which requires massive T1 reconfiguration

Instead of using 850 for BCCH, it would be probably better to use 1900 for BCCH which

ultimately means to make GSM a 1900-Mhz-only network.


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3 carrier + femto layer management strategies - 03182010

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