Bsc6900 Gsm v9r11 Frequency Hopping Issue1

7/28/2019 Bsc6900 Gsm v9r11 Frequency Hopping Issue1

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Copyright 2010 Huawei Technologies Co., Ltd. All rights reserved.

GSM FrequencyHopping


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Copyright 2010 Huawei Technologies Co., Ltd. All rights reserved. Page2

Contents

1. Hopping Overview

2. Hopping Classification

3. Hopping Parameters


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Definition of Frequency Hopping


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Advantages of Hopping

Provide a similar

communication quality

for every user

Tighter reuse

patterns are

possible to be

used for larger

capacity

Get an

agreeable

radio

environment Advantagesof Hopping


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Smoothen the rapid fading (Rayleigh fading)

Frequency Diversity of Hopping


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Smoothen and average the interference

Interference Diversity of Hopping


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Contents

1. Hopping Overview




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Hopping Classification

According to Implementation mode

Baseband HoppingRF HoppingHybrid Hopping

According to the MinimumHopping Time Unit

Timeslot HoppingFrame Hopping


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Baseband Hopping Principle

FH bus


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BCCH carrier attends hopping, on which TS0 can not attend hopping

No HoppingTRX0

TRX1

TRX2

TRX3

TS 0 TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7 ARFCN

5(BCCH carrier)10(TCH carrier)

15(TCH carrier)

20(TCH carrier)

MA={5,10,15,20}MA={10,15,20}


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BCCH carrier does not attends hopping

TRX0

TRX1

TRX2

TRX3

TS 0 TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7

MA={10,15,20}

ARFCN

5(BCCH carrier)10(TCH carrier)

15(TCH carrier)

20(TCH carrier)

No Hopping No Hopping No Hopping No Hopping No Hopping No Hopping No Hopping No Hopping


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RF Hopping Principle


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RF Hopping Principle

BCCH carrier does not attends hopping

TRX0

TRX1

TRX2

TRX3

TS 0 TS 1 TS 2 TS 3 TS 4 TS 5 TS 6 TS 7

No Hopping No Hopping No Hopping No Hopping No Hopping No Hopping No Hopping No Hopping

MA={10,15,20}

MA={10,15,20}

MA={10,15,20}

(BCCH carrier)

(TCHcarrier)


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Hybrid Hopping

In hybrid FH, some TRXs adopt RF FH and other TRXs adopt

baseband FH in a cell.

One TRX, however, can adopt either RF FH or baseband FH.

Generally, hybrid FH is applicable to co-BCCH cells

overlaid

Underlaid

900M/850MHZ

Baseband Hopping

Overlaid

1800M/1900MHZ

RF Hopping


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Hopping Classification

Frame hopping

Frequency changes every TDMA frame.

The different channel of one TRX uses the same MAIO.

Timeslot hopping

Frequency changes every timeslot.

The different channel of one TRX uses the different MAIO.


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Frame Hopping

f 0

Frame 0

f 1

f 2

f 3

f 4

Frame 1 Frame 2 Frame 3 Frame 4

One TRX (none BCCH carrier) hopping on 5 frequencies

RF hopping and baseband hopping without BCCH carrier


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Timeslot Hopping

f 0

Frame 0

f 1

f 2

f 3

f 4


5 timeslots on 1 TRX hopping on 5 frequencies


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Contents

1. Hopping Overview




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Hopping Mode

All the parameters which are related to hopping are

configured in Cell Attributes/Frequency Hopping.

Hopping mode: the mode used by the BTS system

No hopping

Baseband hopping

RF hopping

Hybrid hopping


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Data Configuration of Hopping Mode


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Hopping Parameters

HSNHopping Sequence Number063

HSN=0cycle hopping.

HSN0random hopping. Every sequence number

corresponds a pseudo random sequence.


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Hopping Parameters

MA (Mobile Allocation Set):

MA is the set of available RF bands when hopping, containing at most 64

frequency carriers. The frequency being used must be those of the available

frequency

MAIO (Mobile Allocation Index Offset) MAIO is used to define the initial frequency of the hopping.

Be careful to configure the MAIO of same timeslot in all channels, otherwise

interference occurs.

MAI (Mobile Allocation Index)

At the air interface, the frequency used on a specific burst is an element in MA

set. MAI is used for indication, referring to a specific element in the MA set.

MAI is the function of TDMA FN, HSN and MAIO.


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Example of MAIO

No Hopping0

2

1

2

2

2

3

2

0

2

1

2

2

2

0 11

2

2

2

3

2

0

2

1

2

2

2

3

2

1 12

2

3

2

0

2

1

2

2

2

3

2

0

2

2 13

2

0

2

1

2

2

2

3

2

0

2

1

2

TRX0

TRX1

TRX2

TRX3


5(BCCH carrier)

10(TCH carrier)15(TCH carrier)

20(TCH carrier)

MA2={5,10,15,20}MA1={10,15,20}

MAIO 0 1 2 MAIO 0 1 2 3

MAIO MAI


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Example of MAIO

No Hopping0

2

1

2

2

2

3

2

0

2

1

2

2

2

0 11

2

2

2

3

2

0

2

1

2

2

2

3

2

1 12

2

3

2

0

2

1

2

2

2

3

2

0

2

2 13

2

0

2

1

2

2

2

3

2

0

2

1

2

0 3

1

3

2

3 3 3

0

3

1

3

2

3

3

3

1 32

3

3

3

0

3

1

3

2

3

3

3

0

3

2 33

3

0

3

1

3

2

3

3

3

0

3

1

3

0 1 2 3 0 1 2

TRX0

TRX1

TRX2

TRX3


5(BCCH carrier)

10(TCH carrier)

15(TCH carrier)

20(TCH carrier)

MA2={5,10,15,20}

MA1={10,15,20}

MA3={510,515,520,525}

510(TCH carrier)

515(TCH carrier)

520(TCH carrier)

525(TCH carrier)

TRX4

TRX5

TRX6

TRX7


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Example of MAIO

5

Frame 0

10

15

20

25


MA={5,10,15,20,25}

5 TRXs separately belongs to the same MA hopping on 5frequencies, and uses same HSNs


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Example of Hopping Parameters

f 0

Frame 0

f 1

f 2

f 3

f 4


8 timeslots of 1 TRX separately belongs to different MAs hoppingon 5 frequencies, and uses different HSNs.


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Example of Hopping Parameters

f 0

Frame 0

f 1

f 2

f 3

f 4


5 TRXs separately belongs to different MAs hopping on 5frequencies, and uses different HSNs


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Summary

The function of frequency hopping

The classification of frequency hopping

The realization of frequency hopping


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Bsc6900 Gsm v9r11 Frequency Hopping Issue1

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