TMA PBT

32 PBT

About This Chapter

AvailabilityNo update.

ImpactIf the downlink coverage in the overlaid subcell is restricted, the continuous coverage isunavailable, and the capacity of the underlaid subcell is small, then the underlaid is prone tocongestion and the overlaid subcell might be in idle state. With PBT, only one TRX in a DTRUis used.

Dynamic PBT supports timeslot-based PBT. That is, two TRXs in a DTRU work independentlyexcept in some specific timeslots. This keeps a balance between cost, capacity, and coverage.

Technical DescriptionWith PBT used in the overlaid subcell, the coverage of the overlaid subcell is increased. Thatis, the edge calls can be switched to the overlaid subcell. This keeps a traffic balance betweenthe overlaid and underlaid subcell.

ImplementationSet the parameter Send Mode to DPBT.

Maintenance InformationNo update.

32.1 OverviewThis describes the power boost technology (PBT), which can be used to expand the radiocoverage of BTSs.

32.2 AvailabilityThis lists the NEs, software, and licenses required for the implementation of PBT.

32.3 Impact

HUAWEI BSC6000 Base Station SubsystemBSS Feature Description 32 PBT

Issue 03 (2008-01-25) Huawei Proprietary and ConfidentialCopyright © Huawei Technologies Co., Ltd

32-1

This describes the impact of PBT on system performance and on other features.

32.4 Technical DescriptionThis describes the technical aspects of PBT. In PBT mode, one route of signals is divided intotwo routes. These two routes of signals are amplified respectively and then are combined intoone route and transmitted. Thus, the transmit power is almost doubled.

32.5 CapabilitiesThis describes the combination power of PBT.

32.6 ImplementationThis describes how to configure PBT.

32.7 Maintenance InformationThis lists the alarms and counters related to PBT.

32.8 ReferencesNone

32 PBTHUAWEI BSC6000 Base Station Subsystem

BSS Feature Description

32-2 Huawei Proprietary and ConfidentialCopyright © Huawei Technologies Co., Ltd

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32.1 OverviewThis describes the power boost technology (PBT), which can be used to expand the radiocoverage of BTSs.

Definition

The PBT is a power boost technology. In PBT mode, one route of signals is divided into tworoutes. These two routes of signals are amplified respectively, and then are combined andtransmitted. Thus, the transmit power is boosted and the signal strength over the downlink isenhanced.

Purposes

The PBT can expand the coverage of BTSs.

In PBT mode, one route of signals is divided into two routes. These two routes of signals areamplified respectively, and then are combined and transmitted. Thus, the transmit power isboosted and the signal strength over the downlink is enhanced. If the UL signals are optimizedduring network construction, the overall radio coverage is expended. The PBT can be used forthe areas with wide coverage requirements.

Terms

None

Acronyms and Abbreviations

Acronyms andAbbreviations

Full Spelling

PBT Power Booster Technology

DTRU Double TRansceiver Unit

32.2 AvailabilityThis lists the NEs, software, and licenses required for the implementation of PBT.

Network Elements Involved

Table 32-1 lists the network elements involved in PBT.

Table 32-1 NEs Involved in PBT

MS BTS BSC MSC MGW SGSN GGSN HLR

- √ √ - - - - -



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MS BTS BSC MSC MGW SGSN GGSN HLR

NOTE

l -: not involved

l √: involved

Software ReleasesTable 32-2 describes the software versions of GBSS products that support PBT.

Table 32-2 GBSS products and software versions

Product Version

BSC BSC6000 V900R003C01 and later releases

BTS BTS3012 V100R001 and later releases

MiscellaneousLicense is required.

32.3 ImpactThis describes the impact of PBT on system performance and on other features.

Impact on System PerformanceIn PBT mode, only one TRX in the DTRU can be used. Thus, a fully configured cabinet canprovide only six TRXs.

Impact on Other FeaturesNone

32.4 Technical DescriptionThis describes the technical aspects of PBT. In PBT mode, one route of signals is divided intotwo routes. These two routes of signals are amplified respectively and then are combined intoone route and transmitted. Thus, the transmit power is almost doubled.

Physically, after multiple routes of signals that have the same phase and frequency aresuperposed, you can obtain gained signals. This principle is used in PBT. In PBT mode, oneroute of signals is divided into two routes, which are amplified respectively. Then, the two routesof signals are superposed in the same phase and with the same frequency. Because these tworoutes of signals are aligned in phase, the transmit power after combination is almost doubled(3 dB).




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Figure 32-1 shows the working principle of PBT in the DTRU

Figure 32-1 Working principle of PBT in the DTRU

TCOM

TX

TRX0

TX

TRX1

combiner

TX1

IN1

IN2

TX2

Same phase

The signals from TRX0 are divided into two routes by a divider. Then, one route enters RF unitTX1, and the other enters RF unit TX2. After being amplified by the RF units, the two routesof signals are combined by the combiner. Then, the combining RF signals are transmitted throughthe TCOM port.

When the PBT is used, the uplink coverage may be insufficient if the UL signals are not amplifiedor the uplink receiver sensitivity is not improved. The UL coverage and the DL coverage maybe imbalanced. Thus, measures should be taken to improve the receive quality of UL signals.To improve the receive quality of UL signals, do as follows:

l Configuring Four-Way Receive Diversity

l Configure a tower mounted amplifier (TMA).

NOTEFor details of four-way receive diversity, refer to 34 Four-Way Receive Diversity.

The TMA is a low noise amplifier module that is installed on a tower. After receiving UL signalsfrom the antenna, the TMA amplifies the signals and then transmits them to the feeder. Thus,the receiver sensitivity of the BTS is improved and the UL coverage is expanded. In addition,when the TMA is used, the transmit power of an MS is reduced and the speech quality isimproved.

A triplex TMA is commonly used. It consists of a triplex filter, a low noise amplifier, and afeeder. The triplex filter filters the signals from the antenna to remove the out-band interference.The low noise amplifier amplifies the weak signals. The feeder transmits the amplified signalsto the indoor units. As shown in Figure 32-2, the triplex TMA should be installed close to theantenna.



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Figure 32-2 Installing the TMA

1

4

2

3

56

(1) Antenna (2) Antenna support (3) Jumper(4) TMA (5) Feeder (6) Cabinet

32.5 CapabilitiesThis describes the combination power of PBT.

PBT combination power: 49 dBm (80W)

32.6 ImplementationThis describes how to configure PBT.

32.6.1 Configuring PBTThis describes how to configure the PBT hardware and PBT software.

32.6.1 Configuring PBTThis describes how to configure the PBT hardware and PBT software.

ContextThe DTRUs of the BTS3012 are classified into two types: type A DTRU and type B DTRU.The two types of DTRUs have different panels. Therefore, the cable connection modes are alsodifferent.

Procedurel Configure the PBT hardware

1. Figure 32-3 and Figure 32-4 show the connections between the DTRU and the DDPUin PBT mode.




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Figure 32-3 Connections between the DTRU (type A) and the DDPU in PBT mode

DDPU

TX B

RXB1

RXA1

RXA2

RXA3

RXA4

RXB2

RXB3

RXB4

TX A

DTRU

TX 1

TCOM

RXM 1

RXM 2

RXD 1

RXD 2

TX 2

IN2

IN 1



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Figure 32-4 Connections between the DTRU (type B) and the DDPU in PBT mode

DDPU

TX B

RXB1

RXA1

RXA2

RXA3

RXA4

RXB2

RXB3

RXB4

TX A

DTRU

TX 1

TCOM

RXM 1

RXM 2

RXD 1

RXD 2

TX 2

For details of descriptions of the ports on type A DTRU, type B DTRU, and the DDPU,refer to Table 2 and Table 3 in LEDs and Ports on the DTRU, and Table 2 in LEDs andPorts on the DDPU.

l Configure the PBT software1. On the BSC6000 Local Maintenance Terminal, right-click a TRX on the

Management Tree tab page. Choose Configure TRX Attributes from the shortcutmenu. A dialog box is displayed, as shown in Figure 32-5.




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Figure 32-5 Configure TRX Attributes dialog box

2. Click Set TRX Attributes. A dialog box is displayed, as shown in Figure 32-6.

Figure 32-6 Configure TRX Attributes dialog box - TRX0



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3. Click the Device Attributes tab. In the Send Mode drop-down list, select PowerBoost Technology to set the send mode of the target TRX to PBT.

----End

32.7 Maintenance InformationThis lists the alarms and counters related to PBT.

AlarmsTable 32-3 lists the alarms related to the PBT.

Table 32-3 Alarms

Alarm ID Alarm Name

4110 TRX Power Decrease Alarm

4112 Close HPA Alarm

4140 PAU Temperature Alarm

4144 TRX VSWR Alarm

CountersNone

32.8 ReferencesNone




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TMA PBT

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