HANDOVER SUPPORTING SCHEME IN CELLULAR MOBILE COMMUNICATION SYSTEM

• US 20160302113A1
• Filed: 11/12/2014
• Published: 10/13/2016
• Est. Priority Date: 11/12/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: HWANG, Keun-Chul
• Granted Patent: US 10,455,463 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04L 5/0005 Time-frequency
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The present disclosure proposes a method for supporting a handover by a base station controller in a cellular mobile communication system including a terminal for performing a handover from a serving cell base station to a target cell base station, the method comprising the steps of: determining handover performance of the terminal; checking whether a resource of the same frequency and time slot as a frequency and time slot of a resource in use by the serving cell base station is usable in the target cell base station; and allocating a resource of the same frequency and time slot to the target cell base station, and transmitting a message indicating channel activation of the allocated resource to the target cell base station.

Claims

1. A method of supporting a handover by a base station controller in a cellular mobile communication system including a terminal performing the handover from a base station of a serving cell to a base station of a target cell, the method comprising:

determining to perform the handover of the terminal;

checking whether a resource of the same frequency and time slot as a frequency and time slot of a resource being used by the base station of the serving cell is available to the base station of the target cell; and

allocating the resource of the same frequency and time slot to the base station of the target cell and transmitting a message instructing to activate the channel allocated resource to the base station of the target cell.

2. The method of claim 1, wherein the frequency of the resource being used by the base station of the serving cell is determined by at least one of channel group information, a hopping sequence number (HSN), and a mobile allocation index offset (MAIO).

3. The method of claim 1, further comprising controlling the base station of the serving cell and the base station of the target cell to transmit downlink traffic of the terminal or receive uplink traffic of the terminal.

4. The method of claim 3, further comprising driving a timer for a certain period of time and checking whether a message indicating success in decoding the uplink traffic of the terminal is received from the base station of the target cell before the timer expires.

5. The method of claim 4, further comprising controlling the base station of the target cell to generate a set asynchronous balanced mode (SABM) in a case where the message indicating success in decoding is received as a result of checking whether the message indicating success in decoding is received.

6. The method of claim 5, wherein, before controlling the base station of the target cell to generate the SABM, the base station of the serving cell is controlled to communicate a slow associated control channel (SACCH) signal with the terminal, and after controlling the base station of the target cell to generate the SAMB, the base station of the target cell is controlled to communicate the SACCH signal with the terminal.

7. The method of claim 4, further comprising:

unless the message indicating success in decoding is received as a result of checking whether the message indicating success in decoding is received, transmitting a message instructing to deactivate the channel of the allocated resource and to activate a channel of a new resource to the base station of the target cell; and

transmitting a handover command message including information on the new resource to the terminal via the base station of the serving cell.

8. The method of claim 1, wherein checking whether the resource of the same frequency and time slot as the frequency and time slot of the resource being used by the serving cell base station is available to the target cell base station further includes checking whether an adjacent cell of the target cell uses the resource of the same frequency and time slot.

9. The method of claim 8, further comprising changing the resource allocation to prevent the adjacent cell of the target cell from using the same frequency and time slot in a case where the adjacent cell of the target cell uses the resource of the same frequency and time slot as a result of checking whether the neighbor cell of the target cell uses the resource of the same frequency and time slot.

10. The method of claim 1, further comprising, before determining to perform the handover of the terminal, allocating a call of the terminal to a resource with the least interference from an adjacent cell of the base station of the serving cell.

11. The method of claim 1, further comprising transmitting a message instructing to release the channel of the resource being used by the base station of the serving cell to the base station of the serving cell.

12. A base station control device for supporting handover of a terminal in a cellular mobile communication system including a terminal performing handover from a base station of a serving cell to a base station of a target cell, the base station control device comprising:

a controller determining to perform the handover of the terminal, checking whether a resource of the same frequency and time slot as a frequency and time slot of a resource being used by the base station of the serving cell is available to the base station of the target cell, and allocating the resource of the same frequency and time slot to the base station of the target cell and transmitting a message instructing to activate the channel allocated resource to the base station of the target cell; and

a transceiver transmitting and receiving a message with the terminal controlled by the controller, the base station of the serving cell, and the base station of the target cell.

13. The base station control device of claim 12, wherein the frequency of the resource being used by the base station of the serving cell is determined by at least one of channel group information, a hopping sequence number (HSN), and a mobile allocation index offset (MAIO).

14. The base station control device of claim 12, wherein the controller further controls the base station of the serving cell and the base station of the target cell to transmit downlink traffic of the terminal or receive uplink traffic of the terminal.

15. The base station control device of claim 14, wherein the controller further drives a timer for a certain period of time and checks whether a message indication success in decoding of the uplink traffic of the terminal is received from the base station of the target cell before the timer is expired.

16. The base station control device of claim 15, wherein the controller further controls the base station of the target cell to generate a set asynchronous balanced mode (SABM) in a case where the message indicating success in decoding is received as a result whether the message indicating success in decoding is received.

17. The base station control device of claim 16, wherein, before controlling the base station of the target cell to generate the SABM, the controller controls the base station of the serving cell to communicate a slow associated control channel (SACCH) signal with the terminal, and after controlling the base station of the target cell to generate the SAMB, the controller controls the base station of the target cell to communicate the SACCH signal with the terminal.

18. The base station control device of claim 15, wherein the controller further, unless the message indicating success in decoding is received as a result of checking whether the message indicating success in decoding is received, controls to transmit a message instructing to deactivate the channel of the allocated resource and to activate a channel of a new resource to the base station of the target cell and controls to transmit a handover command message including information on the new resource to the terminal via the base station of the serving cell.

19. The base station control device of claim 12, wherein while checking whether the resource of the same frequency and time slot as the frequency and time slot of a resource being used by the serving cell base station is available to the target cell base station, the controller further checks whether an adjacent cell of the target cell uses the resource of the same frequency and time slot.

20. The base station control device of claim 19, wherein the controller further changes the resource allocation to prevent the adjacent cell of the target cell from using the same frequency and time slot in a case where the adjacent cell of the target cell uses the resource of the same frequency and time slot as a result of checking whether the neighbor cell of the target cell uses the resource of the same frequency and time slot.

21. The base station control device of claim 12, wherein before determining to perform the handover of the terminal, the controller further allocates the call of the terminal to a resource with the least interference from an adjacent cell of the base station of the serving cell.

22. The base station control device of claim 12, wherein the controller further transmits a message instructing to release the channel of the resource being used by the base station of the serving cell to the base station of the serving cell.