4-3G2G Reselection and Handover Principal
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Transcript of 4-3G2G Reselection and Handover Principal
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved
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Internal
3G2G Handover and reselection
ISSUE 1.0
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Chapter 1 Cell selection and reselectionChapter 1 Cell selection and reselection
Chapter 2 Inter-system Hard HandoverChapter 2 Inter-system Hard Handover
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Mise sous tension / couverture retrouvée
USIM 3G SIM 2G
Réseau et technologie d’accès préférés de l’utilisateur
Dernier réseau et technologie d’accès utilisés
Liste des autres réseaux
Réseau et technologie d’accès préférés de l’opérateur
Dernier réseau utilisé
Réseau préféré
Liste des autres Réseaux
Sélection de réseau
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Squal et Srxlev sont les deux critères de sélection d’une cellule:
RSCP: niveau de champ
Sélection d’une cellule WCDMA
Squal >0
Srxlev >0
Ec/No: interference
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SintraSearch(12dB)
SinterSearch(8dB)
SsearchRAT(4dB)
CPICH EcNo- qQualMin
Aucune possibilité de re-sélection
Possibilité de re-sélectionner seulement les cellules
intra-fréquence WCDMA
Possibilité de re-sélectionner seulement les cellules WCDMA
intra/inter- fréquence.
Possibilité de re-sélectionner les cellules WCDMA intra/inter-fréquence et inter-RAT.
Les paramètres de la cellule serveuse Sintrasearch, Sintersearch & SsearchRAT sont comparés avec Squal (CPICH Ec/No - Qqualmin).
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Le déclenchement de le re-sélection
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1èr rangement: de toute les cellules basé sur CPICH RSCP (WCDMA) & RSSI (GSM)
Rs = CPICH RSCP + Qhyst1(0dB)Rn= Rxlev(n) - Qoffset1 (0 dB)
1èr rangement: de toute les cellules basé sur CPICH RSCP (WCDMA) & RSSI (GSM)
Rs = CPICH RSCP + Qhyst1(0dB)Rn= Rxlev(n) - Qoffset1 (0 dB)
Rn (GSM) > Rs (WCDMA)And
Rxlev (GSM) >QrxlevMin(-101dBm)
Rn (GSM) > Rs (WCDMA)And
Rxlev (GSM) >QrxlevMin(-101dBm) YesNo
re-selection d’une cellule GSM
re-selection d’une cellule GSM
voisines WCDMA ou GSM calculées avec le paramètre
offset
UE démarre les mesures GSM si Squal < sSearchRAT(4 dB)
UE démarre les mesures GSM si Squal < sSearchRAT(4 dB)
Le deuxième rangement seulement pour les cellules WCDMA basé
sur CPICH Ec/NoRs = CPICH Ec/No + Qhyst2 (2dB)
Rn=CPICH_Ec/No(n)-Qoffset2 (0dB)
Le deuxième rangement seulement pour les cellules WCDMA basé
sur CPICH Ec/NoRs = CPICH Ec/No + Qhyst2 (2dB)
Rn=CPICH_Ec/No(n)-Qoffset2 (0dB) re-selection de cellule WCDMA ayant la plus
Grande valeur de R
re-selection de cellule WCDMA ayant la plus
Grande valeur de R
cellule WCDMA serveuse Calculée avec hysteresis
Algorithme de resélection
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Chapter 1 Cell selection and reselectionChapter 1 Cell selection and reselection
Chapter 2 Inter-system Hard HandoverChapter 2 Inter-system Hard Handover
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Chapter 2 Inter-system Hard HandoverChapter 2 Inter-system Hard Handover
2.1 Introduction2.1 Introduction
3. 2 Handover Algorithm3. 2 Handover Algorithm
3.3 Key Parameters3.3 Key Parameters
3.4 Signaling flow3.4 Signaling flow
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The Brief Introduction of 3G 2G Handover
Application scenarios
WCDMA FDD < - >GSM
Characters
GSM is used as an access technology after handover
Compressed mode should be used to help the measurement
Advantages
For coverage, it can solve the problems from one system to another system
For capacity, it can enhance the utilizing efficiency of old equipments
Disadvantages
The flow is complicated, and it demands higher compatibility for equipments
Demands more complicated UE
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Compressed Mode Initiated
The inter-system measurement (GSM measurement)
Measurement type:
− GSM Carrier RSSI
− BSIC Identification
− BSIC Reconfirmation
The process of measurement: layer 1 filter, layer 3 filter
Measurement reporting
− Event reporting
▪ 2D Event: initiate GSM measurement
▪ 2F Event: stop GSM measurement
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Les résultats de mesure des cellules GSM voisines doivent satisfaire l’équation suivante
AVE_RXLEV_NCELL(n)>AdjgRxLevMinHO
Decision Algorithm
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BSIC Verification
Le mobile se synchronise à la cellule GSM avant l’exécution du handover.
Vérifier l’identification de la cellule GSM voisine au cas où deux cellule GSM voisines ou plus utilisent la même fréquence BCCH.
Déclenchement ISHO Cellule cible trouvée Commande de ISHO
WCDMA Mesures RSSI Vérification BSIC
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Chapter 2 Inter-system Hard HandoverChapter 2 Inter-system Hard Handover
2.1 Introduction2.1 Introduction
3. 2 Handover Algorithm3. 2 Handover Algorithm
3.3 Key Parameters3.3 Key Parameters
3.4 Signaling flow3.4 Signaling flow
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Mesures dans le mobile
CPICH RSCP CPICH Ec/No
Mobile entre en mode compressé
GSM rapporte les mesuresRSSI
Conditions sur les cellules vérifiées?
Mobile entre en mode compressé
GSM rapporte les mesuresBSIC
Initier Handover
PS
CS
Handover Algorithm
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Decision Algorithm
Inter-system handover caused by coverage
Event reporting:
− 3A event : The estimated quality value of the used UTRAN
frequency is lower than a certain threshold, and that of the other
system is higher than a certain threshold .
Periodic reporting:
− Evaluation : According to the periodic reported GSM RSSI
measurement value and the BSIC confirming state of target cell of
GSM system, and meanwhile the UE evaluates the GSM RSSI of
target cell is greater than the absolute threshold, then consider
the cell confirmed by BSIC.
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Decision Algorithm
Inter-system handover caused by non-coverage
Event reporting
3C event: The estimated quality value of the other
system is higher than a absolute threshold.
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Chapter 2 Inter-system Hard HandoverChapter 2 Inter-system Hard Handover
2.1 Introduction2.1 Introduction
3. 2 Handover Algorithm3. 2 Handover Algorithm
3.3 Key Parameters3.3 Key Parameters
3.4 Signaling flow3.4 Signaling flow
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Key Parameters (I) Inter-system handover caused by coverage parameters
Inter-system measurement initiated and stopped threshold: Considering the different demands of CPICH Ec/No and CPICH RSCP for PS domain and CS domain, the different 2D and 2F parameters are configured
Inter-system measurement values (2D, 2F)
− CPICH Ec/No
− CPICH RSCP
BSIC confirmed (Optional)
Inter-system handover caused by coverage parameters
− configure the GSM RSSI threshold of CS domain and PS domain separately
Using inter-system frequency quality handover threshold
Configure the delay trigger time, hysteresis for each event
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Key Parameters (II)
Inter-system handover caused by non-coverage parameters
The period of inter-system measurement report
The decision threshold for inter-system handover: configure the
CS, PS, signaling separately
Time delay trigger : configure BSIC with acknowledged and
unacknowledged mode
Inter-frequency measurement layer 3 filter coefficient and
hysteresis
Penalty time
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Chapter 2 Inter-system Hard HandoverChapter 2 Inter-system Hard Handover
2.1 Introduction2.1 Introduction
3. 2 Handover Algorithm3. 2 Handover Algorithm
3.3 Key Parameters3.3 Key Parameters
3.4 Signaling flow3.4 Signaling flow
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1. Relocation Required 2. Prepare
Handover 3. Handover
Request
4. Handover Request Ack
12. Iu Release Command
13. Iu Release Complete 14. Send End
Signal Response
5. Prepare Handover Response
6. Relocation Command
7. DCCH : Handover from UTRAN Command
8. Handover
Detect
9. Handover Complete
10. Handover Complete
11. Send End
Signal Request
UE Node B SRNC CN MSC BSC
Inter-system Handover Flow
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