TwinTRX_presentation_NE_Session_Ed03.ppt

Twin TRX Overview & Field Feedback

Maged Sayed, Ramez Soss Network Engineering November 2007, Cairo

All Rights Reserved © Alcatel-Lucent 2007

Agenda

1. Introduction 2. TwinTRX in capacity mode 3. TwinTRX in coverage mode 4. Field test methodology 5. TWIN TRX in the field 6. Conclusion

2 |TwinTRX overview | November 2007


1

Introduction



Introduction TRX evolution

Transceiver Evolution Overview

2000 Edge TRX “TRA”

2004 Edge+ TRX MP & HP

1998 Evolium BTS TRX “TRE”



2006 TWIN 2x TRX

Introduction TRX Evolution

TGTY (Y = 09 for GSM 900 & 18 for GSM 1800) = Twin TRX 5 |TwinTRX overview | November 2007


Introduction TWIN TRX

What is TWIN TRX?  Twin TRX module is a compact TRX module.  Contains the functionality of 2 TRXs.  Has the same size as a single TRX module of the previous generation. Previous generation: 1 module -> 1TRX

New Generation: Twin TRX 1 module -> 2 TRX

TRX T R X TRX



Introduction TwinTRX usage strategies

Two modes for TWIN TRX depending on the usage strategy Reducing the cost of each BTS site  Capacity mode : 2 TRX in one housing TRX1

up to 24 TRX per cabinet typically for urban/suburban

TRX2

Decreasing the number of BTS sites necessary  Coverage mode with Transmit Diversity TRX1

113 to 175W equivalent output power typically for rural areas 7 |TwinTRX overview | November 2007


TRX1

Introduction TwinTRX usage limitations

Is there a limitation on the usage of TWIN TRX with previous HW?

TWIN TRX Configurations • Can be used in any Evolium cabinet (BTS engineering rules have to be respected) • Can be mixed with any TRX generation • Can be used with any antenna network generation • Capacity mode : 2 TRX can belong to different sectors • Frequency band • GSM 900 & 1800 (GSM 850 & 1900 in a second step) Which BSS SW version needed to work with TWIN? Starting from B9 MR4 ed05.



2

Twin TRX in Capacity Mode



Capacity Mode Overview

 1 TWIN module = 2 functional TRX = 16 radio timeslots  The 2 TRX can belong to different sectors TRX1 (Twin TRX sharing).  4 RX diversity not possible (only 2 RX div) TRX2  Up to 24 TRX in MBI5/MBO2 cabinets

Tx : Rx :

GSM 900 : 45 W GMSK / 30 W 8PSK GSM 1800 : 35 W GMSK / 30 W 8PSK Sensitivity : -114.5 to – 117 dBm (*) (2 RX div) (*) environment dependent Reduced power consumption Saving per TRX: -17% in GSM900 -35% in DCS1800



Capacity Mode Normal TRX & TWIN TRX

TX

TX1 Rx1 Rx2

Rx1 Rx2

TX2 Rx3 Rx4

G4 TRX 11 |TwinTRX overview | November 2007

TWIN TRX All Rights Reserved © Alcatel-Lucent 2007

Capacity Mode OMC View

In Capacity mode the TWIN is seen by OMC as 2 TRXs



Capacity Mode Increased capacity per BTS

MBI5 3x4

MBI5 3x8

TRX

twin TRX

TRX

TRX TRX TRX TRX TRX TRX TRX TRX

TRX TRX TRX TRX

A N C

A N C

TRX TRX TRX TRX

A A A N N G Y Y C

S U M

A A A TRX TRX N N G Y Y C TRX TRX

Today: max 12 TRX per BTS New SW feature : more than 12 TRX per BTS (B9 - MR4)  Up to 24 TRX per BTS

S U M

A N C

A A A TRX TRX N N G Y Y C TRX TRX TRX TRX TRX TRX

TRX TRX TRX TRX

TRX TRX TRX TRX




Up to 24 TRXs




Multi-standard Base Station Indoor (G5 –MBI5 Functional Variant) DC in 120A High capacity GSM 24 TRX with Twin Modules

Multi-standard Base Station Outdoor Evolution (G5- MBO2E) High capacity GSM 24 TRX with TWIN Modules



Capacity Mode Increased capacity per BTS (continued)

Impact on A-bis transmission 2 A-bis links can be required for large configurations  Transport of voice + Data on both links



Capacity Mode Increased capacity per BTS (New AGC module)

MBI 5 3x4

MBI 5 3x8

TRX

twin TRX

TRX


TRX TRX TRX TRX

A N C

A N C

TRX TRX TRX TRX

A A A N N G Y Y C

S U M

A N C

A G C


Reduced size : ¼ sub-

rack instead of 1/3 S U M

A N C


Can be used in: Any Evolium cabinet


Any TRX generation

TRX TRX TRX TRX

Mixed with any antenna network generation



Capacity Mode ANC Evolution (AGC)

Features  Reduced module size (1/4th of a subrack instead of 1/3rd)  Powering and supervision of TMAs through the antenna feeders. Product Usage  It is fully compatible with the former ANC; it can be used in any circumstance the former ANC was used, e.g. as replacement or for extensions; ANCs of two generations can be mixed in the same cabinet and even in same sector  Can also be used either with the new Twin TRX module or with any previous TRX generation (e.g. EDGE+ TRX)  Not mandatory for TWIN TRX



Capacity Mode ANC Evolution (AGC) continued

TXin1

Antenna feeder 1

TXin2

For low loss mode unplug jumpers

TXin3

TXin4

Antenna feeder 2



Capacity Mode

T R X

Benefits for small configurations

TRX TRX

TRX

S U M

TRX

TRX TRX

A N C

A N C

MBO1 : 3x2 Each TWIN module is shared over 2 sectors, for Better Reliability 20 |TwinTRX overview | November 2007

3

1

4

TRX

TRX

2

A N C

S U M

TRX TRX

TRX TRX TRX TRX

A N C

A N C

A N C

MBO1 : 3x4 Extend capacity without adding a second cabinet All Rights Reserved © Alcatel-Lucent 2007

TRX

TRX

Capacity Mode Example Configurations

3x2 TRX per sector Low Loss / No TX Div/ 2RX Div

Ant1

Ant2

Ant3

Ant4

AGC1

TGT1

AGC2

TGT2

Sharing of TWIN TRX between sectors 21 |TwinTRX overview | November 2007


Ant5

Ant6

AGC3

TGT3

Capacity Mode Example Configurations 3x4 TRX per sector No TX Div/ 2RX Div

Ant1

Ant3

Ant2

Ant4

AGC1

TGT1

Ant5

AGC2

TGT2

TGT3

AGC3

TGT4

Sharing of TWIN TRX between sectors 22 |TwinTRX overview | November 2007

Ant6


TGT5

TGT6

Capacity Mode

T R X

Increased capacity of installed BTS

TRX

TRX TRX TRX TRX TRX TRX

TRX

TRX

A N C

A N Y

A N C

A N Y

A N C

TRX

TRX TRX TRX

S U M

A N C

S U M

A N Y

A N C

Mixtures of generations of TRX & Antenna Network are supported


TRX

twin TRX

Already installed Evolium BTS can welcome TWIN modules


TRX TRX TRX

Example : MBI5 3 x 4  3 x 6 23 |TwinTRX overview | November 2007

TRX

TRX

TRX TRX

A N C

TRX


Capacity Mode Example Configurations 3x4 TRX per sector extension to 3x6

Ant1

Ant2

Ant1

ANC1

Ant1

ANC1

ANY1


Ant2

Ant2

ANC1

ANY1


ANY1

Capacity Mode UMTS introduction

MBO2 Trans-mission Trans-mission

AC/DC

AC/DC

Trans-mission

Dummy panel T R X 2

T R X 1

A N C

T R X 4

T E U II

T R X 3

A S U M

S U M

A N C

A N C

A G C

A G C

SUMU/ N R TRAB + up to 7 BB U

A G C

III

T R X 4

T R X 3

T R X 2

T R X 1

T R X 4

T R X 3

T R X 2

T E U III

T R X 1

GSM 3x4

GSM 3 x 4

+

3x1/3x4 UMTS w/o Txdiv, 60W 25 |TwinTRX overview | November 2007


A N R U I

A N R U II T E U I

Capacity Mode Common field problems The most common problem when installing TWIN in capacity mode is cross feeder/sector problem. This comes mainly from the policy of sector sharing used with TWIN in ensure better resource reliability Sector1 Ant1

Ant3

Ant2

Ant4

AGC1

TGT1


Sector3

Sector2 Ant5

Ant6

AGC2

TGT2

TGT3

AGC3

TGT4


TGT5

TGT6

Capacity Mode Common field problems The most common problem when installing TWIN in capacity mode is cross feeder/sector problem. This comes mainly from the policy of sector sharing used with TWIN in ensure better resource reliability Sector1 Ant1

Ant3

Ant2

Ant4

AGC1

TGT1


Sector3

Sector2 Ant5

Ant6

AGC2

TGT2

TGT3

AGC3

TGT4


TGT5

TGT6

Capacity Mode Summary

Twin TRX in Capacity Mode •

Twin TRX = 2 TRXs in 1 housing (MP EDGE+ Size (¼ sub-rack)) • Only 2RxDiv is available in this mode like current TRX generation

TX1

Capacity usage: • 900 MHz: 2x45W •1800 MHz: 2x35W

TX2

    Conversion between capacity to coverage mode is done via software


•

Increased capacity per BTS (up to 24 in one cabinet) Small configurations can be extended without adding extra cabinet Ease UMTS introduction Power consumption per TRX reduced by: •-17% for GSM900 vs. current generation •-35% for GSM1800 vs. current generation TWIN TRX should be shared between two sectors for better reliability (check connected feeders)


3

Twin TRX in Coverage Mode


 Transmit diversity  4-way receive diversity & TMA

 Impacts on sites needed  Unbalanced configurations  Recommended configurations


Coverage Mode Principle

     

1 TWIN module = 1 functional TRX = 8 radio TS 2 RX & 4 RX diversity possible TX diversity used ( very high coverage) Gain in sites numbers (less sites needed) This mode is also called TX div mode Up to 12 TRX in MBI5/MBO2 cabinets

Higher Output Power

Higher Sensitivity

Tx :

GSM 900 : 113 to 175 W (*) GMSK GSM 1800 : 88 to 136 W (*) GMSK

Rx :

Equ. sensitivity = -117.4 to - 121 dBm (*) (4RX div)

(*) environment dependent



Coverage Mode Normal TRX & TWIN TRX

TX

TX1

TX

Rx1 Rx2

Rx1 Rx2

TX2

Rx1 Rx2

TX

Rx3 Rx4

G4 TRX


Rx3 Rx4

TWIN TRX

TWIN TRX

Capacity mode

Coverage mode


Coverage Mode Switching between capacity and coverage modes



Coverage Mode OMC View

In Coverage mode the TWIN is seen by OMC as 1 TRX



Coverage Mode Principle of TxDiv / 4RxDiv

Ant1

Ant3

Ant2

AGC1

Ant4

AGC2

Transmission : Same signal is transmitted over 2 antennas with a given time difference

Reception : With 4 Rx diversity, 2 Antenna Networks are required in each sector

TGT

Coverage mode = TxDiv + 4RxDiv Or = TxDiv + (2RxDiv + TMA)



Coverage Mode Diversity principles

Diversity concept  Antenna diversity is defined as the use of multiple antennas with the receive signals weighted and combined to produce an output signal. The reverse is used on transmit

Receive diversity

Diversity key principle  Have the fading at each antenna to be independent of the other antennas to minimize the likelihood of all signals fading identically




Main diversity types Space diversity

Adequate spacing between antennas is required to reach independent fading & uncorrelated signals

Polarization Diversity

Signals with different orthogonal polarizations generally have independent fading

Space + Polarization

Mixtures of space & polarization diversity can be used

 De-correlation increases diversity gain  Diversity gain: How much diversity improves the link budget




Delay spread  Difference in time delays between various paths arriving at a receiver  Increase of delay spread can lead to intersymbol interference at the receiver which can cause bit errors



Coverage Mode Transmit Diversity (TxDiv)

Tx Diversity

Downlink: Tx Div

 Same signal is transmitted over 2 antennas with a given time difference

TX1

TX2

 Gain in downlink:  Dense Urban: 5.9dB,  Sub Urban: 4.6dB,  Rural: 4dB

Antenna Network

 Equivalent to:  900MHz: 113W to 175W  1800MHz: 88W to 136W

Twin TRX



Antenna Network

Coverage Mode Transmit Diversity

Transmit Diversity =  Double the output power by combining two TRXs (“on air combining”)  Take advantage of diversity gain by sending the signal from two antennas Balancing the link budget  Transmit Diversity makes sense with 4-way receive diversity introduction.  Alcatel proposes the 4RxDiv to improve the uplink.  TMA can also be used in some cases

Transmit Diversity is available with Twin TRX only  Twin TRX in coverage mode  up to 12 TRX per cabinet in this mode




Basic Idea:  Transmit twice the same signal from two antennas (on air combining)

 3dB gain Possible Issue:  Coherence between signal can lead to destructive effects

0011000101001

 This effect depends on the environment  a short delay is introduced between two antennas (2 symbols)

0011000101001 short delay




Diversity Gain:  On top of the output power increase

 TxDiv artificially increases the number of multi-paths  The higher the de-correlation between paths, the higher the gain

Example:  2 paths (blue and red)  They show independent amplitude (fast) fading  Probability to fall in a hole is reduced  Fading holes of a channel are often compensated by the other channel

 Additional gain




Summary of the Transmit Diversity effects  3dB increase of the signal strength  Additional up to 2.9dB diversity gain for un-correlated fast fading:  Diversity gains are maximum in dense urban because there are a lot of scatterers  Diversity gains are reduced in rural because we have Line of Sight propagation

 Self-interference due to the artificial increase of the delay spread

Environment

Fading Profile

Power increase

Diversity gain

Total TxDiv gain

Dense Urban

TU3

3dB

2.9dB

5.9dB

Sub-Urban

TU50

3dB

1.6dB

4.6dB

RA100

3dB

1dB

4dB

Rural



Coverage Mode 4-way Receive Diversity

Uplink: 4Rx Div

4 Rx diversity  Received signal from 4 different antennas is combined in the TWIN module

RX1 RX2

RX3 RX4

 Gain in uplink vs. 2RxDiv:  Dense Urban: 4dB,

Antenna Network

 Sub Urban: 3.6dB,  Rural: 2.9dB

2 Antenna Networks are required in each sector ANB or ANC or GANB or GANC



Twin TRX

Antenna Network


4RxDiv = Additional improvement on top of 2RxDiv to improve the uplink sensitivity and reject a strong interferer  Two main effects contribute to global 4Rx gain:  Diversity gain  Power gain

 Third effect is coming from the rejection of strong interferer 4RxDiv is available with the Twin TRX only  Twin TRX in coverage mode  up to 12 TRX per cabinet in this mode




Diversity Gain  The more decorrelated signals, the more diversity gain

 The fading of one signal can be compensated by the other one  Below example shows the impact of diversity gain on overall resulting signal -80 dBm

RxLev_UL difference is calculated at each point on the drive test route RxLev difference

-82 dBm

RxLev UL with 4Rx – RxLev UL with 2Rx

Average difference ~ +1.3* dB

-79 dBm

BTS

-83 dBm

• Difference is environment dependent. • RxLev_UL reported by BTS is the best received signal among the 4 antennas, however, after combining, the equivalent received signal is better that this reported value




Diversity Gain (cont.)

Red signal is better than the blue one Optimum Ratio: coherently combines the two signals used by Evolium BTS

Diversity gain results in SNR gain




Power Gain  Doubling the number of antennas results in more captured power  After phase rotation, signals amplitudes are added  coherent summation

 Optimum Ratio : combining method to take benefit from the diversity gain  Theoretical gain is expected as 3 dB, however, practical gain is slightly less  Power gain is independent of signal correlation

Power gain results in SNR gain




Beam-forming gain  This algorithm adapts the antenna pattern to maximize the C/I in presence of a strong interferer  The algorithm computes complex weight for each antenna to steer a null in the direction of the main interferer

Beam-forming results in SIR gain




Impact on Link Budget: Gain on SNR and so on sensitivity  SNR gain over 2RxDiv is obtained from link level simulations • Dense Urban: 3.7dB • Sub-Urban: 3.4dB • Rural: 2.8dB

Gain on SIR and so on the interference margin  Typical gains on interference margin are computed thanks to Monte Carlo system simulations  Dense Urban: 0.3dB

 Sub-Urban: 0.2dB  Rural: 0.1dB




Summary of 4RxDiv gains

Environment

Recommended diversity scheme

Total Gain with ALU RX diversity

4-

Urban, dense urban

Cross-polarization Diversity

10 dB (4dB Vs. 2Rx)

Residential, suburban

Cross-polarization Diversity

8.6 dB (3.6dB Vs. 2Rx)

Rural

Horizontal diversity

space

6.4 dB (2.9dB Vs. 2Rx)

Note: 6dB / 5dB / 3.5dB taken for 2RxDiv




Two possible configurations:  Space Diversity only  Four vertical-polar antennas  Antenna spacing of at least 10l (recommended 20l in rural)

 Polarization diversity  Two cross-polar antennas  Antenna spacing of 10l (i.e. 3.3m in 900MHz, 1.6m in 1800MHz)

 In rural environments, config 1 (with VPOL antennas) is theoretically more suitable, but not often chosen due to practical constraints



Coverage Mode Example configuration Two ANCs are required per sector

Cross polar antenna2


Space diversity AGC1

AGC2

TGT

LEGEND Tx/Rx Polarization



Rx only Polarization

Coverage Mode Example configuration



AGC1

Space + Polarization diversity

AGC2

More de-correlation More diversity gain TGT

LEGEND Tx/Rx Polarization



Rx only Polarization

Coverage Mode BTS configuration note

 Maximum two TWIN TRXs in coverage mode per sector



 For 3 sector site, 6 AGCs are required per BTS (2 per sector)

 6 AGCs need 12 feeders

AGC1

AGC2

 6 feeders entrances are available only for some cabinets. For example MBO1  Need to add extension BTS to work with 3 sector site with TWIN TRX in TxDiv/ 4 RxDiv (even 1 TWIN per cell)



TGT

TGT

Coverage Mode BTS configuration note

Example from Kenya

Extra feeders used



Coverage Mode Configuration with TMA  Configuration to be used for customers with restrictions on antenna installation  1 cross-polar antenna will be needed per sector

Cross polar antenna

OR

TMA

Two vertical polarized antennas

TMA

 TxDiv in downlink using polarization diversity  Uplink is balanced with TMA instead of 4RxDiv

 DL insertion loss occurs due to TMA (normally around 0.5dB)

1 ANC per sector is needed



AGC1

AGC1

TGT

TGT

Coverage Mode Notes about TMA • Depending on the TMA type, it increases the UL sensitivity by 3-6 dB (TMA contribution) • A DL attenuation of 0.5 dB is expected with TMA (TMA insertion loss) • As long as the TMA gain doesn’t exceed the feeder/connector/jumper losses; there is no negative impact of TMA usage on the BTS performance

DC voltage supply • Normally the TMA is equipped with a Bias tee and a PDU in order to supply it with necessary DC voltage • In case of AGC usage, TMA support function can be enabled which means that AGC supplies DC current to the TMA instead of the Bias Tee (which should be by-passed in this case) • However, TMA support function is strongly not recommended with outdoor BTS, this is because the DC current coming from the cabinet will be clipped by the lightning protector



Coverage Mode TMA settings •If TMA support function is used, some TMA parameters should be set during TMA commissioning; these parameters are copied from the TMA datasheet •If TMA support function is not used, these TMA parameters should be set to zero, in this case the AGC (if used) will act as a normal ANCG



Coverage Mode TMA power gain •TMA contribution is SNR gain, however, UL power gain is typically in the range of 14-15 dB. This power gain cannot be seen as the real SNR gain •The UL power gain results – in some cases - in relatively high path unbalance shown by RMS indicators PathBalance Distribution 70

50000 45000 40000 35000 30000 25000 20000 15000 10000 5000 0

60 50 40 30 20 10 0 [-110,-15[

[-15,-11[

[-11,-7[

[-7,-4[

[-4,0[

[0,4[

[4,7[

[7,11[

[11,15[

% PB distrib Nb PB Samples

[15,110]

Path Balance ( dB )

With TMA usage, path balance becomes more biased to UL direction



Coverage Mode Site Gains

In Rural  900 MHz, S222  Balanced w/ MP, UL limited w/ Twin TRX in TxDiv mode  4RxDiv or TMA RU 900 S222 120 100 80 60 40 20 0

100

100

111

100

94 69

69

A Di v+

TM

TM A Tw in

Tx

HP

TM P M

4R + Di v Tx

Tw in 60 |TwinTRX overview | November 2007

A

xd iv

Di v Tx Tw in

HP

M

P

Twin TxDiv+4RxDiv -26% vs. HP+TMA


Enhanced Flexibility

Unbalanced Config.

Unbalanced configurations MP

TxDiv

Unbalanced Configurations  Possibility to disable automatic power balancing  Declare Concentric cell to ensure correct allocation of resources  Automatic mapping of TRX(s) with highest Tx power to outer zone

Benefits  Increase coverage by introducing/swapping only one TRX  Fill coverage holes  Increase indoor penetration (where typically 70% of calls are generated)  Capture more traffic  more revenues

Inner zone

 Reduce number of sites needed for greenfield areas.

Outer zone



Unbalanced Config.

Enhanced Flexibility Unbalanced configurations

MP

TxDiv

Example of Unbalanced Configuration  2 TRX MP (45W) + 1 Twin TRX TxDiv and 4RxDiv  Sub-urban environment

AGC

AGC

MP

TRX

TxDiv: TRX •129W •-119.6dBm

T R X MP


T R X MP

MP: •45W •-116dBm

4.08 Km 5.16 Km


TxDiv +4RxDiv

Enhanced Flexibility Unbalanced configurations

Example of Unbalanced Configuration • Mixing G4 and TWIN (with Txdiv) along with unbalanced output power activation results in better coverage for outer cell • This can be assessed through the location of intercell HOs

Concentric cell with:

Concentric cell with:

 G4 TRX in inner cell

 G4 TRX in inner cell

 TWIN with Txdiv in outer cell

 TWIN with Txdiv in outer cell

 Feature not activated

 Feature activated



Coverage Mode Recommended configurations

2 points should be kept in mind for decision of used configurations: 1.

The Twin TRX in coverage mode requires double antenna paths compared to a normal TRX

2.

The ANC shall be kept in by-pass mode, because the additional combining loss would cancel the coverage gain brought by the TxDiv

Avoided configurations: • •


2 Twin TRX in coverage mode with only 1 ANC 3 or 4 Twin TRX with one in coverage mode (except if Unbalanced TRX output power is used)


Coverage Mode Recommended configurations: 1 TRX per sector 2 possibilities in UL: Either the 4RxDiv feature OR a TMA



Coverage Mode Recommended configurations: 2 TRX per sector In this case, TMA usage is not efficient as we need 2 ANCs to provide Tx diversity with low loss configuration, so 4Rxdiv is more convenient with 2TRXs

A1

A2

A1

ANC

ANC

G4

G4

TRX

TRX

G4 TRX in low-loss mode


A2

A3

A4

ANC

TWIN

TWIN

TRX

TRX

TwinTRX with TxDiv+4RxDiv


Coverage Mode Recommended configurations: 3 TRX per sector In this case, unbalanced power feature should be activated in order to use TWIN in coverage mode for outer cell (cabled in low loss) while other TRXs are mapped on inner cell as they have less output power

A1

A2

A3

ANC

A4

A1

ANC

G4

G4

G4

TRX

TRX

TRX



A2

A3

ANC

TWIN TRX

A4

ANC

TWIN TRX

1 TwinTRX in coverage mode (TxDiv+4RxDiv) 1 TwinTRX in capacity mode Unbalanced TRX Output Power activated


Coverage Mode Recommended configurations: 4 TRX or more per sector Unbalanced power feature should be activated also for this case in order to use TWIN in coverage mode for outer cell (cabled in low loss) while other TRXs are mapped on inner cell as they encounter more combining losses

A1

A2

A3

ANC

A4

A1

ANC

G4

G4

G4

TRX

TRX

TRX

TRX


A3

ANC

G4


A2

TWIN TRX

A4

ANC

TWIN

TWIN

TRX

TRX

1 TwinTRX in coverage mode (TxDiv+4RxDiv) 2 TwinTRX in capacity mode Unbalanced TRX Output Power activated


Enhanced Flexibility Moving from coverage to capacity mode

ANB

ANB

TWIN

TWIN

4Rx div

4Rx div

TRX1


to/from A-bis

TRX2


2 TRX in one sector with maximum power

Enhanced Flexibility Moving from coverage to capacity mode

ANB

ANB

Without recabling TWIN module can be used in capacity mode

TWIN

TWIN

In one sector : 4Rx div

2Rx div 2Rx div

TRX1 to/from A-bis

TRX2


TRX3


1TRX Max power + 2 TRX Medium Power

4

Field test methodology



Estimation of TxDiv/UL sensitivity gains Abstract

 TwinTRX gains have been computed by the Technical Division, based on simulations and lab measurements

 A strong need appeared to have field measurements of TwinTRX gains in coverage mode, to confirm the simulated gains, and answer questions from customers, network design, marketing…etc



TwinTRX in coverage mode : expected gains TxDiv (equivalent output power) Antenna Network

Higher Output Power

Antenna Network

Twin TRX

Environment

Band

Reference output Power in GMSK (Medium Power TRX)

(Watts / dBm) Dense Urban (TU3) Sub Urban (TU50) Rural (RA100)


Equiv. Tx output power in GMSK with TxDiv (Watts / dBm)

900

45

46.5

175

52.4

1800

35

45.4

136

51.3

900

45

46.5

129

51.1

1800

35

45.4

100

50.0

900

45

46.5

113

50.5

1800

35

45.4

88

49.4


On-air combining gain (dB)

Tx Diversity gain (dB)

3

2.9

3

1.6

3

1

TwinTRX in coverage mode : expected gains 4RxDiv (sensitivity gain) Antenna Network

Higher Sensitivity

Antenna Network

Twin TRX

Environment

No RxDiv

2RxDiv

4RxDiv

Sensitivity

Sensitivity / Gain

Sensitivity / Gain

(dBm)

(dBm / dB)

(dBm / dB)

Dense Urban (TU3)

-111

-117

6

-121

Sub Urban (TU50)

-111

-116

5

-119.6

Rural (RA100)

-111

-114.5

3.5

-117.4



10 (=6+4)

8.6 (=5+3.6)

6.4 (=3.5+2.9)

Estimation of TxDiv/UL sensitivity gains Related Tools View DT results

Mapinfo

QOS follow-up A9156 RNO

DL measurements recording

Drive test car with DT equipments BTS

Agilent (Nitro) TADH_2RxDiv

Example of sensitivity comparison for 2RxDiv and 4RxDiv (on-air lab tests)

RxQual 6

.csv file

.csv file

7 TGT18_4RxDiv TADH_2RxDiv trend

BSC

UL measurements recording

TGT18_4RxDiv trend 5

4

3

2

1

RxLev

DT results (UL & DL) 75 |TwinTRX overview | November 2007

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NE post processing tool All Rights Reserved © Alcatel-Lucent 2007

Tektronix K1205

Estimation of TxDiv/UL sensitivity gains Site configuration & pre-requisites

 Proper TWIN TRX installation at the site has to be ensured including cabling  Site should have right antenna configuration:  Whether two cross polar antennas with proper distance if 4Rx is going to be used  Or one cross polar antenna with TMA

 Right parameters should be ensured from OMC side  Make sure that TWIN TRX in coverage mode  Disable both power control and DTX (UL&DL) in order to avoid signal strength fluctuations and make gain assessment easier  Disable HR to ease the filtering of Abis measurements  No parameter change should occur between reference configuration and TWIN TRX, for example BS_TXPWR_MAX which affects the output power

 Avoid using interfered frequency for tested sites to avoid coverage limitation caused by interference  Choose the right, simpler configurations to be compared  Choice of simple configurations will ease the analysis  Don’t put less TRXs with TWIN than the reference; for example the reference with 3 MP TRXs and with the TWIN there only 2 TRXs



Estimation of TxDiv/UL sensitivity gains Main activities

CS drive test  DT scope is to measure the differences in terms of coverage of downlink received signal level, between TWIN TRX and previous TRX generation

 Tools    

DT MS; for example SAGEM OT290 Measurement Software: preferably Nitro (Agilent) 9.2 Roof-top antenna, to guarantee more accurate measurements GPS

 DT activities  DT On call mode – in order to get the RXLEV and RXQUAL, during the call. It’s important to lock the MS used for measurements on the BCCH, in order to assess the impact on cell coverage. Also the DT should be made till the cell edge to assess real cell coverage  Assessment of the average position of PBGT HO

 Post processing  Mapinfo to view the RxLev distribution on the DT route  NE tool for TxDiv gain estimation (shown in later slides)




Abis traces    

Used to assess the uplink gains brought by 4RX diversity/TMA K12/K15 should be installed with the right configuration and latest B9 stacks K12/K15 has to be started before the beginning of the DT Post processing  Compass tool to get general overview on the performance  NE tool to estimate 4RX/TMA gain

RNO QoS follow-up  Main KPIs should be monitored in addition to RMS indicators  CS indicators example    

CDR CSSR Split of HO causes in UL and DL (PBGT, Level, Quality) HO success rate

 RMS indicators example  RXQUAL/ RXLEV matrix  Average TA per RxLev range  PATH_BALANCE (dB)




PS drive test  GPRS/EDGE tests are done to see the impact of TWIN module on Packet traffic

 Two types of tests: Static tests and Mobility test (mainly to check link adaptation) Test No

Test Description

File size/

Iteration

Packet size 1

FTP Download

3 Mbytes or 500 kbytes

10

2

FTP Upload

1 Mbyte or 300 kbytes

10

3

PING with 0sec delay between the PING

32 bytes

101

4


32 bytes

101

5


1460 bytes

101

6


1460 bytes

101



Estimation of TxDiv/UL sensitivity gains

TX Diversity Gain evaluation Method (Implemented inside NE tool)



Estimation of TxDiv gain Method description

 In DL, the RxLev is directly measured by the Trace mobile (Sagem OT160 with Agilent Nitro)  It is assumed that this RxLev takes into account the global TxDiv gain:  On-air combining of the signal at the output of BTS antenna  Additional diversity gain linked to slight time shifting at Tx

Need to check the gain at each point on drive test route

Blue: RxLevDL for G4 HP Red: RxLevDL for TwinTRX TxDiv

Mapinfo can be used for general performance judgment but not for precise gain calculation 81 |TwinTRX overview | November 2007


Estimation of TxDiv gain Method description

Idea To evaluate the gain, compare average RxLev value taken directly on both routes

Issues Taking direct average will not be so accurate due to:

 Stoppages in regions with bad radio conditions during the DT, may be due to traffic lights will induce a lot of bad samples that will degrade the overall RxLev average on overall the route while it’s not the reality  Measurements taken from drive test to another are not passing exactly (due to also GPS inaccuracy) by the same points which will cause inaccuracy in the results

 Drive test measurements are subjected to changes due for example a truck passing near to the DT car which will cause changes in the measurements in the range of 3 dB



Estimation of TxDiv gain Binning

Solution  Apply binning algorithm to ensure reliable results: RxLevDL is simply binned on a square grid then averaged (in dBm) on the drive test route  The averaged RxLevDL is compared on each drive test route, this is equivalent to comparing point by point but with much higher accuracy

Before

After

Drive test route

Points recorded by GPS

Square grid

Points after applying Binning



Estimation of TxDiv gain NE post-processing tool  NE made a small tool based on MsAccess to perform Grid Binning  In addition to Grid Binning, the tool internally performs some filtering to reject some bad samples recorded during the DT in order to enhance the results reliability

 The tool makes processing for .csv file exported from the Agilent tool  The export plan is available with the tool package

Tip for drive test  Drive test route should be scanned several times to ensure sufficient

number of samples and increase binning accuracy



Estimation of TxDiv gain Example



Average gain is computed by taking the average RxLevDL (after binning and taking only the common points between G4 and Twin traces) over the whole DT route. So there will be 2 RxLevDL averages: one for G4 and the other for Twin



Average gain is then the difference between the RxLevDL_Twin and RxLevDL_G4.



Estimation of TxDiv/UL sensitivity gains

UL sensitivity gain assessment (4RXdiv/TMA) (Implemented inside NE tool)



Estimation of UL sensitivity gain Method principle

4RxDiv gain assessment The global 4RxDiv gain is based on 2 principles (same as for 2RxDiv):  Higher probability to have a good received level with 4 antennas  RxLev gain  Higher probability of successful decoding with 4 signals combined  RxQual gain -80 dBm

Target Evaluate the global sensitivity gain (in dB), taking into account both effects, in other words: what is the lowest RxLev achievable with 4xDiv, compared to 2RxDiv ?

Restriction BTS measurements on Abis for RxLev_UL reflects only the first gain (best of 4 signals). As a consequence, the global gain cannot be directly measured



-82 dBm -79 dBm

BTS

-83 dBm

 RxLev_UL reported by the BTS is -79 dB  Equivalent RxLev_UL after combining can be -76 dB

Estimation of UL sensitivity gain Method principle

TMA sensitivity gain assessment  TMA power gain doesn’t reflect the real SNR gain  By direct comparison of RxLev_UL reported by the BTS with and without TMA, 12-15 dB gain with TMA can be observed  However, real SNR gain (TMA contribution) should be assessed through RxQuality measurements  Same procedure for both 4Rxdiv & TMA gain assessment

Solution:  Plot a graph RxQual=f(RxLev), with the same reference RxLev, independent from the gain due to the 2 additional antennas (or TMA)  Evaluate the sensitivity threshold improvement on this graph

Point GPS2 RxLevUL_Ant1 = -97 RxLevUL_Ant2 = -99 RxLev1 _UL = - 9 7 RxQ ua l1 _UL = 3

Point GPS2 RxLevUL_Ant1 = -97 RxLevUL_Ant2 = -99 RxLevUL_Ant3 = -96 RxLevUL_Ant4 = -100 RxLev2 _UL = - 9 6 RxQ ua l2 _UL = 1 88 |TwinTRX overview | November 2007

7 6 5 4 3 2 1 0

2 RxDiv 4 RxDiv -99 -98 -97 -96 -95 -94 -93 -92 -91 -90

Conclusion : a t RxQ ua l= 1 , sensitivity is improved by 2 dB All Rights Reserved © Alcatel-Lucent 2007

Estimation of UL sensitivity gain Method implementation

NE method (to measure UL sensitivity gain (4RxDiv/TMA vs. 2RxDiv))



At each GPS position (after binning), use RxLev reported in 2RxDiv as “reference RxLev”



For this position, retrieve in the Abis traces RxQual in 2RxDiv and RxQual in 4RxDiv/TMA



Plot “RxQual vs. RxLev” for both configurations (only “reference RxLev” is used)



For a given threshold of RxQual degradation (chosen as RxQual=1), compare the RxLev for both configurations



The delta in RxLev reflects the sensitivity gain of 4RxDiv/TMA compared to 2RxDiv 2 RxDiv

First step, as in DL gain assessment, is to apply square binning for UL measurements

Point GPS1 RxLevUL_Ant1 = -94 RxLevUL_Ant2 = -96 RxLev1_UL = - 94 RxQua l1_UL = 1

Point GPS2 RxLevUL_Ant1 = -97 RxLevUL_Ant2 = -99 RxLev1_UL = - 97 RxQua l1_UL = 3

4 RxDiv



Point GPS1 RxLevUL_Ant1 = -94 RxLevUL_Ant2 = -96 RxLevUL_Ant3 = -93 RxLevUL_Ant4 = -97 RxLev2_UL = - 93 RxQua l2_UL = 0,5

Point GPS2 RxLevUL_Ant1 = -97 RxLevUL_Ant2 = -99 RxLevUL_Ant3 = -96 RxLevUL_Ant4 = -100 RxLev2_UL = - 96 RxQua l2_UL = 1


7 6 5 4 3 2 1 0

2RxDiv 4RxDiv -99 -98 -97 -96 -95 -94 -93 -92 -91 -90

Conclusion : a t RxQua l= 1, sensitivity is improved by 2dB



G4 TWIN G4

G4

TWIN

RxLev1

RxQual1

RxQual2

-103

0.5

0

-107

2

0.5

..


..

..

LEGEND RxLev1: RxLev UL with reference (G4 for example) RxQuaL1: RxQual UL with reference (G4 for example) RxQuaL2: RxQual UL with TWIN


Estimation of UL sensitivity gain Example for 4RxDiv

7 TADH_2RxDiv

Example of sensitivity comparison for 2RxDiv and 4RxDiv (on-air lab tests)

RxQual 6

TGT18_4RxDiv TADH_2RxDiv trend TGT18_4RxDiv trend

5

4

2Rx

3

2

4Rx 3.5dB

1

RxLev



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0


Basic 2 steps applied internally inside the tool for UL gain estimation

K12 trace .rf5

Step1 Correlation between DT GPS positions and K12 Traces

Nitro trace .sd5

Step2

Binning of UL measurements

Step3 Link GPS points from 2 traces together

Time shift

Excel manipulation

UL results 92 |TwinTRX overview | November 2007



Step1: Correlation between DT GPS positions and K12 Traces  Before making the correlation, internally the tool performs first timing synchronization between the Nitro and K12 (clocks are shifted)

 User has to get the time shift (from setup messages) and provide it to the tool Correlation

K12 Trace

Nitro Trace GPS position

Time stamp

RxLev DL

UL measurements linked with GPS positions 93 |TwinTRX overview | November 2007

RxQual DL

GPS position

Time stamp

Time stamp

RxLev UL


RxQual UL

RxLev UL

RxQual UL

Output file


Step2: UL measurements binning  The same processing made for DL Binning is made for UL

Step3: Link GPS position from 2 traces together 4Rx

2Rx

GPS position

Time stamp

RxLev UL1

GPS position

RxQual UL1

RxLev UL1

GPS position

RxQual UL1

Time stamp

RxQual UL2

To excel for producing RxQual/RxLev graph 94 |TwinTRX overview | November 2007


RxLev UL2

RxQual UL2

Estimation of TxDiv/UL sensitivity gains Scope for commercial networks  Deployment of TWIN TRX in coverage mode is normally done massively (not on few number of cells)

 Thus, practical estimation of TxDiv and UL sensitivity gains with precise figures cannot be done for all sites (to minimize needed time & resources)  Accordingly, precise gain estimation with NE methodology can be done for few cells (preferably in different environments)  To assess coverage improvement for all cells having TWIN in coverage mode; normal DTs can be carried out for G4 and TWIN TRX then results can be viewed on Mapinfo to show coverage enhancement with TWIN

 QoS reports as well as RMS indicators are also very useful to assess the impact using TxDiv/4RxDiv or TMA



5

TWIN in the Field



Twin deployment

NPI Slide

9761 TGT delivered* up to July’07 on 11 networks Whose 7921 TGT09 on 10 networks and 1840 TGT18 on 6 networks Twin Introduction (Delivered)

Ju l-0 7

Ap r- 0 7 M ay -0 7 Ju n07

Fe b07 M ar -0 7

12 10 8 6 4 2 0

Ja n07

12000 10000 8000 6000 4000 2000 0

TGT Networks

Customer delivered in TGT09 &TGT18 TMOBILE Germany CELLTEL Sri Lanka CELTEL Kenya CELTEL Niger INTRACOM TELECOMMUNICATIONS Armenia ORASCOM TELECOM Algeria ORASCOM TELECOM Tunisia QATAR PUBLIC TELECOMMUNICATIONS Qatar SPACETEL Yemen VMS Vietnam Mobile Services Co VIETTEL CORPORATION Vietnam

• We can assume that figures for deliveries up to July’07 roughly correspond to number of operational Twin one month after. For information, in August’07 3404 additional Twin have been delivered.

• 1000 TWIN (500 DCS + 500 GSM) delivered to MobiNil (Deployment started) 97 |TwinTRX overview | November 2007


Twin deployment

NPI Slide

Networks & Nb BSCs repartition for Twin & AGC Compatibility

Number of Networks & of BSCs Compatible with Twin TRX (>=B9 MR4) Alcatel-Lucent GSM Networks compatible Twin TRX >=B9 MR4 ( August 2007)

B9>=MR4 26% B9
Alcatel-Lucent GSM BSC's compatible Twin >=B9MR4 TRX (August 2007)

B9>= MR4 38%

B9
B9>=MR4

B9
B9
B9>= MR4

Number of Networks & of BSCs Compatible with AGC (>=B8 MR7 Ed02) Alcatel-Lucent GSM Networks AGC Compatible >=B8 MR7 Ed02 : August 2007

Alcatel-Lucent GSM BSC's AGC Compatible >=B8 MR7 Ed02 : August 2007

< B8 MR7 Ed02 16%

< B8 MR7 Ed02 31%

>= B8 MR7 ed02 69%


< B8 MR7 Ed02

< B8 MR7 Ed02

>= B8 MR7 ed02

>=B8 MR7 ed02 >=B8 MR7 ed02 84%


Field Trials

TWIN TRX Capacity Mode Field Trials Highlights



B9MR4 Pilot in Djezzy (OTA) TWIN Capacity Mode (non regression)

 Reference configuration is two BTS cabinets with 2X4 configuration.  Swapped to one BTS with 4X4 configuration (4 GSM TRXs swapped with 2 TWIN TRXs)

Reference

Configuration

configuration

with TWIN

2 Abis links needed for the combined BTS:

16X2.25 = 36 TS



B9MR4 Pilot in Djezzy (OTA) TWIN Capacity Mode (non regression) Site re-configuration

Non regression of the main KPIs



B9MR4 Pilot in ORANGE France TWIN Capacity Mode (non regression) 20 TWIN modules used (10 TGT09 and TGT18):  4 were used for field tests of TWIN in coverage mode.  16 were used for non-regression tests of TWIN in capacity mode.

G4


TWIN


B9MR4 Pilot in ORANGE France TWIN Capacity Mode (non regression)

RxQual with G4 TRX

RxQual with TWIN TRX

 Drive tests shows non regression with TWIN TRX



ORANGE France TWIN capacity Mode- Consumption test results  Power consumption tests were performed by Alcatel-Lucent in order to assess in a live network the consumption reduction that the TWIN could bring  A site was selected to perform the test Power Supply Power Supply

Current + Voltage Measurement & Measurement & Recorder Recorder



ORANGE France TWIN capacity Mode- Consumption test results

Electrical power consumption reduced by 8%

Need more measurements to qualify exactly the gains



Field Trials

TWIN TRX Coverage Mode Field Trials Highlights



Field Trials Overview  Several field trials have been held for validation of Twin TRX TXDiv/ 4RxDiv features. Operator

Platform

Commercial

Environ.

TWIN Mode

FO

Germany (Stuttgart)

AlcatelLucent

Yes

No

Urban

TxDiv/ 4Rx

FO

France (Velizy)

AlcatelLucent

Yes

No

SubUrban

TxDiv/ 4Rx

France

ORANGE

No

Yes

FO FO


TxDiv/ 2Rx (No TMA)

Kenya

Celtel

Yes

Yes

Rural

TxDiv/ 4Rx TxDiv/ 2Rx +TMA

Algeria

OTA

Yes

Yes

SubUrban

TxDiv/ 4Rx

Niger

Celtel

No

Yes

Rural

TxDiv/ 2Rx +TMA

Sri- Lanka

Celtel

No

Yes

Rural

Mixed Conf


Field trials Validation of the TwinTRX performances in coverage mode

Extensive tests have been done on TxDiv and 4RxDiv,

since end 2006, on two Alcatel-Lucent on-air labs:  Urban environment, in Stuttgart  Suburban environment, in Velizy Objectives of Celtel Kenya & Djezzy Algeria field trials:  Validate the TwinTRX in coverage mode in a Live commercial GSM network  Confirm the theoretical gains for TxDiv and 4RxDiv in rural environment / open area

Dedicated tests campaigns have been run in all environments 108 |TwinTRX overview | November 2007


Field Trials Results summary

Stuttgart

Velizy

Kenya

Gain of TGT18 in TxDiv vs.TRAG(E)

Gain of TGT18 in TxDiv vs.TAGH

Gain of TGT09 in TxDiv vs.TAGH

Theoretical

Theoretical

Theoretical

Measured

5.9 dB

5 dB

2.26 dB

Measured 2.5 dB

Calculation of gain of TGT18 TxDiv Vs. G4 HP  G4 (DCS) HP output power: 47.78 dBm

2.75 dB

Measured 3.2 dB

Algeria

 G4 (DCS) MP output power: 45.44 dBm  Difference: 2.34 dB  Gain (over MP TRX) for sub-Urban environments =

3dB power increase + 1.6 dB diversity gain = 4.6 dB  Gain for HP TRX = (3-2.34)+ 1.6

Theoretical 4 dB

= 2.26 dB 109 |TwinTRX overview | November 2007

Gain of TGT09 in TxDiv vs.TRAG


Measured 4.1 dB

Twin TRX Velizy on-air platform Site & antenna configuration

 Site is over Cantine building  Sub-Urban environment  Frequency band: DCS1800  2XPOL antennas per sector



TwinTRX Velizy on-air platform Site and antenna configuration



Twin TRX Velizy on-air platform BTS Cabinet & Radio Cabling GSM

3G

Multi-standard BTS



Twin TRX Velizy on-air platform Example Drive Test

Red : RxLevDL with TwinTRX in TxDiv Blue : RxLevDL with G4 HP



Twin TRX Velizy on-air platform TxDiv gain results Velizy site : Comparison of RxLev_DL for Twin in capacity and coverage (TxDiv on 2ant.) Samples are averaged over GPS grid 20m large, and ordered by decending RxLev 6

0

Average gain : 3,6 dB 5

-20

4

-40

3

-60

2

-80

Avg_GAIN_2ANT

1

-100

Avg_RxLevDL_CAPA Avg_RxLevDL_COVG_2ANT Linear (Avg_GAIN_2ANT)

0

-120

Average gain is lower than expectations for suburban, but the site coverage is not optimal 114 |TwinTRX overview | November 2007


Twin TRX Velizy on-air platform TxDiv gain results Velizy site: Comparison of RxLev_DL for Twin in capacity and coverage (TxDiv on 1ant.) Samples are averaged over GPS grid 20m large, and ordered by decending RxLev 6

0

Average gain : 3,9 dB 5

-20

4

-40

3

-60

2

-80

Avg_GAIN_1ANT

1

-100

Avg_RxLevDL_CAPA Avg_RxLevDL_COVG_1ANT Linear (Avg_GAIN_1ANT)

0

-120

NB: Practical field measurements show better results with this configuration 115 |TwinTRX overview | November 2007


Twin TRX Velizy on-air platform 4Rxdiv gain results 5,0 4,5

Sensitivity comparison for NoRxDiv, 2RxDiv and 4RxDiv

RxQual

TADH_NoRxDiv TADH_2RxDiv TGT18_4RxDiv Poly. (TADH_NoRxDiv) Poly. (TADH_2RxDiv) Poly. (TGT18_4RxDiv)

4,0 3,5 3,0 2,5 2,0 1,5

7dB

3,5dB

1,0 0,5

4 RxDiv measured gain (vs. 2RxDiv) : 3.5 dB (theoretical=3.6dB in suburban) 116 |TwinTRX overview | November 2007


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-100

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-106

-107

-108

-109

-110

< -110

2 RxDiv measured gain (vs. No RxDiv) : 7 dB (theoretical=5dB in suburban)

-86

RxLev

0,0

Celtel TwinTRX Project Pilot description (1/2)

Two neighbor sites have been selected in rural environment, 50 and 70km south of Nairobi. They have been running commercially B9MR4 and TwinTRX in coverage mode, with two configurations: 1) TxDiv and TMA, on one XPOL antenna TMA

+ -

Only 1 antenna (and ANC) per sector Only efficient if feeder length is high DL insertion loss (~0.5 dB)

Cost effective only with to S111

2) TxDiv / 4RxDiv, on 2 XPOL antennas, ANC

ANC

G4TRX TWIN

Reference config

TxDiv + TMA


vertically spaced (tower constraints)

+ + -

Evolutive configuration (> 1 TRX)

No DL insertion loss Need 2 ANCs (+ antennas) All Rights Reserved © Alcatel-Lucent 2007

ANC

ANC

TWIN

TxDiv + 4RxDiv

Celtel TwinTRX Project Pilot description (2/2)

 Towers height: ~60m  Cell range: ~20 – 25km  Frequency band: GSM900  Environment: very rural / open area  Drive test route: main road (radial) Objective: ensure that TxDiv and 4RxDiv gains can still be observed in line-of-sight conditions (low probability of multi-path, interferences, etc.) Test conditions were “worst case scenario” for TxDiv/4RxDiv gains 118 |TwinTRX overview | November 2007


Celtel TwinTRX Project Txdiv gains: Kajiado with TWIN_4Rx (Polarization diversity) TxDiv/4RxDiv on 2XPOL antennas

 Average Txdiv gain for this configuration is 5.5 dB (exceeded expectations Vs. MP ).  The gain is maximum for bad RxLev values

TRAG TWIN

Ht: 57,5m

2,5m

TMA

3m

Ht: 52m

2,5m

NoTxDiv

TxDiv ANC

ANC

TwinTRX Commercial BTS



Celtel TwinTRX Project Txdiv gains: Kajiado with TWIN_4Rx (Polarization diversity)



Celtel TwinTRX Project Txdiv gains: Isinya with TWIN_2Rx_TMA (Polarization diversity)  Average Txdiv gain for this configuration is 3.9 dB. This gain is higher than with

TxDiv/2RxDiv+TMA on 1XPOL antenna

4Rxdiv, despite the TMA insertion loss, as for this configuration both Tx signals are sent to the upper antenna Gain plot Gain

RxLev > -70 Poly. (Gain)

3m

---> 4.09 dB Gain

TMA

-80 < RxLev <-70 ---> 3.76 dB Gain 2,5m

14

Ht: 57,5m

2,5m

-80 < RxLev <-90 ---> 3.98 dB Gain

Average Gain = 3.9 dB

Ht: 52m

-90 < RxLev <-100 ---> 3.81 dB Gain 12 -100 < RxLev <-110 ---> 3.69 dB Gain 10

Gain (dB)

8

6

4

2

18987

18280

18186

18009

17915

17810

17721

17661

ANC TwinTRX

-4 Distance from site


17611

17481

17301

17133

16976

16699

16250

15824

15297

14755

14178

13640

13082

12544

12005

11486

10948

9956

9431

8898

8385

7859

7326

6738

6187

10461

-2

5682

5182

4587

4043

3455

2893

2327

1791

792

1267

0


Comm. BTS

Celtel TwinTRX Project Txdiv gains: Isinya with TWIN_4Rx (Space & Polarization diversity) TxDiv/4RxDiv on 2XPOL antennas

 Average Txdiv gain for this configuration is 3dB  Among 4Rx different configurations, this configuration is the least recommended

Ht: 57,5m

2,5m

by Alcatel-Lucent, especially in rural environments. Txdiv gain

Gain for RxLev > -70dBm : 4 dB

TMA

3m

Gain

Gain for -70 < RxLev < -80 : 3.6 dB

Poly. (Gain)

Average Gain = 3dB

20

Ht: 52m

2,5m

Gain for -80 < RxLev < -90 : 2.9 dB Gain for -90 < RxLev < -100: 1.74 dB

15

Gain for RxLev < -100dBm : 1.57 dB

5

-5

18230

18010

17858

17740

17657

17565

17381

ANC

ANC

TwinTRX

-10 Distance from site


17199

17011

16693

16219

15780

15209

14609

13994

13431

12873

12297

11714

11239

10758

10291

9810

9266

8753

8226

7738

7105

6339

5662

5055

4486

3961

3398

2849

2308

1773

792

0 1250

Gain(dB)

10


Commercial BTS

Celtel TwinTRX Project Improvement of Radio Measurement Statistics (RMS) with TxDiv (DL)  RMS results show good improvements in the % of samples in ranges of good RxLev_DL with TWIN TRX: More % of samples lie in good RxLev_DL ranges

 An improvement is also noted in RxQual_DL distribution with TWIN TRX

DL_RxLev Distribution Average_TAGH

Average TWIN

21

% samples

16

11

6

1

<-52;-47>

<-59;-53>

<-65;-60>

<-71;-66>

<-78;-72>

<-84;-79>

<-90;-85>

-4

RxLev range



<-96;-91>

<-103;-97>

<-110;-104>

Celtel TwinTRX Project Improvement of Radio Measurement Statistics (RMS) with TxDiv (DL) RMS : Average TA per DL_RxLev range

Far

25

No TxDiv

20

Coverage increase !

TxDiv TA Average TA Average

15

10

Close

5

Ref.

TxDiv

0 <-47;-52>

<-53;-59>

<-60;-65>

<-66;-71>

Good Signal

<-72;-78>

<-79;-84>

<-85;-90>

<-91;-96>

DL_RxLev range DL_RxLev range

<-97;-103> <-104;-110>

Bad Signal Reminder : 1 unit of TA equals ~550m

Difference in TA is maximum for bad levels (<-103 dB) which means coverage enhancement on cell borders 124 |TwinTRX overview | November 2007


Celtel TwinTRX Project 4RxDiv sensitivity gain results (SNR) on drive tests

7

2RxDiv

RxQual

4RxDiv

6

2RxDiv trend

Sensitivity gain with 4RxDiv

5

4RxDiv trend

(Kenya, rural site Isinya)

4

3

2

~ 3 dB gain

3 dB

1

RxLev -85

-86

-87

-88

-89

-90

-91

-92

-93

-94

-95

-96

-97

-98

-99

-100

-101

-102

-103

-104

-105

-106

-107

-108

-109

-110

0


Recom.

config

config

NB : 4RxDiv gain not optimal at cell border, due to 2nd antenna position (too low, due to tower constraints)

NB: 4RxDiv results measured on a different site than TMA due to planning constraints 125 |TwinTRX overview | November 2007

Actual

Celtel TwinTRX Project TMA sensitivity gain results (SNR) on drive tests

7

RxQual

2RxDiv 2RxDiv+TMA

6

TMA

2RxDiv trend

Sensitivity gain with TMA

5

2RxDiv+TMA trend

(Kenya, rural site Kajiado)

4

3

Ref.

2

~ 3 to 3.5dB gain

3.5 dB

1

RxLev



-86

-88

-90

-92

-94

-96

-98

-100

-102

-104

-106

-108

-110

0

TMA

NB : TMA gain is directly linked to feeder length (~70m on this site)

Celtel TwinTRX Project 4RxDiv sensitivity gain results (SNR) with RMS  UL sensitivity gain is justified by less average UL_RxQual per UL_RxLev range

Average UL_RxQual per UL_RxLev range Average_TAGH

Average TWIN

2.3

Average UL_RxQual

1.8

1.3

0.8

0.3

<-65;-60>

<-71;-66>

<-78;-72>

<-84;-79>

<-90;-85>

<-96;-91>

-0.2 UL_RxLev range



<-103;-97>

<-110;-104>

Celtel TwinTRX Project TMA sensitivity gain results (SNR) with RMS  Average RxQual_UL with TMA = 0.246, while with 2Rx RxQual_UL = 0.34  Remarkable improvement in UL average TA per UL_RxQual, a sign of better UL sensitivity

Average TA per DL_RxQual Average TAGH

Average TWIN

20.00 18.00 16.00

Average TA

14.00 12.00 10.00 8.00 6.00 4.00 2.00 0.00 0

1

2

3

4 DL_RxQual



5

6

7

OTA Djezzy Twin TRX project Pilot description

One site was selected mainly in rural environment. The tests were done during B9MR4 pilot and TwinTRX in coverage mode, with one configuration: NoTxDiv/2RxDiv (reference)

TxDiv/4RxDiv on 2XPOL antennas

Ht: 37,5m

2,5m

2,5m

3m

3m

Ht: 32m

2,5m

ANC

2,5m

ANC

ANC TRAG

TRAG

Comm. BTS

Reference config 129 |TwinTRX overview | November 2007

Ht: 37,5m

TwinTRX

Ht: 32m

ANC

TwinTRX Comm. BTS

TxDiv + 4RxDiv All Rights Reserved © Alcatel-Lucent 2007

OTA Djezzy Twin TRX project TxDiv gain results (1/2)

DL_G4.RxLev

-40

1

5

9

13

17

21

25

29

DL_TWIN.RxLev 33

37

41

45

49

53

57

61

65

Linear (DL_TWIN.RxLev) 69

73

77

81

85

89

93

97

101

105

109

113

Linear (DL_G4.RxLev) 117

121

125

129

133

137

141

145

149

153

157

-50 -60 -70 -80 -90 -100 -110

Gain

Linear (Gain)

20 15

Legend RxLev TRAG RxLev TWIN

10 5 0

1

5

9

13 17

21 25 29 33 37

41 45 49 53 57

61 65 69 73 77

81 85 89 93 97 101 105 109 113 117 121 125 129 133 137 141 145 149 153 157

-5 -10

Average gain of 4.1 dB is demonstrated which is inline with simulation results for rural areas



OTA Djezzy Twin TRX project TxDiv gain results (2/2)

Far

RMS : Average TA per DL_RxLev range

Coverage increase !

15 12

TA Avg (G4/ MP)

Average TA

TA Avg (TWIN/ TxDiv)

9 6

Close

3 0 ]-53,-47]

]-60,-53]

Good Signal

]-66,-60]

]-72,-66]

]-79,-72]

]-85,-79]

]-91,-85]

DL_RxLev range

Reminder : 1 unit of TA equals ~550m 131 |TwinTRX overview | November 2007


]-97,-91]

]-104,-97]

[-110,-104]

Bad Signal

OTA Djezzy Twin TRX project 4RxDiv sensitivity gain results (SNR) from RMS

Far

RMS : Average TA per UL_RxQual

12 TA Avg (G4/ 2RxDiv) TA Avg (TWIN/ 4RxDiv)

10

Average TA

Sensitivity increase !

8 6

Close

4 2 0 0

Good Signal


1

2

3

4

5

UL_RxQual


6

7

Bad Signal

OTA Djezzy Twin TRX project Coverage increase effect on traffic TWIN TRX installation

RTCH traffic

Migration to B9MR4Ed5Qd1

07

RTCH avail avg

/0 4

/2 0

07

Erlang total

06

/0 3

/2 0

07 06

/0 2

/2 0

07 06

/0 1

/2 0

07 06

/3 1

/2 0

07 05

/3 0

/2 0

07 05

05

/2 9

/2 0

07 /2 0

05

/2 8

/2 0 /2 7 05

05

/2 6

/2 0

07

13.2 13 12.8 12.6 12.4 12.2 12 11.8 11.6 11.4

07

350 300 250 200 150 100 50 0

RTCH traffic is increased by 45% (from 202.9 Erlang to 294.4 Erlang)

Incoming HOs increased significantly (congestion increased also) Cell range increase leads to more traffic captured by the cell. 133 |TwinTRX overview | November 2007


PS tests in coverage mode Impacts on Uplink GPRS/EDGE Throughputs  Dedicated PS tests are foreseen on Velizy on-air platform with B10  Lab simulations show that better SINR leads to higher throughputs in uplink

EDGE Throughputs

Example: in Dense Urban 50% of the users get at least 10 Kbps more

No Diversity 2RxDiv 4RxDiv



PS tests in coverage mode Impacts on Uplink GPRS/EDGE Throughputs

Impacts of self-interference  8PSK and so MCS5-9 are very sensitive to self-interference  Link level simulations show performance degradation for high MCS  Degradations are hardly compensated by the increase of power  System simulations confirm that the throughput degradation is very small, even in the worst case

Worst case (TU50): -0.5kbps/PDCH with TxDiv

No Diversity Tx Diversity



6

Conclusion



Conclusion

 TWIN TRX allows flexibility in operation between capacity and coverage mode  TWIN TRX in capacity allows to reach high configurations (up to 24 TRXs per cabinet)

 In addition to TWIN TRX in capacity mode gains in terms of space, it has also benefits in terms of power consumption reduction  Twin TRX in coverage mode will allow operators to reach more customers with less sites.  TWIN TRX field trials in coverage mode is proven to bring increase in cell coverage range inline with simulation  Non regression of TWIN TRX in capacity mode is validated (mainly Cs).



Feedback & Resources  Your feedback about TWIN TRX in coverage mode is needed. If you are working on a project and you are going to deploy TWIN TRX in coverage mode, please contact network engineering team. Your contacts inside NE team: Maged Sayed ([email protected]) Ramez Soss ([email protected])  Several documents about TWIN TRX in coverage mode are available on NE intranet page:

http://aro.tm.alcatel.ro/



www.alcatel-lucent.com



TwinTRX_presentation_NE_Session_Ed03.ppt

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