BSS Feature Description (Continue)

20 EGPRSAbout This Chapter

20.1 OverviewThis describes the EGPRS. The Enhanced Data Rate for GSM Evolution (EDGE) can providehigh-rate data services.20.2 AvailabilityThis lists the NEs, software versions, licenses, and other conditions required for theimplementation of EDGE.20.3 ImpactThis describes the impact of EGPRS on system performance.20.4 Technical DescriptionThis describes the technical aspects of EDGE. EDGE is an evolution stage of PS services. It canbe called as 2.75 G mobile communication technology. If the equipment on the current networkremains unchanged, EDGE can be implemented through the upgrade of relevant software. EDGEcan enhance the transmission rate of PS data.20.5 CapabilitiesThis describes the EDGE capabilities of the built-in PCU and external PCU.20.6 ImplementationEDGE implementation consists of configuring EDGE with the built-in PCU and configuringEDGE with the external PCU.20.7 Maintenance InformationThis lists the alarms and counters related to EDGE.20.8 ReferencesThe references indicate the documents about EDGE from the related standard organizations.

HUAWEI BSC6000 Base Station SubsystemBSS Feature Description 20 EGPRS

Issue 03 (2009-06-08) Huawei Proprietary and ConfidentialCopyright Huawei Technologies Co., Ltd.

20-1

20.1 OverviewThis describes the EGPRS. The Enhanced Data Rate for GSM Evolution (EDGE) can providehigh-rate data services.

DefinitionEDGE consists of the Enhanced GPRS (EGPRS) and the Enhanced Circuit Switched Data(ECSD).l EGPRS is the enhanced GPRS. EGPRS uses the 8PSK modulation mode so that the rate

of a single channel is improved. The maximum rate of a single channel is 59.2 kbit/s.l ECSD is the enhanced High Speed Circuit Switched Data (HSCSD).

NOTE

The Huawei BSS supports only EGPRS. Unless otherwise specified, EDGE referred to in this documentindicates EGPRS.

PurposesUsing the new modulation and coding schemes, EDGE greatly improves the data service rates.The data transmission rates on the Um interface in EDGE are almost three times those in GSM.This meets the requirements of high-rate data services.

TermNone.

Acronyms and AbbreviationsAcronym andAbbreviation

Full Spelling

EDGE Enhanced Data Rate for GSM EvolutionGPRS General Packet Radio ServicePCIC Packet Circuit Identity CodeBER Bit Error RateBVC BSSGP Virtual ConnectionBSSGP Base Station System GPRS ProtocolQoS Quality of ServiceTBF Temporary Block FlowCCCH Common Control ChannelPCCCH Packet Common Control ChannelPACCH Packet Associated Control Channel

20 EGPRSHUAWEI BSC6000 Base Station Subsystem

BSS Feature Description

20-2 Huawei Proprietary and ConfidentialCopyright Huawei Technologies Co., Ltd.

Issue 03 (2009-06-08)

Acronym andAbbreviation

Full Spelling

RLC Radio Link Control

20.2 AvailabilityThis lists the NEs, software versions, licenses, and other conditions required for theimplementation of EDGE.

NEs InvolvedTable 20-1 lists the network elements (NEs) involved in EDGE.

Table 20-1 NEs Involved in EDGEMS BTS BSC PCU SGSN GGSN MSC HLR - NOTEl -: not involvedl : involved

Software VersionsTable 20-2 lists the versions of GBSS products that support EDGE.

Table 20-2 GBSS products and software versionsProduct VersionBSC BSC6000 V900R008C01 and later versionsBTS BTS3X G3BTS32V302R002C05 and later versions

BTS3012A All versionsBTS3001C All versionsBTS3002C All versionsBTS3002E BTS3000V100R002C01 and later versionsBTS3006C BTS3000V100R002C01 and later versionsBTS3012 DTRU BTS3000V100R001C01 and later versions

QTRU BTS3000V100R008C01 and later versions



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Product VersionBTS3012AE

DTRU BTS3000V100R001C04 and later versionsQTRU BTS3000V100R008C01 and later versions

BTS3900 GSM BTS3000V100R008C02 and later versionsBTS3900A GSM BTS3000V100R008C02 and later versionsDBS3900 GSM BTS3000V100R008C01 and later versions

Miscellaneousl The EDGE Support can be configured only when the GPRS Support is configured.l For the concentric cell, the configuration between the overlaid subcell and the underlaid

subcell should be the same; that is, the overlaid subcell and underlaid subcell should beconfigured in such as way that they both support EDGE or both do not support EDGE.

20.3 ImpactThis describes the impact of EGPRS on system performance.

Impact on System Performancel When the EDGE function is enabled, the maximum number of TRXs supported by one E1

cable in different network topologies decreases. Thus, the number of TRXs that each GMPSor GEPS supports decreases.

NOTE

The number of idle timeslots and TRXs that each E1 cable can be configured with must meet thefollowing requirement: The number of configured TRXs + the number of configured idle timeslots/8 the maximum number of configurable TRXs.

l When the external PCU is used and the EDGE function is enabled, the capacity of eachRPPU in the PCU decreases. The number of PDCHs that can be activated on each RPPUdecreases from 120 to 100.

Impact on Other FeaturesNone.

20.4 Technical DescriptionThis describes the technical aspects of EDGE. EDGE is an evolution stage of PS services. It canbe called as 2.75 G mobile communication technology. If the equipment on the current networkremains unchanged, EDGE can be implemented through the upgrade of relevant software. EDGEcan enhance the transmission rate of PS data.




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20.4.1 8PSK Modulation ModeThis describes the 8PSK modulation mode. In 8PSK modulation mode, symbols represent theabsolute phases of signals. There are eight possible symbols and each symbol represents threebits of information.The GSM system uses the Gaussian Minimum Shift Keying (GMSK) modulation mode. InGMSK modulation mode, bit 0 or 1 indicates the change in signal phases. Each phase changeis represented by a symbol.In 8PSK modulation mode, symbols represent the absolute phases of signals. There are eightpossible symbols and each symbol represents three bits of information. Therefore, the data rateon the Um interface in EDGE can theoretically be three times that in GSM.Figure 20-1 shows the I/Q relations for the modulation and demodulation in GSM and EDGE.

Figure 20-1 I/Q relations for the modulation and demodulation in GSM and EDGEGPRS:

GMSK modulationEGPRS:

8PSK modulation

1

0

Q

I

Q

I

(0,1,0)

(0,0,0)

(0,0,1)

(1,0,1)

(1,0,0)

(1,1,0)

(1,1,1)

(0,1,1)

NOTE

In terms of performance, the 8PSK modulation mode is better than the GMSK modulation mode. Thedemodulation threshold of the 8PSK mode, however, is higher than the demodulation threshold of theGMSK mode. The modulation mode is radio environment specific. The PCU automatically adjusts themodulation mode based on the BER report from an MS. Therefore, the modulation and demodulation modethat EDGE uses can be 8PSK or GMSK.

Table 20-3 lists the modulation bits and corresponding symbols shown in Figure 20-1.

Table 20-3 Modulation bits and corresponding symbolsModulation Bit Symbol(1,1,1) 0(0,1,1) 1



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Modulation Bit Symbol(0,1,0) 2(0,0,0) 3(0,0,1) 4(1,0,1) 5(1,0,0) 6(1,1,0) 7

NOTE

Table 20-3 lists all the modulation bits and corresponding symbols.

20.4.2 EGPRS Transmit PowerThis describes the transmit power of a BTS that uses 8PSK modulation mode.From the perspective of network operation, the transceiver of the BTS in EDGE must have thesame spectrum features as those of an ordinary transceiver. When sending the signals modulatedin 8PSK modulation mode, the transceiver of the BTS in EDGE uses the transmit power that is2 dB5 dB less than the average power in GMSK modulation mode. Thus, the requirements forspectrum can be met. In the system, the cell parameter 8PSK power attenuation grade and thetrx parameter TRX 8PSK Level can be specified to meet the requirements.On the BCCH, the transmit power of the signals modulated in 8PSK modulation mode is at most4 dB less than the average transmit power of the signals modulated in GMSK modulation mode.On the timeslot located before the timeslot of the BCCH/CCCH, the transmit power of the signalsmodulated in 8PSK mode is at most 2 dB less than that of the signals modulated in GMSKmodulation mode.

20.4.3 MCS-1 to MCS-9 Coding SchemesThis describes MCS-1 to MCS-9 modulation and coding schemes used in EDGE.EDGE uses MCS-1 to MCS-9 modulation and coding schemes, as listed in Table 20-4.

Table 20-4 Modulation and coding schemes in EDGECoding Scheme Modulation Mode Number of Bits

in the Payload ofEach Burst

Rate (kbit/s)

MCS-9 8PSK 2 x 592 59.2MCS-8 2 x 544 54.4MCS-7 2 x 448 44.8




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Coding Scheme Modulation Mode Number of Bitsin the Payload ofEach Burst

Rate (kbit/s)

MCS-6 592544 + 48

29.627.2

MCS-5 448 22.4MCS-4 GMSK 352 17.6MCS-3 296

272 + 2414.813.6

MCS-2 224 11.2MCS-1 176 8.8

NOTE

For 544 + 48 and 272 + 24 in the previous table, 544 and 272 indicate the significant bits, and 48 and 24indicate the padding bits.

The initial coding schemes used in EDGE can be specified through the parameters UplinkDefault MCS Type and Downlink Default MCS Type. When the EDGE service is used,whether the uplink/downlink is adjusted based on the signal transmission quality depends on thesetting of the parameters Uplink Fixed MCS Type and Downlink Fixed MCS Type.Figure 20-2 shows the rates of GPRS channels and those of EDGE channels.

Figure 20-2 Rates of GPRS channels and those of EDGE channelskbit/s

60.0

50.0

40.0

30.0

20.0

10.0

0.0CS-1 CS-2 CS-3 CS-4 MCS-1 MCS-2 MCS-3 MCS-4 MCS-5 MCS-6 MCS-7 MCS-8 MCS-9

8.012.2 14.4

20.2

8.8 11.214.8 17.6

22.429.6

44.8

54.459.2

GPRSEDGE

GMSKmodulation

8PSKmodulation



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20.4.4 Link Quality ControlThis describes the link quality control. The link quality control enables the system to adapt tothe radio transmission environment dynamically by changing modulation and coding schemesduring data transmission, thus improving the link quality.EDGE uses a set of high-efficient link quality control algorithm. EDGE has two link qualitycontrol modes: Link Adaptation (LA) and Incremental Redundancy (IR). The link quality controlmode is set through the parameter Link Quality Control Mode. For the cells where the signalquality on the Um interface is good, this parameter is set to LA.

Basic Principle of LADuring data transmission, the sender retransmits the original data block or segments the originaldata block into two data blocks and then transmits them. The receiver need not restore theprevious erroneous data blocks.

Basic Principle of IRDuring data transmission, the sender does not consider the radio transmission environment atfirst and uses a high data rate coding scheme for the data transmission. Although the data rateis high, the capability of data protection is weak. If the data is received incorrectly, the senderretransmits additional coding information. The receiver combines the new information with theprevious information and then performs decoding. The previous process is repeated until thedecoding succeeds.l During uplink data transmission, the system notifies an MS to use the IR mode by setting

RESEGMENT in the uplink resource assignment message to 0 (segmentation forbidden).In IR mode, the receiver should have sufficient memory to save the history information. Ifthe network memory is insufficient, the system can notify the MS of the memoryinsufficiency by setting RESEGMENT in the UPLINK ACK/NACK message to 1.

l During downlink data transmission, if the memory of an MS is insufficient, the MS cansend MS OUT OF MEMORY to the network through a DOWNLINK ACK/NACKmessage. Then, the network cannot use the IR mode in downlink data transmission.

20.4.5 Types of Preferred EGPRS ChannelsThis describes the types of preferred channels in EGPRS.The preferred channel types are as follows:l EGPRS dedicated channel

EGPRS dedicated channels can be used by only EGPRS MSs.l EGPRS preferred channel

EGPRS preferred channels are preferentially used by EGPRS MSs. The EGPRS preferredchannels can be used by GPRS MSs when the channels are in the idle state. When an EGPRSMS requests an EGPRS preferred channel, the GPRS MS that occupies the EGPRSpreferred channel should be transferred to other channels. The signals of an EGPRS MSand those of a GPRS MS cannot be multiplexed onto one EGPRS preferred channel.

l Normal EGPRS channelNormal EGPRS channels can be used by GPRS MSs and EGPRS MSs.

l GPRS channel




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GPRS channels are used by GPRS MSs. If a cell is not configured with EGPRS channels,EGPRS MSs in the cell preferentially use GPRS channels to process GPRS services.

l Non-GPRS channelNon-GPRS channels are not used for packet services.

When configuring Channel Type on the TRX, you can select the channel type through GPRSChannel Priority Type.When the system allocates PDCHs, the preferred channel type varies according to packet dataservices.l For the GPRS service, the GPRS channels are preferentially assigned. Then the normal

EGPRS channels are assigned and finally the EGPRS preferred channels are assigned.l For the EGPRS service, the EGPRS dedicated channels are preferentially assigned. Then

the EGPRS preferred channels are assigned and finally the normal EGPRS channels areassigned.

On the normal EGPRS channel, the GPRS MS may use the uplink channel, and the EGPRS MSmay use the downlink channel. The parameter Allow E Down G Up Switch can be set to avoidchannel multiplexing. If you want to eliminate the possibility of EDGE/GPRS co-timeslot, donot configure normal EGPRS channels.

NOTE

Channels should be selected according to the preferred channel type. For example, if the channels on theTRX that supports EGPRS are configured as GPRS channels, these channels can be used for only GPRSservices. EGPRS dedicated channels can be configured only as static channels. Other three types ofpreferred channels can be configured as static or dynamic channels.

20.4.6 CCCH 11Bit EGPRS AccessEDGE supports 11Bit EGPRS access on the CCCH. EDGE reduces the access delay andimproves the access performance of the MS.The access process of the 11Bit EGPRS on the CCCH is as follows:1. The MS sends the 11bit EGPRS PAKCET CHANNEL REQUEST message on the CCCH

for one phase packet access.2. The network assigns the EDGE channel for the MS through the IMMEDIATE

ASSIGNMENT message. Therefore, the EGPRS TBF is established.Whether to enable CCCH 11Bit EGPRS access depends on the setting of the parameter Support11BIT EGPRS Access.

20.4.7 Assignment of Idle TimeslotsFor packet data services, the Abis interface supports the mapping of several timeslots to onetraffic channel. Then, the timeslots are divided and combined on the TX and RX ends.The data rate of each timeslot on the Abis interface is 16 kbit/s. In EDGE, the data rate can be59.2 kbit/s. In GPRS, the CS-3/CS-4 coding scheme needs to be added with a subtimeslot. InEDGE, each PDCH can be added with three subtimeslots. EDGE coding schemes are MCS1 toMCS9. The number of Abis links required for different coding schemes is different, as describedin Table 20-5.



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Table 20-5 Coding schemes and number of required Abis linksCoding Scheme Number of Required Abis LinksMCS-1MCS-2 1MCS-3MCS-6 2MCS-7 3MCS-8MCS-9 4

The number of idle timeslots on the Abis interface requested during EDGE coding schemeadjustment is related to the coding scheme. As described in Table 20-5, when EDGE uses codingschemes MCS-3-MCS-6, an idle timeslot on the Abis interface is required. The idle timeslotson the Abis interface in the same BTS can be allocated to any PDCH on any TRX in the samecabinet group. The idle timeslot on the Abis interface is set through the parameter IdleTimeslots.

NOTE

l When the Abis interface uses IP or HDLC transmission, there is no idle timeslot configuration.l When the Flex Abis feature of the BTS is enabled, if the CS traffic is light, idle timeslots may not be

configured and the EDGE service can still run normally.l When the Flex Abis feature of the BTS is enabled, if the CS traffic is heavy, idle timeslots should be

configured. Otherwise, the EDGE service may fail for a long time.

20.5 CapabilitiesThis describes the EDGE capabilities of the built-in PCU and external PCU.

Built-in PCUThe EDGE capabilities of the built-in PCU are as follows:l The system uses the resource pool redundancy configuration mode. The maximum

configuration that the system can support is 8 + 1 = 9 GDPUPs.l The maximum number of cells supported by each GDPUP is 1,024.l The maximum number of activated PDCHs supported by each GDPUP is 1,024. All the

channels support the MCS9 coding scheme.l The maximum number of configurable PDCHs is 15,360.l The maximum number of activated PDCHs in full configuration is 8,192. All the channels

support the MCS9 coding scheme.l The maximum throughput on the Gb interface is 512 Mbit/s.l The maximum number of uplink PDCHs that can be used by a single MS is 4.l The maximum number of downlink PDCHs that can be used by a single MS is 5.l The maximum number of pairs of configured GFGUGs/GEPUGs are 8.




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External PCUThe EDGE capabilities of the external PCU are as follows:l The BSC supports 256 E1 lines on the Pb interface.l Each GMPS/GEPS subrack supports 64 E1 lines on the Pb interface.l Each GEIUP/GOIUP supports 32 E1 lines on the Pb interface.l The GOIUP provides one STM-1 port, which carries 63 E1 links.

20.6 ImplementationEDGE implementation consists of configuring EDGE with the built-in PCU and configuringEDGE with the external PCU.

20.6.1 Configuring EGPRS (with Built-in PCU)This describes how to configure EDGE on the BSC6000 Local Maintenance Terminal.

Prerequisitel The system is configured to support GPRS. For details about how to configure GPRS with

the built-in PCU, see 19.6.5 Configuring GPRS (with External PCU).l The subrack-OSP mapping is configured. For details, refer to Configuring the Subrack-

OSP Mapping.l The license is applied and activated. To apply for and activate the license, do as follows:

1. In the BSC6000V900R008 Exceptional Commercial License Application Template,fill in the following information. Fill in the number of PDCHs to be purchased in the Number of resources column

corresponding to the Maximum Number of PDCH Groups Activated in theResource control items column.

Fill in the number of TRXs to be purchased in the Number of resources columncorresponding to the Number of the TRX Supporting EDGE in the Resourcecontrol items column.

2. Activate the license on the Local Maintenance Terminal. For details, refer toActivating the BSC License.

ProcedureStep 1 Configure site idle timeslot.

1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-click the target BTS, and then choose Configure Site Idle Timeslot from the shortcutmenu. A dialog box is displayed, as shown in Figure 20-3.



20-11

Figure 20-3 Configure Site Idle Timeslot dialog box

2. In the Idle Timeslot area, click the box under the Idle Timeslots area, and then enter the

number of idle timeslots to be configured.3. Click Finish to end the configuration.

NOTE

l Idle Timeslots should be configured only when TransType of the BSC is set to TDM.l When the Flex Abis feature of the BTS is enabled, if the CS traffic is light, idle timeslots may not be

configured and the EDGE service can still run normally.l When the Flex Abis feature of the BTS is enabled, if the CS traffic is heavy, idle timeslots should be

configured. Otherwise, the EDGE service may fail for a long time.

Step 2 Configure the cell to support EDGE.1. On the BSC6000 Local Maintenance Terminal, right-click a cell on the Management

Tree tab page, and then choose Set Cell Attributes from the shortcut menu.2. In the displayed dialog box, double-click the target cell in the Cell view list box to add it

to the Selected cells list box. Then, click Next.3. In the Cells to be set list box, select the target cell, and then click Set Cell Attributes. A

dialog box is displayed, as shown in Figure 20-4.




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Figure 20-4 Set Other Parameter dialog box

4. Select EDGE Support.5. Click OK to end the configuration.

Step 3 Configure the channel type.1. On the BSC6000 Local Maintenance Terminal, right-click a TRX on the Management

Tree tab page, and then choose Configure TRX Attributes from the shortcut menu.2. In the displayed dialog box, select the target TRX in the TRX view list box, and then click

Configure TRX Attributes.3. In the displayed dialog box, click the Channel Attributes tab, as shown in Figure 20-5.



20-13

Figure 20-5 Channel Attributes tab page

4. Select Channel No., and then select the channel type that supports packet services such as

PDTCH or TCH Full Rate in the Channel Type drop-down list box. Then, set GPRSChannel Priority Type.

5. Click OK to end the configuration.----End

20.6.2 Configuring EGPRS (with External PCU)This describes how to configure EDGE on the BSC6000 Local Maintenance Terminal.

Prerequisitel The system is configured to support GPRS. For details about how to configure GPRS with

the external PCU, refer to 19.6.5 Configuring GPRS (with External PCU).l The subrack-OSP mapping is configured. For details, refer to Configuring the Subrack-

OSP Mapping.l The license is applied and activated. To apply for and activate the license, do as follows:

1. In the BSC6000V900R008 Exceptional Commercial License Application Template,fill in the following information. Fill in the number of PDCHs to be purchased in the Number of resources column

corresponding to the Maximum Number of PDCH Groups Activated in theResource control items column.




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Fill in the number of TRXs to be purchased in the Number of resources columncorresponding to the Number of the TRX Supporting EDGE in the Resourcecontrol items column.

2. Activate the license on the Local Maintenance Terminal. For details, refer toActivating the BSC License.

ProcedureStep 1 Configure Site Idle Timeslot dialog box

1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-click the target BTS, and then choose Configure Site Idle Timeslot from the shortcutmenu. A dialog box is displayed, as shown in Figure 20-6.

Figure 20-6 Configure Site Idle Timeslot dialog box

2. In the Idle Timeslot area, click the box under the Idle Timeslots area, and then enter the

number of idle timeslots to be configured.3. Click Finish to end the configuration.

NOTE

l Idle Timeslots should be configured only when TransType of the BSC is set to TDM.l When the Flex Abis feature of the BTS is enabled, idle timeslots may not be configured and the EDGE

service can still run normally,if the CS traffic is light.l When the Flex Abis feature of the BTS is enabled, idle timeslots should be configured. Otherwise, the

EDGE service may fail for a long time,if the CS traffic is heavy.

Step 2 Configure the cell to support EDGE.



20-15

1. On the BSC6000 Local Maintenance Terminal, right-click a cell on the ManagementTree tab page, and then choose Configure Cell Attributes from the shortcut menu.

2. In the displayed dialog box, double-click the target cell in the Cell view list box to add itto the Selected cells list box. Then, click Next.

3. In the Cells to be set list box, select the target cell, and then click Set Cell Attributes. Adialog box is displayed, as shown in Figure 20-7.

Figure 20-7 Set Other Parameter dialog box

4. Select EDGE Support.5. Click OK to end the configuration.

Step 3 Configure the channel type.1. On the BSC6000 Local Maintenance Terminal, right-click a TRX on the Management

Tree tab page, and then choose Configure TRX Attributes from the shortcut menu.




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2. In the displayed dialog box, select the target TRX in the TRX view list box, and then clickConfigure TRX Attributes.

3. In the displayed dialog box, click the Channel Attributes tab, as shown in Figure 20-8.

Figure 20-8 Channel Attributes tab page

4. Select Channel No., and then select PDTCH or Dynamic PDCH in the Channel Type

drop-down list box. Then, set GPRS Channel Priority Type.5. Click OK to end the configuration.----End

20.7 Maintenance InformationThis lists the alarms and counters related to EDGE.

AlarmsThe alarms related to EDGE consist of alarms related to the built-in PCU and alarms related tothe external PCU, as listed in Table 20-6 and Table 20-7.



20-17

Table 20-6 Alarms related to the built-in PCUAlarm ID Alarm Name291 Cell Transmission Delay Abnormal293 GB BC Faulty294 TRX Config Error331 NSVC Faulty332 NSVL Faulty333 NSE Faulty340 Cell PS Service Faulty341 DSP Resource Overload342 PTP BVC Faulty343 NSVL Dynamic Configuration Process Failure344 FAULTY DSP OVER LIMIT

Table 20-7 Alarms related to the external PCUAlarm ID Alarm Name104 All PBSLs in the PCU Are Faulty128 No Circuit Configured in the PCU

CountersThe counters related to EDGE consist of counters related to the built-in PCU and counters relatedto the external PCU, as listed in Table 20-8 and Table 20-9.

Table 20-8 Counters related to the built-in PCUCounter DescriptionA331 Delivered Paging Messages for PS ServiceZTA308H Immediate Assignment Requests per BSC (PS

Service)A031 SGSN-Initiated Paging Requests for PS

ServiceL3188D PACKET CCCH LOAD IND Messages Sent

on Abis Interface




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Counter DescriptionA9201 Number of Uplink EGPRS TBF

Establishment AttemptsA9202 Number of Successful Uplink EGPRS TBF

EstablishmentsA9203 Number of Failed Uplink EGPRS TBF

Establishments due to No ChannelA9204 Number of Failed Uplink EGPRS TBF

Establishments due to MS No ResponseA9205 Number of Uplink EGPRS TBF Normal

ReleasesA9206 Number of Uplink EGPRS TBF Abnormal

Releases due to N3101 Overflow (MS NoResponse)

A9207 Number of Uplink EGPRS TBF AbnormalReleases due to N3103 Overflow (MS NoResponse)

A9208 Number of Uplink EGPRS TBF AbnormalReleases due to SUSPEND

A9209 Number of Uplink EGPRS TBF AbnormalReleases due to FLUSH

A9210 Number of Uplink EGPRS TBF AbnormalReleases due to No Channel

A9211 Total Number of Sampled Concurrent UplinkEGPRS TBFs

A9212 Sampling Times of Concurrent UplinkEGPRS TBFs

AA9213 Average Number of Concurrent UplinkEGPRS TBFs

A9214 Total Duration of Uplink EGPRS TBF (ms)AA9215 Average Duration of Uplink EGPRS TBF (s)A9301 Number of Downlink EGPRS TBF

Establishment AttemptsA9302 Number of Successful Downlink EGPRS

TBF EstablishmentsA9303 Number of Failed Downlink EGPRS TBF

Establishments due to No ChannelA9304 Number of Failed Downlink EGPRS TBF

Establishments due to MS No Response



20-19

Counter DescriptionA9305 Number of Downlink EGPRS TBF Normal

ReleasesA9306 Number of Downlink EGPRS TBF Abnormal

Releases due to N3105 OverflowA9307 Number of Downlink EGPRS TBF Abnormal

Releases due to SUSPENDA9308 Number of Downlink EGPRS TBF Abnormal

Releases due to FLUSHA9309 Number of Downlink EGPRS TBF Abnormal

Releases due to No ChannelA9310 Total Number of Sampled Concurrent

Downlink EGPRS TBFsA9311 Sampling Times of Concurrent Downlink

EGPRS TBFsAA9312 Average Number of Concurrent Downlink

EGPRS TBFsA9313 Total Duration of Downlink EGPRS TBF

(ms)AA9314 Average Duration of Downlink EGPRS TBF

(s)L9201 Total Number of Uplink EGPRS RLC Data

BlocksL9202 Total Number of Uplink EGPRS MCS1 RLC

Data BlocksL9203 Total Number of Uplink EGPRS MCS2 RLC







Data Blocks




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Counter DescriptionL9210 Total Number of Uplink EGPRS MCS9 RLC

Data BlocksL9211 Total Number of Valid Uplink EGPRS MCS1

RLC Data BlocksL9212 Total Number of Valid Uplink EGPRS MCS2








RLC Data BlocksRL9220 Retransmission Rate of Uplink EGPRS

MCS1 RLC Data Block (%)RL9221 Retransmission Rate of Uplink EGPRS








MCS9 RLC Data Block (%)



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Counter DescriptionL9229 Number of MCS Upgrades on Uplink EGPRS

TBFL9230 Number of MCS Degrades on Uplink EGPRS

TBFL9231 Number of Uplink EGPRS RLC Control

BlocksTL9232 Average Throughput of Uplink EGPRS RLC

(kbit/s)TL9233 Average Payload of Single Uplink EGPRS

TBF (KB)L9234 Total Number of Uplink EGPRS TBFsL9301 Total Number of Downlink EGPRS RLC

Data BlocksL9302 Total Number of Downlink EGPRS MCS1

RLC Data BlocksL9303 Total Number of Downlink EGPRS MCS2





RLC data blocksL9308 Total Number of Downlink EGPRS MCS7



RLC Data BlocksL9311 Total Number of Valid Downlink EGPRS

MCS1 RLC Data BlocksL9312 Total Number of Valid Downlink EGPRS


MCS3 RLC Data Blocks




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Counter DescriptionL9314 Total Number of Valid Downlink EGPRS






MCS9 RLC Data BlocksRL9320 Retransmission Rate of Downlink EGPRS

MCS1 RLC Data Blocks (%)RL9321 Retransmission Rate of Downlink EGPRS








MCS9 RLC Data Blocks (%)L9329 Number of MCS Upgrades on Downlink

EGPRS TBFL9330 Number of MCS Degrades on Downlink

EGPRS TBFL9331 Number of Downlink EGPRS RLC Control

BlocksL9332 Number of Downlink EGPRS RLC Dummy

Blocks



20-23

Counter DescriptionTL9333 Average Throughput of Downlink EGPRS

RLC (kbit/s)TL9334 Average Payload of Single Downlink EGPRS

TBF (KB)L9335 Total Number of Downlink EGPRS TBFsS9101 Number of Times 8PSK_MEAN_BEP=1S9102 Number of Times 8PSK_MEAN_BEP=2S9103 Number of Times 8PSK_MEAN_BEP=3S9104 Number of Times 8PSK_MEAN_BEP=4S9105 Number of Times 8PSK_MEAN_BEP=5S9106 Number of Times 8PSK_MEAN_BEP=6S9107 Number of Times 8PSK_MEAN_BEP=7S9108 Number of Times 8PSK_MEAN_BEP=8S9109 Number of Times 8PSK_MEAN_BEP=9S9110 Number of Times 8PSK_MEAN_BEP=10S9111 Number of Times 8PSK_MEAN_BEP=11S9112 Number of Times 8PSK_MEAN_BEP=12S9113 Number of Times 8PSK_MEAN_BEP=13S9114 Number of Times 8PSK_MEAN_BEP=14S9115 Number of Times 8PSK_MEAN_BEP=15S9116 Number of Times 8PSK_MEAN_BEP=16S9117 Number of Times 8PSK_MEAN_BEP=17S9118 Number of Times 8PSK_MEAN_BEP=18S9119 Number of Times 8PSK_MEAN_BEP=19S9120 Number of Times 8PSK_MEAN_BEP=20S9121 Number of Times 8PSK_MEAN_BEP=21S9122 Number of Times 8PSK_MEAN_BEP=22S9123 Number of Times 8PSK_MEAN_BEP=23S9124 Number of Times 8PSK_MEAN_BEP=24S9125 Number of Times 8PSK_MEAN_BEP=25S9126 Number of Times 8PSK_MEAN_BEP=26




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Counter DescriptionS9127 Number of Times 8PSK_MEAN_BEP=27S9128 Number of Times 8PSK_MEAN_BEP=28S9129 Number of Times 8PSK_MEAN_BEP=29S9130 Number of Times 8PSK_MEAN_BEP=30S9131 Number of Times 8PSK_MEAN_BEP=31S9132 Number of Times 8PSK_MEAN_BEP=32

Table 20-9 Counters related to the external PCUCounter DescriptionAR3015A Mean Number of Dynamically Configured

Channels (EDGE) (900/850 Cell)AR3015B Mean Number of Dynamically Configured

Channels (EDGE) (1800/1900 Cell)CR3015 Mean Number of Dynamically Configured

Channels (EDGE)AR3025A Mean Number of Available Channels

(EDGE) (900/850 Cell)AR3025B Mean Number of Available Channels

(EDGE) (1800/1900 Cell)CR3025 Mean Number of Available Channels

(EDGE)R3005A Number of Initially Configured Channels

(Static EDGE) (900/850 Cell)R3005B Number of Initially Configured Channels

(Static EDGE) (1800/1900 Cell)R3006A Number of Initially Configured Channels

(Dynamic EDGE) (900/850 Cell)R3006B Number of Initially Configured Channels

(Dynamic EDGE) (1800/1900 Cell)CR3005 Number of Initially Configured Channels

(Static EDGE)CR3006 Number of Initially Configured Channels

(Dynamic EDGE)AL8351 Mean Number of Faulty Circuits on the Pb

Interface



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Counter DescriptionAL8353 Mean Number of Blocked Circuits on the Pb

InterfaceAL8354 Mean Number of Idle Circuits on the Pb

InterfaceAL8355 Mean Number of Busy Circuits on the Pb

InterfaceAL8352 Mean Number of Circuits in Maintenance

State on the Pb InterfaceL0387 Total Number of Messages Received from

PCUL8387 Messages Received from a PCUR3140 Requests for TCH from the PCUR3141 Successful Requests for TCH from the PCUAR3011A Mean Number of Dynamically Configured

Channels (PDCH) (900/850 Cell)AR3011B Mean Number of Dynamically Configured

Channels (PDCH) (1800/1900 Cell)CR3011 Mean Number of Dynamically Configured

Channels (PDCH)AR3021A Mean Number of Available Channels

(PDCH) (900/850 Cell)AR3021B Mean Number of Available Channels

(PDCH) (1800/1900 Cell)CR3021 Mean Number of Available Channels

(PDCH)R3001A Number of Initially Configured Channels

(Static PDCH) (900/850 Cell)R3001B Number of Initially Configured Channels

(Static PDCH) (1800/1900 Cell)R3002A Number of Initially Configured Channels

(Dynamic PDCH) (900/850 Cell)R3002B Number of Initially Configured Channels

(Dynamic PDCH) (1800/1900 Cell)CR3001 Number of Initially Configured Channels

(Static PDCH)CR3002 Number of Initially Configured Channels

(Dynamic PDCH)




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Counter DescriptionZTA331 Paging Requests on the Abis Interface per

BSC (PS Service)ZTA301H Immediate Assignment Commands per BSC

(PS Service)ZTL3188D PCH Overloads due to PS Service Counted

through the Indications from the AbisInterface per BSC

20.8 ReferencesThe references indicate the documents about EDGE from the related standard organizations.The references are as follows:3GPP TS 50.059"Enhanced Data rates for GSM Evolution (EDGE); Project scheduling and open issues forEDGE"



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21 Co-BCCH CellAbout This Chapter

21.1 OverviewThis describes the definition and purposes of the Co-BCCH cell. The Co-BCCH cell adopts thedual-band technique and features expanded cell capacity and minimized handover occurrences.21.2 AvailabilityThis lists the NEs, software, and hardware configuration of the BTS required for theimplementation of the Co-BCCH cell.21.3 ImpactThis describes the impact of the Co-BCCH cell on system performance.21.4 Technical DescriptionThis describes the implementation of channel assignment and handover.21.5 CapabilitiesNone.21.6 ImplementationThis describes the configuration principle, configuration preparation, scenario analysis,configuration procedure, and deactivation of the Co-BCCH cell.21.7 Maintenance InformationThis lists the performance counters related to the Co-BCCH cell.21.8 References

HUAWEI BSC6000 Base Station SubsystemBSS Feature Description 21 Co-BCCH Cell


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21.1 OverviewThis describes the definition and purposes of the Co-BCCH cell. The Co-BCCH cell adopts thedual-band technique and features expanded cell capacity and minimized handover occurrences.

DefinitionThe Co-BCCH cell refers to a cell where the GSM900&DCS1800 TRXs coexist (orGSM850&DCS1800, GSM850&PCS1900). The TRXs on the two bands use one main BCCH.In a dual-band network, a dual-band MS can work on either of the bands. A single-band MS canalso work normally on its band.The GSM900 band consists of the P-GSM, E-GSM, and R-GSM.

PurposesThe Co-BCCH cell improves the continuous coverage and sparse coverage in hot spots.With the rapid increase of mobile users, the dual-band network solution becomes a growingtrend around the globe. The dual-band network has the following three networking modes:l Independent MSC Networkingl Co-MSC Independent BSC Networkingl Co-BSC NetworkingThe highlight of the dual-band network with the Co-BCCH cell is that the primary frequencyband and the secondary frequency band are the same and they coexist in one cell. The secondaryfrequency band is the extension of the primary frequency band. This feature eliminates thetechnical bottleneck on cell reselection and handover in other networking modes. Specifically,the advantages of the dual-band network with the Co-BCCH cell are listed as follows:l The capacity of the cell is expanded and the occurrences of cell reselection for the MS are

reduced.For example, a site is configured with a GSM900 cell and a DCS1800 cell. Each cell isconfigured with two TRXs. You can obtain the data as listed in Table 21-1 when queryingthe ERLANG B.

Table 21-1 Data in ERLANG BNetworkingMode

QuantityofBCCHs

QuantityofSDCCHs

Quantityof TCHs

Call LossRate

Traffic Volume

Commondual-bandnetwork

2 2 28 2% 16.40 ERL

Dual-bandnetworkwith Co-BCCHcell

1 2 29 2% 21.04 ERL

21 Co-BCCH CellHUAWEI BSC6000 Base Station Subsystem



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l The inter-cell handover occurrences are reduced.

When an MS initiates a handover request, the MS is handed over to the channels on theother frequency band in the serving cell.

l The number of the BCCH TRXs is reduced and the interference caused by the BCCH TRXsis reduced.

l Convenient maintenanceThe number of cells and neighboring cells of the Co-BCCH cell network is less than thatof the common dual-band network. Thus, the maintenance workload is reduced.

The system assigns channels on different frequency bands to the MS based on the RX level, RXquality and TA value. The underlaid subcell is used for cell coverage and the overlaid subcellis used for traffic absorption. Thus, the cell coverage is maximized and the capacity balancebetween the overlaid subcell and the underlaid subcell is maintained.

TermsTerms DefinitionM criteria Indicates a criteria that selects only the neighbor cells of which the

RX level is higher than the lowest MS RX level threshold and sortsthe qualified cells in the candidate cell list. The serving cell andneighbor cells are sorted based on the RX level.

ERLANG B Indicates the relation among the number of common channels, callloss rate, and traffic volume in busy hours. The ERLANG B isdeveloped from the ERLANG call loss formula.

Primary frequencyband

Indicates the frequency band containing the main BCCH frequencyin a Co-BCCH cell.

Secondary frequencyband

Indicates the frequency band that does not contain the main BCCHfrequency in a Co-BCCH cell.

Acronyms and AbbreviationsAcronyms and Abbreviations Full SpellingBCCH Broadcast Control ChannelSDCCH Stand-alone Dedicated Control ChannelPBGT Power BudgetBQ Bad QualityMR Measurement ReportTA Timing Advance



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21.2 AvailabilityThis lists the NEs, software, and hardware configuration of the BTS required for theimplementation of the Co-BCCH cell.

NEs InvolvedTable 21-2 lists the network elements involved in the Co-BCCH cell.

Table 21-2 NEs involved in Co-BCCH cellMS BTS BSC MSC MGW SGSN GGSN HLR- - - - - -NOTEl -: not involvedl : involved

Software ReleasesTable 21-3 lists the NEs and software versions that support Co-BCCH cell.

Table 21-3 GBSS products and software versionsProduct VersionBSC BSC6000 V900R008C01 and later releasesBTS BTS3012 DTRU BTS3000V100R001C01 and later releases

QTRU BTS3000V100R008C01 and later releasesBTS3012 DTRU BTS3000V100R001C04 and later releases

QTRU BTS3000V100R008C01 and later releasesBTS3006C BTS3000V100R002C01 and later releasesBTS3002E BTS3000V100R008C01 and later releasesDBS3900 GSM BTS3000V100R008C01 and later releasesBTS3900 GSM BTS3000V100R008C02 and later releasesBTS3900A GSM BTS3000V100R008C02 and later releasesBTS2X All releasesBTS3001C All releasesBTS3002C All releases




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Product VersionBTS3X All releasesDouble-transceiver BTSs All releases

MiscellaneousThe BTS must meet the following requirements if you configure Co-BCCH.l Number of TRXs

The number of GSM900 TRXs or DCS1800 TRXs should be less than or equal to four ina Co-BCCH cell. If the number exceeds four, enough antenna output ports and antennamodels are required. The coverage of the TRXs on the same frequency band should be thesame in the case of antenna installation.

l Antenna types and azimuth If the GSM900 TRX and the DCS1800 TRX use the same antenna, the dual-band

antenna is required. If the GSM900 TRX and the DCS1800 TRX use the antenna respectively, either the

dual-band antenna or the single-band antenna is allowed. When the sing-band antennais used, the azimuth of the antennas used for the GSM900 TRX and the DCS1800 TRXin the same cell must be the same.

l Type of the combinerAs a combiner cannot support the GSM900 and the DCS1800 at the same time, the GSM900TRX and the DCS1800 TRX must use different combiners.

l Combination modeThe combination mode of the TRXs on the same frequency band in a cell must be the same.Otherwise, the TX power levels of the TRXs on the same frequency band in a cell are notconsistent, and the coverage of these TRXs is not consistent. Thus, the Co-BCCH cellcannot be enabled because of a 3-layer or more-layer concentric cell.

21.3 ImpactThis describes the impact of the Co-BCCH cell on system performance.

Impact on System PerformanceThe impact of the Co-BCCH cell on system performance is as follows:l Co-BCCH cell can be applied to specific scenarios only. If Co-BCCH is applied to

unqualified scenarios, the network KPI is deteriorated.For details of the application scenarios of the Co-BCCH, refer to 21.6.3 Risk Analysis ofthe Configuration Scenarios.

l The neighboring cell of the Co-BCCH cell is limited.The neighboring cell of the Co-BCCH cell cannot be GSM900 cell or DCS1800 cell.Otherwise, the traffic volume is unbalanced.



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NOTE

If the GSM900 cell and the DCS1800 cell are at the same layer, they can be neighboring cell of theCo-BCCH cell.For details of network layer and network hierarchy, refer to 7.3.2.10 Fast-Moving Micro CellHandover.

l The configuration of network optimization parameters of the Co-BCCH cell is moredifficult than that of the common cell.

Impact on Other FeaturesThe Co-BCCH cell and the double-timeslot cell cannot coexist.

21.4 Technical DescriptionThis describes the implementation of channel assignment and handover.

21.4.1 GSM900/DSC1800 Co-BCCH Cell Channel AssignmentThis describes the Co-BCCH cell channel assignment. Channel assignment strategy of the Co-BCCH cell complies with the channel assignment algorithm of the concentric cell and isassociated with the frequency band supported by the MS.The GSM900&DCS1800 (or GSM850&DCS1800, GSM850&PCS1900) Co-BCCH cell isrealized based on the principles of the concentric cell, which are described as follows:l GSM900 (or GSM850) TRXs are configured in the underlaid subcell for network coverage.l DCS1800 (or PCS1900) TRXs are configured in the overlaid subcell for traffic absorption.Therefore, the channel assignment of the Co-BCCH cell should comply with the channelassignment strategy of the concentric cell. Before the channel assignment, however, the networkneeds to determine the frequency bands supported by the MS. If the MS supports the bands inthe underlaid and overlaid subcell, the channel assignment strategy of the concentric cell isapplied. Otherwise, the network assigns only the channels in the underlaid subcell to the MS.

Immediate AssignmentIn the immediate assignment procedure, the BSC does not receive any information about theMS. If TA exists, the BSC assigns underlaid or overlaid channels to the MS based on TA. TheBSC preferentially assigns the channels in the underlaid subcell to the MS to ensure that theconversation can be established.

AssignmentIn the assignment procedure, the channel assignment is related to MS classmark 3.l If the BSC does not obtain MS classmark 3, or if MS classmark 3 indicates that the MS

supports only the underlaid frequency band, then the BSC assigns only the underlaidchannels to the MS.

l If MS classmark 3 indicates that the MS supports the underlaid and overlaid frequencybands, the BSC assigns underlaid or overlaid channels to the MS based on AssignOptimum Layer and Assign-optimum-level Threshold.




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Incoming Internal Inter-Cell HandoverIn the incoming internal inter-cell handover procedure, the channel assignment is related to MSclassmark 3.l If the BSC does not obtain MS classmark 3, or if MS classmark 3 indicates that the MS


l If MS classmark 3 indicates that the MS supports the underlaid and overlaid frequencybands, the BSC assigns underlaid or overlaid channels to the MS based on Pref. Subcellin HO of Intra-BSC.

Because the inter-cell handover is generally triggered on the cell edge, you are advised to setthe Pref. Subcell in HO of Intra-BSC to Underlaid Subcell.

Incoming External Inter-Cell HandoverIn the incoming external inter-cell handover procedure, the channel assignment is related to MSclassmark 3.l If the BSC does not obtain MS classmark 3, or if MS classmark 3 indicates that the MS


l If MS classmark 3 indicates that the MS supports the underlaid and overlaid frequencybands, the BSC assigns underlaid or overlaid channels to the MS based on Incoming-to-BSC HO Optimum Layer.

Because the inter-cell handover is generally triggered on the cell edge, you are advised to setthe Incoming-to-BSC HO Optimum Layer to Underlaid Subcell.

21.4.2 GSM900/DCS1800 Co-BCCH Cell HandoverThis describes the GSM900/DCS1800 Co-BCCH cell handover. The Co-BCCH cell handoveris based on the handover algorithm of the concentric cell.

Neighbor Cell SelectionBased on the M criteria, the actual RX level of the serving cell is used for the handover decisionand the RX level of the neighbor cells is used for neighbor cell queuing, no matter the MS islocated in the overlaid subcell or the underlaid subcell. When the MS is in the overlaid subcell,the underlaid subcell is handled as a special neighbor cell.

Handover Within an Enhanced Concentric CellThe underlaid subcell can provide better speech quality in a concentric cell. Therefore, theutilization ratio of the underlaid subcell is maximized.The underlaid-to-overlaid subcell handover occurs only when the traffic volume in the underlaidcell is high, the RX level of the MS is high, the RX quality of the MS is good, and the TA valueis low. In other words, all the following conditions must be met:l DL RX Level UtoO HO Received Level Threshold

This condition is controlled by RX_LEV for UO HO Allowed.l DL RX Quality < RX_QUAL Threshold



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This condition is controlled by RX_QUAL for UO HO Allowed.l TA < (TA Threshold TA Hysteresis)

This condition is controlled by TA for UO HO Allowed.l Traffic of the underlaid subcell > Tch Traffic Busy Underlay Threshold

This condition is controlled by Underlaid Subcell HO Step Period (s) and UnderlaidSubcell HO Step Level.

If the serving cell has the highest priority in the neighbor cell queue, the overlaid-to-underlaidsubcell handover occurs when the RX level of the MS, the RX quality of the MS, or the TAdeteriorates. In other words, one of the following conditions should be met:l DL RX Level < OtoU HO Received Level Threshold

This condition is controlled by RX_LEV for UO HO Allowed.l DL RX Quality RX_QUAL Threshold

This condition is controlled by RX_QUAL for UO HO Allowed.l TA (TA Threshold TA Hysteresis)

This condition is controlled by TA for UO HO Allowed.If the serving cell does not have the highest priority in the neighbor cell queue, the MS is handedover to another neighbor cell.

Inter-Subcell HandoverThe actual RX level of the cell is used for all the handover decision algorithms except the PBGThandover decision algorithm.The PBGT algorithm calculates the path loss of the neighbor cell at the same layer and hierarchyby using the RX level of the underlaid cell for handover decision. Because of fast fading of thesignal level transmitted by the DCS1800 TRXs in the overlaid subcell, the handover decisionbased on the actual RX level in the overlaid subcell is improper when compared with the RXlevel in a neighbor cell. To ensure the accuracy of the PBGT handover decision, the handoverdecision should be based on the RX level in the underlaid subcell.For the incoming inter-cell handover and the incoming-to-BSC handover in the Co-BCCH cell,to avoid a low handover success rate due to inaccurate signal level of the target cell, set Pref.Subcell in HO of Intra-BSC and Incoming-to-BSC HO Optimum Layer to UnderlaidSubcell.

21.5 CapabilitiesNone.

21.6 ImplementationThis describes the configuration principle, configuration preparation, scenario analysis,configuration procedure, and deactivation of the Co-BCCH cell.

21.6.1 Configuration PrinciplesThis describes the configuration principles of the Co-BCCH cell.




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A Co-BCCH cell consists of an overlaid subcell and an underlaid subcell. The specific bandconfiguration is as follows:l If the overlaid subcell is configured with the DCS1800 TRX, the underlaid subcell is

configured with the GSM900 or GSM850 TRX.l If the overlaid subcell is configured with the PCS1900 TRX, the underlaid subcell is

configured with the GSM850 TRX.NOTE

The path loss of the DCS1800 TRX is fast. At the distance of 0.5 to 1 km, the signal power of the DCS1800TRX is about 15 dB less than the signal power of the GSM900 TRX.

Configure the Co-BCCH cell based on the following principles:l Generally, do not assign the overlaid subcell channel to a call, do not assign the incoming

inter-cell handover request directly to the overlaid subcell, and do not forcibly assign a callbeyond coverage of the DCS1800 TRX to the overlaid subcell.

l Properly assign the traffic volume in the underlaid subcell and the overlaid subcell tomaintain the traffic balance between the overlaid subcell and the underlaid subcell.

l Configure the BCCH in the GSM900 TRX. The priority of the TRX types from high to lowis: P-GSM, E-GSM, and R-GSM.

l Configure the SDCCH, PDCH, and BCCH in the same TRX.l The frequency hopping between the GSM900 frequencies and the DCS1800 frequencies

is not allowed. The frequency hopping between frequencies within the same frequencyband is allowed.

l Prevent a multi-layer concentric cell due to inconsistent combination mode of the TRXson the same frequency band. A multi-layer concentric cell deteriorates the network KPI,such as handover success rate and assignment success rate.

21.6.2 Preparations for the ConfigurationThis describes the preparations for configuring the Co-BCCH cell. You are required to befamiliar with the related information based on which the parameter configuration is performed.Get familiar with the state of the current cell, which includes the following items:l User distribution and traffic volume in the coverage area of the sitel Ratio of the coverage of the DCS1800/PCS1900 TRX to the coverage of the entire celll Ratio of the coverage of the GSM900/GSM850 TRX to the coverage of the entire celll Whether the GSM900/GSM850 TRXs can carry all the traffic in the cell.l Number of the GSM900/GSM850 TRXs and the DCS1800/PCS1900 TRXs. Whether the

frequency reuse on the GSM900/GSM850 band is tight and whether the interference exists.Pay attention to the following restrictions on network planning:l Number of TRXs

If the traffic is distributed mainly in the overlaid subcell and if the congestion is unlikelyto occur in the underlaid subcell, the number of TRXs configured in the underlaid subcellcan be small.

If the traffic volume in the underlaid subcell is high, the TRXs in the underlaid subcellshould outnumber or be equal to the TRXs in the overlaid subcell to prevent thecongestion in the underlaid subcell.



21-9

If the TRXs in the underlaid subcell are not enough, the TRXs in a fully-loaded underlaidsubcell are likely to be congested in high traffic hours. This deteriorates the networkKPIs, such as TCH Seizure Success Rate and handover success ratio.

l Neighbor cell This factor is neglectable if the Co-BCCH cell is not adjacent to two or more single-

band cells at the same time. If the Co-BCCH cell is adjacent to two single-band cells using the two bands of the Co-

BCCH cell at the same time, you should consider the network hierarchy. This factor is neglectable if the Co-BCCH cell has a low priority. If the Co-BCCH cell is adjacent to two single-band cells using the two bands of the

Co-BCCH cell at the same time, you should consider the network hierarchy. You should consider the traffic load of neighbor cells if the Co-BCCH cell has

a high priority. If the traffic load of neighbor cells is high, the traffic distributedon edge of a common cell is absorbed by the Co-BCCH cell. Thus, the TRXs inthe underlaid subcell are likely to be congested and the network KPIs, such asTCH Seizure Success Rate and handover success ratio are deteriorated. In thiscase, the Co-BCCH cell is not recommended.

If the Co-BCCH cell has to be used, you should analyze the traffic distributionbased on the congestion conditions in the underlaid subcell and then adjust thehandover parameters of related cells. The purpose is to prevent the calls on edgeof a common cell from being handed over to the Co-BCCH cell.

21.6.3 Risk Analysis of the Configuration ScenariosThis describes the risk analysis of the configuration scenarios. The configuration scenariosconsist of common and special scenarios.In the Co-BCCH cell, two types of TRXs with different coverage capabilities are configured.Therefore, the traffic volume of the overlaid and underlaid subcells should be properly assignedwithout deteriorating the network KPIs. The traffic assignment of the overlaid and underlaidsubcells is influenced by two factors. One is the number of TRXs in the overlaid and underlaidsubcells, and the other is the actual coverage of the overlaid and underlaid subcells (representedby the inter-site distance).

Risk Analysis in Common ScenariosTable 21-4 lists the risk analysis in common scenarios.




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Table 21-4 Risk analysis in common scenariosNo.

ScenarioDescription

Scenario Analysis Risk Solution

1 The inter-site distanceis within800 m.

The coverage capability ofthe DCS1800 TRXs isequivalent to that of theGSM900 TRXs.Therefore, the underlaid-to-overlaid or overlaid-to-underlaid handover in theCo-BCCH cell is unlikelyto fail.

There is no risk,and the Co-BCCH cell canbe enabled.

None

2 l The inter-sitedistanceis from800 m to1,600 m.

l Thenumberof TRXsin theunderlaidsubcell isequal toor morethan thenumberof TRXsin theoverlaidsubcell.

The overlaid subcell onlycovers about half of thecoverage area of a Co-BCCH cell. The underlaidsubcell configured withenough TRXs can coverthe remaining area of a Co-BCCH cell. Therefore, therisk is low.

The risk issmall, and theCo-BCCH cellcan be enabled.

Assigns enough trafficvolume to the underlaidsubcell withprecondition that nocongestion occurs inthe underlaid subcell.Thus, the risk ofunderlaid-to-overlaidhandover in high traffichours is minimized.Adjust UtoO HOReceived LevelThreshold to arrangethe traffic of theoverlaid and underlaidsubcells.l If the value of this

parameter isreduced, the numberof underlaid subcellto overlaid subcellhandovers increases.

l If the value of thisparameter isincreased, thenumber of underlaidsubcell to overlaidsubcell handoversdecreases.



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No.

ScenarioDescription


3 l The inter-sitedistanceis from800 m to1,600 m.

l Thenumberof TRXsin theunderlaidsubcell isless thanthenumberof TRXsin theoverlaidsubcell.

The overlaid subcell onlycovers about half of thecoverage area of a Co-BCCH cell. The underlaidsubcell with few TRXsmay not (or just be able to)cover the remaining areaof a Co-BCCH cell.Therefore, most of thetraffic is handed over tothe overlaid subcell in hightraffic hours. Possiblerisks are as follows:l Certain calls beyond the

coverage of the overlaidsubcell are likely to behanded over to theoverlaid subcell and thehandover fails.

l With the increase of celltraffic, the underlaidsubcell becomes badlycongested while theoverlaid subcellremains idle. Inaddition, theperformance indicators,such as the underlaid-to-overlaid handoversuccess rate and theDCS1800 channelseizure success rate aredeteriorated.

The risk ismedium, andyou are advisednot to enable theCo-BCCH. Ifyou enable theCo-BCCH, youare advised toenable halfratechannels in theunderlaidsubcell or to addunderlaidTRXs.

Enable the half-rateservices or increase theTRXs in the underlaidsubcell.




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No.

ScenarioDescription


4 l The inter-sitedistanceis morethan1,600 m.

l Thenumberof TRXsin theunderlaidsubcell isequal toor morethan thenumberof TRXsin theoverlaidsubcell.

The overlaid subcellcovers less than half of thecoverage area of a Co-BCCH cell and theunderlaid subcell isconfigured with enoughTRXs. Based on thequantity and distributionof users, either of thefollowing scenarios mayoccur:l Scenario 1

Most users are in theoverlaid subcell. TheTRXs of the underlaidsubcell can carry thetraffic in coverage ofthe underlaid subcell. Inthis situation, theunderlaid subcellshould carry most of thetraffic to reduce the riskcause by the underlaid-to-overlaid handover inhigh traffic hours.

l Scenario 2Users are distributedevenly and theunderlaid subcell TRXscannot (or just be ableto) carry the traffic inthe coverage area of theunderlaid subcell. Thus,the underlaid subcellbecomes badlycongested and theoverlaid subcellremains idle. Inaddition, theperformance indicators,such as the underlaid-to-overlaid handoversuccess rate and theDCS1800 channelseizure success rate aredeteriorated.

The risk ismedium.l For scenario

1, the Co-BCCH can beenabled.

l For scenario2, you areadvised not toenable theCo-BCCH. Ifyou enablethe Co-BCCH, youare advised toenablehalfratechannels inthe underlaidsubcell or toadd underlaidTRXs.

None



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No.

ScenarioDescription


5 l The inter-sitedistanceis morethan1,600 m.

l Thenumberof TRXsin theunderlaidsubcell isless thanthenumberof TRXsin theoverlaidsubcell.

The overlaid subcellcovers less than half of thecoverage area of a Co-BCCH cell. The underlaidsubcell with few TRXscannot (or just be able to)carry the traffic in thecoverage of the underlaidsubcell. Possible risks areas follows:l The underlaid subcell is

badly congested.l The overlaid subcell

remains idle.l The underlaid-to-

overlaid handoversuccess rate and theDCS1800 channelseizure success rate aredeteriorated.

The risk is large,and the Co-BCCH cannotbe enabled.

Enable the half-rateservices or increase theTRXs in the underlaidsubcell.

The methods for determining the risks are as follows:l In a common dual-band network, if the congestion does not occur in the overlaid or

underlaid subcell, the related performance indicators have no change after the Co-BCCHcell is enabled.

l In a common dual-band network, if the congestion in the GSM900 subcell occurs at anearlier time than in the DCS1800 subcell, a forcible traffic transfer from the GSM900subcell to the DCS1800 subcell is likely to deteriorate the KPIs. In this case, relatedperformance indicators are deteriorated if the Co-BCCH cell is enabled. For example, theunderlaid-to-overlaid handover success rate and the DCS1800 channel seizure success rateare reduced.

Risk Analysis in Special ScenariosUse the following methods to eliminate problems which may occur when the Co-BCCH cell isenabled in special scenarios:l The TRXs number in the overlaid and underlaid subcells is equivalent and most of the

traffic should be assigned in the overlaid subcell.You can lower the value of UtoO HO Received Level Threshold to increase the trafficin the overlaid subcell. To avoid ping-pong handovers because of signal level fluctuation,the value of OtoU HO Received Level Threshold should be less than 25.

l Severe interference exists in the GSM900 subcell.




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You can suppress the interference to some extent by adjusting the parameters related toconcentric cell.

When the inter-site distance is less than 1,000 m, add the traffic in the overlaid subcell.NOTE

You can determine that the GSM900 channel is seriously interfered if the interference band is high,the RX quality is bad, and the call drop rate is 1.2 times or more than the call drop rate of the DSC1800channel.

l In a common dual-band network, only few cells are configured to be the Co-BCCH cells.The neighbor cells are single-band or dual-band cells.In a common dual-band network, the DCS1800 cell is at Level 2 and the GSM900 cell isat level 3. That is, the DCS1800 cell level is higher than the GSM900 cell level. In thissituation, the following may occur when the Co-BCCH cell is enabled: If the Co-BCCH cell is set to level 2, the traffic absorption capability of the GSM900

TRX becomes enhanced. The traffic of the neighbor cells is absorbed. Thus, the trafficvolume of the cell increases sharply and related performance indicators are deteriorated.

If the Co-BCCH cell is set to level 3, the traffic in the coverage of the DCS1800 TRXis absorbed by the neighbor cells. The cell traffic volume is decreased.

To avoid these risks, you must enable the Co-BCCH cell in the neighbor sites.

21.6.4 Configuring the Co-BCCH CellThis describes how to configure the Co-BCCH cell on the BSC6000 Local MaintenanceTerminal.

ProcedureStep 1 Add a Co-BCCH cell

1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-click the target BTS and then choose Add Cell on the shortcut menu. The Add Cell dialogbox is displayed.

2. Click Add Cell. A dialog box is displayed, as shown in Figure 21-1.

Figure 21-1 Add New Cell dialog box



21-15

NOTE

Figure 21-1 takes an example of external PCU. When the PCU is in built-in mode, there is no PCUName in Figure 21-1.

3. In Figure 21-1, set Frequency Band to GSM900&DCS1800 or GSM850&DCS1800,and then click OK. The Add Cell dialog box is returned.

NOTE

If you select GSM850&PCS1900, you must set High Frequency Band to PCS1900.4. Click Next. The Set Site Attributes dialog box is displayed.5. Select a site from the Site List, and then click Set Site Device to set related parameters.

NOTE

You must set Add Chain and Manual Abis according to transmission path and customerrequirements.

Step 2 Configure cell attributes1. Click Next. The Set Cell Attributes dialog box is displayed. Select cells from the Cells to

be set list box, and then click Set Cell Attributes. A dialog box is displayed, as shown inFigure 21-2.




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Figure 21-2 Set Cell Attributes dialog box

2. Set BCCH IUO Attribute.

Step 3 Assign TRXs for the add cell1. In the dialog box shown in Figure 21-2, click Frequency Config. A dialog box is displayed,

as shown in Figure 21-3.



21-17

Figure 21-3 Set Cell Frequency dialog box

2. Select the GSM900 frequencies and DCS1800 frequencies, and then click OK to return to

the dialog box shown in Figure 21-2.Step 4 Set the attributes of the newly assigned TRXs

1. In the dialog box shown in Figure 21-2, click TRX Config. A dialog box is displayed, asshown in Figure 21-4.

Figure 21-4 Configure TRX Attributes dialog box (1)




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2. On the Frequency Attributes tab page, double-click a target frequency in Available

Frequencies to add the frequency to Assigned Frequencies.3. On the Device Attributes tab page, check Value of the HW_Concentric Attribute

parameter, as shown in Figure 21-5.NOTEThe Value of the HW_Concentric Attribute cannot be set. Instead, it is determined by the value ofthe BCCH IUO Attribute in Figure 21-2.

Figure 21-5 Configure TRX Attributes dialog box (2)

Step 5 Set ECSC

1. In the dialog box shown in Figure 21-2, click Call Control. A dialog box is displayed, asshown in Figure 21-6.



21-19

Figure 21-6 Set Call Control Parameter dialog box

2. Specify ECSC based on the actual situations.

NOTE

If you set ECSC to No, the MS reports classmark 3 only when the MSC queries. Before the MSCqueries MS classmark 3, the MS is preferentially assigned to the channels on the GSM900 TRXs.Thus, the traffic load in the underlaid subcell may be too high.

Step 6 Set the handover parameters1. Click Handover Data in the dialog box shown in Figure 21-2. A dialog box is displayed,

as shown in Figure 21-7.




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Figure 21-7 Set Handover Parameter dialog box (1)

2. Select Enhanced Concentric Allowed.3. Click Advanced. A dialog box is displayed, as shown in Figure 21-8.



21-21

Figure 21-8 Set Handover Parameter dialog box (2)

4. Set UtoO Traffic HO Allowed to Yes.

NOTE

UtoO Traffic HO Allowed is available only when Enhanced Concentric Allowed is set to Yes.When Enhanced Concentric Allowed is set to Yes, the serving cell automatically becomes aneighbor cell of itself and cannot be deleted. In the handover algorithm of the enhanced concentriccell, the signal strength of the BCCH TRX is measured in the same way as the signal strength of theneighbor cell. Therefore, the error caused by estimation of the signal strength of the BCCH TRX inthe handover algorithm of the common concentric cell can be eliminated.

Step 7 Set other parameters1. In the dialog box shown in Figure 21-8, set Pref. Subcell in HO of Intra-BSC and

Incoming-to-BSC HO Optimum Layer to Underlaid Subcell.2. Set Assign Optimum Layer, Assign-optimum-level Threshold, and TA Threshold of

Assignment Pref..3. Set Concentric Circles HO Allowed, UL to OL HO Allowed, and OL to UL HO

Allowed.4. Set TA for UO HO Allowed, RX_LEV for UO HO Allowed, and RX_QUAL for UO

HO Allowed.----End

21.6.5 Deactivating the Co-BCCH CellThis describes how to deactivate the Co-BCCH cell on the BSC6000 Local MaintenanceTerminal.

PrerequisiteTo deactivate a non Co-BCCH cell, you need to delete the cell and then add a cell according tothe actual command.




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ProcedureStep 1 Delete the existing cell.

1. On the Management Tree tab page of the BSC6000 Local Maintenance Terminal, right-click the target cell and then choose Delete Cell from the shortcut menu. The Delete Celldialog box is displayed.

2. In the Delete Cell dialog box, double-click the target cell in the Cell view area to add thecell to the Cells to be deleted area.

3. Click Finish. The deletion is complete.Step 2 Add a new cell and complete the cell configuration.

----End

21.7 Maintenance InformationThis lists the performance counters related to the Co-BCCH cell.

AlarmsNone

CountersTable 21-5 lists the performance counters related to the Co-BCCH cell.

Table 21-5 Counters related to the Co-BCCH cellCounter DescriptionAS330A Mean Uplink Receive Level during

Concentric Cell Handover Initiation (Overlayto Underlay)

AS332A Mean Downlink Receive Level duringConcentric Cell Handover Initiation (Overlayto Underlay)

AS330B Mean Uplink Receive Level duringConcentric Cell Handover Initiation(Underlay to Overlay)

AS332B Mean Downlink Receive Level duringConcentric Cell Handover Initiation(Underlay to Overlay)

AS334A Mean Timing Advance during ConcentricCell Handover Initiation (Overlay toUnderlay)

AS334B Mean Timing Advance during ConcentricCell Handover Initiation (Underlay toOverlay)



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Counter DescriptionH3001 Internal Intra-Cell Handover Requests

(Overlay to Underlay)H3002 Internal Intra-Cell Handover Requests

(Underlay to Overlay)H3012 Internal Intra-Cell Handover Commands

(Underlay to Overlay)H3011 Internal Intra-Cell Handover Commands

(Overlay to Underlay)H3022A Failed Internal Intra-Cell Handovers

(Channel Unavailable) (Underlay to Overlay)H3021A Failed Internal Intra-Cell Handovers

(Channel Unavailable) (Overlay to Underlay)H3022M Failed Internal Intra-Cell Handovers (Other

Causes) (Underlay to Overlay)H3021M Failed Internal Intra-Cell Handovers (Other

Causes) (Overlay to Underlay)TH3032 Success Rate of Internal Intra-Cell Handover

(Underlaid Subcell to Overlaid Subcell)TH3031 Success Rate of Internal Intra-Cell Handover

(Overlay to Underlay)S3012 MRs on Signaling Channels (Underlaid

Subcell)S3011 MRs on Signaling Channels (Overlaid

Subcell)S3002 MRs on TCHs (Underlaid Subcell)S3001 MRs on TCHs (Overlaid Subcell)CR3557 Traffic Volume of TCHs (Underlaid Subcell)CR3558 Traffic Volume of TCHs (Overlaid Subcell)R3200 Channel Assignment Requests (Underlaid

Subcell Only)R3201 Channel Assignment Requests (Overlaid

Subcell Only)R3202 Channel Assignment Requests (Underlaid

Subcell Preferred)R3203 Channel Assignment Requests (Overlaid

Subcell Preferred)




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Counter DescriptionR3202B TCH Assignment Requests (Underlaid

Subcell Preferred)R3203B TCH Assignment Requests (Overlaid Subcell

Preferred)R3202D Channel Assignment Requests in Incoming

Internal Inter-Cell Handover Procedure(TCH)(Underlaid Subcell Preferred)

R3203D Channel Assignment Requests in IncomingInternal Inter-Cell Handover Procedure(TCH) (Overlaid Subcell Preferred)

R3202E Channel Assignment Requests in IncomingExternal Inter-Cell Handover Procedure(TCH) (Underlaid Subcell Preferred)

R3203E Channel Assignment Requests in IncomingExternal Inter-Cell Handover Procedure(TCH) (Overlaid Subcell Preferred)

R3222B Channel Assignment Overflows (TCH)(Underlaid Subcell Preferred)

R3223B Channel Assignment Overflows (TCH)(Overlaid Subcell Preferred)

R3222D Channel Assignment Overflows in IncomingInternal Inter-Cell Handover Procedure(TCH) (Underlaid Subcell Preferred)

R3223D Channel Assignment Overflows in IncomingInternal Inter-Cell Handover Procedure(TCH) (Overlaid Subcell Preferred)

R3222E Channel Assignment Overflows in IncomingExternal Inter-Cell Handover Procedure(TCH) (Underlaid Subcell Preferred)

R3223E Channel Assignment Overflows in IncomingExternal Inter-Cell Handover Procedure(TCH) (Overlaid Subcell Preferred)

R3225J Channel Assignment Overflows in UnderlaidSubcell (TCH)

R3224J Channel Assignment Overflows in OverlaidSubcell (TCH)

R3225G Channel Assignment Overflows in UnderlaidSubcell (SDCCH)

R3224G Channel Assignment Overflows in OverlaidSubcell (SDCCH)



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Counter DescriptionR3225H Channel Assignment Overflows in Underlaid

Subcell (TCHF)R3224H Channel Assignment Overflows in Overlaid

Subcell (TCHF)R3225I Channel Assignment Overflows in Underlaid

Subcell (TCHH)R3224I Channel Assignment Overflows in Overlaid

Subcell (TCHH)R3224K Failed Handovers from Underlaid Subcell to

Overlaid Subcell due to Busy Channels inOverlaid Subcell

R3225K Failed Handovers from Overlaid Subcell toUnderlaid Subcell due to Busy Channels inUnderlaid Subcell

21.8 Referencesl GSM 08.08:

"Mobile Switching Centre - Base Station system (MSC-BSS) Interface Layer 3Specification"

l GSM 04.08"Mobile Radio Interface - Layer 3 Specification"




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22 Satellite TransmissionAbout This Chapter

22.1 OverviewThis describes the application of satellite transmission, which is mainly adopted in remotemountainous areas or sparsely populated plains.22.2 AvailabilityThis lists the NEs and software required for the implementation of satellite transmission.22.3 ImpactThe describes the impact of satellite transmission on system performance and other features.22.4 Technical DescriptionThis describes the network topologies of satellite transmission and the application of satellitetransmission over the Abis interface. Huawei BSS supports the satellite transmission over theAter, A, Abis, Pb interface, and Gb interfaces.22.5 ImplementationThis describes how to configure satellite transmission on the Ater, A, Abis, and Pb interfaces.22.6 Maintenance InformationNone.22.7 ReferencesNone.

HUAWEI BSC6000 Base Station SubsystemBSS Feature Description 22 Satellite Transmission


22-1

22.1 OverviewThis describes the application of satellite transmission, which is mainly adopted in remotemountainous areas or sparsely populated plains.

DefinitionSatellite transmission enables different entities to communicate with each other by using thesatellites orbiting the earth.Compared with traditional terrestrial transmission, satellite transmission encounters theproblems such as delay, jitter, and bit error.Huawei BSS eliminates the delay, jitter, and bit error problems over satellite transmissionthrough the optimization of signaling procedures and the adjustment of relevant timers. HuaweiBSS supports the satellite transmission over the A, Ater, Abis, Pb, and Gb interfaces.

PurposesThe satellite transmission features wide coverage, long transmission distance, and flexible linkscheduling. This enables satellite transmission to be used beyond geographical difference andtransmission distance. Satellite transmission is widely used in remote mountainous areas orsparsely populated plains.

TermsNone

Acronyms and AbbreviationsAcronyms andAbbreviations

Full Spelling

BC Bear ChannelDCE Data Circuit-Terminating EquipmentDTE Data Terminal EquipmentVSAT Very Satellite Communications Terminal

22.2 AvailabilityThis lists the NEs and software required for the implementation of satellite transmission.

NEs InvolvedTable 22-1 describes the NEs involved in satellite transmission.

22 Satellite TransmissionHUAWEI BSC6000 Base Station Subsystem



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Table 22-1 NEs involved in satellite transmissionMS BTS BSC MSC MGW SGSN GGSN HLR- - - -NOTEl -: not involvedl : involved

Software ReleasesTable 22-2 describes the versions of GBSS products that support satellite transmission.

Table 22-2 GBSS products and software versionsProduct VersionBSC BSC6000 V900R008C01 and later releasesBTS BTS3012 DTRU BTS3000V100R001C01 and later releases

QTRU BTS3000V100R008C01 and later releasesBTS3012AE

DTRU BTS3000V100R001C04 and later releasesQTRU BTS3000V100R008C01 and later releases

BTS3006C BTS3000V100R002C01 and later releasesBTS3002E BTS3000V100R002C01 and later releasesDBS3900 GSM BTS3000V100R008C01 and later releasesBTS3900 GSM BTS3000V100R008C02 and later releasesBTS3900A GSM BTS3000V100R008C02 and later releasesBTS30 All releasesBTS312 All releasesBTS3012A All releasesBTS3001C All releasesBTS3002C All releases

MiscellaneousNone

HUAWEI BSC6000 Base Station SubsystemBSS Feature Description 22 Satellite Transmission


22-3

22.3 ImpactThe describes the impact of satellite transmission on system performance and other features.

Impact on System PerformanceThe delay involved in satellite transmission may affect the counters such as call drop rate,handover success rate, and assignment success rate.

Impact on Other FeaturesCall drops occur when the forward link and reverse link in the Huawei BTS ring topologyare switched over.

22.4 Technical DescriptionThis describes the network topologies of satellite transmission and the application of satellitetransmission over the Abis interface. Huawei BSS supports the satellite transmission over theAter, A, Abis, Pb interface, and Gb interfaces.

22.4.1 Network Topologies of Satellite TransmissionThis topic describes the networking of the satellite transmission over the Abis interface.Star topology is generally adopted when the satellite transmission is implemented over the Abisinterface. Figure 22-1 shows a typical networking of satellite transmission.

NOTEThe principle of satellite transmissio

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