METHOD AND APPARATUS FOR CONNECTING TO NETWORK IN A SHORT-RANGE MOBILE COMMUNICATION TERMINAL

• US 20090081952A1
• Filed: 09/22/2008
• Published: 03/26/2009
• Est. Priority Date: 09/21/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KIM, Jae-Ho, CHOI, Woo-Jun, SIM, Dae-Hyun, HAN, Young-Seop, LEE, Jeong-Eun
• Granted Patent: US 8,200,155 B2
• Time in Patent Office: Days
• US Class Current: 455/41.200
• CPC Class Codes: H04W 40/12 based on transmission quality or channel quality
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 48/14 using user query or user detection
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and apparatus for connecting to a network in a short-range mobile communication terminal are provided, in which a neighbor terminal information request message is periodically broadcast, a neighbor terminal information response message is received from at least one neighbor short-range mobile communication terminal, an RSSI of the neighbor terminal information response message is measured, the RSSI and neighbor terminal information included in the neighbor terminal information response message are stored for the at least one neighbor short-range mobile communication terminal, a closest neighbor WPAN is determined using the RSSI, a WPAN to join is selected based on the determination, and the selected WPAN is connected to.

Claims

1. A method for reconnecting from a serving coordinator of a serving Wireless Personal Area Network (WPAN) to a coordinator of another WPAN by Zigbee communications in a terminal, the method comprising:

broadcasting a neighbor terminal information request message periodically to neighbor terminals;

receiving a neighbor information response message from at least one neighbor terminal;

storing a neighbor table having neighbor terminal information included in the neighbor information response message, the neighbor terminal information including Link Quality Information (LQI) and neighbor router information about the at least one neighbor terminal; and

reconnecting to the coordinator of the another WPAN using the LQI and the neighbor router information and communicating with the coordinator of the another WPAN.

2. The method of claim 1, wherein the neighbor router information includes information about routers within neighbor candidate WPANs, the routers relaying data of the terminal to coordinators within the neighbor candidate WPANs.

3. The method of claim 1, wherein the neighbor table further includes information indicating whether the at least one neighbor terminal is a coordinator, a router, or a terminal.

4. The method of claim 1, wherein the neighbor table further includes relation information indicating whether the at least one neighbor terminal is a parent, a child, a previous child, or none to the terminal.

5. The method of claim 1, wherein the LQI is a ratio between a data transmission power value and an error rate between the at least one neighbor terminal and the terminal.

6. The method of claim 1, wherein the reconnection and communication comprises:

detecting a greatest LQI from among stored LQIs;

reconnecting, if there is one greatest LQI and a WPAN connected to a terminal with the largest LQI is different from the serving WPAN, to a coordinator of the WPAN and communicating with the coordinator of the WPAN;

maintaining a connection to the serving coordinator of the serving WPAN, if there are at least two greatest LQIs and one of WPANs connected to terminals with the largest LQIs is the serving WPAN; and

selecting, if there are at least two greatest LQIs and WPANs connected to terminals with the largest LQIs are different from the serving WPAN, one of the terminals with the greatest LQIs, reconnecting to a coordinator of the WPAN connected to the selected terminal, and communicating with the coordinator of the WPAN.

7. The method of claim 1, wherein the reconnection and communication comprises:

detecting a greatest LQI from among stored LQIs; and

reconnecting, if a WPAN connected to a terminal with the greatest LQI is different from the serving WPAN and the LQI of the terminal increases continuously for a predetermined time, to a coordinator of the WPAN and communicating with the coordinator of the WPAN.

8. The method of claim 1, wherein the reconnection and communication comprises:

requesting joining to a coordinator of a WPAN corresponding to a greatest LQI;

receiving a response for the joining request; and

transmitting a leave message to the serving coordinator of the serving WPAN.

9. An apparatus for reconnecting from a serving coordinator of a serving Wireless Personal Area Network (WPAN) to a coordinator of another WPAN by Zigbee communications in a terminal, the apparatus comprising:

a transceiver for transmitting and receiving signals and messages by Zigbee communication and receiving a neighbor information response message from at least one neighbor terminal; and

a controller for controlling the transceiver according to the Zigbee communication, broadcasting a neighbor terminal information request message periodically through the transceiver, storing a neighbor table having neighbor terminal information included in the neighbor information response message, the neighbor terminal information including Link Quality Information (LQI) and neighbor router information about the at least one neighbor terminal, and reconnecting to the coordinator of the another WPAN using the LQI and the neighbor router information and communicating with the coordinator of the another WPAN.

10. The apparatus of claim 9, wherein the neighbor router information includes information about routers within neighbor candidate WPANs, the routers relaying data of the terminal to coordinators within the neighbor candidate WPANs.

11. The apparatus of claim 9, wherein the neighbor table further includes information indicating whether the at least one neighbor terminal is a coordinator, a router, or a terminal.

12. The apparatus of claim 9, wherein the neighbor table further includes relation information indicating whether the at least one neighbor terminal is a parent, a child, a previous child, or none to the terminal.

13. The apparatus of claim 9, wherein the LQI is a ratio between a data transmission power value and an error rate between the at least one neighbor terminal and the terminal.

14. The apparatus of claim 9, wherein the controller detects a greatest LQI from among stored LQIs, and if there is one greatest LQI and a WPAN connected to a terminal with the greatest LQI is different from the serving WPAN, the controller reconnects to the coordinator of the WPAN and communicates with the coordinator of the WPAN

15. The apparatus of claim 14, wherein if there are at least two greatest LQIs and one of WPANs connected to terminals with the greatest LQIs is the serving WPAN, the controller maintains a connection to the serving coordinator of the serving WPAN.

16. The apparatus of claim 15, wherein if there are at least two greatest LQIs and WPANs connected to terminals with the greatest LQIs are different from the serving WPAN, the controller selects one of the terminals with the greatest LQIs, reconnects to a coordinator of the WPAN connected to the selected terminal, and communicates with the coordinator of the WPAN.

17. The apparatus of claim 9, wherein when the controller reconnects to the coordinator of the another WPAN and communicates with the coordinator of the another WPAN, the controller detects a greatest LQI from among stored LQIs, and if a WPAN connected to a terminal with the greatest LQI is different from the serving WPAN and the LQI of the terminal increases continuously for a predetermined time, the controller reconnects to a coordinator of the WPAN and communicates with the coordinator of the WPAN.

18. The apparatus of claim 9, wherein when the controller reconnects to the coordinator of the another WPAN and communicates with the coordinator of the another WPAN, the controller requests joining to a coordinator of a WPAN corresponding to a greatest LQI, receives a response for the joining request, and transmits a leave message to the serving coordinator of the serving WPAN.