Wireless communication system and base station

• US 20070086379A1
• Filed: 06/28/2006
• Published: 04/19/2007
• Est. Priority Date: 10/13/2005
• Status: Active Grant

• Current Assignee: FIPA Frohwitter Intellectual Property AG
• Original Assignee: Hitachi, Ltd.
• Inventors: Kawamoto, Kiyoshi, Mazawa, Shiro, Takayanagi, Daigo
• Granted Patent: US 7,634,278 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

There is provided admission control in view of wireless resources. A base station 120 obtains a down wireless resource available rate (available rate of slot allocation) based on a down QoS requested bandwidth B_i requested by a terminal i during QoS communication and a data rate R_i which the terminal can receive. A down wireless resource usage rate necessary to ensure the requested bandwidth B is obtained by dividing a down QoS requested bandwidth B requested by the terminal trying to perform QoS communication by the data rate R which the terminal can receive. The base station 120 obtains an up wireless resource available rate based on ROT of an up channel and a threshold value T₁ indicating an allowable upper limit of the ROT. Besides, an up wireless resource usage rate necessary to ensure an up requested bandwidth requested by the terminal is obtained. The QoS communication is performed on the terminal in which the up and down wireless resource available rates are respectively equal to or more than the up and down wireless resource usage rates.

Claims

1. A base station in a wireless communication system comprising the base station to communicate with a terminal by wireless and by time division multiplexing, and a node to perform best effort communication and QoS communication with the terminal through the base station,

wherein the base station comprises:

a requested bandwidth storage part in which a first requested bandwidth requested by one or plurality of first terminals during QoS communication and a second requested bandwidth requested by a second terminal trying to perform QoS communication are stored for each terminal;

a data rate reception management part that receives a data amount which the first and the second terminal can receive in each time slot from the terminals, which depends on changing the data amount stored in each time slot according to wireless environment, calculates a first and a second data rates which the first and the second terminals can receive by obtaining a time average value of the data amount for each terminal, and stores the data rates for each terminal; and

a control part to control the base station, and

wherein

the control part obtains a wireless resource available rate, based on a first requested bandwidth B_i which is stored in the requested bandwidth storage part and is requested by the first terminal i, and a first data rate R_i which the first terminal i can receive and which is stored in the data rate reception management part, by a following expression;

$1-\underset{i}{\sum <br><br>}<br><br>\frac{B_i}{R_i}$

the control part obtains a wireless resource usage rate of the second terminal necessary to ensure the second requested bandwidth B, by dividing the second requested bandwidth B which is stored in the requested bandwidth storage part and is requested by the second terminal by the second data rate R which the second terminal can receive and which is stored in the data rate reception management part, and

the control part transmits, with respect to the second terminal in which the wireless resource available rate is equal to or more than the wireless resource usage rate, a connection establishment request for QoS, for performing QoS communication between the second terminal and the node, to the node.

4. The base station according to claim 1, wherein the base station further comprises

a QoS information table in which a requested bandwidth requested by a terminal is previously stored correspondingly to an identifier of the terminal,

wherein

a connection establishment request including an identifier of the second terminal is received from the second terminal,

a requested bandwidth corresponding to the received identifier of the second terminal is acquired by referring to the QoS information table, and

the wireless resource usage rate is obtained based on the acquired requested bandwidth.

2. A base station in a wireless communication system comprising the base station to communicate with a terminal by wireless and by code division multiplexing, and a node to perform best effort communication and QoS communication with the terminal through the base station,

wherein the base station comprises:

a requested bandwidth storage part in which a requested bandwidth is stored for each terminal;

an S/N management part to store a value of S/N of a pilot channel for each terminal;

an ROT management part to store a value of ROT (Rise Over Thermal) for each channel;

a threshold value storage part to store a previously determined threshold value indicating an allowable upper limit of the ROT; and

a control part to control the base station, and

wherein

the control part obtains a wireless resource available rate, based on a value T of ROT of a channel stored in the ROT management part and a threshold value T₁ stored in the threshold value storage part, by a following expression;

1−

T/T₁,

the control part obtains a wireless resource usage rate of the second terminal, which is necessary to ensure the requested bandwidth stored in the requested bandwidth storage part and is requested by the second terminal, by a following expression;

A×

P×

T/T₁,

where, A is a ratio of total transmission power to transmission power of a pilot channel when the second terminal transmits data in the requested bandwidth, and uniquely determined according to the requested bandwidth, P is an S/N value of the pilot channel of the second terminal stored in the S/N management part, T is ROT of a channel stored in the ROT management part, and T₁ is a previously determined threshold value indicating an allowable upper limit of ROT, which is stored in the threshold value storage part, and

the control part transmits, with respect to the second terminal in which the wireless resource available rate is equal to on more than the wireless resource usage rate, a connection establishment request for QoS, for performing QoS communication between the second terminal and the node, to the node.

5. The base station according to claim 2, wherein the base station further comprises

a QoS information table in which a requested bandwidth requested by a terminal is previously stored correspondingly to an identifier of the terminal,

wherein

a connection establishment request including an identifier of the second terminal is received from the second terminal,

a requested bandwidth corresponding to the received identifier of the second terminal is acquired by referring to the QoS information table, and

the wireless resource usage rate is obtained based on the acquired requested bandwidth.

3. A base station in a wireless communication system comprising the base station to communicate with a terminal by wireless, by time division multiplexing in a downward direction to the terminal, and by code division multiplexing in an upward direction from the terminal, and a node to perform best effort communication and QoS communication with the terminal through the base station,

wherein the base station comprises:

a requested bandwidth storage part in which a first down requested bandwidth requested by one or plurality of first terminals during QoS communication, a second down requested bandwidth requested by a second terminal trying to perform QoS communication, and an up requested bandwidth are stored for each terminal;

a data rate reception management part that receives a data amount which the first and the second terminals can receive in each time slot from the terminals, which depends on changing the data amount stored in each time slot according to wireless environment, calculates a first and a second data rates which the first and the second terminals can receive by obtaining a time average value of the data amount for each terminal, and stores the data rates for each terminal;

an S/N management part to store a value of S/N of a pilot channel for each terminal;

an ROT management part to store a value of ROT (Rise Over Thermal) for each up channel;

a threshold value storage part to store a previously determined threshold value indicating an allowable upper limit of the ROT; and

a control part to control the base station, and

wherein

the control part obtains a down wireless resource available rate, based on a first down requested bandwidth B_i which is stored in the requested bandwidth storage part and is requested by the first terminal i, and a first data rate R_i which the first terminal i can receive and which is stored in the data rate reception management part, by a following expression;

$1-\underset{i}{\sum <br><br>}<br><br>\frac{B_i}{R_i}$

the control part obtains a down wireless resource usage rate of the second terminal necessary to ensure the second requested bandwidth B, by dividing the second down requested bandwidth B which is stored in the requested bandwidth storage part and is requested by the second terminal by the second data rate R which the second terminal can receive and which is stored in the data rate reception management part,

the control part obtains an up wireless resource available rate, based on a value T of ROT of an up channel stored in the ROT management part and a threshold value T₁ stored in the threshold value storage part, by a following expression;

1−

T/T₁,

the control part obtains an up wireless resource usage rate of the second terminal, which is necessary to ensure the up requested bandwidth stored in the requested bandwidth storage part and is requested by the second terminal, by a following expression;

A×

P×

T/T₁,

where, A is a ratio of total transmission power to transmission power of a pilot channel when the second terminal transmits data in the up requested bandwidth, and uniquely determined according to the up requested bandwidth, P is an S/N value of the pilot channel of the second terminal stored in the S/N management part, T is ROT of an up channel stored in the ROT management part, and T₁ is a previously determined threshold value indicating an allowable upper limit of ROT, which is stored in the threshold value storage part, and

the control part transmits, with respect to the second terminal in which the down wireless resource available rate is equal to or more than the wireless resource usage rate, and in which the up wireless resource available rate is equal to or more than the up wireless resource usage rate, a connection establishment request for QoS, for performing QoS communication between the second terminal and the node, to the node.

6. A base station in a wireless communication system comprising the base station having a first and a second channels and communicating with a terminal by wireless and by time division multiplexing, and a node to perform best effort communication and QoS communication with the terminal, wherein

the base station obtains a first wireless resource usage rate in the first channel, based on a first requested bandwidth B_i requested by one or plurality of first terminals i during QoS communication through the first channel and a first data rate R_i which the first terminal i can receive and which depends on changing a data amount stored in each time slot according to wireless environment, by a following expression:

$\underset{i}{\sum <br><br>}<br><br>\frac{B_i}{R_i}$

the base station obtains a second wireless resource usage rate of the second terminal, which is necessary to ensure a requested bandwidth B, by dividing the second requested bandwidth B requested by an arbitrary second terminal during QoS communication through the first channel by a second data rate R which the second terminal can receive,

the base station obtains a predicted value of a wireless resource usage rate in the first channel after the second terminal hands off to the second channel by subtracting the second wireless resource usage rate of the second terminal from the first wireless resource usage rate in the first channel,

the base station obtains a third wireless resource usage rate in the second channel, based on a third requested bandwidth B_k requested by one or plurality of third terminals k during QoS communication through the second channel and a third data rate R_k which the third terminal k can receive, which depends on changing a data amount stored in each time slot according to wireless environment, by a following expression;

$\underset{k}{\sum <br><br>}<br><br>\frac{B_k}{R_k}$

the base station obtains a fourth wireless resource usage rate of the second terminal after the second terminal hands off to the second channel, by dividing the second requested bandwidth B requested by the second terminal by an average R_AVE of the data rate which each terminal communicating through the second channel can receive,

the base station obtains a predicted value of a wireless resource usage rate in the second channel after the second terminal hands off to the second channel by adding the fourth wireless resource usage rate in the second terminal to the third wireless resource usage rate in the second channel, and

the base station hands off the second terminal from the first channel to the second channel in a case where both the obtained predicted value of the wireless resource usage rate in the first channel and the predicted value of the wireless resource usage rate in the second channel respectively become equal to or less than previously determined threshold values.

8. The base station according to claim 6, wherein

in a case where the obtained second wireless resource usage rate of the second terminal is larger than the previously determined second threshold value, the base station changes the second terminal from the QoS communication to the best effort communication.

10. The base station according to claim 6, further comprising:

a requested bandwidth storage part in which a first requested bandwidth requested by one or plurality of first terminals during QoS communication and a second requested bandwidth requested by the second terminal trying to perform QoS communication are stored for each terminal;

a data rate reception management part that receives a data amount which the first and the second terminals can receive in each time slot from the terminals, which depends on changing the data amount stored in each time slot according to wireless environment, calculates a first and a second data rates which the first and the second terminals can receive by obtaining a time average value of the data amount for each terminal, and stores the data rates for each terminal; and

a control part to control the base station.

7. A base station in a wireless communication system comprising the base station having a first and a second channels and communicating with a terminal by wireless and by code division multiplexing, and a node to perform best effort communication and QoS communication with the terminal, wherein

the base station obtains a first wireless resource usage rate in the first channel, by dividing ROT (Rise Over Thermal) T_a of the first channel by a previously determined first ROT threshold value T₁ indicating an allowable upper limit of the ROT,

the base station obtains a second wireless resource usage rate of the second terminal, which is necessary to ensure a requested bandwidth requested by an arbitrary second terminal during QoS communication through the first channel, by a following expression:

A×

P×

T_a/T₁,

where, A is a ratio of total transmission power to transmission power of a pilot channel when the second terminal transmits data in the requested bandwidth, and uniquely determined according to the requested bandwidth, P is S/N of the pilot channel of the second terminal, T_a is ROT of the first channel, and T₁ is a previously determined first ROT threshold value indicating an allowable upper limit of ROT,

the base station obtains a predicted value of a wireless resource usage rate in the first channel after the second terminal hands off to the second channel by subtracting the second wireless resource usage rate in the second terminal from the first wireless resource usage rate in the first channel,

the base station obtains a third wireless resource usage rate in the second channel, by dividing ROT T_b of the second channel by a previously determined second threshold value T₂ indicating an allowable upper limit of the ROT,

the base station obtains a fourth wireless resource usage rate of the second terminal after the second terminal hands off to the second channel by a following expression;

A×

P_AVE×

T_b/T₂,

where, A is a ratio of total transmission power to transmission power of the pilot channel when the second terminal transmits data in the requested bandwidth, and uniquely determined according to the requested bandwidth, P_AVE is an average of S/N of the pilot channel of all terminals communicating through the second channel, T_b is ROT of the second channel, and T₂ is a previously determined second ROT threshold value indicating an allowable upper limit of the ROT,

the base station obtains a predicted value of a wireless resource usage rate in the second channel after the second terminal hands off to the second channel by adding the fourth wireless resource usage rate in the second terminal to the third wireless resource usage rate in the second channel, and

the base station hands off the second terminal from the first channel to the second channel in a case where both the obtained predicted value of the wireless resource usage rate in the first channel and the predicted value of the wireless resource usage rate in the second channel respectively become equal to or less than previously determined threshold values.

9. The base station according to claim 7, wherein

in a case where the obtained second wireless resource usage rate of the second terminal is larger than the previously determined second threshold value, the base station changes the second terminal from the QoS communication to the best effort communication.

11. The base station according to claim 7, further comprising:

a requested bandwidth storage part in which a requested bandwidth is previously stored for each terminal;

an S/N management part to store a value of S/N of a pilot channel for each terminal;

an ROT management part to store a value of ROT (Rise Over Thermal) for each channel;

a threshold value storage part to store a previously determined threshold value indicating an allowable upper limit of the ROT, and

a control part to control the base station.

12. A wireless communication system comprising:

a base station to communicate with a terminal by wireless and by time division multiplexing; and

a node that has a QoS information table in which a requested bandwidth requested by the terminal is previously stored correspondingly to an identifier of the terminal and performs best effort communication and QoS communication with the terminal through the base station,

wherein the base station comprises;

a requested bandwidth storage part in which a first requested bandwidth requested by one or plurality of first terminals during QoS communication and a second requested bandwidth requested by a second terminal trying to perform QoS communication are stored for each terminal;

a data rate reception management part that receives a data amount which the first and the second terminals can receive in each time slot from the terminals, which depends on changing the data amount stored in each time slot according to wireless environment, calculates a first and a second data rates which the first and the second terminals can receive by obtaining a time average value of the data amount for each terminal, and stores the data rates for each terminal; and

a control part to control the base station,

wherein

the node receives a connection establishment request for best effort, which includes an identifier of the second terminal trying to perform QoS communication, from the base station, and previously establishes connection for best effort between the second terminal and the node, and

the node refers to the QoS information table and transmits a second requested bandwidth corresponding to the identifier of the second terminal included in the establishment request to the base station,

the control part stores the second requested bandwidth received from the node into the requested bandwidth storage part, the control part obtains a wireless resource available rate, based on a first requested bandwidth B_i which is stored in the requested bandwidth storage part and is requested by the first terminal i and a first data rate R_i which the first terminal i can receive and which is stored in the data rate reception management part, by a following expression;

$1-\underset{i}{\sum <br><br>}<br><br>\frac{B_i}{R_i}$

the control part obtains a wireless resource usage rate of the second terminal, which is necessary to ensure the second requested bandwidth B, by dividing the second requested bandwidth B which is stored in the requested bandwidth storage part and is requested by the second terminal by the second data rate R which the second terminal can receive and which is stored in the data rate reception management part, and

the control part transmits, with respect to the second terminal in which the wireless resource available rate is equal to or more than the wireless resource usage rate, a connection establishment request for QoS, for performing QoS communication between the second terminal and the node, to the node.

13. A wireless communication system comprising:

a base station to communicate with a terminal by wireless and by code division multiplexing; and

a node that has a QoS information table in which a requested bandwidth requested by the terminal is previously stored correspondingly to an identifier of the terminal and performs best effort communication and QoS communication with the terminal through the base station,

wherein the base station comprises;

a requested bandwidth storage part in which a requested bandwidth is stored for each terminal;

an S/N management part to store a value of S/N of a pilot channel for each terminal;

an ROT management part to store a value of ROT (Rise Over Thermal) for each channel;

a threshold value storage part to store a previously determined threshold value indicating an allowable upper limit of the ROT; and

a control part to control the base station,

wherein

the node receives a connection establishment request for best effort, which includes an identifier of a second terminal trying to perform QoS communication, from the base station, and previously establishes connection for best effort between the second terminal and the node, and

the node refers to the QoS information table and transmits a requested bandwidth corresponding to the identifier of the second terminal included in the establishment request to the base station,

the control part stores the second requested bandwidth received from the node into the requested bandwidth storage part,

the control part obtains a wireless resource available rate, based on a value T of ROT of a channel stored in the ROT management part and a threshold value T₁ stored in the threshold value storage part, by a following expression;

1−

T/T₁,

the control part obtains a wireless resource usage rate of the second terminal, which is necessary to ensure a requested bandwidth stored in the requested bandwidth storage part and is requested by the second terminal, by a following expression;

A×

P×

T/T₁,

where, A is a ratio of total transmission power to transmission power of a pilot channel when the second terminal transmits data in the requested bandwidth, and uniquely determined according to the requested bandwidth, P is an S/N value of the pilot channel of the second terminal stored in the S/N management part, T is ROT of a channel stored in the ROT management part, and T₁ is a previously determined threshold value indicating an allowable upper limit of ROT, which is stored in the threshold value storage part, and

the control part transmits, with respect to the second terminal in which the wireless resource available rate is equal to or more than the wireless resource usage rate, a connection establishment request for QoS, for performing QoS communication between the second terminal and the node, to the node.