2g 3g handover

HUAWEI TECHNOLOGIES CO., LTD.

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Huawei Confidential

Security Level:2008-4-22

2G 3G Handover

Content

1. Constringent Transmit mode2. Handover CS 3G to 2G3. Handover CS 2G to 3G4. Handover PS 3G to 2.5G5. Handover PS 2.5G to 3G

HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential

Constringent Transmit Mode for UMTSConstringent Transmit Mode for UMTSHandover flow include measurement control, measurement, measurement report, handover judgment and handover execution. Measurement for intersystem is very importantConstringent Transmit mode: measurement for Inter-frequency and Inter-systemFor FDD transmit mode of UMTS network, UE need to receive DL data from NODEB for whole the time. UE can’t receive signal from other frequency or other system. Constringent transmit mode is used as giving some idle timeslot to measure other frequency or other system


Constringent Transmit Mode for UMTSConstringent Transmit Mode for UMTS

One frame(10 ms) Transmission gap available for

inter-frequency measurements

Using Puncturing half reducing Spreading factor and High level schedule actualize transmit GAP 7 timeslot is the biggest idle length for each 10ms frameWhen GAP span two radio frame, system using at least 8 timeslot as transmit data for each radio frame


Handover CS 3G to 2GHandover CS 3G to 2GHandover include these steps

measurement control

measurement report

handover judgment

handover executionIf there is only one RF mode in one UE, it must use constringent mode to

measure the different systemIf there are two RF mode in one UE, it can measure GSM network without

constringent modeHO Process:

UE send a bad quality information to RNC

RNC originate a constringent transmit mode to measure 2G networkRNC originate a handover from UMTS to GSM after find a good quality

GSM neighbor cell


Handover flow for CS 3G to 2GHandover flow for CS 3G to 2G

UE use measurement report of GSM get information of GSM (Rx_LEV. BSIC)


Handover CS 2G to 3GHandover CS 2G to 3G

For GSM handover to UMTS:When there are UMTS neighbors for GSM cells, measurement control

information is sent in system information

UE measure the UMTS system information in idle timeslot then send it to BSC

BSC make a judgment of handover using the measurement report.

Because GSM is a TDMA system:It can finish the UMTS’s measurement in idle timeslot

GSM needn’t support constringent mode .


Handover flow for CS 2G to 3GHandover flow for CS 2G to 3G

There is some judgment flow before handover using measurement report from UMTS system


Handover PS 3G to 2.5GHandover PS 3G to 2.5GUMTS to GRPS HO is data service HO from UMTS to GPRS;

1. UE update the measurement report that UMTS cell work in bad quality2. RNC send RL RECONFIG PREPARE command to NODEB. Asking

NODEB use constringent mode3. NODEB send RL RECONFIG READY information to RNC, when it

constringent mode is prepared4. RNC send PHYSICAL CHANNEL RECONFIG information to UE.

Asking UE use constringent mode5. RNC confirm UE had received the PHYSICAL CHANNEL RECONFIG

information，send a RL RECONFIG COMMIT information to NODEB，

tell NODEB the time of staring constringent mode6. UE send PHYSICAL CHANNEL RECONFIG COMPLETE information

to RNC，tell RNC that it had finished staring constringent mode

7. RNC send measurement control let UE begin to measure GSM system


Handover flow for PS 3G to 2.5G Handover flow for PS 3G to 2.5G

RNC originate handover flow after judgment using measure report of GSM Network.


Handover flow for PS 3G to 2.5GHandover flow for PS 3G to 2.5G


Handover flow for PS 2.5G to 3GHandover flow for PS 2.5G to 3G

Intersystem Change is the same with CS handover .The difference is when RNC received measure report of UMTS system will send a cell change information to UE


Handover flow for 2.5G to 3GHandover flow for 2.5G to 3G

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2g 3g handover

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