Mobile communication system, transmission station, reception station, relay station, communication path deciding method, and communication path deciding program

• US 20040242154A1
• Filed: 06/08/2004
• Published: 12/02/2004
• Est. Priority Date: 05/27/2002
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Yoshino, Hitoshi, Otsu, Toru, Takeda, Shinji, Fujiwara, Atsushi, Yamao, Yasushi
• Granted Patent: US 7,702,280 B2
• Time in Patent Office: Days
• US Class Current: 455/16
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/122 by minimising distances, e.g. by selecting a route with minimum of number of hops
• CPC Class Codes: H04L 45/125 based on throughput or bandwidth
• CPC Class Codes: H04L 45/20 Hop count for routing purposes, e.g. TTL
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 45/85 Selection among different networks
• CPC Class Codes: H04W 40/08 based on transmission power
• CPC Class Codes: H04W 40/12 based on transmission quality or channel quality
• CPC Class Codes: H04W 40/16 based on interference
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile communication system capable of determining a communication path to implement fast communication by multihop connection. The mobile communication system includes a mobile station, at least one relay station, and a base station and implements packet transmission from the mobile station to the base station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station. The mobile communication system is provided with a communication path determiner for determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path between the transmitting station and the receiving station, and at the base station.

Claims

1. A mobile communication system comprising a transmitting station, at least one relay station, and a receiving station and configured to implement packet transmission from the transmitting station to the receiving station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station,

the mobile communication system comprising communication path determining means for determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path between the transmitting station and the receiving station, and at the receiving station.

2. The mobile communication system according to claim 1, wherein the communication path determining means further comprises:

interstation communication speed determining means for determining an interstation communication speed between each pair of stations, based on interference levels at respective stations constituting a communication path; and

communication speed determining means for determining a communication speed on each communication path from the transmitting station to the receiving station on the basis of the interstation communication speed between each pair of stations determined by the interstation communication speed determining means;

wherein the communication path determining means determines a communication path on the basis of communication speeds on respective communication paths determined by the communication speed determining means.

3. The mobile communication system according to claim 1, wherein, where there are a plurality of communication paths satisfying the required line quality, the communication path determining means determines a path with a smallest hop count between the transmitting station and the receiving station, as a communication path.

4. The mobile communication system according to claim 1, wherein, where there are a plurality of communication paths satisfying the required line quality, the communication path determining means determines a path with a small total of transmission powers at the transmitting station and at the relay station constituting the communication path, as a communication path.

5. The mobile communication system according to claim 1, wherein, where there are a plurality of communication paths satisfying the required line quality, the communication path determining means determines a path with a small transmission power at the transmitting station, as a communication path.

6. The mobile communication system according to claim 1, wherein the communication path determining means determines a communication path out of communication paths each having a hop count between the transmitting station and the receiving station of not more than a predetermined threshold.

20. The mobile communication system according to claim 1, wherein the receiving station and relay station comprise:

request signal receiving means for receiving a request signal transmitted from the transmitting station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station;

interference level measuring means for measuring an interference level at the host station when the request signal receiving means receives a request signal; and

communication propriety determining means for memorizing either of a receiving-station target value and a relay-station target value for control of transmission power independently set at the receiving station and at the relay station;

wherein the communication propriety determining means of the receiving station determines whether it is possible to perform communication requested by the request signal, based on the interference level measured by the interference level measuring means and based on the receiving-station target value, and the communication propriety determining means of the relay station determines whether it is possible to perform communication requested by the request signal, based on the interference level and the relay-station target value; and

wherein the communication path determining means determines a communication path on the basis of proprieties of the communications determined by the respective communication propriety determining means.

21. The mobile communication system according to claim 2, wherein the interstation communication speed determining means memorizes a receiving-station target value and a relay-station target value for control of transmission power independently set at the receiving station and at the relay station and determines the interstation communication speed, based on the interference levels at the respective stations constituting the communication path, the receiving-station target value, and the relay-station target value.

7. A transmitting station applied to a mobile communication system and configured to transmit a packet to a receiving station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station,

the transmitting station comprising communication path determining means for determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path to the receiving station, and at the receiving station.

22. The transmitting station according to claim 7, wherein the communication path determining means memorizes a receiving-station target value and a relay-station target value for control of transmission power independently set at the receiving station and at the relay station, and determines the communication path with the largest communication speed or the communication path satisfying the required line quality, based on the interference levels of the respective signals received at the relay station constituting the communication path and at the receiving station, the receiving-station target value, and the relay-station target value.

23. The transmitting station according to claim 7, wherein the communication path determining means comprises:

request signal transmitting means for transmitting a request signal;

request response signal receiving means for receiving a request response signal to the request signal transmitted by the request signal transmitting means;

interstation communication speed determining means for determining an interstation communication speed between the transmitting station and the receiving station or the relay station as a source of the request response signal, based on an interference level at the receiving station or the relay station as a source of the request response signal included in the request response signal;

communication speed determining means for determining a communication speed on the communication path from the transmitting station to the receiving station, based on the interstation communication speed determined by the interstation communication speed determining means and, where the request response signal is one transmitted from the relay station, also based on interstation communication speed information between each pair of stations constituting a communication path from the relay station to the receiving station, included in the request response signal; and

communication path selecting means for selecting a communication path on the basis of communication speeds on respective communication paths determined by the communication speed determining means;

wherein the interstation communication speed determining means memorizes a receiving-station target value and a relay-station target value for control of transmission power independently set at the receiving station and at the relay station, and determines the interstation communication speed, based on an interference level at the receiving station or the relay station as a source of the request response signal, the receiving-station target value, and the relay-station target value.

8. A receiving station applied to a mobile communication system and configured to receive a packet from a transmitting station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station,

the receiving station comprising communication path determining means for determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path between the transmitting station and the receiving station, and at the receiving station.

9. The receiving station according to claim 8, wherein the communication path determining means comprises:

request signal receiving means for receiving a request signal transmitted from the transmitting station or from the relay station;

interference level measuring means for measuring an interference level at the receiving station when the request signal receiving means receives a request signal;

interstation communication speed determining means for determining an interstation communication speed between the receiving station and the transmitting station or the relay station as a source of the request signal, based on the interference level measured by the interference level measuring means;

communication speed determining means for determining a communication speed between the transmitting station and the receiving station, based on the interstation communication speed determined by the interstation communication speed determining means and, where the request signal is one received from the relay station, also based on interstation communication speed information between each pair of stations constituting a communication path from the transmitting station to said relay station, included in the request signal; and

communication path selecting means for selecting a communication path, based on communication speeds on respective communication paths determined by the communication speed determining means.

10. The receiving station according to claim 8, wherein the communication path determining means comprises:

request signal receiving means for receiving a request signal transmitted from the transmitting station or from the relay station;

interference level measuring means for measuring an interference level at the receiving station when the request signal receiving means receives a request signal;

interstation communication speed determining means for determining an interstation communication speed between each pair of stations constituting a communication path, based on the interference level measured by the interference level measuring means and, where the request signal is one transmitted from the relay station, also based on an interference level included in the request signal;

communication speed determining means for determining a communication speed between the transmitting station and the receiving station on the basis of the interstation communication speed determined by the interstation communication speed determining means; and

communication path selecting means for selecting a communication path, based on communication speeds on respective communication paths determined by the communication speed determining means.

11. A receiving station comprising:

request signal receiving means for receiving a request signal transmitted from a transmitting station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station;

interference level measuring means for measuring an interference level at the receiving station when the request signal receiving means receives a request signal;

communication propriety determining means for determining whether it is possible to perform communication at a communication speed included in the request signal, based on the interference level measured by the interference level measuring means; and

request response signal transmitting means for transmitting a request response signal containing information on propriety of communication determined by the communication propriety determining means, through the communication path to the transmitting station.

24. The receiving station according to claim 11, wherein the communication propriety determining means memorizes a receiving-station target value for control of transmission power set independently of the relay station, and determines whether it is possible to perform the communication at the communication speed included in the request signal, based on the interference level and the receiving-station target value.

12. A receiving station comprising:

request signal receiving means for receiving a request signal transmitted from the transmitting station or from a relay station;

interference level measuring means for measuring an interference level at the receiving station when the request signal receiving means receives a request signal;

interstation communication speed determining means for determining an interstation communication speed between the receiving station and the transmitting station or the relay station as a source of the request signal, based on the interference level measured by the interference level measuring means; and

request response signal transmitting means for transmitting a request response signal containing the interstation communication speed information determined by the interstation communication speed determining means, to the transmitting station or the relay station as a source of the request signal.

13. A relay station comprising:

request signal receiving means for receiving a request signal transmitted from a transmitting station through a communication path with an intermediary of at least one relay station or through a communication path without an intermediary of a relay station;

interference level measuring means for measuring an interference level at the host relay station when the request signal receiving means receives a request signal;

communication propriety determining means for determining whether it is possible to perform communication at a communication speed included in the request signal, based on the interference level measured by the interference level measuring means; and

request response signal transmitting means for transmitting a request response signal containing information on propriety of communication determined by the communication propriety determining means, through the communication path to the transmitting station.

14. The relay station according to claim 13, further comprising:

request signal transmitting means for transmitting a request signal to the receiving station or to another said relay station only when the communication propriety determining means determines that it is possible to perform the communication; and

request response signal receiving means for receiving a request response signal to the request signal transmitted by the request signal transmitting means.

25. The relay station according to claim 13, wherein the communication propriety determining means memorizes a relay-station target value for control of transmission power set independently of the receiving station for performing packet transmission, and determines whether it is possible to perform the communication at the communication speed included in the request signal, based on the interference level and the relay-station target value.

15. A relay station comprising:

request signal receiving means for receiving a request signal transmitted from the transmitting station or from another relay station;

interference level measuring means for measuring an interference level at the host relay station when the request signal receiving means receives a request signal;

request signal transmitting means for transmitting a request signal;

request response signal receiving means for receiving a request response signal transmitted from a receiving station or from a second other relay station, in response to the request signal transmitted by the request signal transmitting means;

interstation communication speed determining means for determining an interstation communication speed between the host relay station and the receiving station or the second other relay station as a source of the request response signal, based on an interference level included in the request response signal received by the request response signal receiving means; and

request response signal transmitting means for transmitting a request response signal containing the interference level measured by the interference level measuring means and the interstation communication speed information determined by the interstation communication speed determining means, and, where the request response signal is one received from the second other relay station, also containing interstation communication speed information included in the request response signal, to the transmitting station or the other relay station as a source of the request signal.

26. The relay station according to claim 15, wherein the interstation communication speed determining means memorizes a relay-station target value for control of transmission power set independently of the receiving station for performing packet transmission, and determines the interstation communication speed, based on the interference level and the relay-station target value.

16. A relay station comprising:

request signal receiving means for receiving a request signal transmitted from the transmitting station or from another relay station;

interference level measuring means for measuring an interference level at the host relay station when the request signal receiving means receives a request signal;

interstation communication speed determining means for determining an interstation communication speed between the host relay station and the transmitting station or the other relay station as a source of the request signal, based on the interference level measured by the interference level measuring means;

request signal transmitting means for transmitting a request signal;

request response signal receiving means for receiving a request response signal transmitted from a receiving station or from a second other relay station, in response to the request signal transmitted by the request signal transmitting means; and

request response signal transmitting means for transmitting a request response signal containing the interstation communication speed information determined by the interstation communication speed determining means, and interstation communication speed information included in the request response signal received by the request response signal receiving means, to the transmitting station or the other relay station as a source of the request signal.

17. A relay station comprising:

request signal receiving means for receiving a request signal transmitted from the transmitting station or from another relay station;

interference level measuring means for measuring an interference level at the host relay station when the request signal receiving means receives a request signal;

interstation communication speed determining means for determining an interstation communication speed between the host relay station and the transmitting station or the other relay station as a source of the request signal, based on the interference level measured by the interference level measuring means; and

request signal transmitting means for transmitting a request signal containing the interstation communication speed information determined by the interstation communication speed determining means, and, where the request signal is one received from the other relay station, also containing interstation communication speed information included in the request signal.

18. A communication path determining method applied to a mobile communication system comprising a transmitting station, at least one relay station, and a receiving station and adapted to determine a communication path between the transmitting station and the receiving station,

the communication path determining method comprising a communication path determining step of determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path between the transmitting station and the receiving station, and at the receiving station.

27. The communication path determining method according to claim 18, wherein the communication path determining step is to determine the communication path with the largest communication speed or the communication path satisfying the required line quality, based on the interference levels of the respective signals received at the relay station and at the receiving station, and based on a receiving-station target value and a relay-station target value for control of transmission power independently set at the receiving station and at the relay station.

19. A communication path determining program applied to a mobile communication system comprising a transmitting station, at least one relay station, and a receiving station, for determining a communication path with an intermediary of at least one relay station or a communication path without an intermediary of a relay station,

the communication path determining program letting a computer execute a communication path determining step of determining a communication path with a largest communication speed or a communication path satisfying a required line quality, based on interference levels of respective signals received at a relay station constituting a communication path between the transmitting station and the receiving station, and at the receiving station.