201450621 frequency hopping

17 Frequency Hopping

About This Chapter

17.1 OverviewThis describes the definition of frequency hopping and the purposes of using it in the GSM.Frequency hopping is the technique that allows the transmit frequencies to vary within theallocated frequency spectrum based on a sequence. The frequency hopping has the features suchas anti-interference, anti-attenuation, and high security.

17.2 AvailabilityThis lists the NEs and software required for the implementation of frequency hopping.

17.3 ImpactThis describes the impact of frequency hopping on voice quality and data services.

17.4 Technical DescriptionThis describes the principles, category, and parameters of frequency hopping. The frequencyhopping technique can help decrease the influence of Rayleigh attenuation and increase the anti-interference capability of the system. There are two types of frequency hopping in terms offrequency varying speed: slow frequency hopping and fast frequency hopping.

17.5 CapabilitiesThis describes the capabilities of frequency hopping. The signal gain achieved through frequencyhopping is generally 2–3 dB.

17.6 ImplementationThis describes how to configure frequency hopping.

17.7 Maintenance InformationThis lists the alarms related to frequency hopping.

17.8 References

HUAWEI BSC6000 Base Station SubsystemBSS Feature Description 17 Frequency Hopping

Issue 01 (2007-11-26) Huawei Technologies Proprietary 17-1

17.1 OverviewThis describes the definition of frequency hopping and the purposes of using it in the GSM.Frequency hopping is the technique that allows the transmit frequencies to vary within theallocated frequency spectrum based on a sequence. The frequency hopping has the features suchas anti-interference, anti-attenuation, and high security.

Definition

A carrier frequency implemented with frequency hopping feature can hop to any frequencywithin a specified frequency band based on a sequence.

Frequency hopping minimizes the interference on a radio channel from a single interferencesource. Thus, it is widely used in telecommunications system with its features such as anti-interference, anti-attenuation, and high security.

Purposes

The application of frequency hopping in the GSM enhances the anti-interference capability andincreases the capacity of the system.

Terms

None.

Acronyms and Abbreviations

Acronyms or Abbreviations Full Spelling

SFH Slow Frequency Hopping

SFH Synthesized Frequency Hopping

BFH Baseband Frequency Hopping

FER Frame Error Rate

CA Cell Allocation

FN Frame Number

MAIO Mobile Allocation Index Offset

HSN Hopping Sequence Number

MA Mobile Allocation

17.2 AvailabilityThis lists the NEs and software required for the implementation of frequency hopping.

17 Frequency HoppingHUAWEI BSC6000 Base Station Subsystem

BSS Feature Description

17-2 Huawei Technologies Proprietary Issue 01 (2007-11-26)

Network Elements InvolvedTable 17-1 lists the network elements involved in frequency hopping.

Table 17-1 NEs involved in frequency hopping

MS BTS BSC MSC MGW SGSN GGSN HLR

√ √ √ - - - - -

NOTE

l –: not involved

l √: involved

Software ReleasesTable 17-2 describes the versions of GBSS products that support frequency hopping.

Table 17-2 GBSS products and software versions

Product Version

BSC BSC6000 V900R003C01 and later releases

BTS DTRU BTS3012 BTS3000V100R001C01 and later releases

BTS3012AE BTS3000V100R001C04 and later releases

BTS3006C BTS3000V100R002C01 and later releases

BTS3.0 BTS312 G3BTS32.30000.00.1130 and later releases

BTS30 G3BTS32.30000.00.1130 and later releases

BTS3012A G3BTS32V302R002C06 and later releases

BTS3006A G3BTS32.30000.00.1130 and later releases

BTS3002C G3BTS36.30000.01.0820A and later releases

MiscellaneousNone

17.3 ImpactThis describes the impact of frequency hopping on voice quality and data services.



Impact on Voice QualityThe introduction of frequency diversity gain and interference averaging in the frequency hoppingmode can effectively improve voice quality. In frequency-restricted networks, the applicationof frequency hopping can help simplify frequency planning and improve system capacity.

Impact on Data ServicesFrequency hopping technique has a negative impact on data services, especially in the high datarate schemes such as CS3–4 and MCS5–9.

Impact on Other FeaturesNone.

17.4 Technical DescriptionThis describes the principles, category, and parameters of frequency hopping. The frequencyhopping technique can help decrease the influence of Rayleigh attenuation and increase the anti-interference capability of the system. There are two types of frequency hopping in terms offrequency varying speed: slow frequency hopping and fast frequency hopping.

17.4.1 Principle of Frequency HoppingThis describes the principle of frequency hopping. As signal attenuation varies with frequencyspacing, the application of frequency hopping can minimize the impact of Rayleigh attenuation.

17.4.2 Category of Frequency HoppingThis describes the categories of frequency hopping. Generally, there are two types of frequencyhopping: fast frequency hopping and slow frequency hopping. The GSM system requires that acarrier frequency remains unchanged during a burst period. Thus, the frequency hopping in GSMis a slow frequency hopping.

17.4.3 Parameters of Frequency HoppingThis describes the parameters related to frequency hopping. These parameters specify the carrierfrequency used by each timeslot.

17.4.1 Principle of Frequency HoppingThis describes the principle of frequency hopping. As signal attenuation varies with frequencyspacing, the application of frequency hopping can minimize the impact of Rayleigh attenuation.

Frequency hopping can minimize the varying signal strength impact caused by multipathpropagation. This feature is equal to that achieved through frequency diversity. In mobiletelecommunications, the radio signals in transmission might vary abruptly in a short period dueto the impact of Rayleigh attenuation. The varying of the radio signals is frequency dependent.As the difference of frequencies increases, the attenuation becomes more independent. Take thefrequency band allocated for mobile telecommunications for example. Basically, 200 kHz offrequency spacing can guarantee the irrelevancy of attenuation within the frequencies, while 2MHz of frequency spacing can fully guarantee the irrelevancy of attenuation within thefrequencies.

The application of frequency hopping prevents all the bursts that carry the bits within one speechframe from being damaged by Rayleigh attenuation in the same manner, as shown in Figure17-1.




Figure 17-1 Attenuation model

Level for receiving signals

Distance

The frequency hopping technique has the following features:

l The signal gain achieved through frequency hopping is concerned with the environment,especially with the moving speed of an MS.– When the MS moves at high speed, the location change of any two bursts within a

channel is affected by other attenuation. The faster the MS moves, the lower the signalgain is achieved.

– For large number of slowly moving MSs, frequency diversity is a better choice.l The signal gain achieved by frequency hopping is also concerned with the available

frequencies. As the number of frequencies decreases, the signal gain achieved alsodecreases.Actually, frequency hopping is a pseudo frequency spreading technique; that is, the signalgain achieved through frequency hopping is equal to the signal gain processed after thefrequency band that carries the valid signals is spread.When testing the signal gain achieved through frequency hopping, different C/I ratios isspecified for the frequencies allocated for a transmitter, given the Frame Error Rate (FER)is the same. The difference between these C/I ratios is the signal gain achieved throughfrequency hopping.

l Frequency hopping provides interference offset along the transmission path. This preventsall the bursts that contain the bits from being damaged by the interference in the samemanner.– The application of error-correction coding and interleaving technique enables a receiver

to reassemble the original data from the received data stream.– If the interference is narrowband distributed, frequency hopping can achieve some

signal gain.– If the interference is broadband distributed and all the bursts are damaged, the original

data cannot be reassembled and no signal gain is achieved.NOTE

The interference is generally narrowband distributed in the existing networks.

In the frequency hopping mode, there might be cases where the Bit Error Rate (BER) increases,whereas you feel that the speech quality is improved. The improving of speech quality is causedby the improved FER specification as the BER increases.



17.4.2 Category of Frequency HoppingThis describes the categories of frequency hopping. Generally, there are two types of frequencyhopping: fast frequency hopping and slow frequency hopping. The GSM system requires that acarrier frequency remains unchanged during a burst period. Thus, the frequency hopping in GSMis a slow frequency hopping.

In terms of time, frequency hopping is classified into the following types:

l Frame frequency hoppingIn frame frequency hopping, the carrier frequencies change with every TDMA frame whilethe carrier frequency assigned for the eight timeslots of the TDMA frame remainsunchanged. The BCCH TRX does not use the frequency hopping mechanism in this mode.

l Timeslot frequency hoppingIn timeslot frequency hopping, the carrier frequency changes with every timeslot of aTDMA frame. The TCHs of the BCCH TRX can use the frequency hopping mechanismin this mode.

In terms of TRX implementation, frequency hopping is classified into the following types:

l RF frequency hoppingIn RF frequency hopping, the carrier frequencies for the transmitter and receiver of TRXparticipate in frequency hopping. The carrier frequencies assigned for frequency hoppingin a cell are specified by the hopping sequence. The number of carrier frequencies assignedfor frequency hopping can exceed the number of TRXs assigned for the cell.

l Baseband frequency hoppingIn baseband frequency hopping, the carrier frequency assigned for the transmitter of theTRX does not participate in frequency hopping and remains unchanged. The transmitfrequency hopping is achieved with the switching of baseband signals among differentTRXs. The receiver of the TRX, however, must participate in frequency hopping. Thecarrier frequency assigned for the receiver changes with the carrier frequency used by anMS. The number of carrier frequencies assigned for frequency hopping in a cell cannotexceed the number of TRXs assigned for the cell.

Irrespective of the frequency hopping mode adopted on the network side, the carrier frequencyassigned for the transmitter of the TRX and that assigned for the receiver of the TRX must remainconsistent in terms of the MS. The carrier frequency assigned for each burst can change.

NOTE

In RF frequency hopping, the carrier frequency assigned for the transmitter of the TRX varies with eachburst. Thus, the tuning of the RF front-end device must match the varying speed of the carrier frequencies.An alternative broadband device can be used in this case. The DFCU (cavity combiner) is a narrowbandcombiner and its tuning speed cannot keep up with the varying speed of the carrier frequencies assignedfor the TRX. Thus, only baseband frequency hopping, instead of RF frequency hopping, can be used forthe DFCU.

17.4.3 Parameters of Frequency HoppingThis describes the parameters related to frequency hopping. These parameters specify the carrierfrequency used by each timeslot.

The parameters related to frequency hopping are as follows:

l Cell Allocation table (CA)




CA table collects all the ARFCNs assigned for the cells.l TDMA Frame Number (FN)

FN is broadcast on the SCH. The MS synchronizes with the BTS by monitoring the FN (0–2715647).

l Mobile Allocation table (MA)MA is a subset of CA. It is a frequency sequence set used for the MS frequency hopping.The MA table comprises N frequency sequences, where 1 ≤ N ≤ 64.

l Mobile Allocation Index (MAI) (0 to N-1)MAI specifies an element in the MA table. In other words, the carrier frequency actuallyused is specified by the MAI.

l Mobile Allocation Index Offset (MAIO) (0 to N-1)In mobile telecommunications, the radio frequency sequence adopted on the Um interfaceis an element in the MA table.MAIO is an initial offset of the MAI. It is used to prevent multiple channels from gainingaccess to one TRX at the same time.

l Hopping Sequence Number (HSN) (0–63)The carrier frequencies hop along the time, controlled by a sequence called HSN. Onehopping sequence is a queue of the N carrier frequencies computed through certainalgorithms, given the HSN, MAIO, and FN. Different channels allocated on differenttimeslots can use the same hopping sequence. Different channels allocated on the sametimeslots of the same cell use different MAIOs.HSN=0 means cyclic hopping and HSN≠0 means pseudorandom hopping.

17.5 CapabilitiesThis describes the capabilities of frequency hopping. The signal gain achieved through frequencyhopping is generally 2–3 dB.

The uplink and downlink signal gain achieved through frequency hopping is symmetrical. Thesignal gain achieved through frequency hopping varies a little with the antennas having diversityreceiver feature. Generally, the signal gain achieved through frequency hopping is regarded as2–3 dB.

17.6 ImplementationThis describes how to configure frequency hopping.

17.6.1 Changing None FH to RF FHThis describes how to change the FH mode of a cell from none FH to RF FH to achieve frequencyreuse and interference averaging.

17.6.2 Changing None FH to Baseband FHThis describes how to change the FH mode of a cell from none FH to baseband FH to achievefrequency reuse and interference averaging.

17.6.3 Changing RF FH to Baseband FHThis describes how to change the FH mode of a cell from RF FH to baseband FH to optimizenetwork performance.



17.6.4 Changing Baseband FH to RF FHThis describes how to change the FH mode of a cell from baseband FH to RF FH to optimizenetwork performance.

17.6.5 Changing RF FH to None FHThis describes how to change the FH mode of a cell from RF FH to none FH to optimize networkperformance.

17.6.6 Changing Baseband FH to None FHThis describes how to change the FH mode of a cell from baseband FH to none FH to optimizenetwork performance.

17.6.1 Changing None FH to RF FHThis describes how to change the FH mode of a cell from none FH to RF FH to achieve frequencyreuse and interference averaging.

Scenario Network optimization

Impact After the FH mode of a cell is changed, the cell is reset.

NEs InvolvedBSC and BTS

FH can reduce the possibility of a channel being affected by the same interference source.Therefore, FH has features such as anti-interference, anti-attenuation, and high security. It iswidely used in telecommunications.

In FH mode, frequency diversity gain and interference averaging are adopted to improve speechquality. In addition, FH technologies are used to simplify frequency planning and improvesystem capacity in networks with limited frequencies. However, FH technologies may have anegative impact on data services. Especially for high-rate data services, such as CS3–CS4 andMCS5–MCS9, FH may be harmful.

In RF FH mode, the TX frequencies and RX frequencies of each TRX may change. Both theTX frequencies and the RX frequencies of TRXs participate in FH. In a cell, the number offrequencies joining in FH is defined by the Hopping Sequence Number (HSN). The number offrequencies participating in FH can exceed the number of TRXs in the cell.

In RF FH mode, the TX frequency of a TRX changes with every burst. Therefore, the tuning ofthe RF front-end device must be able to keep pace with the changes. Otherwise, a widebanddevice must be used. The DFCU is a narrowband combiner. Its tuning rate is lower than thechanging rate of frequencies. Therefore, the DFCU can be used only for baseband FH insteadof RF FH.

Prerequisitel The LMT runs normally.

l The communication between the LMT and the BSC is normal.

l The communication between the BTS and the BSC is normal.

Preparation

Table 17-3 lists the data to be negotiated and planned before you change none FH to RF FH.




Table 17-3 Data to be negotiated and planned for changing none FH to RF FH

Category Source Description

FH Mode Networkplanning

FH has three modes: RF FH, Baseband FH, and NoneFH.

TRXs The cell must be configured with at least two TRXs.

Frequencies The number of frequencies in a cell must be greater thanthe number of TRXs joining in FH.

Table 17-4 lists the data to be negotiated and planned for changing none FH to RF FH.

Table 17-4 Example of the data negotiated and planned for changing none FH to RF FH

Category Original Configuration Data Modified Configuration Data

FH Mode None FH RF FH (HSN = 1, MAIO = 0, 1, 2)

TRXs l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12

l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12




Frequencies l Frequencies of cell 3012-1:– 0

– 10

– 13

– 16

– 19

l Frequencies of cell 3012-2:– 11

– 14

– 17

– 20


– 15

– 18

– 21

l MA of cell 3012-1:– 0

– 10

– 13

– 16

– 19

l MA of cell 3012-2:– 11

– 14

– 17

– 20

l MA of cell 3012-4:– 12

– 15

– 18

– 21

Procedure

Step 1 On the BSC6000 Local Maintenance Terminal, right-click the target cell. A shortcut menu isdisplayed, as shown in Figure 17-2.

Figure 17-2 Choosing Configure Cell Attributes

Step 2 Choose Configure Cell Attributes. A dialog box is displayed, as shown in Figure 17-3.




Figure 17-3 Configuring Cells Attributes dialog box

Step 3 Add the cell from the Cell view list box to the Selected cells list box, as shown in Figure17-4.

Figure 17-4 Selecting a cell

Step 4 Click Next. A dialog box is displayed, as shown in Figure 17-5.



Figure 17-5 Set Cell Attributes dialog box

Step 5 Select 3012-1 from the Cells to be set list box, and then click Set Cell Properties. A dialog boxis displayed, as shown in Figure 17-6.





Step 6 Click Frequency Hopping. A dialog box is displayed, as shown in Figure 17-7.



Figure 17-7 Configuring FH attributes

Step 7 Select RF FH from the FH Mode drop-down list. A dialog box is displayed, as shown in Figure17-8.

Figure 17-8 Selecting the RF FH mode

Step 8 Click Configure MA Group. A dialog box is displayed, as shown in Figure 17-9.




Figure 17-9 Configuring cell MA group attributes

NOTE

In RF FH mode, one cell is usually configured with only one MA group.

Step 9 Click OK to finish the configuration of cell MA group attributes and return to the dialog boxshown in Figure 17-8.

Step 10 Click OK to finish the configuration of FH attributes and return to the dialog box shown inFigure 17-6.

Step 11 Click OK to finish the changing of the FH mode of cell 3012-1 and return to the dialog boxshown in Figure 17-5.




Figure 17-10 Configuring BTS equipment

Step 13 Click Finish.

NOTE

The procedure for changing the FH mode of cell 3012-2 or cell 3012-4 is the same as that of cell 3012-1.

----End

17.6.2 Changing None FH to Baseband FHThis describes how to change the FH mode of a cell from none FH to baseband FH to achievefrequency reuse and interference averaging.






In baseband FH mode, the TX frequencies do not participate in FH and remain unchanged. TheTX FH is achieved through the switch of baseband signals between different TRXs. The RXfrequencies must participate in RF FH. The RX frequencies change with the frequencies used




by the current MS. The number of frequencies participating in FH in a cell should not exceedthe number of TRXs in the cell.





PreparationTable 17-5 lists the data to be negotiated and planned before you change none FH to basebandFH.

Table 17-5 Data to be negotiated and planned for changing none FH to baseband FH






Table 17-6 lists the data to be negotiated and planned for changing none FH to baseband FH.

Table 17-6 Example of the data negotiated and planned for changing none FH to baseband FH


FH Mode None FH Baseband FH (HSN = 1, MAIO = 0,1, 2)




TRXs l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12

l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12

Frequencies


– 10

– 13

– 16

– 19


– 14

– 17

– 20


– 15

– 18

– 21

l MA of cell 3012-1:– 0

– 10

– 13

– 16

– 19

l MA of cell 3012-2:– 11

– 14

– 17

– 20

l MA of cell 3012-4:– 12

– 15

– 18

– 21

Procedure






Step 7 Select Baseband FH from the FH Mode drop-down list. A dialog box is displayed, as shownin Figure 17-17.

Figure 17-17 Selecting the baseband FH mode

NOTE

During this operation, a dialog box is displayed, asking you to decide whether to allow the BCCH frequencyto participate in baseband FH. Select Yes.






NOTE

l Under normal conditions, one cell is configured with only one MA group. In baseband FH mode, twoMA groups must be configured if the BCCH frequency joins in baseband FH.

l Under normal conditions, use the default settings.








Step 13 Click Finish.NOTE


----End

17.6.3 Changing RF FH to Baseband FHThis describes how to change the FH mode of a cell from RF FH to baseband FH to optimizenetwork performance.






In RF FH mode, the TX frequencies and RX frequencies of each TRX may change. Both theTX and RX of TRXs participate in FH. In a cell, the number of frequencies joining in FH isdefined by the Hopping Sequence Number (HSN). The number of frequencies participating inFH can exceed the number of TRXs in the cell.




In baseband FH mode, the TX frequencies do not participate in FH and remain unchanged. TheTX FH is achieved through the switch of baseband signals between different TRXs. The RXfrequencies must participate in RF FH. The RX frequencies change with the frequencies usedby the current MS. The number of frequencies participating in FH in a cell should not exceedthe number of TRXs in the cell.





PreparationTable 17-7 lists the data to be negotiated and planned before you change RF FH to basebandFH.

Table 17-7 Data to be negotiated and planned for changing RF FH to baseband FH






Table 17-8 lists the data to be negotiated and planned for changing RF FH to baseband FH.

Table 17-8 Example of the data negotiated and planned for changing RF FH to baseband FH


FH Mode RF FH (HSN = 1, MAIO = 0, 1, 2) Baseband FH (HSN = 1, MAIO = 0, 1,2)




TRXs l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12

l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12


– 10

– 13

– 16

– 19


– 14

– 17

– 20


– 15

– 18

– 21

l MA of cell 3012-1:– 0

– 10

– 13

– 16

– 19

l MA of cell 3012-2:– 11

– 14

– 17

– 20

l MA of cell 3012-4:– 12

– 15

– 18

– 21

Procedure






Step 7 Select None FH from the FH Mode drop-down list. An information box is displayed, as shownin Figure 17-26.

Figure 17-26 Information box

NOTE

Before changing the FH mode of a cell from RF FH to baseband FH or from baseband FH to RF FH, youmust set the FH mode of the cell to None FH.

Step 8 Click OK. A dialog box is displayed, as shown in Figure 17-27.




Figure 17-27 Reconfiguring FH attributes

NOTE

You need to reassign frequencies for all the TRXs except the TRX carrying the BCCH.

Step 9 Double-click TRX 2. A dialog box is displayed, as shown in Figure 17-28.

Figure 17-28 Configuring TRX attributes

Step 10 Select a frequency from the Available Frequencies list box and add it to the AssignedFrequencies list box, as shown in Figure 17-29.



Figure 17-29 Assigning a frequency to TRX 2

Step 11 Click OK. TRX 2 is assigned a frequency. Use the same method to assign frequencies 13, 16,and 19 to TRX 4, TRX 6, and TRX 8 respectively. Figure 17-30 shows the dialog box after thefrequencies are assigned.

Figure 17-30 Assigning frequencies completed

Step 12 Select Baseband FH from the FH Mode drop-down list. A dialog box is displayed, as shownin Figure 17-31.




NOTE

During this operation, a dialog box is displayed, asking you to decide whether to allow the BCCH frequencyto participate in baseband FH. Select Yes.

Figure 17-31 Configuring attributes of baseband FH



NOTE

Under normal conditions, one cell is configured with only one MA group.






Step 17 In the dialog box shown in Figure 17-23, select 3012-2 and change the FH mode of 3012-2 fromRF FH to Baseband FH using the same method as changing the FH mode of cell 3012-1.

NOTE

The procedure for changing the FH mode of cell 3012-4 from RF FH to Baseband FH is the same as thatfor changing the FH mode of cell 3012-1.

Step 18 After changing the FH modes of cells 3012-1, 3012-2, and 3012-4, click Next in the dialog boxshown in Figure 17-23. A dialog box is displayed, as shown in Figure 17-33.


Step 19 Click Finish.

----End

17.6.4 Changing Baseband FH to RF FHThis describes how to change the FH mode of a cell from baseband FH to RF FH to optimizenetwork performance.









In RF FH mode, the TX frequencies and RX frequencies of each TRX may change. Both theTX and RX of TRXs participate in FH. In a cell, the number of frequencies joining in FH isdefined by the Hopping Sequence Number (HSN). The number of frequencies participating inFH can exceed the number of TRXs in the cell.






PreparationTable 17-9 lists the data to be negotiated and planned before you change baseband FH to RFFH.

Table 17-9 Data to be negotiated and planned for changing baseband FH to RF FH






Table 17-10 lists the data to be negotiated and planned for changing baseband FH to RF FH.



Table 17-10 Example of the data negotiated and planned for changing baseband FH to RF FH


FH Mode Baseband FH (HSN = 1, MAIO =0, 1, 2)

RF FH (HSN = 1, MAIO = 0, 1, 2)

TRXs l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12

l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12


– 10

– 13

– 16

– 19


– 14

– 17

– 20


– 15

– 18

– 21

l MA of cell 3012-1:– 0

– 10

– 13

– 16

– 19

l MA of cell 3012-2:– 11

– 14

– 17

– 20

l MA of cell 3012-4:– 12

– 15

– 18

– 21

Procedure






Step 7 Select None FH from the FH Mode drop-down list. A dialog box is displayed, as shown inFigure 17-40.

Figure 17-40 Changing to none FH mode

NOTE

Before changing the FH mode of a cell from RF FH to baseband FH or from baseband FH to RF FH, youmust set the FH mode of the cell to None FH.

Step 8 Select RF FH from the FH Mode drop-down list. A dialog box is displayed, as shown in Figure17-41.




Figure 17-41 Configuring attributes of RF FH



NOTE

Under normal conditions, one cell is configured with only one MA group.








Step 14 Click Finish.NOTE


----End

17.6.5 Changing RF FH to None FHThis describes how to change the FH mode of a cell from RF FH to none FH to optimize networkperformance.









In RF FH mode, the TX frequencies and RX frequencies of each TRX may change. Both theTX frequencies and the RX frequencies of TRXs participate in FH. In a cell, the number offrequencies joining in FH is defined by the Hopping Sequence Number (HSN). The number offrequencies participating in FH can exceed the number of TRXs in the cell.





PreparationTable 17-11 lists the data to be negotiated and planned before you change RF FH to none FH.

Table 17-11 Data to be negotiated and planned for changing RF FH to none FH






Table 17-12 lists the data to be negotiated and planned for changing RF FH to none FH.

Table 17-12 Example of the data negotiated and planned for changing RF FH to none FH


FH Mode RF FH (HSN = 1, MAIO = 0, 1, 2) None FH




TRXs l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12

l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12


– 10

– 13

– 16

– 19


– 14

– 17

– 20


– 15

– 18

– 21

l MA of cell 3012-1:– 0

– 10

– 13

– 16

– 19

l MA of cell 3012-2:– 11

– 14

– 17

– 20

l MA of cell 3012-4:– 12

– 15

– 18

– 21

Procedure






Step 7 Select None FH from the FH Mode drop-down list. An information box is displayed, as shownin Figure 17-50.

Figure 17-50 Information box

Step 8 Click OK. A dialog box is displayed, as shown in Figure 17-51.




Figure 17-51 Reconfiguring FH attributes

NOTE

You need to reassign frequencies for all the TRXs except the TRX carrying the BCCH.

Step 9 Double-click TRX 2. A dialog box is displayed, as shown in Figure 17-52.

Figure 17-52 Configuring TRX attributes

Step 10 Select a frequency from the Available Frequencies list box and add it to the AssignedFrequencies list box, as shown in Figure 17-53.



Figure 17-53 Assigning a frequency to TRX 2

Step 11 Click OK. TRX 2 is assigned a frequency. Use the same method to assign frequencies 13, 16,and 19 to TRX 4, TRX 6, and TRX 8 respectively. Figure 17-54 shows the dialog box after thefrequencies are assigned.

Figure 17-54 Assigning frequencies completed





Step 13 Click OK to finish changing the FH mode and return to the dialog box shown in Figure17-47.

Step 14 Select 3012-2 from the Cells to be set list box and modify the FH mode of cell 3012-2 by usingthe same method as modifying the FH mode of cell 3012-1.

NOTE

The procedure for changing the FH mode of cell 3012-4 is the same as that for changing the FH mode ofcell 3012-1.

Step 15 After changing the FH modes of cells 3012-1, 3012-2, and 3012-4, click Finish in the dialogbox shown in Figure 17-47.

----End

17.6.6 Changing Baseband FH to None FHThis describes how to change the FH mode of a cell from baseband FH to none FH to optimizenetwork performance.













PreparationTable 17-13 lists the data to be negotiated and planned before you change baseband FH to noneFH.

Table 17-13 Data to be negotiated and planned for changing baseband FH to none FH






Table 17-14 lists the data to be negotiated and planned for changing baseband FH to none FH.

Table 17-14 Example of the data negotiated and planned for changing baseband FH to none FH


FH Mode Baseband FH (HSN = 1, MAIO = 0,1, 2)

None FH

TRXs l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12

l TRX 1

l TRX 2

l TRX 3

l TRX 4

l TRX 5

l TRX 6

l TRX 7

l TRX 8

l TRX 9

l TRX 10

l TRX 11

l TRX 12






– 10

– 13

– 16

– 19


– 14

– 17

– 20


– 15

– 18

– 21

l MA of cell 3012-1:– 0

– 10

– 13

– 16

– 19

l MA of cell 3012-2:– 11

– 14

– 17

– 20

l MA of cell 3012-4:– 12

– 15

– 18

– 21

Procedure







Step 7 Select None FH from the FH Mode drop-down list. A dialog box is displayed, as shown inFigure 17-61.

Figure 17-61 Changing to none FH mode



Step 10 Select 3012-2 from the Cells to be set list box and modify the FH mode of cell 3012-2 by usingthe same method as modifying the FH mode of cell 3012-1.



NOTE

The procedure for changing the FH mode of cell 3012-4 is the same as that for changing the FH mode ofcell 3012-1.

Step 11 After changing the FH modes of cells 3012-1, 3012-2, and 3012-4, click Finish in the dialogbox shown in Figure 17-58.

----End

17.7 Maintenance InformationThis lists the alarms related to frequency hopping.

AlarmsTable 17-15 lists the alarms related to frequency hopping.

Table 17-15 Alarms

Alarm ID Alarm Name

403 Baseband FH Mutual Aid in a Cell

404 Switchback after Baseband FH Mutual Aid in a Cell

CountersNone.

17.8 References

GSM 05.02 / ETS 300 908

Multiplexing and multiple access on the radio path




201450621 frequency hopping

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