Method for handover, mobile station for handover and base station for handover

• US 6,879,830 B1
• Filed: 01/06/2000
• Issued: 04/12/2005
• Est. Priority Date: 01/08/1999
• Status: Expired due to Term

• Current Assignee: IPCom GmbH & Co KG
• Original Assignee: Robert Bosch GmbH
• Inventors: Vollmer, Vasco, Radimirsch, Markus
• Primary Examiner(s): Milord, Marceau
• Application Number:
  US09/478,586
• Time in Patent Office: 1,923 Days
• Field of Search: 455/442, 455/436, 455/437, 455/439, 455/524, 455/525, 455/502, 455/67.1, 455/62, 455/422, 370/331, 370/328, 370/329
• US Class Current: 455/442
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 76/30 Connection release
• CPC Class Codes: H04W 92/20 between access points

Abstract

A method for handing over a link between a mobile station and a network from a first base station to a second base station of the network. In the case of an existing link, link data for the link are stored in the base station in question and resources of the base station are held in reserve for the link. When a link is handed over, the link data initially remain stored in the first base station and the resources of the first base station initially remain held in reserve. At a later timepoint the link data are deleted and the resources are freed up. Furthermore, a method is used in which in the case of a handover the mobile station sends the network a query as to whether the network can support the handover by transferring the link data from the first mobile station to the second mobile station. If the mobile station is informed that the network cannot support the handover the mobile station makes the link data available to the second base station.

Claims

1. A mobile station for use with a network including a first base station and a second base station that achieves a handover from the first base station to the second base station by:

storing link data for a link in a first base station,

holding in reserve for the link resources of the first base station, and

when the link is to be handed over to the second base station;

initially maintaining a storage of the link data in the first base station,

initially causing the resources of the first base station to remain held in reserve, and

at a later timepoint determined by a fixed period of time predefined at a beginning of the handover, deleting the link data from the first base station and freeing up the resources of the first base station, the mobile station comprising;

an arrangement for reactivating the link with the first base station if the handover is unsuccessful.

2. A method for handing over a link existing between a mobile station and a network by transferring from a first base station of the network to a second base station of the network, comprising the steps of:

storing link data for the link in the first base station;

when a handover is to be attempted, causing the mobile station to send to the network a query as to whether the network is capable of supporting the handover by transferring the link data from the first base station to the second base station; and

if the mobile station is informed that the network cannot support the handover, causing the mobile station to make the link data available to the second base station.

3. A mobile station for use in a network that is capable of handing over an existing link with the mobile station from a first base station of the network that stores link data to a second base station of the network, the mobile station comprising:

an arrangement for sending to the network a query as to whether the network is capable of supporting the handover by transferring the link data from the first base station to the second base station; and

an arrangement for making the link data available to the second base station if the mobile station is informed that the network is incapable of supporting the handover.

4. A base station for use as one of a first base station and a second base station in a network capable of establishing with a mobile station a link that is capable of being handed over from the first base station of the network to the second base station of the network, comprising:

an arrangement for storing link data for the link;

an arrangement for processing a query sent by the mobile station to the network as to whether the network is capable of supporting a handover involving a transfer of the link data from the first base station to the second base station;

an arrangement for informing the mobile station whether the network is capable of supporting the handover; and

an arrangement for asking the mobile station for the link data if the network is incapable of supporting the handover.

5. A method for handing over a link between a mobile station and a network having at least a first base station and a second base station, the link being handed over from the first base station to the second base station, comprising:

storing in the first base station link data until at least a later timepoint, the link data containing current parameters of the link;

reserving in the first base station a link resource for the link until at least the later timepoint;

receiving at the network a query from the mobile station as to whether the network is capable of transferring the link data from the first base station to the second base station;

causing the mobile station to transmit the link data to the second base station, if the network cannot transfer the link data; and

handing over the link from the first base station to the second base station.

6. The method of claim 5, further comprising:

receiving at the second base station a handover request from the mobile station.

7. The method of claim 5, further comprising:

deleting the link data stored in the first base station and releasing the link resource reserved in the first base station, in response to a successful completion of handing over the link.

8. The method of claim 5, further comprising:

re-establishing the link with the first base station using the stored link data and the reserved link resource in the first base station for the link, in response to an unsuccessful completion of handing over the link.

9. The method of claim 5, further comprising:

determining the later timepoint based on a message from one of the mobile station and the second base station regarding the successful completion of handing over the link.

10. The method of claim 5, further comprising:

determining the later timepoint by predefining a fixed period of time at a beginning of handing over the link.

11. The method of claim 5, further comprising:

causing the first base station to transfer the link data to the second base station, if the network can transfer the link data.

12. A mobile station, comprising:

an arrangement for transmitting link data for a link between the mobile station and a first base station of a network to a second base station of the network, the link data containing current parameters of the link; and

an arrangement for reestablishing the link with the first base station, wherein;

the first base station stores the link data;

the first base station reserves a link resource for the link between the mobile station and the first base station;

if the network cannot support handing over the link by transferring the link data from the first base station to the second base station, the mobile station transmits the link data to the second base station;

in response to the second base station receiving the link data, the link is handed over from the first base station to the second base station;

in response to a successful completion of handing over the link, the link data stored in the first base station is deleted and the link resource reserved in the first base station is released; and

in response to an unsuccessful completion of handing over the link, the link between the mobile station and the first base station is re-established using the stored link data and the reserved link resource in the first base station for the link.

13. The mobile station of claim 12, further comprising:

an arrangement for transmitting a request to the network for handing over the link between the mobile station and the network from the first base station to the second base station.

14. The mobile station of claim 12, further comprising:

an arrangement for transmitting a query to the network as to whether the network is capable of supporting the handover by transferring the link data from the first base station to the second base station.

15. The mobile station of claim 12, further comprising:

an arrangement for receiving a message from the network indicating whether the network is capable of supporting the handover by transferring the link data from the first base station to the second base station.

16. A first base station of a network for use with a mobile station, the network achieving handing over of a link between the mobile station and the network from a first base station to a second base station of the network, comprising:

an arrangement for storing link data for the link, the link data containing current parameters for the link; and

an arrangement for reserving a link resource for the link, wherein;

if the network is able to support handing over the link by transferring the link data from the first base station to the second base station, the first base station transfers the link data to the second base station;

if the network cannot support handing over the link by transferring the link data from the first base station to the second base station, the mobile station transmits the link data to the second base station;

in response to the second base station receiving the link data, the link is handed over from the first base station to the second base station;

in response to a successful completion of handing over the link, the link data stored in the first base station is deleted and the link resource reserved in the first base station is released; and

in response to an unsuccessful completion of handing over the link, the link between the mobile station and the first base station is re-established using the stored link data and the reserved link resource in the first base station for the link.

17. The first base station of claim 16, further comprising:

an arrangement for re-establishing the link between the first base station and the mobile station.

18. A mobile station for use with a network including a first base station and a second base station that achieves a handover from the first base station to the second base station by:

storing link data for a link in a first base station,

holding in reserve for the link resources of the first base station, and

when the link is to be handed over to the second base station;

initially maintaining a storage of the link data in the first base station,

initially causing the resources of the first base station to remain held in reserve, and

at a later timepoint determined based on a message from one of the mobile station and the second base station regarding a successful completion of handing over the link, deleting the link data from the first base station and freeing up the resources of the first base station, the mobile station comprising;

an arrangement for reactivating the link with the first base station if the handover is unsuccessful.