JP2010251936A - Radio terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the power efficiency of a radio system mounted on a radio terminal device. <P>SOLUTION: An information terminal device mounts the radio system 63 including a plurality of antennas 65 to 69 thereon. Destination information of a server and the number of antennas to be set in the radio system are registered in a reference table 115. A device driver 113 refers to the reference table in accordance with a connection operation to a specific server by executing a web browser 105, and sets the radio system so as to operate the number of antennas registered in accordance with the destination information of the server. After the completion of setting the antennas, the radio system is connected to an access point. Then, the radio terminal device can perform radio communication having high power efficiency based on the past history from the point of time of starting access. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a technique for reducing the power consumption of a wireless system by controlling the number of operating antennas in a wireless terminal device having a plurality of antennas, and more specifically, a request for a combination of an application program and a server. The present invention relates to a technique for improving the power efficiency of a wireless system while satisfying a transmission rate that is set.

  Server-client networks include the Internet and intranets that employ TCP / IP technology composed of TCP (Transmission Control Protocol) and IP (Internet Protocol). A notebook personal computer (hereinafter referred to as a notebook PC) or PDA as a client is equipped with a wireless communication system, and can access various servers connected to the network via an access point. . When a wireless transmission path and a wired transmission path are interposed in a data line between a client and a server, the wireless transmission path may become a bottleneck with respect to transmission speed. Since the client wants the transmission speed with the server to be as fast as possible, a method with a high transmission speed is adopted for the wireless transmission path.

  IEEE802.11a / b / g has put into practical use a wireless communication specification that realizes a maximum transmission rate of 54 Mbps in the physical layer, and IEEE802.11n has a wireless communication specification that realizes a transmission rate of 100 Mbps or more in the MAC layer. It has been put into practical use. IEEE 802.11n employs a SDM (Space Division Multiplexing) transmission technique that uses a MIMO (Multiple Input Multiple Output) scheme. In this technique, a plurality of antennas are installed on each of the transmission side and the reception side to form a plurality of radio propagation paths (spatial streams) in the space, thereby increasing the transmission capacity (throughput).

  For example, when the transmission side is equipped with M antennas and the reception side is equipped with N antennas, the transmission side divides transmission data into M information channels by serial / parallel conversion, Transmit simultaneously from each antenna at the same frequency. Data transmitted from the M antennas on the transmitting side reaches the N antennas on the receiving side. At this time, there are M × N MIMO channels or propagation paths called multipaths between the transmission side and the reception side. Since data transmitted from each antenna on the transmission side is affected by reflection and attenuation of the transmission path, the signal received by each antenna on the reception side is a synthesized signal that is distorted. The transmission signal vectors transmitted from the respective antennas on the transmitting side are t1 to tm, the received signal vectors received by the respective antennas on the receiving side are r1 to rn, the transmission coefficients of the propagation paths are h11 to hnm, and the noise vector is n1. When ˜nn, the transmission signal can be estimated from the received signal by obtaining a transfer function from the pilot signal or preamble signal in the determinant (1).

  The number of spatial streams is equal to the smaller of the number M of antennas on the transmission side and the number N of reception side antennas. The transmission capacity of the wireless transmission path is basically proportional to the number of spatial streams. However, when the number of spatial streams is increased, the amount of calculation of Equation (1) increases with the third power of the transmission capacity. Therefore, the power consumption of the processor that executes Equation (1) increases exponentially with respect to the transmission capacity. Therefore, it becomes necessary to select the number of antennas to be actually used according to the communication status from the viewpoint of the power consumption of the client with respect to the number of mounted antennas.

  Patent Document 1 discloses an invention that reduces power consumption by controlling the number of reception units connected to an antenna in a wireless terminal equipped with a MIMO system. In the invention of this document, at the time of association, the radio base station recognizes the number of antennas mounted on the radio terminal, and then sends a frame specifying the number of antennas from the radio base station to the radio terminal and sets the number of antennas to the radio terminal. I am letting.

  Patent Document 2 discloses an invention for reducing power consumption during a packet detection standby period and power consumption during packet reception on a spatially multiplexed channel. In the invention of this document, in the reception standby state, packet detection is performed using only one reception branch of a plurality of reception branches, and the reception operation of the remaining reception branches that do not perform packet detection is stopped, thereby A reduction in power consumption during detection waiting is achieved. In the packet reception state, only the minimum reception branch necessary to receive a spatially multiplexed signal by MIMO transmission is operated, thereby reducing the power consumption even during the period of receiving the MIMO signal.

  Patent Document 3 discloses an invention that simplifies wireless communication settings using a registration table. The registration table of this document describes IP addresses and protocols.

JP 2006-115414 A JP 2006-42075 A JP 2007-60234 A

  The client wants the transmission speed to be as fast as possible, but in reality, when a specific application program accesses a specific server, data transfer is performed at a predetermined time extracted from the characteristics of the application program. The request will be satisfied if possible. In order to satisfy the client's request, the actual transmission rate (actual transmission rate) needs to be equal to or higher than the allowable transmission rate. If the wireless transmission path is the bottleneck, that is, it dominates the lowest value of the actual transmission speed in the entire transmission system and the actual transmission speed does not satisfy the allowable transmission speed, it can be improved by increasing the number of operating antennas. it can. However, when the wireless transmission path is not a bottleneck, even if the number of operating antennas is increased, the actual transmission speed cannot be increased and the wireless system consumes useless power. Further, even if the actual transmission rate is equal to or higher than the allowable transmission rate, and the allowable transmission rate can be maintained even if the number of antennas is further reduced, the power efficiency of the wireless system cannot be said to be appropriate.

  The actual transmission rate when the client and server transfer data is lower than the maximum transmission rate of the transmission system due to various factors. In the server, the number of clients accessing at the same time and the processing capacity of the server are factors. For example, since many clients access a Web server that is open to the Internet, the server often becomes a bottleneck. In addition, since the file transfer server disclosed on the intranet has a small number of clients, the wireless transmission path tends to be a bottleneck.

  In a wired LAN (Local Area Network), many clients share the same transmission path. In order to avoid collision between data, if other client's data is transferred, it will wait for the end of the communication, and if a data collision occurs, it will wait for a random time and start transmission again. A communication procedure called CSMA / CD (Carrier Sense Multiple Access / Collision Detection) is adopted. In the wireless LAN, if there is another client that uses the transmission path first, CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) that starts transmission after a random waiting time elapses from the end of the client. ) Is used. Therefore, the number of clients that simultaneously use the transmission path becomes a determinant of the actual transmission rate.

  In the case of data transfer using TCP / IP, if the transmission side does not receive a reception response packet even after a predetermined time has elapsed from the reception side, it is retransmitted. Therefore, the time zone in which the number of clients sharing the same transmission path increases, noise, and radio wave intensity are determinants of the actual transmission rate. Noise and field strength are related to the location of the client when accessing the network. On the other hand, when data is transferred using UDP / IP configured by UDP (User Datagram Protocol) and IP, even if an error occurs in the packet during data transfer, retransmission is not performed. However, the actual transmission speed becomes faster.

  In this way, the actual transmission speed between the server and the client depends on the network environment (Internet / Intranet) to which the server is connected, the protocol used for data transfer (TCP / UDP), the location of the client when connecting to the network, and It depends on the time of access. Therefore, in order to reduce the power consumption of the wireless system while satisfying the allowable transmission rate, it is necessary to recognize the number of effective spatial streams for the access on the wireless transmission path when the client starts access to the server. There is. In the method of setting the number of antennas based on the actual transmission rate measured after starting data transfer, if the number of spatial streams is insufficient, the stress on the user at the time of data transfer by the first access increases. Therefore, it is necessary to set the number of effective antennas before starting access.

  In the method of determining the number of antennas that the wireless base station operates on the wireless terminal device as in Patent Document 1, it is difficult for the wireless base station to grasp individual access conditions between the server and the client. An appropriate number of antennas cannot be indicated. In particular, since the allowable transmission rate of the client is different for each application program that accesses the server, it is impossible for the radio base station to grasp it. Further, unless the client grasps the state where the wireless transmission path is a bottleneck and the allowable transmission rate is satisfied, wireless communication cannot be performed with optimum power efficiency.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless terminal device that can improve the power efficiency of a wireless system while satisfying an allowable transmission rate required by a client or an application program. A further object of the present invention is to provide a wireless terminal device capable of improving the power efficiency of the wireless system while satisfying the allowable transmission rate required by the client or application program from the start of access. A further object of the present invention is to provide a computer program and a control method that operate in such a wireless terminal device.

  The wireless terminal device according to the present invention is equipped with a wireless system capable of executing an application program and individually controlling operations of a plurality of antennas. The wireless terminal device stores the destination information of the server that transfers data through the wireless system and the number of registered antennas, which is the number of antennas set at that time, in the reference table. When the application program starts data transfer with the server specified by the destination information stored in the reference table, the wireless terminal device refers to the reference table and operates the wireless system so that the number of registered antennas operates. Set. Then, after the setting of the number of antennas is completed, the wireless system is connected to the access point.

  According to such a configuration, when an application program newly transfers data to or from a server specified by arbitrary destination information, wireless communication with high power efficiency from the start of data transfer based on the reference table Can do. The wireless system can preferably employ the MIMO scheme. In the reference table, transmission source information related to the application program can be stored in association with the destination information. The wireless system can be set with the number of registered antennas corresponding to the set of destination information and transmission source information. The minimum transmission rate allowed for each application program and server group is different, but if the destination information, source information, and the number of registered antennas are stored in correspondence in the reference table, the data under the same conditions for the next time is stored. The number of registered antennas can be set at the time of transfer.

  After starting the data transfer, measure the actual transmission rate for the application program. When the actual transmission rate is slower than the minimum reference value, a request for increasing the number of antennas operated by the application program can be generated, and the wireless system can be set based on the request. If the number of spatial streams is a bottleneck with respect to the overall transmission rate, increasing the number of antennas increases the actual transmission rate for the application program and makes it faster than the minimum reference value. Furthermore, after measuring the actual transmission rate for the application program after increasing the number of antennas, if the actual transmission rate does not increase more than a predetermined value from before the increase in the number of antennas, it can be determined that the number of spatial streams is not a bottleneck. Therefore, the application program can request to reduce the number of antennas to be operated.

  When the actual transmission rate is faster than the maximum reference value, a request for reducing the number of antennas operated by the application program can be generated, and the wireless system can be set based on the request. When the number of spatial streams is a bottleneck with respect to the overall transmission rate, the actual transmission rate for the application program can be made slower than the maximum reference value by reducing the number of antennas. At this time, if the actual transmission rate is higher than the minimum reference value, the allowable transmission rate for the application program is satisfied, so that the power efficiency of the wireless system can be improved.

  Furthermore, after reducing the number of antennas, the actual transmission rate for the application program is measured, and if the actual transmission rate is still faster than the maximum reference value, it can be determined that the number of spatial streams is not a bottleneck. • The program can request that the number of antennas to be operated be further reduced. If the number of antennas is reduced after the number of spatial streams becomes a bottleneck, the actual transmission rate can be made slower than the maximum reference value. The system can maintain the transmission rate required by the application program with less power consumption. The maximum reference value and the minimum reference value are the satisfaction regarding the actual transmission speed of the user, such as no streaming data missing in each application program or data transfer within a predetermined time, and the minimum number of antennas or By setting so as to satisfy the satisfaction regarding the power consumption such as the realization with the lowest power consumption, wireless communication with high power efficiency can be performed.

  When multiple application programs operate on a wireless terminal device, all applications must be used to reduce the number of antennas so that wireless communication can be performed with more than the number of antennas required by any application program. -Set the wireless system with the maximum number of antennas required from the program. When the execution of the application program is stopped, the reference table is updated with the number of antennas requested by the application program. You can respond with information.

  According to the present invention, it is possible to provide a wireless terminal device capable of improving the power efficiency of a wireless system while satisfying an allowable transmission rate required by a client or an application program. Furthermore, according to the present invention, it is possible to provide a wireless terminal device capable of improving the power efficiency of the wireless system while satisfying the allowable transmission rate required by the client or application program from the start of access. Further, according to the present invention, it is possible to provide a computer program and a control method that operate on such a wireless terminal device.

It is a figure which shows an example of the network environment by which this invention is implemented. It is a schematic block diagram which shows the structure of notebook PC. It is a schematic block diagram which shows the structure of a MIMO controller. It is a functional block diagram which shows the structure of the software and hardware which implement | achieve the method of controlling the number of the spatial streams in a wireless transmission path. It is a figure which shows an example of the data structure of an antenna registration table. It is a block diagram which shows the structure of the application program for accessing a server. It is a flowchart which shows the procedure which controls the number of the spatial streams concerning this Embodiment. It is a figure which shows the data structure of the antenna management table which stored the request | requirement antenna number from each application. It is the figure which modeled the transmission path | route concerning this invention.

  FIG. 9 is a diagram modeling a transmission system related to data transfer between an application program and a server in order to explain the outline of the present invention. In FIG. 9A, a plurality of application programs 401 a, 401 b and 401 c operate on the client 403. The client 403 is connected to the server 409 via the wireless transmission path 405 and the wired transmission path 407. The application programs 401a, 401b, and 401c have a transmission speed that is requested in this order in relation to their characteristics. For example, the application program 401a is a Web browser that reproduces a moving image, and the application program 401c is a mail application program that reads mail from a mail box in the background.

  Alternatively, the application programs 401a, 401b, and 401c have a transmission speed that is requested in this order in relation to the server that is accessing. For example, the application program 401a is accessing a server connected to an intranet, and the application program 401c is accessing a server published on the Internet. Here, the user can define an allowable transmission rate that is a minimum transmission rate required for data transfer between the application programs 401 a to 401 c and the server 409. The allowable transmission rate is, for example, a transmission rate at which streaming data read into the frame buffer of the video circuit is not depleted when playing a video, and an allowance until the user recognizes a new incoming mail when reading a mail. The transmission rate obtained from time can be obtained. Whether or not data transfer can be performed at an actual transmission rate that is equal to or higher than an allowable transmission rate when a set of an application program and a server that transfer data to each other is determined, depends on the processing capability in each of the client 403 and the server 409. It depends on the transmission capacity of the wireless transmission line 405 and the wired transmission line 407.

  In this model, the client 403 can control the transmission capacity by adjusting the number of spatial streams in the wireless transmission path 405. However, the transmission capacity of the wireless transmission path 405 varies not only with the number of spatial streams but also with the number of other clients to be shared, radio wave intensity, noise, and the like. Further, the processing capabilities of the client 403 and the server 409 change depending on the internal load status, and change depending on the number of other clients sharing the transmission capacity of the wired transmission path 407. Moreover, the application program cannot directly recognize the processing capability of the server 409, the transmission capacity of the wired transmission path 407, and the transmission capacity of the wireless transmission path 405 individually. 9A to 9D, the width of a block indicating each element indicates a transmission capacity or a processing capability comparable to the transmission capacity. When the transmission capacity of the wireless transmission path 405 is increased, power consumption in the wireless system is increased according to the number of spatial streams.

  When the transmission capacity of the wireless transmission path 405 is a bottleneck in the entire transmission system as shown in FIG. 9A, the number of spatial streams can be increased as shown in FIG. The transmission rate is changed by lowering as shown in FIG. At this time, if the transmission capacity of the wireless transmission path 405 becomes a bottleneck and the minimum value necessary to satisfy the allowable transmission rate required by the application program, the power efficiency with respect to the transmission capacity is maximum. I can say that.

  As shown in FIG. 9D, when the processing capacity of the server 409 is a bottleneck in the entire transmission system with respect to the actual transmission rate, the number of spatial streams on the wireless transmission path 405 is increased or decreased. Is not reflected in the change in the actual transmission rate. The actual transmission rate changes in a direction in which the wireless transmission path 405 becomes a bottleneck when the transmission capacity of the wireless transmission path 405 is reduced below the processing capacity of the server 409. Even if the actual transmission rate falls, the power efficiency with respect to the transmission capacity can be said to be maximum if the allowable transmission rate for the application program and server pair is satisfied.

  In the case of FIG. 9D, even if the permissible transmission rate regarding the combination of the application program and the server is satisfied, the wireless transmission path 405 consumes more power than necessary. When the transmission capacity of the wireless transmission path 405 is not a bottleneck in the entire transmission system, it cannot be said that the power efficiency with respect to the transmission capacity is appropriate. To achieve maximum power efficiency, the client recognizes whether or not the wireless transmission path is a bottleneck in data transfer performed by a combination of an application program and a server. Although it is necessary to perform data transfer satisfying the speed, a method for realizing this will be described below.

  FIG. 1 is a diagram illustrating an example of a network environment in which the present invention is implemented. In FIG. 1, an intranet 10 and the Internet 30 that transfer data using both TCP / IP and UDP / IP are connected to each other. In the intranet 10, a Web server 13, a file server 15, and a mail server 17 are connected to a wired LAN 11 that conforms to the Ethernet (registered trademark) standard. In the Web server 13, in addition to a program that provides services such as hypertext, video, and audio described in HTML (HyperText Markup Language) or XML (Extensible Markup Language) using HTTP (HyperText Transfer Protocol), A program for providing a file transfer service using FTP (File Transfer Protocol) and a program for providing an electronic mail transfer service using SMTP (Simple Mail Transfer Protocol) operate.

  The file server 15 is a dedicated server that provides a file transfer service using FTP, and the mail server is a dedicated server that provides an email transfer service using SMTP. The access point 21 is also referred to as a wireless base station, and is a wireless device for connecting the wireless terminal device 50 to the wired LAN 11. The gateway server 23 also functions as a proxy and a firewall and mediates the connection between the intranet 10 and the Internet 30. The Internet 30 has a transmission path connected by a plurality of routers, and a wired LAN 31 is formed under a router 33 provided by a service provider.

  A web server 35, a file server 37, a mail server 39, and an access point 41 are connected to the wired LAN 31. The wireless terminal device 50 is configured by a notebook PC, and can freely move in the wireless space of the intranet 10 and the Internet 30 and access each server through the access point 21 or 41. In the context of the present invention, the configurations of the intranet 10 and the Internet 30 are well known.

  FIG. 2 is a schematic block diagram showing the configuration of the notebook PC 50. The notebook PC 50 includes a central processing unit (CPU) 51, a main memory 53, a hard disk drive (HDD) 55, a liquid crystal display device (LCD) 59, an input / output device 61, and a MIMO controller 63 that performs wireless communication using the MIMO method. It is connected to the bus 52. The HDD 56 stores a program related to the present embodiment. Three antennas 65 to 69 are connected to the MIMI controller 63. The notebook PC 50 operates with power supplied from the battery 57 when used in a mobile manner.

  FIG. 3 is a schematic block diagram showing the configuration of the MIMO controller 63. The MIMO controller 63 operates as a transmitter and a receiver. The interface 81 includes a frame buffer, and is connected to a bus 52 and a MAC frame processing unit 83 conforming to a standard such as PCI (Peripheral Component Interconnect), and has a buffer function and a bus protocol when bidirectionally transferring an IP packet. Perform the conversion function. The MAC frame processing unit 83 reads an IP packet from the frame buffer of the interface 81 at the time of transmission, adds a MAC header generated by itself to the MAC frame (hereinafter simply referred to as a MAC frame) defined in IEEE 802.11. Generate and output to the baseband processing unit 85. The MAC frame processing unit 83 removes the MAC header from the MAC frame received from the baseband processing unit 85 at the time of reception, converts the MAC header into an IP packet, and writes the IP packet in the frame buffer of the interface 81.

  The baseband processing unit 85 outputs a transmission baseband signal generated by performing encoding, modulation, and MIMO processing on the MAC frame received from the MAC frame processing unit 83 during transmission to the high frequency circuit unit 87. The baseband processing unit 85 performs MIMO processing, demodulation, and error correction processing on the received baseband signal received from the high frequency circuit unit 87 during reception, and outputs the result to the MAC frame processing unit 83. The high-frequency circuit unit 85 up-converts the transmission baseband signal received from the baseband processing unit 83 during transmission into a high-frequency signal and outputs the high-frequency signal to the antennas 65, 67, and 69 operating at that time. The high-frequency circuit unit 85 down-converts the high-frequency signal received from the antennas 65, 67, and 69 that are operating at the time of reception and outputs the high-frequency signal to the baseband processing unit 83.

  The control unit 89 controls the entire operation of the MIMO controller 63 based on instructions of a program executed by the CPU 51, or individually selects and sets an antenna that operates by controlling the high frequency circuit unit 85. The baseband processing unit 83 can perform arithmetic processing corresponding to the number of antennas set to operate at the time of transmission and reception, but requires a larger amount of calculation as the number of operating antennas increases. . Also, when the number of operating antennas is one, MIMO communication is not performed. The MIMO controller 63 can increase the transmission capacity of the wireless transmission path as the number of operating antennas increases. However, the power consumption of the baseband processing unit 85 that performs the MIMO calculation increases. Since changing the number of operating antennas corresponds to changing the number of spatial streams, setting the number of operating antennas can be rephrased as setting the number of spatial streams.

  FIGS. 2 and 3 merely show a simplified configuration and connection relationship of main hardware related to the present embodiment. In addition to those mentioned above, many devices are used to configure the notebook PC 50 and the MIMO controller 63. However, they are well known to those skilled in the art and will not be described in detail here. A person skilled in the art also arbitrarily selects a plurality of blocks described in the figure as one integrated circuit or device, or conversely, a block is divided into a plurality of integrated circuits or devices. Is included in the scope of the present invention.

  FIG. 4 is a functional block diagram showing software and hardware configurations for realizing a method for controlling the number of spatial streams in the wireless transmission path according to the present invention. The mail software air 101, the file transfer software air 103, and the web browser 105 are application programs that operate in the application layer in the TCP / IP protocol layer. The mail software 101 is an application program for receiving an e-mail service from a server using a similar protocol using a protocol called SMTP.

  The file transfer software 103 is an application program for receiving a file transfer service from a server using a similar protocol using a protocol called FTP. The Web browser 105 is an application program for receiving a delivery service such as hypertext, moving image, or voice from a server using a similar protocol in addition to using SMTP or FTP. .

  The wireless management program 107 displays a parameter setting screen for the user on the LCD 59 so that the notebook PC 50 performs wireless communication, and collects and stores information on the current time and day of the week from elements inside the notebook PC 10. Or When the notebook PC 10 includes a GPS (Global Positioning System), the wireless management program 107 collects and holds position information from the GPS. The OS 109 is basic software that abstracts hardware by providing an API (Application Programming Interface) to an application program. In the context of the present invention, the OS 109 is a transport layer (TCP / UDP) in the TCP / IP protocol hierarchy. A TCP / IP program 111 for realizing the network layer (IP) is included.

  The TCP / IP program 111 includes programs such as TCP, UDP, IP, and resolver. In both TCP and UDP, a TCP or UDP header including a source port number and a destination port number is added to the transmission data received from the application program and passed to the IP, or the TCP or UDP header is received from the reception data received from the IP. And pass it to the application program specified by the destination port number.

  However, TCP is a connection-type protocol that has a function to retransmit when data indicating confirmation of arrival of a packet is not sent from the receiving side within a predetermined time, whereas UDP does not include such a function. It differs in that it is a connectionless protocol. TCP is suitable for the case of exchanging data with certainty, but the communication time becomes long when the transmission path is noisy or there are many clients to share. UDP is suitable for cases where communication speed is more important than reliability, such as streaming data files such as music and moving images.

  The IP adds the IP header including the transmission source IP address and the destination IP address to the transmission data received from TCP or UDP and passes it to the device driver 113, or removes the IP header from the reception data received from the device driver 113. To TCP or UDP. The resolver is called from the application program when the application program accesses one of the servers, and inquires the nearby DNS (Domain Name System) server for the IP address corresponding to the specified URL (Uniform Resource Locator). -Pass to the program. The application program can specify the destination URL and pass the IP address obtained from the resolver to the TCP / IP program 111 as the destination IP address.

  Both the device driver 113 and the MIMO controller 63 operate at the network interface layer in the TCP / IP protocol layer. The device driver 113 is a program that controls communication and operation of the MIMO controller 119. The device driver 113 can further read the antenna registration table 115 described later and set the number of antennas to be operated by the MIMO controller 63. The device driver 113 updates the data in the antenna registration table 115 based on an instruction from the application program or the wireless management program 107. The TCP monitor 117 counts the number of IP packets passing through the MIMO controller 63 to detect an actual transmission rate (hereinafter simply referred to as an actual transmission rate) that is an average value for each predetermined time for each application program. Send to application program specified by port number.

  FIG. 5 is a diagram illustrating an example of the data structure of the antenna registration table 115. In this embodiment, the number of antennas is set in the antenna registration table 115 so that the power efficiency of the MIMO controller 63 is maximized in the past data transfer related to a specific application program of the notebook PC 50 and a specific server. The communication conditions and the number of registered antennas are stored as the history information at the time. When accessing the site where the application program is located, if there is an entry that matches the communication conditions in the antenna registration table 115, the number of registered antennas set there is also set this time, so that wireless communication with high power efficiency is possible. Can do.

  The antenna registration table 115 includes a communication condition when data transfer related to a set of a specific application program and a specific server is performed, and the number of registered antennas which is the number of antennas requested by the application program at that time. It is configured. When data transfer is performed between the notebook PC 10 and the intranet 10 or the server of the Internet 30 via a wireless transmission path, the user is interested not in the actual transmission speed of the transmission path in the middle. The actual transmission rate for the application program. There are a plurality of factors that determine the actual transmission rate for the application program, and the number of antennas that are actually operated by the MIMO controller 63 that determines the number of spatial streams is also a part thereof.

  Therefore, if the bottleneck when the minimum transmission rate is not met when the application program transfers data to or from a specific server is the number of spatial streams, increasing the number of antennas increases power efficiency. Wireless communication is possible. However, if the number of spatial streams is not a bottleneck, increasing the number of antennas does not increase the actual transmission rate for the application program. Rather, user dissatisfaction with the power consumption of the MIMO controller 63 increases. In the antenna registration table 115, communication conditions that affect the actual transmission rate when data is transferred between the application program and the destination server are recorded, and the allowable actual transmission rate is satisfied within the range. Are stored as the number of registered antennas.

  The communication condition includes destination information and transmission source information. The destination information includes a destination IP address and a destination port number. The destination server has different response speeds for the application program depending on whether it is connected to the intranet 10 with few sharers or the Internet 30 with many sharers. Also, the transfer rate differs depending on whether TCP or UDP is used. For servers with a fast response speed, set the allowable transmission speed of the application program fast to register a large number of antennas, or for servers with a slow response speed, set the allowable actual transmission speed to a low value. The number of antennas can be registered.

  When a plurality of application programs operate on the server, if the response speed does not change with the application program of any port number, only the IP address may be used as the destination information. In addition, since the response speed of the former is high overall between the server connected to the intranet 10 and the server connected to the Internet 30, only the distinction may be used as the destination information. The transmission source information includes an access point (AP) identifier, a use time zone when the notebook PC 50 is performing wireless communication, and holiday information. As the access point identifier, an ESSID (Extended Service Set Identifier) of the access point can be used. Furthermore, when the notebook PC 50 is equipped with GPS, the current position information acquired from the GPS can be used.

  The use time zone distinguishes between daytime and nighttime. The holiday information distinguishes whether or not the day on which wireless communication is performed is a holiday. The transmission source port number is a port number assigned to an application program operating on the notebook PC 50. The access point identifier, usage time zone, and holiday information reflect the number of sharers who use the same transmission path to the server, and allowances required by application programs when there are many sharers. Register a small number of antennas by setting the transmission speed to be slow, or register a large number of antennas by setting the allowable transmission speed to be high when there are few sharing conditions. can do. The number of registered antennas is updated with the power efficient number verified under the communication conditions in the past data transfer as described in the procedure of FIG.

  The number of registered antennas is power-efficient for the communication conditions when data is transferred between the application program and a specific server, and is registered here when data is transferred next time under the same communication conditions. By operating the number of antennas, power efficient wireless communication can be performed from the first access to the server. The registration numbers 1 and 2 in the antenna registration table 115 differ only in the AP identifier. Here, it is assumed that the same application program accesses a server having the same destination information from different APs provided in the same building where the office is located. Since there is no difference, the number of registered antennas is three. In the registration number 3, the AP identifier and the number of registered antennas are different from those in the registration numbers 1 and 2. Here, it is assumed that access is made from home using a VPN (Virtual Private Network). Unlike the registration numbers 1 and 2, the number of registered antennas is registered as one with high power efficiency because the transmission speed of the Internet on which the intermediate VPN is formed is slow. In the registration numbers 4 to 6, the number of antennas with high power efficiency is registered due to the difference between the destination information and the transmission source information. The use of the number of registered antennas and the method for updating the antenna registration table will be described later based on the flowchart of FIG.

  FIG. 6 is a block diagram showing the configuration of an application program for accessing the server shown as mail software 101, file transfer software 103, and Web browser 105 in FIG. 6A shows a schematic functional configuration of the application program 200, FIG. 6B shows a data structure of the reference value table 205, and FIG. 6C shows the reference value table 205. The relationship between the reference value and the allowable transmission rate is shown. In FIG. 6A, each application program includes a traffic monitoring unit 203 and a reference value table 205 according to the present embodiment, in addition to a known application program main body 201.

  The traffic monitoring unit 203 and the reference value table 205 may be incorporated in each application program from the beginning, but in the case of the Web browser 105, it can be configured by an applet. The traffic monitoring unit 203 monitors the actual transmission speed of the IP packet performed between the application program and the server from the TCP monitor 117, and refers to the reference value stored in the reference value table 205. In response to this, a request for increasing or decreasing the number of antennas is sent to the device driver 113.

  In the present embodiment, when the application program accesses the server, the number of antennas is set with reference to the antenna registration table 115, but the actual transmission rate for the registered communication conditions is different between the past and the present. There is. The traffic monitoring unit 203 always monitors the actual transmission rate sent from the TCP monitor 117 to determine an appropriate number of antennas. The reference value table 205 includes destination information composed of an IP address and a port number, and a minimum actual transmission speed (minimum transmission speed) and a maximum actual transmission speed (maximum transmission speed) related to an application program that accesses the destination. Store.

  The maximum transmission rate is effective even if data transfer is performed at a higher actual transmission rate when the application program transfers data to or from the server specified by the destination information or the application program running on the server. The value is set as a value that does not improve the degree of satisfaction, and therefore causes user dissatisfaction in terms of power consumption. The minimum transmission speed is set to a value larger than the minimum actual transmission speed (allowable transmission speed) that is permitted when the application program transfers data to or from the server specified by the destination information or the application program that runs on the server. Is set. The minimum transmission rate is set to a value that is somewhat larger than the allowable transmission rate so that the actual transmission rate does not become slower than the allowable transmission rate when controlling the number of antennas. A width greater than the amount of change in the transmission rate when the number is increased or decreased by one is provided.

  In this way, when the actual transmission rate exceeds the maximum transmission rate and the wireless transmission path is a bottleneck of the entire transmission system, as in region 1 in FIG. By reducing this, the actual transmission rate can be maintained within the range of the region 2 between the lowest transmission rate and the highest transmission rate. Further, when the actual transmission rate is lower than the minimum transmission rate as in the area 3 and the wireless transmission path is a bottleneck of the entire transmission system, the actual transmission rate is increased by increasing the number of operating antennas by one. Can be maintained within the range of region 2. When the wireless transmission path is a bottleneck, the MIMO controller 63 maintains the allowable transmission speed with the lowest power consumption by setting the number of antennas that operate so that the actual transmission speed enters the area 2 from the area 1 or the area 3. Therefore, wireless communication with high power efficiency can be performed.

  While the wireless transmission path is not the bottleneck of the entire transmission system, the actual transmission rate does not change even if the number of operating antennas is changed. In addition, the power efficiency of the wireless transmission path is not optimal for the data transfer. When the actual transmission rate is in the range of area 1, reducing the number of antennas operating until the actual transmission rate enters between the areas 2 while satisfying the allowable transmission rate, the wireless transmission path becomes a bottleneck, improving the power efficiency can do. When the actual transmission rate is within the range of the region 3, even if the number of operating antennas is increased, the actual transmission rate does not exceed the minimum transmission rate, so that the MIMO controller 63 consumes useless power for the increase. Therefore, an increase in power consumption can be suppressed by returning the number of antennas to the state before the increase.

  Even when the actual transmission speed is in the range of the region 2, it cannot be said that the power efficiency of the wireless transmission path is appropriate unless the wireless transmission path is a bottleneck. In this case, once the number of antennas is increased, the bottleneck can be confirmed if the actual transmission rate increases. If it is not a bottleneck, the actual transmission rate may maintain the range of region 2 even if the number of antennas is further reduced. The combination of the maximum transmission rate and the minimum transmission rate varies depending on the destination server for the application program. For example, file transfer for back-up performed in the background may have a low allowable transmission rate, but transfer of streaming video data for moving images requires comfortable use of application programs unless the allowable transmission rate is high. I can't do that.

  FIG. 7 is a flowchart showing a procedure for controlling the number of spatial streams according to the present embodiment. FIG. 8 shows an antenna management table 350 that stores, for each application program, the number of required antennas calculated from the increase / decrease request of the number of antennas from each application program with respect to the number of antennas that the device driver 113 is currently operating. It is a figure which shows an example of a data structure. The antenna management table 350 is stored in the main memory 53 while the notebook PC 50 is operating, but disappears when the main memory 350 is powered off.

  In block 301, the notebook PC 50 operates the MIMO controller 63 to scan a beacon emitted from the AP 41 or transmit a probe request to detect the ESSID of the AP 41, and to the AP 41 through mutual authentication and association. Connected wirelessly. The device driver 113 stores the ESSID of the AP 41 in the main memory 53. The notebook PC 50 executes the Web browser 105 to display a browser screen on the LCD 57 and is connected to the portal site of the Web server 35 connected to the Internet 30.

  At this time, the mail software 101 and the file transfer software 103 may communicate wirelessly with any server through the MIMO controller 63. The TCP monitor 117 indicates the current actual transmission speed of each of the mail software 101, the file transfer software 103, and the Web browser 105 (hereinafter simply referred to as an application if these three software are not specified). It is sent to. The device driver 113 stores the number of antennas that are currently operating among the antennas 65 to 69 in the main memory 53.

  Now, when the user clicks on a hyperlink on the browser screen or inputs into the input window from the input device 61, any one of another site of the Web server 35, another server in the Internet 30, or in the intranet 10. Access one of the servers. The Web browser 105 acquires a destination IP address corresponding to the specified URL from a nearby DNS (Domain Name System) server through a resolver, and a TCP / IP program together with a request message for starting access to the destination server. Pass to 111. In TCP, a TCP header including a source port number and a destination port number is added to a request message and passed to IP. The IP adds an IP header including a source IP address and a destination IP address to the IP, generates an IP packet, and passes it to the device driver 113. The device driver 113 stores the IP packet in the frame buffer of the interface unit 81.

  In block 303, the device driver 113 extracts the destination IP address and the destination port number from the IP packet, and acquires the current time and holiday information from the radio management program 107. Furthermore, since the device driver 113 has also acquired the ESSID when it is first connected to the AP 41, whether or not an entry that matches all the communication conditions regarding the current wireless communication is registered with reference to the antenna registration table 115. Judging. Then, if there is a matched entry, the controller 89 of the MIMO controller 63 is instructed to operate only the specified number of registered antennas.

  When the number of designated antennas is different from the number of currently operating antennas, the control unit 89 changes the setting of the high frequency unit 87 to operate only the designated number of antennas. If an entry that matches the communication conditions of the current communication is not registered in the antenna registration table 115, the device driver 113 operates the device to operate the three antennas that are the maximum number set in advance as a default. Instruct the driver 113. Alternatively, the device driver 113 may maintain the number of antennas operating at that time. Then, when the number of antennas to be used is changed, the control unit 89 causes the MAC frame processing unit 83 to generate a management frame in which a new number of antennas is set and notifies the AP 41 of it.

  In block 305, the MAC frame processing unit 83 extracts the IP packet of the request message from the frame buffer, adds a MAC header thereto, and sends it to the baseband processing unit 85. The baseband processing unit 85 divides transmission data so as to correspond to the number of operating antennas and sends it to the high frequency unit 87, and the high frequency unit 87 transmits the divided data from the currently operating antenna. Therefore, when the number of antennas is set based on the information registered in the antenna registration table 115, wireless communication with high power efficiency of the MIMO controller 63 is performed from the first communication as long as there is an entry with the same communication condition. Can do. As shown in the following procedure, the antenna registration table 115 is updated each time a new communication is performed.

  When the default number is set, the user's satisfaction with the transmission speed is satisfied, but there may be too many antennas in operation. Further, if the number of antennas operating at that time is maintained, the number of antennas may not be optimal for the communication conditions. However, as shown in the following procedure, the number of antennas satisfying the degree of satisfaction with the power consumption and the actual transmission speed of the user is set and registered in the antenna registration table 115. Therefore, wireless communication with high power efficiency can be performed.

  In block 307, data transfer in the request / response mode is started between the Web browser 105 and the Web server 35, and the TCP monitor 117 determines the actual transmission rate for each port number from the number of IP packets passing through the device driver 113. Is detected and sent to the corresponding application. In blocks 309 and 311, the traffic monitoring unit 203 of the Web browser 105 that has received the current transmission rate from the TCP monitor 117 refers to the reference value table 205, and the current MIMO controller 63 sets an appropriate antenna corresponding to the actual transmission rate. It is determined whether or not the number is set. When the default number of antennas is set in block 303 or when the number of antennas operating at that time is maintained, the actual transmission rate may deviate from the reference value. Even when the number of antennas is set based on the antenna registration table 115, the relationship between past communication conditions and actual transmission rates may be currently changing.

  In block 309, the traffic monitoring unit 203 refers to the reference value table 205 and compares the actual transmission rate received from the TCP monitor 117 with the minimum transmission rate determined for the currently connected destination information. When the actual transmission rate is lower than the minimum transmission rate, the process proceeds to block 317, and when it is higher, the process proceeds to block 311. In block 317, the Web browser 105 requests the device driver 113 to increase the number of antennas through the OS 109. The device driver 113 stores a number obtained by adding 1 to the number of currently operating antennas as the required number of antennas, together with the port number of the Web browser 105, in the antenna management table (FIG. 8) 350.

  The device driver 113 controls the MIMO controller 63 to move to block 318 and increase the number of antennas by one if the current number of antennas is more than the requested number of antennas from the web browser 105. Transition to block 319. At this time, if necessary, the device driver 113 performs authentication and association with the AP 41 again. If the current number of antennas has already reached the maximum value, the number of antennas cannot be increased any further, and the process proceeds to block 325. In block 319, the TCP monitor 117 detects the actual transmission rate related to the web browser 105 from the number of IP packets passing through the device driver 113 and sends it to the web browser 105. In block 320, the traffic monitoring unit 203 of the web browser 105 calculates a change in the actual transmission rate before and after the increase in the number of antennas. If the actual transmission rate is increased by a predetermined value or more, the number of spatial streams is a bottleneck. The process proceeds to block 321 and if the actual transmission rate has not increased by a predetermined value or more, it is determined that the increase in the number of antennas in block 318 is not a bottleneck and the increase in the number of antennas is useless, and the process proceeds to block 323 .

  The traffic monitoring unit 203 requests the device driver 113 to reduce the number of antennas in block 323. The device driver 113 that has received the decrease request stores the number obtained by subtracting 1 from the current number of antennas in the antenna management table 350 as the number of requested antennas from the Web browser 105, and requests from the application that is currently transferring network data. If the number of antennas can be reduced by checking the number of antennas, it is executed and the process proceeds to block 325. In block 321, the traffic monitoring unit 203 of the web browser 105 determines whether or not the actual transmission rate exceeds the minimum transmission rate. If the actual transmission rate does not exceed the minimum transmission rate, the process returns to block 317, and the device driver 113 determines whether the number of antennas can be increased. Even when the number of antennas is increased, even if the actual transmission rate does not increase above the minimum transmission rate due to temporary deterioration of radio wave conditions, etc. Since it turns out that the number of streams is a bottleneck, it is desirable to increase the number of antennas until the actual transmission rate exceeds the minimum transmission rate as much as possible.

  When the Web browser 105 returns to the procedure of block 317 again via the block 323, block 307, and block 309, the device driver 113 operates with respect to the server that is already accessing the web browser 105. We recognize that the increase in actual transmission speed cannot be expected even if the number is increased. Therefore, when the actual transmission rate is still below the minimum transmission rate in block 317, the number of spatial streams is not a bottleneck, and the process proceeds to block 325 without increasing the number of antennas. When the traffic monitoring unit 203 determines in block 321 that the actual transmission rate has exceeded the minimum transmission rate, the process proceeds to block 325. In this case, the number of spatial streams has become a bottleneck and the actual transmission rate has increased to the minimum transmission rate or more, so the user has obtained a satisfactory actual transmission rate with the minimum number of antennas, and power-efficient wireless communication Will be doing.

  In block 311, the traffic monitoring unit 203 refers to the reference value table 205 and compares the actual transmission rate received from the TCP monitor 117 with the maximum transmission rate determined for the currently connected destination information. When the actual transmission rate is higher than the maximum transmission rate, the process proceeds to block 313, and when it is lower, the process proceeds to block 325. In block 313, the Web browser 105 requests the device driver 113 to reduce the number of antennas through the OS 109. The device driver 113 that has received the request stores the number obtained by subtracting 1 from the number of currently operating antennas in the antenna management table 350 together with the port number of the Web browser 105 as the number of requested antennas. When each application stores in the antenna management table 350, if the number of requested antennas has been recorded in the past for its own port number, it is overwritten.

  After the device driver 113 calculates the requested number of antennas from the increase / decrease request received from any application and stores it in the antenna management table 350, the device driver 113 sets the maximum number of requested antennas from each application registered therein to the MIMO. Set in the controller 63. In this way, any application can perform wireless communication at an actual transmission rate that is equal to or higher than an allowable transmission rate. If the device driver 113 refers to the antenna management table 350 and determines that the number of currently operating antennas is greater than the maximum number of requested antennas corresponding to all port numbers, the device driver 113 proceeds to block 314. The MIMO controller 63 is set so as to decrease the number of antennas by one, and the process proceeds to block 315. At this time, if necessary, the device driver 113 performs authentication and association with the AP 41 again. In block 315, the TCP monitor 117 detects the actual transmission rate related to the web browser 105 from the number of IP packets passing through the device driver 113 and sends it to the web browser 105.

  In block 316, the traffic monitoring unit 203 of the web browser 105 determines whether or not the actual transmission rate is lower than the maximum transmission rate. If the number of spatial streams of MIMO is not a bottleneck at the actual transmission rate between the Web browser 105 and the AP 41, even if the number of operating antennas is reduced by one, the actual transmission rate is less than the maximum transmission rate. May not descend. In that case, the traffic monitoring unit 203 returns to the block 313 and requests the device driver 113 to further reduce the number of antennas.

  Eventually, at block 316, it is determined that the actual transmission rate has fallen below the maximum transmission rate. At this time, the number of spatial streams becomes a bottleneck in the entire transmission system. By doing so, the number of spatial streams becomes the minimum number to satisfy the allowable transmission rate, and the MIMO controller 63 operates with the maximum power efficiency. If the number of antennas currently operating in block 313 has already reached the maximum value of the required number of antennas stored in the antenna management table 350, the process cannot proceed to block 325 because it cannot be further reduced.

  In block 325, a user who executes the Web browser 105 to view the screen of the LCD 57 or plays a movie or music gains satisfaction by accessing the current site from the viewpoint of power consumption and actual transmission speed. If it is not satisfied, the process proceeds to block 327 and the radio management program 107 is executed. Then, the user changes the reference value in the reference value table 205 through the operation screen provided by the wireless management program 107. The user sees the reproduction status of the data transferred at the actual transmission rate by the Web browser 105, changes the minimum transmission rate and the maximum transmission rate as a unit, and returns to block 307. In the current situation, the user lowers the minimum transmission speed and the maximum transmission speed if it determines that the demand for power consumption reduction in the notebook PC 50 is high, and the minimum transmission speed and the maximum transmission speed if it determines that the request for an increase in transmission speed is strong. Can be raised. When a part of video stream or audio stream data distributed from the network is lost, normally, an application program that reproduces the data can automatically detect it. Therefore, when the web browser 105 detects a data loss, the user automatically increases the minimum transmission speed and the maximum transmission speed of the reference value table 205 without performing any user operation in the process of block 325, and the number of antennas. Can be increased.

  When the actual transmission speed from the first access is within the range of area 2 in FIG. 6, that is, when the path from block 301 to block 311 to block 325 is established, the wireless transmission path is not a bottleneck. In addition, there is a possibility that the power efficiency can be increased by reducing the number of antennas. To confirm that, when the number of antennas is increased by changing the minimum transmission rate and the maximum transmission rate in the reference value table 205 so that the actual transmission rate is lower than the minimum transmission rate in block 325, the actual transmission rate is Determine whether to rise. When the actual transmission rate increases, the number of spatial streams is a bottleneck and the number of antennas is appropriate, so the original reference value is maintained. If the actual transmission rate does not increase, it can be determined that the bottleneck has not occurred, so the number of antennas may be decreased at block 327. At this time, the device driver 113 stores the number after reduction as the number of required antennas in the antenna management table 350. This operation may be performed by the user from the wireless management program 107 or by the device driver 113.

  In block 329, the Web browser 105 whose execution has been stopped by the user moves to block 331 and instructs the device driver 113 to update the antenna registration table 115 with the number of antennas stored in the antenna management table 350. In the antenna registration table 115, the device driver 113 relates to data transfer between the Web browser 105 and the destination server, and if there is an entry in which all items of destination information and transmission source information match, the number of registered antennas corresponds to the number of requested antennas. If there is no matching entry, a new entry is created and the requested number of antennas is recorded in the antenna registration table 115 as the number of registered antennas. Both the number of updated registered antennas and the number of newly registered antennas are registered based on user satisfaction from the viewpoint of power efficiency when the application actually communicates wirelessly or missing data detected by the application itself. It is registered in the table 115 as an optimum value under the communication condition. If execution of the Web browser 105 is not stopped at block 329, the process returns to block 307.

  The antenna registration table 115 is stored in the HDD 55 when the power of the notebook PC 50 is stopped, and is loaded into the main memory 53 when the power is turned on next time and the MIMO controller 63 operates. When a site is first accessed, if the number of antennas is set higher and transmission speed is given priority, the user may monitor the traffic and then reduce the number of antennas as appropriate. Such an operation is a heavy burden on the user, so the initial number of antennas is maintained and there is a tendency to waste useless power. In addition, when priority is given to reducing power consumption by setting a small number of antennas, the response speed when accessing the site for the first time is too slow, and the user feels stressed.

  According to the present embodiment, when there is an entry with the same communication condition in the antenna registration table 115 when the application starts wireless communication, the number of antennas registered there is set before starting communication. The user can perform wireless communication using the number of power efficient stream streams from the beginning of access. In addition, after starting communication, the TCP monitor 117 monitors the actual transmission rate and determines and sets the optimum number of antennas under the communication conditions, so that power efficiency can be maintained. Furthermore, since the number of registered antennas is stored in the antenna registration table 115 together with actual communication conditions when the application ends, wireless communication can be performed next time using the updated antenna registration table 115.

  As described above, the MIMO wireless system has been described as an example. However, the present invention includes a plurality of antennas, and the number of antennas to be actually operated is any other multi-wires related to the transmission capacity and power consumption of the wireless transmission path. The present invention can also be applied to an antenna wireless system. In the present invention, the number of antennas provided in the wireless system may be two or more. The number of antennas to be increased or decreased at a time is not limited to one, and a plurality of antennas may be increased or decreased at a time depending on the situation. In FIG. 6, the traffic monitoring unit 203 and the reference value table 205 are provided in each application program. However, the wireless management program 107 may incorporate similar functions related to all application programs.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

10 ... Intranet 11, 31 ... Wired LAN
30 ... Internet 50 ... Notebook personal computer 115 ... Antenna registration table 200 ... Application program 205 ... Reference value table 350 ... Antenna management table

Claims (10)

In a wireless terminal device equipped with a wireless system that can execute application programs and control the operation of multiple antennas individually,
Storing the destination information of a server that transfers data through the wireless system and the number of registered antennas, which is the number of antennas set when accessing the server, in a reference table;
Configuring the wireless system to operate the number of registered antennas with reference to the reference table when the application program starts data transfer with a server;
A computer program for executing a process including a step of connecting the wireless system to an access point after the setting of the number of antennas is completed.   The reference table further stores transmission source information related to the application program, and the step of setting the wireless system operates the antennas of the number of registered antennas corresponding to the set of the destination information and the transmission source information. The computer program according to claim 1, wherein the wireless system is set in a computer.   The computer program according to claim 2, wherein the destination information includes an IP address, and the transmission source information includes a port number of the application program. The process is
Measuring an actual transmission rate for the application program;
Requesting that the number of antennas operated by the application program be increased when the actual transmission rate is slower than a minimum reference value;
The computer program according to any one of claims 1 to 3, further comprising: setting the wireless system to operate the requested number of antennas.   Measure the actual transmission rate for the application program after increasing the number of antennas, and reduce the number of antennas that the application program operates if the actual transmission rate does not increase more than a predetermined value from before the increase in the number of antennas The computer program product according to claim 4, further comprising a step of requesting to execute the program. The process is
Measuring an actual transmission rate for the application program;
Requesting that the number of antennas operated by the application program be reduced when the actual transmission rate is faster than a maximum reference value;
The computer program according to any one of claims 1 to 5, further comprising: setting the wireless system to operate the requested number of antennas.   Measuring the actual transmission rate for the application program after reducing the number of antennas, and requesting the application program to further reduce the number of antennas when the actual transmission rate is faster than the maximum reference value The computer program according to claim 6.   The computer program according to claim 4, further comprising a step of updating the reference table with the number of antennas requested by the application program when the execution of the application program is stopped. .   A wireless terminal device in which the computer program according to any one of claims 1 to 8 is installed. A method for controlling the wireless system in a wireless terminal device equipped with a wireless system capable of executing an application program and capable of individually controlling operations of a plurality of antennas,
Storing the destination information of a server that transfers data through the wireless system and the number of registered antennas, which is the number of antennas set when accessing the server, in a reference table;
When the application program starts data transfer with the server, the wireless terminal device sets the wireless system to operate the antennas of the number of registered antennas with reference to the reference table;
And a step of connecting the wireless system to an access point after the setting of the number of antennas is completed.

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