Multi-Mode Control Station, Radio Communication System, Radio Station, and Radio Communication Control Method

• US 20080200195A1
• Filed: 03/07/2005
• Published: 08/21/2008
• Est. Priority Date: 05/28/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation), Ryuji Kohno
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Sakamoto, Takenori, Kohno, Ryuji, Matsuoka, Akihiko, Abe, Katsuaki, Taniguchi, Motoko
• Granted Patent: US 8,355,748 B2
• Time in Patent Office: Days
• US Class Current: 455/501
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

The overall throughput of the radio communication traffic in a radio communication area in a radio communication environment where a plurality of types of radio communication systems are mixedly used in a neighboring radio communication area is improved. When a multi-mode control station (101) performs communication with a terminal station in a network through a plurality of types of communication systems, a communication link parameter collecting section (10141) collects parameters indicating the states of the communication links. A resource allocation determining section (10143) determines communication resource allocation for which the throughput is the greatest for each resource allocation period according to the parameters. A communication control section (1015) controls a multi-mode communication unit (1012) according to the result of the determination.

Claims

1. A multimode control station used in a different schemes mixing type wireless communication system configured with a multimode control station compatible with a plurality of types of wireless communication standards by changing functions under a wireless communication environment where communication links by means of wireless communication schemes conforming to a plurality of types of wireless communication standards are mixed and used, and with a plurality of wireless stations that carry out communication using a wireless communication scheme conforming to at least one wireless communication standard of the plurality of types of wireless communication standards, wherein:

information relating to the communication links used by the plurality of wireless stations is collected; and

communication resource allocation used in the communication links is decided based on the collected information so that total throughput of wireless communication traffic under the wireless communication environment is improved.

2. The multimode control station according to claim 1, wherein:

the communication link used by the wireless station is a wireless communication link between the wireless station and the multimode control station; and

the multimode control station decides communication resources allocation used in the wireless communication link so that throughput of wireless communication traffic under the wireless communication environment is maximized.

3. The multimode control station according to claim 2, comprising:

a communication link parameter collecting section that collects information relating to the communication links with the plurality of wireless stations;

a resource allocation deciding section that decides communication resource allocation used at the wireless communication links with the wireless stations based on the collected information so that throughput of data transmission traffic within the wireless communication network is maximized; and

a multimode communication section that controls communication conditions for the wireless communication links based on the decided communication resource allocation to the wireless stations, and carries out communication.

4. The multimode control station according to claim 3, wherein information collected by the communication link parameter collection section contains at least one of:

a communication link quality parameter denoting communication quality of the wireless communication links with the wireless stations;

a permitted QoS parameter for data transmitted to the wireless stations;

data capacity transmitted to the wireless stations;

required mode switching time that is necessary when switching the communication schemes at the communication links with the wireless stations; and

required link connection time that is necessary when starting data transmission at the communication links with the wireless stations.

5. The multimode control station according to claim 3, wherein information collected by the communication link parameter collection section contains a combination of at least two or more of:

a communication link quality parameter denoting communication quality of the wireless communication links with the wireless stations;

a permitted QoS parameter for data transmitted to the wireless stations;

data capacity transmitted to the wireless stations;

required mode switching time that is necessary when switching the communication schemes at the communication links with the wireless stations; and

required link connection time that is necessary when starting data transmission at the communication links with the wireless stations.

6. The multimode control station according to claim 3, wherein the communication resources decided by the resource allocation deciding section contains one of:

a communication scheme used at a communication link with a multimode wireless station among the wireless stations;

transmission speed set by the communication scheme; and

communication time allocation rate allocated to the communication links with the wireless stations.

7. The multimode control station according to claim 3, wherein the communication resource decided by the resource allocation deciding section contains at least two or more of:

a communication scheme used at a communication link with a multimode wireless station among the wireless stations;

transmission speed set by the communication scheme; and

communication time allocation rate allocated to the communication links with the wireless stations.

8. The multimode control station according to claim 3, wherein the resource allocation deciding section decides communication resource allocation used at the wireless communication links with the wireless station by setting an objective function relating to throughput and restriction conditions based on information collected at the communication link parameter collection section and obtaining an optimum combination of control parameters that maximizes an objective function value is maximized under the restriction conditions.

9. The multimode control station according to claim 8, wherein the resource allocation deciding section uses, as the objective function:

a function that obtains a total amount of data that can be transmitted per resource allocation period at the communication links with the wireless stations within the wireless communication network; and

a product of transmission speed used at the communication links with the wireless stations and time for carrying out communication by means of the communication links when calculating the total amount of data, the time for carrying out communication using time where time required for switching communication functions by the multimode control station or the multimode wireless station and time required for link connection along with change of the communication scheme are reduced from communication time allocated to the communication link.

10. The multimode control station according to claim 9, wherein, when calculating the total amount of data, the multimode control station uses a product of transmission speed used at the communication links with the wireless station, time for carrying out communication by means of the communication links, and a received bit non-error rate by means of the communication links.

11. The multimode control station according to claim 8, wherein the resource allocation deciding section obtains an optimum combination of the control parameters by extracting an optimal solution for the objective function using mathematical programming under the restriction conditions.

12. The multimode control station according to claim 8, wherein the resource allocation deciding section uses the following equation as the objective function:

[Equation 1]

$\begin{array}{cc}{Z}_{\mathrm{mi}}=\frac{\left\{\underset{n=1}{\overset{N}{\sum <br><br>}}<br><br>B_{n,\mathrm{mi}}\times <br><br>\left({\mathrm{Tf}}_{n,\mathrm{mi}}-\left({\mathrm{Tr}}_{n,\mathrm{mi}}+{\mathrm{Ts}}_{n,\mathrm{mi}}\right)\right)\times <br><br>\left(1-{\mathrm{Pe}}_{n,\mathrm{mi}}\right)\right\}}{\mathrm{Ta}}& \left(1\right)\end{array}$

where Z_mi denotes throughput per resource allocation period within the network, n denotes wireless station number of a communication target, mi denotes a combination of communication schemes used by the communication links, B denotes transmission speed, Tf denotes time allocation, Tr denotes time required for switching communication schemes, Ts denotes time required for link connection, and Ta denotes time until communication carried out one at a time for all N stations is complete.

13. The multimode control station according to claim 8, wherein the resource allocation deciding section uses, as the restriction conditions, a combination of one or more of:

a communication scheme compatible with the multimode control station, the communication scheme being used by the communication links between the multimode control station and the wireless stations;

communication quality satisfying permitted communication quality when communicating using the communication schemes and communication speeds selected at the communication links; and

resource allocation setting in which communication time required for data transmission does not exceed a maximum permitted value of required communication time.

14. The multimode control station according to claim 12, wherein the resource allocation deciding section uses a combination of one or more of the following equations as the restriction conditions:

[Equation 2]

miε

S  

 

(2)

[Equation 3]

(I_n,mi−

1)×

Ta+Tf_n,mi≦

Tt_maxn  

 

(3)

[Equation 4]

$\begin{array}{cc}{I}_{n,\mathrm{mi}}=\lfloor <br><br>\frac{D_n}{B_{n,\mathrm{mi}}<br><br>\left\{{\mathrm{Tf}}_{n,\mathrm{mi}}-\left({\mathrm{Tr}}_{n,\mathrm{mi}}+{\mathrm{Ts}}_{n,\mathrm{mi}}\right)\right\}}\rfloor <br><br>& \left(4\right)\end{array}$

where └

x┘

denoting a minimum integer larger than x.

[Equation 5]

Pe_n,mi≦

Pe_maxn  

 

(5)

where S denotes a set of communication schemes used within the network, D denotes not-yet transmitted data amount, and Pe denotes a bit error rate.

15. The multimode control station according to claim 8, wherein the resource allocation deciding section obtains an optimum combination of the control parameters by extracting an optimal solution for the objective function using dynamic programming under the restriction conditions.

16. The multimode control station according to claim 15, wherein the resource allocation deciding section uses as the objective function:

a function that obtains a total amount of data that can be transmitted per resource allocation period at the communication links with the wireless stations within the wireless communication network; and

a product of transmission speed used at the communication links with the wireless stations and time for carrying out communication by means of the communication links when calculating the total amount of data, the time for carrying out communication using time where time required for switching communication functions by the multimode control station or the multimode wireless station and time required for link connection along with change of the communication scheme are reduced from communication time allocated to the communication link.

17. The multimode control station according to claim 16, wherein, when calculating the total amount of data, the multimode control station uses a product of transmission speed used at the communication links with the wireless station, time for carrying out communication by means of the communication links, and a received bit non-error rate by means of the communication links.

18. The multimode control station according to claim 15, wherein the resource allocation deciding section uses a combination of the following equations as the objective function:

[Equation 7]

$\begin{array}{cc}{f}_N<br><br>\left(k_N\right)=\max <br><br>\left[{\mathrm{TH}}_N\right],k_N=\underset{n=1}{\overset{N}{\sum <br><br>}}<br><br>a_n=1& \left(7\right)\end{array}$

[Equation 8]

$\begin{array}{cc}{\mathrm{TH}}_N=\frac{\left\{\underset{n=1}{\overset{N}{\sum <br><br>}}<br><br>{\mathrm{th}}_n<br><br>\left(a_n\right)\right\}}{T_a}& \left(8\right)\end{array}$

[Equation 9]

th_n(a_n)=B_n×

(1−

Pe_n)×

{T_a×

a_n−

(Tr_n+Ts_n)} 

 

(9)

19. The multimode control station according to claim 15, wherein the resource allocation deciding section uses one of or both of the following equations as the restriction conditions:

[Equation 10]

$\begin{array}{cc}\underset{n=1}{\overset{N}{\sum <br><br>}}<br><br>a_n=1<br><br><br><br>\left(a_n><br><br>\left({\mathrm{Tr}}_n+{\mathrm{Ts}}_n\right)/T\right)& \left(10\right)\end{array}$

[Equation 14]

$\begin{array}{cc}{a}_n\ge <br><br>a_{\mathrm{min\_n}}=\frac{D_n}{B_n\times <br><br>T_a}& \left(14\right)\end{array}$

20. The multimode control station according to claim 2, wherein the multimode control section is able to compatible with a communication scheme conforming to the IEEE802.11a standard and a communication scheme conforming to the IEEE802.11b standard.

31. The multimode control station according to claim 1, wherein a communication link for the wireless station is a wireless communication link with another wireless station under the wireless communication environment, and

the multimode control station collects information relating to interference the wireless station is subjected to from other wireless stations as information relating to the communication link and decides communication resource allocation used by the wireless station so that interference the wireless stations is subjected to from other wireless stations under the wireless communication environment is reduced.

32. The multimode control station according to claim 31, comprising:

a communication link information collecting section that collects information relating to the communication links with the wireless stations;

a resource allocation deciding section that decides communication resource allocation used at the wireless stations based on the collected information so that interference the wireless station is subjected to is reduced, and

a multimode communication section that reports the decided results of communication resource allocation to the wireless stations, to the wireless stations.

33. The multimode control station according to claim 32, wherein information collected by the communication link information collecting section contains one of:

a communication link quality parameter denoting communication quality of the wireless communication links with the wireless stations;

an interference attribute parameter denoting whether or not interference the wireless stations are subjected to is due to a signal transmitted from a wireless station that can be controlled by the multimode control station;

interference signal power denoting strength of an interference signal the wireless stations are subjected to;

an interference source ID denoting a wireless station estimated as an emission source of an interference signal the wireless stations are subjected to; and

a wireless communication scheme parameter indicating a wireless communication scheme estimated as being used for the interference signal the wireless stations are subjected to.

34. The multimode control station according to claim 32, wherein information collected by the communication link information collecting section contains a combination of two or more of:

a communication link quality parameter denoting communication quality of the wireless communication links with the wireless stations;

an interference attribute parameter denoting whether or not interference the wireless stations are subjected to is due to a signal transmitted from a wireless station that can be controlled by the multimode control station;

interference signal power denoting strength of an interference signal the wireless stations are subjected to;

an interference source ID denoting a wireless station estimated as an emission source of an interference signal the wireless stations are subjected to; and

a wireless communication scheme parameter indicating a wireless communication scheme estimated as being used for the interference signal the wireless stations are subjected to.

35. The multimode control station according to claim 32, wherein the communication resources decided-by the resource allocation deciding section contains one of:

a communication scheme used at the communication links with the wireless stations;

transmission speed set by the communication scheme;

a frequency channel set by the communication scheme; and

transmission power set by the communication scheme.

36. The multimode control station according to claim 32, wherein the communication resources decided by the resource allocation deciding section contains a combination of two or more of:

a communication scheme used at the communication links with the wireless stations;

transmission speed set by the communication scheme;

a frequency channel set by the communication scheme; and

transmission power set by the communication scheme.

21. A multimode control station comprising:

an antenna that is compatible with frequency bands conforming to a plurality of wireless communication standards;

a multimode communication section that is able to change functions to communication schemes compatible with a plurality of wireless communication standards based on an inputted function switching control signal, outputs a received data string obtained by carrying out reception signal processing corresponding to communication schemes selected by the function switching control signal among the communication schemes conforming to the plurality of wireless communication standards received by the antenna using timing and setting conditions based on the inputted communication control signal, and supplies a transmission signal obtained by carrying out predetermined transmission processing corresponding to the communication scheme selected for the inputted transmission data, to the antenna;

an application processing section that is connected to the multimode communication section and carries out processing at a higher layer of data transmitted and received to and from wireless stations;

a reception quality estimating section that estimates reception quality using a signal used when carrying out reception processing by the multimode communication section;

a resource allocation control section that takes reception quality estimation results for the communication links outputted from the reception quality estimating section and setting information for the communication links supplied by the application processing section as inputs, decides communication resource allocation to the communication links with the wireless stations so as to maximize throughput of data traffic within the network, and outputs the decided resource allocation results; and

a communication control section that supplies a function changing control signal and communication control signal to the multimode communication section based on the resource allocation results when communicating with the wireless stations.

22. A wireless communication control method carried out at a multimode control station in a wireless communication network including a multimode control station that is able to communicate in a manner compatible with a plurality of communication schemes and a multimode wireless station that is able to communicate in a manner compatible with a plurality of communication schemes, the wireless communication control method comprising:

a collection step of collecting information relating to communication links with a plurality of wireless stations;

a resource allocation step of deciding communication resource allocation used at the communication links with the wireless stations based on collected information relating to the communication links so that throughput of data transmission traffic within the wireless communication network is maximized; and

a communication control step of controlling communication conditions for the communication links based on communication resource allocation to the decided wireless stations, and carries out communication.

23. The wireless communication control method according to claim 22, wherein the resource allocation step comprising:

a step of setting an objective function denoting total throughput for the wireless communication network based on collected information for the communication links;

a step of setting combination of communication schemes used by the communication links with the wireless stations, maximum communication time permitted for data transmission carried out with the wireless stations, and restriction conditions based on communication quality permitted during data transmission, based on collected setting information for the communication links; and

a step of detecting combinations of resources that maximize the objective function based on the set restriction conditions.

24. The wireless communication control method according to claim 23, wherein the wireless communication control method uses, as the objective function:

a function that obtains a total amount of data that can be transmitted per resource allocation period at the communication links with the wireless stations within the wireless communication network;

a product of transmission speed used at the communication links with the wireless stations and time for carrying out communication by means of the communication links when calculating the total amount of data, the time for carrying out communication using time where time required for switching communication functions by the multimode control station or the multimode wireless station and time required for link connection along with change of the communication scheme are reduced from communication time allocated to the communication link.

25. The wireless communication control method according to claim 24, wherein, when calculating the total amount of data, the wireless communication control method uses the product of transmission speed used at the communication links with the wireless station, time for carrying out communication at the communication links, and a received bit non-error rate by means of the communication links.

26. The wireless communication control method according to claim 23, wherein the maximum communication time permitted in data transmission with the wireless stations is calculated based on time required for switching communication functions by the multimode control station or the multimode wireless station and time required for link connection along with change of the communication scheme.

27. The wireless communication control method according to claim 22, further comprising:

a step of detecting a change in the communication environment per communication resource allocation period; and

a step of selecting communication resources allocated to communication links with the wireless stations again only when detecting a change in the communication environment.

28. The wireless communication control method according to claim 27, wherein the wireless communication control method uses, as parameters for detecting changes in the communication environment, one or a combination of a plurality of:

a total number of the wireless stations that needs data transmission within the network;

the number of the multimode wireless stations among wireless stations; and

communication quality of the communication links.

29. The wireless communication control method according to claim 22, further comprising:

a step of grouping wireless stations according to the presence or absence of time restriction conditions for transmission data required at the communication links with the wireless stations;

a step of deciding communication time allocation to groups based on the time restriction conditions; and

a step of setting an objective function and restriction conditions per group, and carrying out communication time allocation to the wireless stations.

30. A wireless communication system that is a different schemes mixing type and that is configured with a multimode control station compatible with a plurality of types of wireless communication standards by changing functions under a wireless communication environment where communication links by means of wireless communication schemes conforming to a plurality of types of wireless communication standards are mixed and used, and with a plurality of wireless stations that carry out communication using a wireless communication scheme conforming to at least one wireless communication standard of the plurality of types of wireless communication standards, wherein:

the multimode control station collects information relating to communication links by means of the plurality of wireless stations and decides communication resource allocation used at the communication links based on the collected information so that total throughput for wireless communication traffic under the wireless communication environment increases improved; and

the wireless stations control their own communication based on communication resource allocation decided by the multimode control station.

37. A wireless station in a different schemes mixing type wireless communication system configured with a multimode control station compatible with a plurality of types of wireless communication standards by changing functions under a wireless communication environment where communication links by means of wireless communication schemes conforming to a plurality of types of wireless communication standards are mixed and used, and with a plurality of wireless stations that carry out communication using a wireless communication scheme conforming to at least one wireless communication standard of the plurality of types of wireless communication standards, the wireless station comprising:

an interference detection section that detects information relating to interference the subject station is subjected to by means of the communication link for the wireless station; and

a multimode communication section that reports the interference detection result to the multimode control station.

38. The wireless station according to claim 37, wherein information detected by the interference detection section containing one of:

an interference attribute parameter denoting whether or not the detected interference is due to a signal transmitted from a wireless station that can be controlled by the multimode control station;

interference signal power denoting strength of the detected interference signal;

an interference source ID denoting a wireless station estimated as an emission source of the detected interference signal; and

a wireless communication scheme parameter indicating a wireless communication scheme estimated as being used for the detected interference signal.

39. The wireless station according to claim 37, information detected by the interference detection section containing a combination of two or more of:

an interference attribute parameter denoting whether or not the detected interference is due to a signal transmitted from a wireless station that can be controlled by the multimode control station;

interference signal power denoting strength of the detected interference signal;

an interference source ID denoting a wireless station estimated as an emission source of the detected interference signal; and

a wireless communication scheme parameter indicating a wireless communication scheme estimated as being used for the detected interference signal.

40. A wireless communication control method carried out at a multimode control station in a wireless communication network including a multimode control station that is able to communicate in a manner compatible with a plurality of communication schemes and a multimode wireless station that is able to communicate in a manner compatible with a plurality of communication schemes, the wireless communication control method comprising:

a collection step of collecting information relating to communication links with a plurality of wireless stations;

a resource allocation step of deciding communication resource allocation used at the wireless communication links with the wireless stations based on collected information relating to the wireless communication links so that interference the wireless stations are subjected to within the wireless communication network is reduced.

41. A wireless communication control method carried out at the wireless station in a wireless communication network including a multimode control station that is able to communicate in a manner compatible with a plurality of communication schemes and a multimode wireless station that is able to communicate in a manner compatible with a plurality of communication schemes, the wireless communication control method comprising:

an interference detection step of distinguishing and detecting whether or not interference the subject station is subjected to is due to a signal transmitted from a wireless station that can be controlled by the multimode station by means of using a communication link for the wireless station; and

a step of reporting the interference detection result to the multimode control station.

42. The wireless communication control method according to claim 41, wherein the interference detection step is carried out before starting communication with the wireless station or periodically during communication.