Nokia Ultrasite Mha System

1 © NOKIA 1999 FILENAMs.PPT/ DATE / NN

Nokia UltraSite MastHead Amplifier SYSTEMs

Jouni Pelkonen

PE Project ManagerDelivery OperationsNokia Networks


CONTENT

•Backround for MHA

•UltraSite BTS sensitivity and Rx level reporting

•MHA main parts and features

•MHA power feed and gain control

•Installation and installation verification

•MHA Reliability


Backround for MHA


Benefits of Nokia MHA• Increase coverage (50…100%)• Balance Rx-Tx link in case of uplink limitation• Improve system sensitivity• Decrease mobile transmitted power• MHA and Bias Tee interfaces smoothly with Nokia BTS's

=> no extra PDU's or complicated cable sets needed=> type approved with Nokia BTS, to meet GSM specs (in

terms of blocking, intermodulation and sensitivity)

BTS RX w/o MHA BTS RX with MHA

BTS TX


What is noise? (2)What is noise? (2)

• Dependent on the receivers bandwidth, a certain level of noise can be captured. This noise is subsequently referred to as the thermal "noise floor" of the receiver

• As an example, what is the thermal noise floor expressed in dBm in a GSM system at a temperature of +17 deg. Celcius, and a receiver demodulator bandwidth of 271 kHz ?

Solution:

271000]290101.3810log[1000N 23GSM ××××= −

NGSM = -119.6 dBm

Note: Thermal Noise Floor is the noisefloor without TX or RX non-idealities


Facts/Formula Overview (1)

• System Sensistivity - The minimum usable signal level at the input of the system. This level must exceed the noise floor by the required carrier to noise ratio (C/N)

• Noise Figure for Amplifiers - Amplifiers generate additional noise relatively to the noise floor. The noise at the output of an amplifier with a noise factor F and a gain G is defined by

dBdBdBmdBmsystem NCFBkTP system ))/(()()()( min1 ++=

)()( 1BFGkTN linearamp =

)1000log(10)( 1BFGkTN dBmamp ×=


Facts/Formula Overview (2)

• System Noise Factor - When cascading matchedmatched amplifiers/attenuators a resulting system noise factor will be generated according to Friis formula. It can be seen that the most dominant factors in the formula is the noise factor and gain of the first amplifier/attenuator in the cascade --> F1 and G1:

21

3

1

21

11GG

FGFFFsystem

−+

−+=

Note 1. In Friis formula Noise factors and Gainsare linear values and not dB values

Noise factor = linearNoise figure = dB

Note 2. Conversion from dB values to linears are done according to:x (dB) = 10x/10 (linear)


Implementation Overview 1

HypotheticalGeneral Case

Noise FactorF1

Noise FactorF2

System Input

Gain = G1

1st

Amplifier Stage

Gain = G2

2nd

amplifier stage

Resulting Noise Factor - Fsystem

Noise FactorFn

Gain = Gn

nth

subsequent amplifier stage

The system noise factor for this implementation can be derived using Friis formula:Here we note that the stage 3 quotient F3-1/G1G2=0

211

21)(

11GG

FGFFF n

linearsystem−

+−

+=1

21)(

1GFFF linearsystem

−+=-->


Implementation Overview 2Feeder Base Station

Without MHA Noise Factor - F1 Noise FactorF2

Receiving Antenna

Feeder Loss = LGain G1= 1/L

Gain = G2


The system noise factor for this implementation can be derived using Friis formula:Here we note that the stage 3 quotient F3-1/G1G2=0 and that the feeder loss iseqvivalent to the feeder noise factor, hence L=F1-->G1=1/F1

21

3

1

21)(

11GG

FGFFF linearsystem

−+

−+=

1

21)(

/11F

FFF linearsystem−

+=-->

1121)( FFFFF linearsystem −×+= -->12)( FFF linearsystem ×=

)log(10)log(10 12)( FFF dBsystem +=


Implementation Overview 3

With MHA Noise Factor - F1 Noise FactorF3

Receiving Antenna

Gain= G1 Gain = G3


MHA Feeder + Base Station

Noise Factor - F2

Feeder Loss = LGain G2= 1/L

The system noise factor for this implementation can be derived using Friis formula:We include the stage 3 quotient F3-1/G1G2 and note this time that L=F2 and henceG2=1/F2

21

3

1

21)(

11GG

FGFFF linearsystem

−+

−+=

2/1

3

1

21)(

111FG

FGFFF linearsystem

×

−+

−+=-->

]1[12232

1

1)( FFFFG

FF linearsystem −×+−+= ]1[123

1

1)( −×+= FFG

FF linearsystem-->

]1log[1011

231)(

GGFFFF dBsystem −

×+=


MHA - A Dramatic System Improvement, Example 3 - WCDMA

Feeder + System SensitivityConnector Loss System NF System Sensitivity System NF System Sensitivity Improvement

(dB) (dB) (dBm) (dB) (dBm) (dB)0 3 -99.0 2.17 -99.8 0.81 4 -98.0 2.25 -99.7 1.72 5 -97.0 2.36 -99.6 2.63 6 -96.0 2.49 -99.5 3.54 7 -95.0 2.64 -99.3 4.45 8 -94.0 2.83 -99.2 5.26 9 -93.0 3.06 -98.9 5.97 10 -92.0 3.33 -98.7 6.78 11 -91.0 3.65 -98.3 7.49 12 -90.0 4.02 -98.0 8.0

10 13 -89.0 4.44 -97.5 8.6

Without an MHA With an MHA

Assumptions:- BS NF is 3 dB- BS Demod BW is 5000 KHz- MHA NF is 2 dB- MHA Gain is 12dB- Digital Detection Threshold is 5 dB (Eb/No)- Temperature 17ºC = 290 K- Processing gain will improve the sensitivity additionally (e.g. 25 dB for Voice as an example)

HALF the System Noise Factor

DOUBLE the System Sensitivity


Nokia UltraSite EDGE BTSRF Performance

• BTS Receiver Sensitivity

Minimum BTS sensitivity value measured at BTS antenna connector (without MHA) or at MHA input connector when MHA is used.

BTS sensitivity value with MHA is with high gain mast head amplifier especially designed for UltraSite BTS. Maximum feeder loss can be 7 dB in GSM900 and 10 dB in GSM1800/1900.

Note that there is no full-band MHA1800 available.


UltraSite BTS sensitivity and Rx level reporting


UltraSite EDGE RX chain with/without MHA

ANTENNA

UltraSite EDGE BTS

High gain: +29,4dB(GSM1800)

DVxx/RTxx

TRX

Low Gain: -3.6dB...+6.4dB(GSM1800)

DVxx/RTxx

• UltraSite EDGE filter unit (DVxx/RTxx) has two gain settings:

High gain (fixed): Without MHALow gain (variable): With MHA

• When using UltraSite GSM/EDGE MHA, feeder loss information is inputted withthe HW configurator. Based on this data, needed RX chain gain is determined and filter unit variable gain is set accordinglyto provide optimal performance.UltraSite EDGE BTS

TRX

FEEDERCABLE

ANTENNA

FEEDERCABLE

MHA: 33dB


RX level reporting in UltraSite EDGE and TalkWithout MHA

Ultra-Site EDGEBTS

FEEDERCABLE: 3dB

ANTENNA

-90dBm

ReportedRX level: -93dBm

• UltraSite EDGE and Talk:Received signal level of the BTS is measured in the TRX. From this

measurement value, reported RX level is calculated such way that it shows RX level at the BTS antenna port (top of cabinet).

It is noted that the signal received by the antenna is attenuated by the amount of the antenna feeder loss.

TalkBTS

FEEDERCABLE: 3dB

ANTENNA

-90dBm


RX level reporting point



RX level reporting in UltraSite EDGE and TalkWith MHA

FEEDERCABLE: 3dB


ANTENNA

Ultra-Site EDGEBTS

FEEDERCABLE: 3dB

MHA: 33dB

ANTENNA-90dBm -90dBm


MHA: 12dBReportedRX level: -81dBm

RX level reporting point Talk

BTS

Talk:• RX level is reported at the BTS

antenna connector the same way as without MHA

Ultrasite EDGE:• RX level is reported at the input of

the MHA. Since antenna feeder loss information is fed to the BTS HWconfigurator, RX level reporting shows correct received signal value at the antenna


RX level reporting in UltraSite EDGE and Talk

• Note: Talk family BTS always reports RX level at BTS antenna connector and therefore addition of MHA is seen as an increase of RX level. With UltraSite EDGE, addition of MHA does no change RX level reporting values that much, since reporting reference point is at MHA input when it is used.

• Example:

• Change in RX level reporting, when adding a MHA, however, does not mean that system sensitivity would increase the same amount.

-81dBm-90dBmWith MHA-93dBm-93dBmWithout MHA

TalkUltraSite EDGEReported RX levelPin,ant=-90dBm

Feeder loss=3dB


System sensitivity without MHA

• Definition of system sensitivity: Receiver input power level, at which specified bit error rate (BER) is achieved in

a defined reference point• GSM spec defines sensitivity to be measured at BER=2%• Reference point for system sensitivity = Antenna• BTS sensitivity without MHA is typically specified at the BTS antenna connector• System sensitivity w/o MHA = ( BTS sensitivity ) – ( antenna feeder cable losses )

BTS sensitivity w/o MHA is specifiedat BTS antenna connector

ANTENNA

FEEDERCABLE

Reference point for system sensitivity

BTS


System sensitivity with MHA

• Degradation of system sensitivity due to feeder cable losses can be compensated by using a MHA

• Specification of BTS sensitivity with MHA may vary from product to product:

Talk: BTS sensitivity is only specified at BTS antenna connector, affect of MHA must be calculated separately

UltraSite: When using a MHA, BTS sensitivity is specified at MHA input and separate sensitivity figures with MHA can be found from product documentation


System sensitivity with MHA• System sensitivity:

Talk: Calculated from BTS and MHA noise figure + feeder loss, see table on next page. Sensitivity is a function of feeder cable loss.

UltraSite: System sensitivity = UltraSitesensitivity specification with MHA (see product documentation). Note that sensitivity remains constant regardless of the feeder loss !

Talk BTS sensitivity is only specifiedat BTS antenna connector

BTS

FEEDERCABLE

ANTENNA

MHA

UltraSite BTS sensitivity withMHA is specified at MHA input


System sensitivity with MHA

Antenna UltraSite EDGE system sensitivity (GSM1800) Talk system sensitivity (GSM1800)feeder Without With MHA Without With MHA

loss MHA MHA improvement MHA MHA improvementdB dBm dBm dB dBm dBm dB

0 -112 -112.5 0.5 -110 -111.7 1.71 -111 -112.5 1.5 -109 -111.6 2.62 -110 -112.5 2.5 -108 -111.5 3.53 -109 -112.5 3.5 -107 -111.4 4.44 -108 -112.5 4.5 -106 -111.2 5.25 -107 -112.5 5.5 -105 -110.9 5.96 -106 -112.5 6.5 -104 -110.7 6.77 -105 -112.5 7.5 -103 -110.4 7.48 -104 -112.5 8.5 -102 -110.0 8.09 -103 -112.5 9.5 -101 -109.6 8.610 -102 -112.5 10.5 -100 -109.1 9.1

Note: UltraSite system sensitivity remains constant regardless of feeder loss !!


Up/downlink balance without MHAUp/down linkbalance / dB

+38

Uplink limitedoutput power range • In the uplink limited

output power range, cell size is limited byBTS RX sensitivity resulting smaller RX coverage than TX

• This imbalance can be compensated by using a MHA

+6

+4

0

+2

-2

-4

+36 +40 +42 +44

WBC 4:1

WBC 2:1

RTC

Bypass

Output powerat BTS antenna connector / dBm

Uplink limited

Downlink limited

Bypass+SRC/IDD

UltraSite GSM/EDGE output power rangeper combining type

Assumptions (GSM900):BTS RX sensitivity (2-way div): -113,5dBmMobile RX sensitivity: -104dBmMobile output power: +30dBm


MHA main parts and features


Hi! I aman UltraSiteMHA1800…...

And I must be the famous

WCDMA Dual MHA...

And I must be the

famous

WCDMA Dual MHA...


Dual Duplex (Nokia uses only this!)

Bias Tee

Antenna Port

BTS Port& DC Feed

LNABypassSwitch(notavailable in Ultra)

Tx

Rx

Rx

DuplexFilter

DuplexFilter


MHA main parts

• dual low noise AMPLIFIERS in 2…3 staged and balanced design.

• high Q dual DUPLEX FILTERS with integrated transmit filters.

• LIGHTNING PROTECTION circuitry at BTS port (DC short at antenna port).

• CURRENT EXTRACTION circuitry at BTS port for DC feed via feeder.

• SUPERVISION CIRCUITRY (monitors the status of the amplifiers and sends an alarm signal to the BTS in case of an LNA failure).

• VENTED DESIGN for maintenance free operation (GoreTex, drainpipe etc.).


UltraSite EDGE MHA block diagram

TX FILTER

GAIN ADJUSTMENT

RX FILTER

RX FILTER

CURRENT SENSE CIRCUIT

BTS

DC CURRENT

ANTENNA


MHA current levels

UltraSite EDGE WCDMA

Normal operation, typical 500…600 mA 50-190 mA

Failure of one amplifier 800…900 mA (MHA Alarm) 230…295 mA

Failure of both amplifiers 800…900 mA (MHA Alarm) 230…295 mA


MHA Alarms• Alarm numbers UltraSite EDGE WCDMA

7606 TRX faulty 76537607 TRX degraded 7654

• Reported fault reasons

UltraSite EDGE:* Fault in VSWR antenna monitoring - caused by high VSWR of the antenna line or low Tx power in the BiasT* Fault in the chain between power unit and MHA- MHA is broken or there is a problem in the chain from power unit to the MHA

WCDMA:

* Cell operation degraded, Mast head amplifier fault* Cell faulty, Antenna connection fault


Bias Tee (with or w/o VSWR)• Functions: to feed power to MHA, to monitor VSWR, to provide lighting protection

BTS port ANT portDC block(capacitor)

RF choke (inductor)

Broadband detectorslevel comparatorsalarm-sense logic

Lightning protectionTranszorb fast-react

GDT long-cycle

Fwd. powercoupler

Rvrs. power coupler

DC pwr in

Alarm out


UltraSite EDGE Bias Tee equipment


Antenna Monitoring (VSWR)- Voltage Standing Wave Ratio (VSWR) monitoring is optional in Ultra Bias Tee.- at the moment VSWR monitoring can be performed only on antenna lines including Tx, on BCCH antennas. - Pure Rx diversity antenna (TCH) can not be monitored by VSWR -"Comparing RSSI Value" will do it in CX3 from BTS

- The fixed VSWR thresholds are as follows: VSWR 2.6 or lower: antenna operation OK

VSWR greater than 2.6: indicates antenna fault

- An alarm is generated in case of antenna fault when VSWR threshold exceeded. -> alarm raised in the O&M system and the affected TRXsturned off.


More about VSWR...

- VSWR is designed to detect major faults in antenna line, not tobe a high accuracy measurement feature- Note a big RL difference between the antenna line with MHA (e.g.15 dB) and without MHA (e.g. 20 dB)!- After BTS or sector reset the Bias Tees can automatically be 'placed' to pure Rx line by default

-> use "Preferred BCCH TRX" feature- 'Call drop rate' and 'Handover success rate' are still good features/ referencies to make sure antenna line is OK


MHA generationsSystem Bandwith Gain NF(dB) By-pass Connectors BiasTee

(MHz) switch

Talk family:MHA900 25/35 12dB adj. 2.3 yes On bottom BasicMHA1800 3x25/FB 12dB 1.8 yes Bottom/In-line ->>-MHA1900 3x20 12dB 1.8 yes - >> - ->>-

UltraSite:MHA900 35 32dB 2.5 no In-line Basic/VSWRMHA1800 2x45 33dB 1.9 no ->>- ->>-MHA1900 3x20/FB 33dB 1.8/2.2 no/yes ->>- ->>-

WCDMA 60 12dB 1.9 yes In-line Basic/VSWR


High gain or low gain MHA?

• UltraSite MHA includes practically all receiver gain.• with an MHA, the front end of BTS is passive power splitter, with loss only. • without an MHA, an LNA in BTS is used. • the gain of LNA can be chosen/adjusted so that UltraBTS accepts also a Talk MHA without

blocking or deterioration in sensitivity.

• Talk and WCDMA MHA:• fixed gain LNA continuously switched ON in the front end of BTS receiver, before receiving

multicoupler. • May overdrive if 33 dB MHA is installed before that.• these MHAs are only used to compensate for feeder loss.

• Differences:• if all the gain in MHA (high gain) -> 0.3–0.5 dB better (front end) noise figure and respectively

the better system sensitivity that is very stabile and can not be affected by any level of feeder loss.

• an MHA with low gain is a bit unexpensive because the amplification is done with one FET only and not with two serial FETs. Additionally an LNA with fixed gain in BTS is cheaper.

• Decision between these two solution has been done program by program.


MHA power feed and gain control


UltraSite EDGE BTS - MHA control principal

B O I P W S P W S

I2 C - B U S

C o m m o n S u b r a c k

+ 1 2 V

B IA S - T

M H A

6

P W S

6

1 2

6 6 6 6

A n te n n a c o n n e c to r s1 - 1 2

M H A D C c o n n e c to r s1 - 1 2

In te r f a c e M o d u le

V S W R a la r m in p u t s1 - 1 2

I2 C - B U S

B ia s - TIn te r f a c e M o d u le

1 2

M H A D C p o w e r ( 1 2 V )1 - 1 2

M H A P W R c o n n e c t o r

V S W R M O N P W R c o n n e c t o r

Base Operations and Interface unit


UltraSite EDGE BTS - The rules to use MHA output lines in PWS unit

# of PWS unit PWS location 1 PWS location 2 PWS location 3 (left most) (middle) (right most)

2 7-12 1-6 Not installed

2 1-6 Not installed 7-12

2 Not installed 7-12 1-6

3 1-6 Outputs OFF (Redundant) 7-12

If one PWS unit gets faulty or is removed from the cabinet then redundant unit will start immediately feeding unpopulated MHA output lines. If two PWS units are installed and the (1-6) PWS gets faulty, then the (7-12) PWS is switched to (1-6).


Gain setting in UltraSite EDGE BTS

1. Open Nokia BTS HW Configurator

2. Choose masthead amplifier type: MHA, MNxx, or None for each antenna

MHA -> Talk family MHAs (12dB)MNxx -> UltraSite MHA (33dB).

Note! If Talk MHA is chosen, the BTS/DVD gain will be fixed/high.

If UltraSite MNxx is chosen, the gain/attenuation of the BTS/DVD can still be adjusted between low and high (appr. -3.6 dB… +6.4 dB).

Either Cable Loss or Gain Settings value can be changed.

3. Operation and alarm current tresholds adjust accordingly

4. Finally, configuration must be sent to BTS for it to take effect


…gain setting in UltraSite EDGE BTS


RX-chain gain UltraSite EDGE MHA -UltraSite EDGE BTS

ANTENNA

BTS

Detection

Feeder cable

TSDA

MH2ADVDB

MHA Gain: 33dB ±1dB

Gain: 0 ... -10 dB (Loss)

Gain -0.45dB (Loss) Gain-0.35dB(Loss)

Gain -0.2dB(Loss)

Mobile RF powerat antenna connector:

BTS RX-chain nominal gain is 30.5 dBDVDx high gain - MH2A - BTS Internal cables + TSDA = 30.5 dB

When Ultra MHA is used DVDx is set to Low gain. DVDx Low gain path isvariable. GSM 1800 DVDx Low gain can set between -3.6dB...+6.4dB.Adjustment range is 10 dB (GSM1800 and GSM1900).

Now feeder cable loss is also taken into account.MHA - Feeder cable + (or -) DVDx low gain - MH2A - BTS Internal cables+ TSDA = 30.5 dB

Example when feeder cable loss is -6 dB and MHA is used. DVDx Low gainis to +2.4dB.+33dB-6dB+2.4dB-8.3dB-1.0dB+10.4dB = 30.5 dB

Cable Cable Cable

High Gain: 29.4dB ±1.6 dBLow Gain: -3.6dB to +6.4dB

Gain: -8.3 dB ±0.5dB

Gain: 10.4 dB ±2,5dB


Installation and Installation Verification


MHA pole installation (MHA 900/1800 in pic.)

Metalbands

Draining pipepointingdownwards.

Pole

MHA

Groundingstud


MHA wall installation


Correct installation?


BTS/Bias Tee Interface module, UltraSiteEDGE

Power connectorsSMB female 12 pcs

DC Power Inputconnectors from BTS

VSWR Alm connectorVSWR alarm connectorsSMB male 12 pcs


Bias Tee Installation – Indoor, UltraSite EDGE


Bias Tee Installation – Outdoor, UltraSite EDGE(Note! Termination Plate to be used only in Outdoor cabinet with AC filter Unit.)


Bias Tee installation in Outdoor UltraSite EDGE BTS


Connecting jumpers to Bias Tees


Bias Tee Installation in WCDMA Optima Compact BTS


Bias Tee Installation in WCDMA Indoor Supreme BTS


Bias Tee Installation in Ultrasite (WCDMA Mods) - Outdoor


Bias Tee Installation in Ultrasite (WCDMA Mods) - Indoor


MHA installation hints• All MHA eqmt have been fully tested in production; no need to repeat

stand alone testing in the field, visual check is enough• Check that you are using correct sub band (1800!)• Only vertical installation allowed!• Max. 1/2” jumper allowed to connect to the MHA• 25...30 Nm torque for MHA connectors allowed• Improper installation can cause intermittent alarms or decrease

functionality, e.g. water in connection, however the MHA can be OK!• Touching to 7/16” connectors can decrease system performance!• MHA grounding always recommended• In coastal areas and in islands, use extreme weather proofing for all

connections (see Antenna Line Technical Bulletin)!


MHA System installation verification

• Basic msmt: Return loss for the antenna line, first without, then with an MHA

• VSWR more accurate than RL msmt when converted to DTF mode

• If all reflections (of connectors, jumpers, feeder) are in the same phase -> can cause very poor result even if individual components are ok -> RL can be as low as 9-10 dB

- use DTF- if no peak is higher than the others, the result can be true- if result remains lower than 11 dB, contact Site Mgr


...MHA System installation verification

• Always do calibration properly- for tst cables, adapters, connectors- good calibration kit

• With SiteMaster- check that you are using cont. sweep mode, not single sweep - check that msmt is not out-of-scale (->use autoscale)

• Bias Tee- Return Loss msmt- DC continuity, between center pin of 7/16 and opposite end's

SMB connetors


MHA TesterMHA Tester Tool is used to monitor the condition of MHA. It measures the current drawn by MHA and shows if MHA is operating normally or not. The tool can monitor Nokia Talk-, Ultra- and WCDMA MHA’s.

Tool can be used for two purposes:To monitor MHA condition.To power up the MHA for antenna line VSWR if msmt in Rx band.


MHA Installation Verification

1) Check all connections

2) Any component in antenna line can be broken;

However MHA is the only active eqmt that can generate an alarm, also MHA alarm is the only alarm that is reported

-> it is not necessarily MHA that is broken!!


•


UltraSite EDGE & WCDMA MHA Products CS72991.01 Masth.Amp.MNGA900, Rx:880-915 MHzCS72991.02 Masth.Amp.MNTB850 R, Rx:824-849 MHzCS72992.02 Masth.Amp.MNDB1800, Rx:1740-1785 MHzCS72992.03 Masth.Amp.MNDA1800, Rx:1710-1755 MHzCS72993.08 Masth.Amp.MNPF FB1900, Rx:1850-1910 MHz CS72995.05 WMHB, WCDMA Dual MHA, Rx:1920-1980 MHz

CS7299411 Bias Tee WBNB 800/1900 EDGE non VSWRCS7299412 Bias Tee WBVC 800/900 EDGE with VSWRCS7299413 Bias Tee WBVB 1800/1900 EDGE with VSWRCS7299611 Bias Tee WBVA 1900/2100 WCDMA with VSWRCS7299613 Bias Tee WBNB 1900/2100 WCDMA non VSWRCS7299420 Bias Tee 1800/1900, VSWR and sniffer

Note! MHAs always include pole mounting bracket. Bias Tees always include pwr/alm cable.


MHA Reliability


MHA Validation by Nokia

• Component level, layouts, etc. according to Nokia requirements

• All electrical figures compatibility fully tested

• Environmental tests (incl. salt spray test)

• Operational and alarm current window testing

• Other tests done in co-operation with vendors: Vibration, chock tests, lightning, max.power handling, etc. -> for operation, storage and transportation

• System and Type Approval tests-EMC -RF (IM, sensitivity, blocking)- safety


MHA Reliability

• MTBF is - a design comparison done in favourable conditions (at 25°C)- typically Nokia MHAs have a very high MTBF value (400kh…)

• Field Returns- MTBF design data don't take into account:

- installation quality - other handling of units- mechanical/operator issues- NFF units

- Even 30% of returned units can be NFF “no fault found”!- Field MTBF have been proven to be 2 times the calculated figure!

• Nokia delivered nearly half a mill. MHAs by today


MHA Support

MHA Contacts:

Product Mgr Tomi Karvonen

Aux PE Project Mgr Jouni Pelkonen

Aux Customer Care Juha Kassinen

BSS System Support Mgr Juha Määttä

Nokia Ultrasite Mha System

Documents

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