02-10-2012, 03:16 PM
3G HANDOVER ISSUES
[attachment=35037]
UMTS Handover
Intra-system Handover:
Intra-frequency HO
Inter-frequency HO
Inter-system HO
• Different radio access technologies (e.g.
UMTS and GSM/EDGE)
• Different radio access modes (e.g.
FDD/WCDMA and TDD/TD-CDMA)
Hard handover
Hard handover `break-before-make' is applied when the user’s equipment communicates with only just one Node B. Connection with the old Node B is broken before the new connection is established
Soft handover
UE is located in the coverage area of two or more different Node Bs. The UE simultaneously communicates with two or more Node Bs via two or more radio channels. A received signal in Node B is routed to the RNC (Radio Network Controller). The RNC compares the signal on the frame by- frame basis. The best frame is selected for the next processing; the others frames are discarded.
Handover Detection
One of the responsibilities of the handover entity is monitoring and triggering the handover.
[attachment=35037]
UMTS Handover
Intra-system Handover:
Intra-frequency HO
Inter-frequency HO
Inter-system HO
• Different radio access technologies (e.g.
UMTS and GSM/EDGE)
• Different radio access modes (e.g.
FDD/WCDMA and TDD/TD-CDMA)
Hard handover
Hard handover `break-before-make' is applied when the user’s equipment communicates with only just one Node B. Connection with the old Node B is broken before the new connection is established
Soft handover
UE is located in the coverage area of two or more different Node Bs. The UE simultaneously communicates with two or more Node Bs via two or more radio channels. A received signal in Node B is routed to the RNC (Radio Network Controller). The RNC compares the signal on the frame by- frame basis. The best frame is selected for the next processing; the others frames are discarded.
Handover Detection
One of the responsibilities of the handover entity is monitoring and triggering the handover.