Hard handover method, controller and communication system

• US 20060073828A1
• Filed: 06/02/2005
• Published: 04/06/2006
• Est. Priority Date: 10/06/2004
• Status: Active Grant

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Sipila, Juha
• Granted Patent: US 7,359,708 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/10 Reselecting an access point controller

Abstract

The invention is related to a controller of a communication system, the controller comprising: means for determining user terminal time delay between delivery and acknowledgement of a transmission; means for conveying the user terminal time delay; means for calculating switching time delay; and means for transferring user terminal data conveyance to the handover target network controller at a moment based on the switching time delay.

Claims

1. A hard handover method in a communication system, the method comprising:

determining user terminal time delay between delivery and acknowledgement of a transmission, in a handover source network controller;

conveying the user terminal time delay to a handover target network controller;

calculating a switching time delay in the handover target network controller using the user terminal time delay; and

transferring user terminal data conveyance to the handover target network controller based on the switching time delay.

3. The method of claim 1, wherein the user terminal time delay is conveyed by adding a new field to a container that is passed to the handover target network controller during an inter-RNC hard handover.

4. The method of claim 1, wherein the switching time delay is calculated by using an equation comprising

$\frac{\mathrm{round}}{}$

- ⁢

trip ⁢

 

⁢

 

⁢

time 2 + UE ⁢

 

⁢

cell ⁢

 

⁢

changeover ⁢

 

⁢

 

⁢

time ,

wherein

UE means a user terminal or a user equipment, and

the UE cell changeover time is a previously known parameter or is estimated during an intra-RNC hard handover, where a round-trip time is measured during a configuration management and subtracted from the switching time delay caused by the hard handover target network controller.

6. The method of claim 1, wherein a round-trip time is determined as the user terminal time delay between the delivery and the acknowledgement of the transmission.

7. The method of claim 1, wherein the switching time delay is controlled by delaying sending of a relocation detect message from a target radio network controller (RNC).

2. A hard handover method in a communication system, the method comprising:

determining user terminal time delay between delivery and acknowledgement of a transmission, in a handover source network controller;

conveying the user terminal time delay to a handover target network controller;

calculating a switching time delay in the handover target network controller; and

transferring user terminal data conveyance to the handover target network controller based on the switching time delay.

5. The method of claim 2, wherein the switching time delay is calculated using user terminal cell changeover time and the user terminal time delay between the delivery and the acknowledgement of the transmission.

8. A controller of a communication system, the controller comprising:

means for determining user terminal time delay between delivery and acknowledgement of a transmission;

means for conveying the user terminal time delay;

means for calculating a switching time delay; and

means for transferring user terminal data conveyance to a handover target network controller based on the switching time delay.

9. The controller of a communication system of claim 8, further comprising:

means to convey the user terminal time delay by adding a new field to a container that is passed to the handover target network controller during an inter-RNC hard handover.

10. The controller of a communication system of claim 8, further comprising:

means to calculate the switching time by using an equation comprising

$\frac{\mathrm{round}<br><br>\text{-}<br><br>\mathrm{trip}<br><br>\text{\hspace{1em}<br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{time}}{2}+\mathrm{UE}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{cell}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{changeover}<br><br>\text{\hspace{1em}<br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{time},$

wherein

UE means a user terminal or a user equipment, and

UE cell changeover time is a previously known parameter or is estimated during an intra-RNC hard handover, where a round-trip time is measured during a configuration management and subtracted from the switching time delay caused by the hard handover target network controller.

11. The controller of a communication system of claim 8, further comprising:

means to calculate the switching time delay using user terminal cell changeover time and the user terminal time delay between the delivery and the acknowledgement of the transmission.

12. The controller of a communication system of claim 8, further comprising:

means to determine a round-trip time as the user terminal time delay between the delivery and the acknowledgement of the transmission.

13. The controller of a communication system of claim 8, further comprising:

means to control the switching time delay by delaying sending of a relocation detect message from a target radio network controller (RNC).

14. A communication system, comprising:

a controller being configured to

determine user terminal time delay between delivery and acknowledgement of a transmission;

convey the user terminal time delay;

calculate a switching time delay; and

transfer user terminal data conveyance to a handover target network controller based on the switching time delay.

15. A communication system, the system comprising:

means for determining user terminal time delay between delivery and acknowledgement of a transmission;

means for conveying the user terminal time delay;

means for calculating a switching time delay; and

means for transferring user terminal data conveyance to a handover target network controller based on the switching time delay.

16. The communication system of claim 15, further comprising:

means to convey the user terminal time delay by adding a new field to a container that is passed to the handover target network controller during an inter-RNC hard handover.

17. The communication system of claim 15, further comprising:

means to calculate the switching time by using an equation comprising

$\frac{\mathrm{round}<br><br>\text{-}<br><br>\mathrm{trip}<br><br>\text{\hspace{1em}<br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{time}}{2}+\mathrm{UE}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{cell}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{changeover}<br><br>\text{\hspace{1em}<br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{time},$

wherein

UE means a user terminal or a user equipment, and

UE cell changeover time is a previously known parameter or is estimated during an intra-RNC hard handover, where a round-trip time is measured during a configuration management and subtracted from the switching time delay caused by the hard handover target network controller.

18. The communication system of claim 15, further comprising:

means to calculate the switching time delay using user terminal cell changeover time and the user terminal time delay between the delivery and the acknowledgement of the transmission.

19. The communication system of claim 15, further comprising:

means to determine a round-trip time as the user terminal time delay between the delivery and the acknowledgement of the transmission.

20. The communication system of claim 15, further comprising:

means to control the switching time delay by delaying sending of a relocation detect message from a target radio network controller (RNC).

21. A communication system, the system being configured to:

determine user terminal time delay between delivery and acknowledgement of a transmission;

convey the user terminal time delay;

calculate a switching time delay; and

transfer user terminal data conveyance to a handover target network controller based on the switching time delay.