Relaying method of a mobile communication system and system thereof

• US 20080013459A1
• Filed: 06/19/2007
• Published: 01/17/2008
• Est. Priority Date: 06/20/2006
• Status: Active Grant

• Current Assignee: Industry Academic Cooperation Foundation, Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Bang, Jongho, Do, Mi-Sun, Lee, Jaiyong, Kwon, Eunhyun
• Granted Patent: US 8,223,659 B2
• Time in Patent Office: Days
• US Class Current: 370/248
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 40/12 based on transmission quality or channel quality
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point

Abstract

A method for setting a path by a base station in a mobile communication system and a system thereof are provided. The base station measures quality of a link directly connected to the mobile terminal using the received signal, if a signal is directly received from a mobile terminal. If the signal is received via at least one relaying node, the base station calculates quality of an entire path determined taking quality of each link into account, depending on the signal received via the at least one relaying node. The base station compares the calculated quality of the entire path with the quality of the directly connected link, and determines an optimal path according to the comparison result. The base station sends a relaying request message to a relaying node corresponding to the optimal path. Upon receipt of a relaying response message from the relaying node, the base station configures new broadcast information and broadcasts the newly configured broadcast information.

Claims

1. A method for setting a path by a base station in a mobile communication system, the method comprising:

if a signal is directly received from a mobile terminal, measuring quality of a link directly connected to the mobile terminal using the received signal;

if the signal is received via at least one relaying node, calculating quality of an entire path determined while taking quality of each link into account depending on the signal received via the at least one relaying node;

comparing the calculated quality of the entire path with the quality of the directly connected link, and determining an optimal path according to the comparison result;

sending a relaying request message to a relaying node corresponding to the optimal path; and

upon receipt of a relaying response message from the relaying node, configuring new broadcast information and broadcasting the newly configured broadcast information.

2. The method of claim 1, further comprising:

if the optimal path is changed, updating previously stored routing information based on the changed path, and broadcasting broadcast information including the updated routing information.

3. The method of claim 1, wherein the broadcasting comprises:

upon receipt of a relaying response message indicating approval of relaying from the relaying node, updating the previously stored routing information and broadcasting broadcast information including the updated routing information.

4. The method of claim 1, wherein the routing path between the base station and the relaying node is at least one of previously set and configured using link quality information broadcasted by the relaying node.

5. The method of claim 4, wherein the link quality information comprises at least one of information regarding a path over which the signal is transmitted, unique information of the relaying node, hop information between nodes, and channel quality information between the nodes.

6. The method of claim 1, wherein the relaying request message comprises at least one of an identifier (ID) of the relaying node, an ID of the mobile terminal, and an Uplink Interval Usage Code (UIUC) and a Downlink Interval Usage Code (DIUC) to be used for relying, based on the signal received via the at least one relaying node.

7. The method of claim 6, wherein the UIUC and DIUC comprise information on modulation, coding, and error correcting.

8. The method of claim 1, wherein the relaying response message comprises at least one of a confirmation code for the relaying request, a direction field used for identifying an uplink or a downlink, an ID of the relaying node, and a connection ID (CID) of the mobile terminal.

9. The method of claim 1, wherein the quality of a link is measured depending on at least one of channel status, channel quality, a Carrier-to-Interference Noise Ratio (CINR), and a data rate of each node.

10. The method of claim 1, wherein the optimal path indicates a link comprising a higher data rate determined as a result of comparing a data rate obtained while taking into account CINR of the directly connected link with a data rate of the entire path obtained while taking into account CINR of each link.

11. The method of claim 1, wherein a reciprocal of the data rate of the directly connected link is calculated taking Shannon capacity into account using the following equation,

$b=\underset{i\in }{\mathrm{argmin}}$

B ⁡

[ 1 log 2 ⁡

( 1 + γ

B i ⁢

M ) ]

where γ

_BM denotes CINR between a base station and a mobile terminal.

12. The method of claim 1, wherein a reciprocal of the data rate determined while taking quality of each link into account is calculated using the following equation,

$r=\underset{j\in }{\mathrm{argmin}}$

R ⁡

[ 1 log 2 ⁡

( 1 + γ

B j ⁢

R j ) + 1 log 2 ⁡

( 1 + γ

R j ⁢

M ) ]

where γ

_BR denotes a CINR from a relaying node to a base station, and γ

_RM denotes a CINR from a mobile terminal to a relaying node.

13. The method of claim 1, wherein the optimal path is determined using the following equation,

$\min$

[ 1 log 2 ⁡

( 1 + γ

B b ⁢

M ) , 1 log 2 ⁡

( 1 + γ

B r ⁢

R r ) + 1 log 2 ⁡

( 1 + γ

R r ⁢

M ) ]

where γ

_BM denotes a CINR of a link between a mobile terminal and a base station, γ

_BR denotes a CINR of a link between a relaying node and a base station, and γ

_RM denotes a CINR of a link between a mobile terminal and a relaying nodes.

14. A mobile communication system comprising:

a mobile terminal for transmitting an uplink signal;

a relaying node for measuring quality of a channel to the mobile terminal by detecting the uplink signal, and transmitting information including the measured quality to a base station; and

the base station for measuring quality of a channel to the relaying node using the transmitted information, measuring quality of a channel to the mobile terminal using an uplink signal directly transmitted from the mobile terminal, determining an optimal path to the mobile terminal, sending a relaying request message to a relaying node corresponding to the optimal path, and upon receipt of a relaying response message from the relaying node, configuring and broadcasting new broadcast information.

15. The mobile communication system of claim 14, wherein the optimal path indicates a link comprising a higher data rate determined as a result of comparing a data rate obtained while taking into account Carrier-to-Interference Noise Ratio (CINR) of the link directly connected to the mobile terminal with a data rate of an entire path obtained while taking into account CINR of each link connected to the relaying node that has detected the signal transmitted by the mobile terminal.

16. The mobile communication system of claim 14, wherein the routing path between the base station and the relaying node is configured, depending on channel quality information broadcast by the relaying node, wherein channel quality information comprises at least one of path information of the relaying node, unique information of the relaying node, hop information between nodes, and channel quality level between the nodes.

17. A method for relaying data in a mobile communication system, the method comprising:

transmitting, by a mobile terminal, an uplink signal;

measuring, by a relaying node, quality of a channel to the mobile terminal by detecting the uplink signal, and transmitting information including the measured quality to a base station; and

measuring, by the base station, quality of a channel to the relaying node using the transmitted information, measuring quality of a channel to the mobile terminal using an uplink signal directly transmitted from the mobile terminal, determining an optimal path to the mobile terminal, sending a relaying request message to a relaying node corresponding to the optimal path, and upon receipt of a relaying response message from the relaying node, configuring and broadcasting new broadcast information.

18. The method of claim 17, wherein the optimal path indicates a link comprising a higher data rate determined as a result of comparing a data rate obtained while taking into account Carrier-to-Interference Noise Ratio (CINR) of the link directly connected to the mobile terminal with a data rate of an entire path obtained while taking into account CINR of each link connected to the relaying node that has detected the signal transmitted by the mobile terminal.

19. The method of claim 17, wherein the routing path between the base station and the relaying node is configured, depending on channel quality information broadcast by the relaying node, wherein channel quality information comprises at least one of path information of the relaying node, unique information of the relaying node, hop information between nodes, and channel quality level between the nodes.