Communication control system and method of controlling communication

• US 6,172,982 B1
• Filed: 02/24/1998
• Issued: 01/09/2001
• Est. Priority Date: 02/25/1997
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ishii, Kenichi, Osawa, Tomoki
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Pham, Brenda H.
• Application Number:
  US09/028,812
• Time in Patent Office: 1,050 Days
• Field of Search: 370/338, 370/401, 370/402, 370/331, 370/332, 455/432, 455/433, 455/435
• US Class Current: 370/401
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 80/02 Data link layer protocols

Abstract

A communication control system in a packet communication network having a plurality of radio sub-networks, the radio sub-networks being connected to a wired sub-network by learning type bridges, respectively, the system including a radio terminal for communicating with the radio sub-networks, the radio terminal including first means for detecting whether or not the terminal moves from one of the radio sub-networks to other radio sub-networks, and second means for transmitting a dummy packet when movement between the radio sub-networks is detected.

Claims

1. A communication control system in a packet communication network having a plurality of radio sub-networks, said radio sub-networks being connected to a wired sub-network by learning type bridges, respectively, said system comprising:

a radio terminal for communicating with said radio sub-networks,

said radio terminal including;

first means for detecting whether or not said radio terminal moves from one of said radio sub-networks to other radio sub-networks; and

second means for transmitting a dummy packet when movement between said radio sub-networks is detected.

2. The communication control system according to claim 1, wherein said dummy packet is a packet that does not need a response packet.

3. The communication control system according to claim 1, wherein said learning type bridges comprise transmission means for transmitting a control packet to said sub-networks on a radio side, said control packet including sub-network discriminating signals that are different for each of said learning type bridges, and said first means is adapted to detect movement between said radio sub-networks when said sub-network discriminating signals included in a received control packet are different from a previously received sub-network discriminating signals.

4. The communication control system according to claim 2, wherein said learning type bridges comprise transmission means for transmitting a control packet to said sub-networks on a radio side, said control packet including sub-network discriminating signals that are different for each of said learning type bridges, and said first means is adapted to detect movement between said radio sub-networks when said sub-network discriminating signals included in a received control packet are different from a previously received sub-network discriminating signals.

5. The communication control system according to claim 1, wherein said first means is adapted to detect movement between said radio sub-networks when a registration discriminating signal is not registered in said radio terminal.

6. The communication control system according to claim 2, wherein said first means is adapted to detect movement between said radio sub-networks when a registration discriminating signal is not registered in said radio terminal.

7. The communication control system according to claim 1, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said first means is adapted to detect movement between said radio sub-networks when said radio channels are different from each other.

8. The communication control system according to claim 2, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said first means is adapted to detect movement between said radio sub-networks when said radio channels are different from each other.

9. The communication control system according to claim 3, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said first means is adapted to detect movement between said radio sub-networks when said radio channels are different from each other.

10. The communication control system according to claim 4, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said first means is adapted to detect movement between said radio sub-networks when said radio channels are different from each other.

11. A method of controlling communication in a packet communication network having a plurality of radio sub-networks, said radio sub-networks being connected to a wired sub-network by learning type bridges, respectively, said packet communication network comprising a radio terminal for communicating with said radio sub-networks, said method comprising steps of:

detecting whether or not said radio terminal moves from one of said radio sub-networks to other radio sub-networks; and

transmitting a dummy packet when movement of said radio terminal between said radio sub-networks is detected.

12. The method of controlling communication according to claim 11, wherein said dummy packet is a packet that does not need a response packet.

13. The method of controlling communication according to claim 11, wherein before said detecting step, said method further comprises a step of transmitting a control packet to said sub-networks on a radio side, said control packet including sub-network discriminating signals that are different for each of said learning type bridges, and said detecting step includes a step of detecting movement of said radio terminal between said radio sub-networks when said sub-network discriminating signals included in a received control packet are different from a previously received sub-network discriminating signals.

14. The method of controlling communication according to claim 12, wherein before said detecting step, said method further comprises a step of transmitting a control packet to said sub-networks on a radio side, said control packet including sub-network discriminating signals that are different for each of said learning type bridges, and said detecting step includes a step of detecting movement of said radio terminal between said radio sub-networks when said sub-network discriminating signals included in a received control packet are different from a previously received sub-network discriminating signals.

15. The method of controlling communication according to claim 11, wherein said detecting step includes a step of detecting movement of said radio terminal between said radio sub-networks when a registration discriminating signal is not registered in said radio terminal.

16. The method of controlling communication according to claim 12, wherein said detecting step includes a step of detecting movement of said radio terminal between said radio sub-networks when a registration discriminating signal is not registered in said radio terminal.

17. The method of controlling communication according to claim 11, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said detecting step includes of a step of detecting movement of said radio terminal between said radio sub-networks when said radio channels are different from each other.

18. The method of controlling communication according to claim 12, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said detecting step includes a step of detecting movement of said radio terminal between said radio sub-networks when said radio channels are different from each other.

19. The method of controlling communication according to claim 13, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said detecting step includes a step of detecting movement of said radio terminal between said radio sub-networks when said radio channels are different from each other.

20. The method of controlling communication according to claim 14, wherein each of said radio sub-networks uses radio channels that are different from each other, said radio terminal selects said radio channels in accordance with a predetermined radio channel selecting procedure, and said detecting step includes a step of detecting movement of said radio terminal between said radio sub-networks when said radio channels are different from each other.