Communication management method, central control station, communication station, communication management program, and computer-readale recording medium storing communication management program

• US 20060057968A1
• Filed: 10/06/2003
• Published: 03/16/2006
• Est. Priority Date: 10/23/2002
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ohtani, Yoshihiro
• Granted Patent: US 7,508,762 B2
• Time in Patent Office: Days
• US Class Current: 455/67.160
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04W 72/543 based on requested quality, e.g. QoS

Abstract

A central control station carries out allocations of transmission rights according to a rule that a value obtained by subtracting (i) a value of a broken line (11) from (ii) a value of a straight line (10) is always limited according to a certain constant value (TXOP bound) smaller than C-T delay, where the broken line (11) indicates a sum of transmission granting time periods allocated from a certain time point to by “an actual transmission right allocation”, the straight line (10) indicates a sum of transmission right granted time periods allocated according to “a reference transmission right allocation obtained by the average data rate or the like of a communication station”, and C·T delay is an average sum of transmission right granted time periods allocated to the tolerable transmission delay time according to the reference transmission right allocation. In a communication network, a communication path quality required by a transmission station to a communication path can be realized while maintaining flexibility of the scheduling carried out by the central control station.

Claims

1-28. -28. (canceled)

29. A method of managing communication, comprising the step of causing a central control station to schedule such that allowance to transmit data is given, as a transmission right, to only one of communication stations in each time period by determining a timing of transmitting data from a communication station that is to transmit the data, to a communication station that is to receive the data, the method comprising the step of:

causing the central control station to carry out the scheduling, by using parameters C, TXOP bound, and T bound, so that a sum of transmission right granted time periods actually granted in a time period {t0, t0+t} is always equal to or more than C·

t−

TXOP bound where t0 is an arbitrary time point, C is an average ratio of the sum of the transmission right granted time periods allocated, to the communication station that is to transmit the data, by the central control station according to a reference transmission right allocation, and T delay is a maximum tolerable delay time of the data to be transmitted by the communication station that is to transmit the data, C, TXOP bound, and T bound satisfying following formulas;

0≧

T bound<

T delay;

 

 

Formula 1;


0<

C<

1; and

 

 

Formula 2;


TXOP bound=C·

T bound.  

 

Formula 3;

34. The method as set forth in claim 29, wherein:

a communication station transmitting a data packet under a control of the central control station previously reserves, to the control station, information concerning a traffic property of the data packet, and

the central control station uses the information when determining the reference transmission right allocation, the information given from each communication station.

35. The method as set forth in claim 29, wherein:

the central control station uses a fixed value as a concrete value of TXOP bound or T bound.

36. The method as set forth in claim 29, comprising the step of causing the central control station to concretely determine TXOP bound or T bound according to information given from a communication station side.

37. The method as set forth in claim 36, comprising the step of causing the central control station to concretely determine TXOP bound or T bound as a function of “

a maximum time interval between two successive times at which polling is desired”

T max requested from a communication station side.

38. The method as set forth in claim 37, comprising the step of causing the central control station to concretely determine TXOP bound such that TXOP bound is especially C·

T max.

39. The method as set forth in claim 37, comprising the step of causing the central control station to concretely determine T bound such that T bound is especially T max.

40. The method as set forth in claim 36, comprising the step of causing the central control station to concretely determine that TXOP bound or T bound is a function of a smallest value among values of T max of a plurality of streams to be transmitted from the communication station side, where T max is a maximum time interval between two successive times at which polling is desired.

41. The method as set forth in claim 36, comprising the step of causing the central control station to concretely determine that TXOP bound or T bound is a function of T delay where T delay is a maximum tolerable delay time of the data to be transmitted by the communication station.

42. The method as set forth in claim 36, comprising the step of causing the central control station to concretely determine that TXOP bound or T bound is a function of a smallest value among values of T delay of a plurality of streams to be transmitted by the communication station, where delay is a maximum tolerable delay time of the data to be transmitted by the communication station.

43. The method as set forth in claim 29, wherein:

transmission is burst transmission.

44. The method as set forth in claim 36, comprising the step of causing the central control station to concretely determine TXOP bound or T bound according to “

information concerning which to use, Normal ACK or Group ACK”

given from the communication station.

45. A method of managing communication, comprising the step of causing a central control station to judge, according to the formulas as set forth in claim 29, whether or not a new stream is able to be accepted.

46. A communication station wherein:

the communication station is in a network adopting the method as set forth in claim 29;

and

if the communication station judges that the central control station does not satisfy the method,

the communication station notifies a user of a fact that “

the transmission right granting carried out by the central control station does not satisfy minimum requirement”

or “

due to the central control station, problems occur when transmitting a stream data”

.

47. A method of managing communication, comprising the step of:

carrying out communication by using a mechanism in which;

(i) in a case in which a central control station uses the method as set forth in claim 29, a communication station obtains n by a following formula;

using a packet error rate PER and a packet loss rate PLR of a communication path;

n=ceiling {log(PLR)/log(PER)},

where n is a desirable maximum number of times transmission is able to be carried out,

(ii) an average burst output cycle (T burst) is defined as a certain time period equal to or less than a time period T burstmax obtained by dividing, by n, a time period obtained by a formula (an tolerable transmission delay time−

TXOP bound/C), and

(iii) a plurality of packets needed to be outputted in T burst are transmitted in a burst manner, and a reception station gives, to a communication station, acknowledgements with respect to the packets at once.

48. A method of managing communication, comprising the step of:

carrying out communication by using a mechanism in which;

(i) in a case in which a central control station uses the method as set forth in claim 29, a communication station obtains n by a following formula using a packet error rate PER and a packet loss rate PLR of a communication path;

n=ceiling {log(PLR)/log(PER)},

where n is a desirable maximum number of times transmission is able to be carried out,

(ii) an average burst output cycle (T burst) is defined as a certain time period equal to or less than a time period T burstmax obtained by dividing, by n, a time period obtained by a formula (an tolerable transmission delay time−

TXOP bound/C), and

(iii) a plurality of packets needed to be outputted in T burst are transmitted in a burst manner, and a reception station notifies to the communication station, acknowledgements with respect to the packets at once.

51. The method as set forth in claim 47, wherein:

the communication stations use, as a concrete value of the packet error rate PER, a value of PER actually measured by each communication station.

52. The method as set forth in claim 48, wherein:

the communication stations use, as a concrete value of the packet error rate PER, a value of PER actually measured by each communication station.

54. The method as set forth in claim 47, wherein:

the communication stations use a fixed value as a concrete value of the packet error rate PER.

55. The method as set forth in claim 48, wherein:

the communication stations use a fixed value as a concrete value of the packet error rate PER.

57. The method as set forth in claim 29, being adopted especially in a wireless network.

58. The method as set forth in claim 29, being adopted especially in a power line network.

59. The method as set forth in claim 29, using a communication method conforming to IEEE Std 802.11/D3.3 2002.

60. A central control station, managing communication according to the method as set forth in claim 29.

61. A communication station, carrying out communication according to the method as set forth in claim 29.

62. A communication managing program for causing a computer to execute the steps of the method as set forth in claim 29.

63. A computer-readable recording medium storing a program for managing communication, wherein the computer-readable recording medium stores the program as set forth in claim 62.

30. A method of managing communication, comprising the step of causing a central control station to schedule such that allowance to transmit data is given, as a transmission right, to only one of communication stations in each time period by determining a timing of transmitting data from a communication station that is to transmit the data, to a communication station that is to receive the data, the method comprising the step of:

causing the central control station to carry out the scheduling, by using parameters C and T bound, so that a sum of transmission right granted time periods actually granted in a time period {t1, t2} is always equal to or more than C·

{(t2−

T bound)−

t1=} where t1 and t2 are arbitrary time points (t1<

t2), C is an average rate of change of the sum of the transmission right granted time periods allocated, to the communication station that is to transmit the data, by the central control station according to a reference transmission right allocation, and T delay is a maximum tolerable delay time of the data to be transmitted by the communication station that is to transmit the data, C and T bound satisfying following formulae;

0≦

T bound<

T delay  

 

Formula 1;


0<

C<

1  

 

Formula 2;

31. A method of managing communication, comprising the step of causing a central control station to schedule such that allowance to transmit data is given, as a transmission right, to only one of communication stations in each time period by determining a timing of transmitting data from a communication station that is to transmit the data, to a communication station that is to receive the data, the method comprising the step of:

causing the central control station to carry out the scheduling, by using a parameter Tboud and based on information concerning a traffic property of the data or a polling request, so that a sum of transmission right granted time periods actually granted in a time period {t1, t2} is a value equal to or more than a value of a time period necessary for transmitting MSDUs arriving in a time period (t1, t2−

T bound), where t1 and t2 are arbitrary time points (t1<

t2), and T delay is a tolerable maximum delay time (Delay bound) of the data to be transmitted by said one communication station, T bound satisfying a following formula;

0≦

T bound<

T delay  

 

Formula 1;

32. A method of managing communication, comprising the step of causing a central control station to schedule such that allowance to transmit data is given, as a transmission right, to only one of communication stations in each time period by determining a timing of transmitting data from a communication station that is to transmit the data, to a communication station that is to receive the data, the method comprising the step of:

causing the central control station to carry out the scheduling so that (i) a value smaller than a maximum tolerable delay time (Delay bound) of the data to be transmitted by the communication station that is to transmit the data is used as a maximum value of an interval between two successive timings of granting the transmission right, and (ii) a sum of transmission right granted time periods actually granted in a time period {t1, t2} is a value equal to or more than a value of a time period necessary for transmitting MSDUs of a normal MSDU size arriving in a time period (t1, t2−

T bound) with a mean data rate of a traffic, where t1 and t2 are arbitrary time points (t1<

t2).

33. A method of managing communication, comprising the step of causing a central control station to schedule such that allowance to transmit data is given, as a transmission right, to only one of communication stations in each time period by determining a timing of transmitting data from a communication station that is to transmit the data, to a communication station that is to receive the data, the method comprising the step of:

causing the central control station to carry out the scheduling, by using parameters C, TXOP1 bound, T1 bound, TXOP2 bound, and T2 bound, so that a sum of transmission right granted time periods actually granted in a time period {t0, t0+t} is always equal to or more than C·

t−

TXOP1 bound and equal to or less than C·

t+TXOP2 bound where t0 is an arbitrary time point, C is an average ratio of the sum of the transmission right granted time periods allocated, to the communication station that is to transmit the data, by the central control station according to a reference transmission right allocation, and T delay is a maximum tolerable delay time of the data to be transmitted by the communication station that is to transmit the data, C, TXOP1 bound, T1 bound, TXOP2 bound, and T2 bound satisfying the following formulas;

0≦

T1 bound<

T delay, 0≦

T2 bound;

 

 

Formula 4;


0<

C<

1; and

 

 

Formula 5;


TXOP1 bound=C·

T1 bound,  

 

Formula 6;


TXOP2 bound=C·

T2 bound.

49. A method of managing communication, comprising the step of causing a central control station to schedule such that allowance to transmit data is given, as a transmission right, to only one of communication stations in each time period by determining a timing of transmitting data from a communication station that is to transmit the data, to a communication station that is to receive the data, the method comprising the step of:

causing said one communication station to derive n by a following formula using a packet error rate PER and a packet loss rate of a communication path;

n=ceiling {log(PLR)/log(PER)}

where n is a desirable maximum number of times transmission is able to be carried out; and

notifying the central control station that a time period equal to or less than a time period obtained by dividing, by n, a value of an tolerable transmission delay time T delay is “

a maximum time interval between two successive times at which polling is desired”

.

50. The method as set forth in claim 49, comprising the step of carrying out communication by using a mechanism in which (i) the communication stations calculate a number of packets needed to be outputted in the maximum time interval between two successive times at which polling is desired, (ii) the packets are transmitted in a burst manner, and (iii) a reception station gives, to the communication station, acknowledgements with respect to a plurality of the received packets at once.

53. The method as set forth in claim 49, wherein:

the communication stations use, as a concrete value of the packet error rate PER, a value of PER actually measured by each communication station.

56. The method as set forth in claim 49, wherein:

the communication stations use a fixed value as a concrete value of the packet error rate PER.