JP2009071385A - Communication terminal device, power saving mode control system and power saving mode control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication terminal device operating in a power saving mode, which can prevent delay of packets during communication requiring real time performance such as audio and video, and to provide a power saving mode control system and a power saving mode control method. <P>SOLUTION: A communication control section 154 of a streaming processing section 150 calculates a cache residual amount of data in streaming processing on the basis of the data amount from a data acquiring section 151, a storage section 152 and a multimedia processing section 153, judges the presence or absence of a real-time request and controls the power saving mode to be ON or OFF. Thus, the presence or absence of the real-time request can be properly judged even at start/interruption of communication and during communication. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication terminal device that operates in a power save mode, a power save mode control system, and a power save mode control method.

  In recent years, in consideration of easiness of installation, economics of introduction cost, and the like, there are an increasing number of cases where a wireless local area network (WLAN) is constructed in an office or home. As a typical technique of wireless LAN, there is a method standardized by the IEEE (Institute of Electrical and Electronics Engineers) 802 Committee. Examples of the system standardized by the IEEE 802 committee include the IEEE 802.11 standard system, the IEEE 802.11a standard system, the IEEE 802.11b standard system, and the IEEE 802.11g standard system. Further, Bluetooth (registered trademark) is a wireless communication protocol defined by IEEE 802.15.1.

  The communication standard related to wireless LAN-compatible communication terminals defines a power save mode (PS mode) in which the reception of packets addressed to the device from the access point is periodically stopped to intermittently become a nap and save power. (See, for example, the IEEE 802.11 standard). In a wireless LAN-compatible communication terminal device, the power consumption of the wireless LAN unit is large, so if it is always turned on, the battery of the portable device will be consumed in a short time. Therefore, the reception of packets addressed to itself from the access point is periodically performed, and at least a part of the wireless communication unit (A / D converter may be included) that consumes much power during the packet reception stop period. Turn off the power supply to reduce power consumption.

  When the power save mode (PS mode) is on, the wireless communication unit of the communication terminal device having the power save mode intermittently receives packets transmitted from the access point AP. When the power save mode (PS mode) is off, the data packet reaches the communication terminal device via the access point AP with almost no delay. In addition, a beacon is periodically transmitted from the access point AP to the communication terminal device. This beacon is time information (time stamp information) for ensuring time synchronization. The beacon is included in the beacon frame, and the beacon frame also includes information indicating a cycle in which the beacon is transmitted.

In Patent Document 1, when a beacon from a radio base station is intermittently received, an information element is expanded after receiving the received beacon, and a packet addressed to itself is buffered by a TIM (Traffic Indication Map) Describes a wireless terminal device that transmits a control packet (PS-Poll packet) that prompts delivery to a wireless base station and receives a packet addressed to itself that is buffered in the wireless base station.
JP 2004-260386 A

  However, such a wireless terminal device that operates in the conventional power save mode has a general problem that a packet delay occurs in communication that requires real-time performance such as voice and moving images. For example, there is VoIP (Voice over Internet Protocol) as communication that requires real-time characteristics, and there is a problem that audio quality deteriorates due to a delay or images and audio are interrupted.

Further, the apparatus described in Patent Document 1 has the following problems in addition to the above general problems. The wireless terminal device determines whether or not there is a real-time request when communication is not vertically symmetric for each application when communication is started / disconnected.
Real-time due to the nature of the application, assuming streaming using a cache such as progressive download or pseudo-streaming (a method in which multimedia data is received and stored in the cache, and the stored multimedia data is played back simultaneously) It is difficult to determine the presence / absence of a request when communication is started / disconnected. In pseudo-streaming, packets are not transmitted and received regularly.

Therefore, in the above determination of the presence / absence of a real-time request, (1) If there is a real-time request at the start of communication, if sufficient bandwidth can be secured even in the power save mode, wireless communication is performed at shorter intervals than the original power save mode. Since the LAN is activated, power consumption increases. In addition, since mobile terminals that perform streaming transmit PS-Poll packets spontaneously and simultaneously, the PS-Poll packet itself has an overhead, which squeezes the bandwidth.
(2) If there is no real-time request at the start of communication, there is a problem that the image / sound stops if a sufficient bandwidth cannot be secured in the power save mode.

  The present invention has been made in view of such points, and in a communication terminal device that operates in a power save mode, a communication terminal device that can prevent packet delay in communication that requires real-time performance such as voice and video, An object is to provide a power save mode control system and a power save mode control method.

  The communication terminal device of the present invention is a communication terminal device that operates in a power save mode, a cache remaining amount calculating means for calculating a remaining amount of data cache during streaming processing, and a real-time request based on the calculated remaining cache amount The configuration includes a real-time request determination unit that determines whether or not the power save mode is present, and a control unit that controls on / off of the power save mode in accordance with the determined presence or absence of the real-time request.

  The power save mode control system of the present invention is a power save mode control system comprising a communication terminal device that operates in a power save mode and a radio base station that performs radio communication with the communication terminal device, wherein the communication terminal The device is any one of the communication terminal devices described above.

  The power save mode control method of the present invention is a power save mode control method for a communication terminal device operating in the power save mode, the step of calculating the remaining amount of data cache during streaming processing, and the calculated remaining amount of cache. And determining whether or not there is a real-time request, and controlling on / off of the power save mode according to the determined real-time request.

  According to the present invention, in the communication terminal device operating in the power save mode by determining the presence / absence of a real-time request based on the calculated cache remaining amount, in communication requiring real-time characteristics such as voice and moving images, Delay can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a communication terminal apparatus and a power save mode control system according to Embodiment 1 of the present invention. The present embodiment is an example applied to a wireless communication system that performs power save mode control when streaming.

  1, the wireless communication system includes a communication terminal device 100, an access point AP (Access Point) 200, a network 300, and a streaming server 400.

  The communication terminal device 100 is a mobile terminal device such as a PHS (Personal Handy-Phone System) / mobile phone having a wireless LAN function, a PDA (Personal Digital Assistants), etc., and connects to the access point 200 to perform wireless communication. The communication terminal device 100 receives a beacon from an access point 200 existing in the vicinity, and acquires the network name of the access point 200, the communication speed of the communication device, the security strength, the communication channel, and the radio wave strength.

  The communication terminal device 100 may be a mobile terminal having a wireless LAN connection function, and is not limited to the above mobile phone, and may be a mobile information terminal such as PHS or PDA. Further, the form is not limited, such as a PCMCIA card or CF card type wireless LAN connection device. Further, the wireless communication is not limited to the wireless LAN, and may be Bluetooth (registered trademark), UWB (Ultra Wideband), or WiMAX. In addition, a wireless communication terminal that can move a place of use, such as an FWA (Fixed Wireless Access) terminal, is also included. The detailed configuration and function of the communication terminal device 100 will be described later with reference to FIGS.

  The access point 200 is a wireless LAN access point having a power save mode function, and connects the communication terminal apparatus 100 and the network 300 using the wireless LAN. The access point 200 relays communication between the communication terminal device 100 and the streaming server 400. The access point 200 is used, for example, in a home having an Internet connection environment or a public wireless LAN service, and forms a wireless LAN usable area.

  The network 300 includes the Internet or a dedicated line that connects the access point 200 and the streaming server 400. The network 300 is a network composed of a mobile communication network, a public telephone network, a LAN, the Internet, and the like, and the type of network and the type of protocol such as a wired system or a wireless system are not particularly limited. In addition, as the access line of the network 300, FTTH (Fiber To The Home), HFC (Hybrid Fiber Coax), ADSL (Asymmetric Digital Subscriber Line) / VDSL (Very high data rate Digital Subscriber Line), etc. A capacity line is available.

  The streaming server 400 distributes multimedia data stored in a content database (not shown) to the communication terminal apparatus 100 through the network 300 and the access point 200 in accordance with a request from the communication terminal apparatus 100. The streaming server 400 may be connected to a management server of a business entity that manages carrier or customer information.

  The content includes a page data file (for example, an HTML (Hyper Text Markup Language) file) stored in the streaming server 400, an image data file that constitutes various images (still images and moving images), and various music. There are various files such as music data files and program files, and streaming data such as images and music.

  FIG. 2 is a block diagram showing an internal configuration of communication terminal apparatus 100.

  2, the communication terminal device 100 includes a control unit 110, a key input unit 120, a display unit 130, an audio output unit 140, a streaming processing unit 150, a WLAN communication unit 160, and a vibration unit 170. Although illustration is omitted, communication terminal apparatus 100 includes an antenna, a speaker, a microphone, a sub LCD display unit, and the like.

  The control unit 110 is composed of a CPU and the like, and controls the communication terminal device 100 as a whole using a memory storing a control program and data used for calculation, and executes streaming control and power save mode control for each unit. To do. Upon receiving the streaming start / end instruction from the streaming processing unit 150, the control unit 110 causes the WLAN communication unit 160 to transmit a streaming start request. When the control unit 110 receives the power save mode control start notification from the streaming processing unit 150, the control unit 110 controls the display unit 130, the audio output unit 140, and the vibration unit 170 to display the power save mode according to the display, sound, and vibration. Notify that control has started.

  The key input unit 120 inputs and generates key operation information from the user. For example, it is configured with a keyboard for performing data input and setting, various function instructions, a dedicated key, or a pointing device such as a GUI (Graphical User Interface) button and a stick key. In addition, the communication terminal device 100 is an input device that performs input to a user terminal such as a key or jog dial if the PDA is a touch panel or keyboard or a mobile phone.

  The display unit 130 includes an LCD display that can display colors in a dot matrix configuration, an EL (Electro Luminescence), a white LED backlight, and drivers. The display unit 130 displays a message input by a key. When no input is made, various screens for the telephone function, icons indicating the operational state of the telephone function, and the like are displayed. A display example of the display unit 130 will be described later with reference to FIG.

  The audio output unit 140 is configured by a speaker or the like, and when receiving a power save mode control start notification, it outputs a sound indicating that control of the power save mode has started.

  The streaming processing unit 150 includes a communication control unit 154, which will be described later, and performs a streaming process without preventing packet delay during communication that requires real-time characteristics such as voice and moving images. Details of the configuration of the streaming processing unit 150 will be described later with reference to FIG.

  The WLAN communication unit 160 includes an interface for inputting / outputting a wireless LAN, and performs wireless connection with the access point 200 via an antenna (not shown). In the present embodiment, the WLAN communication unit 160 performs wireless communication by WLAN based on the IEEE802.11x standard. Wireless LANs are widely used in portable information terminals such as portable notebook personal computers and PDAs having a wireless LAN function. Instead of the wireless LAN, a low-power short-distance two-way wireless communication system such as Bluetooth or UWB that can reduce power consumption may be used.

  When the vibration unit 170 is configured by a vibrator and receives a power save mode control start notification, the vibration unit 170 vibrates to indicate that control of the power save mode is started.

  FIG. 3 is a diagram illustrating a display example of the display unit 130 of the communication terminal device 100. As shown in FIG. 3, the display screen 130 </ b> A of the display unit 130 includes a display area 131 for displaying data, an operation area 132, and a status display area 133 for remaining battery level, reception status, time, and the like. In 133, an icon 134 indicating that control of the power save mode has been started is displayed.

  FIG. 4 is a diagram illustrating a configuration of the streaming processing unit 150 of the communication terminal device 100.

  In FIG. 4, the streaming processing unit 150 includes a data acquisition unit 151, a storage unit 152, a multimedia processing unit 153, and a communication control unit 154.

  The data acquisition unit 151 acquires the total amount of multimedia data. The storage unit 152 sequentially stores the acquired multimedia data. The multimedia processing unit 153 processes the multimedia data when more than a certain amount of data is stored in the storage unit 152.

  The communication control unit 154 determines the presence or absence of a real-time request by calculating the remaining amount of data cache during streaming processing based on the data amount from the data acquisition unit 151, the storage unit 152, and the multimedia processing unit 153, and saves power. Control mode on / off.

  The communication control unit 154 has determined a cache remaining amount calculating unit 154a that calculates the remaining amount of cache of data during streaming processing, and a real time request determining unit 154b that determines the presence or absence of a real time request based on the calculated remaining amount of cache. Control means 154c for controlling on / off of the power save mode according to the presence or absence of a real-time request.

  FIG. 5 is a diagram illustrating a configuration example of an operation mode of the communication terminal device 100.

  The communication terminal device 100 is a portable terminal that has a wireless LAN function and performs a streaming client that connects to the access point 200 using the wireless LAN. The communication terminal apparatus 100 has an operation mode shown in FIG. 5 and can be selected by a user operation. The above operation modes are communication control function OFF mode, communication control function ON (fixed) mode, communication control function ON (fixed) mode 1, communication control function ON (fixed) mode 2, and communication control function ON (optimization) mode. is there. In each operation mode, a threshold is set, and a control operation according to the threshold is set. Here, the case of “communication control function OFF mode”, “communication control function ON (fixed) mode”, and “communication control function ON (optimization) mode” will be described as operation modes.

  Communication control function OFF mode: The power save mode is not controlled without setting a threshold.

  Communication control function ON (fixed) mode: The power save mode is controlled according to the set threshold value. However, the threshold is fixed during communication. For example, in the communication control function ON (fixed) mode 2, the power save mode is terminated when the threshold value is below 20%, and the power save mode is started when the threshold value is above 40%. When the threshold value is 60%, the PS-Poll packet is transmitted autonomously at the beacon period interval when the threshold value is exceeded / below, and when the threshold value is 80%, the PS-Poll packet is transmitted at the beacon period. Transmit autonomously at ¼ interval.

  Communication control function ON (optimization) mode: The power saving mode is controlled according to the set threshold value. However, the threshold is optimized during communication. For example, when the threshold value is 20%, the power save mode is terminated when the threshold value is below the threshold value, and when the threshold value is 40%, the power save mode is started.

  One or more operation modes are set, and in the case of one, the operation mode is not selected.

  The operation mode is not limited to the above. For example, the above operation mode may not be present, or may be plural, other operation modes, or a combination thereof.

  In the present embodiment, the case where the threshold value and the control operation are set in advance has been described, but may be set at the start of streaming. In this case, the number of threshold values in each operation mode is not limited and may not be present (the control operation is fixed). The operation mode is assumed to be held by the streaming processing unit 150, but is not limited thereto.

  Hereinafter, the operation of the communication terminal apparatus configured as described above will be described. In the present embodiment, a case where the operation mode is “communication control function ON (fixed) mode” will be described as an example.

An example of controlling the power save mode according to the remaining amount of cache when streaming will be described. That is,
・ Starting of streaming ・ Streaming: When the remaining amount of cache is increased ・ Streaming: When the remaining amount of cache is decreased ・ End of streaming. In FIG. 1, it is assumed that the communication terminal apparatus 100 and the access point 200 are already connected and operate in the power save mode (intermittent reception) defined by IEEE802.11 shown in FIG.

  FIG. 6 is a timing chart of the power save mode defined by IEEE 802.11.

  As shown in FIG. 6a, the access point 200 receives data addressed to the communication terminal device 100 connected to the wireless LAN from the network 300 and buffers it in the memory (see FIG. 6b).

  The communication terminal device 100 operating in the power save mode intermittently receives the beacon from the access point 200. After receiving the received beacon (see FIG. 6c), the beacon is expanded and the packet addressed to itself is buffered. If it is recognized, a PS-Poll packet that prompts delivery to the access point 200 is transmitted (see FIG. 6d), and a packet addressed to itself that is buffered in the access point 200 is received (see FIG. 6e). The above is performed during a period in which the wireless LAN of the communication terminal device 100 is activated (see FIG. 6f). Further, since the communication terminal apparatus 100 performs an intermittent reception operation, a delay occurs until the access point 200 receives and buffers data addressed to the communication terminal apparatus 100 from the network 300 and transmits the data to the communication terminal apparatus 100 ( See FIG. 6g).

  Here, the same applies to the case of operating in the power save mode defined in IEEE802.11e / WiFi WMM-PS, and the PS-Poll packet may be replaced with a QoS-null packet.

[Start streaming]
A case where streaming is started by a user operation will be described.

  In FIG. 2, the key input unit 120 of the communication terminal device 100 receives a streaming start instruction via the control unit 110 when one or more predetermined keys are pressed to start streaming. 150. As shown in FIG. 4, when the data acquisition unit 151 of the streaming processing unit 150 receives the streaming start instruction, the data acquisition unit 151 starts streaming to the streaming server 400 via the control unit 110, the WLAN communication unit 160, the access point 200, and the network 300. Send a request.

  When the streaming start request is processed normally, the data acquisition unit 151 of the streaming processing unit 150 transmits a communication control start instruction to the communication control unit 154. When receiving the communication control start instruction, the communication control unit 154 performs the following processing.

  FIG. 7 is a flowchart showing an operation at the start of streaming of the communication control unit 154 of the streaming processing unit 150. In the figure, S indicates each step of the flow.

  In step S1, the communication control unit 154 determines whether or not a communication control start instruction has been received. If the communication control start instruction has not been received, the process of this flow is terminated. When the communication control start instruction is received, the preset operation mode is confirmed in step S2.

  When the operation mode is “communication control function OFF mode”, the process of this flow is terminated. When the operation mode is “communication control function ON (fixed) mode” or “communication control function ON (optimization) mode”, the communication control unit 154 determines whether the WLAN communication unit 160 is operating in the power save mode in step S3. Is determined.

  When not operating in the power save mode, the process of this flow is terminated. When operating in the power save mode, control in the power save mode is started in step S4 and subsequent steps. That is, in step S4, the communication control unit 154 stores the power save state and wireless LAN communication parameters (communication rate, number of retransmissions, transmission power) in the storage unit 152. Next, in step S5, the communication control unit 154 performs processing at the start of streaming. Specifically, at the start of streaming, the power saving mode control at the start of streaming is performed without calculating the remaining amount of cache. Here, a case where a control operation of 20%, which is the minimum threshold value, is performed as an example of the control operations when the threshold value is below is taken.

  In step S <b> 6, the communication control unit 154 transmits a power save mode control start notification instruction to the WLAN communication unit 160 via the control unit 110.

  When receiving the power save mode control start notification instruction, the WLAN communication unit 160 ends the power save mode and ends the intermittent reception.

  FIG. 8 is a diagram showing a timing chart when the power save mode defined in IEEE 802.11 is finished.

  At this time, the WLAN communication unit 160 also controls the communication parameters of the wireless LAN. For example, the transmission rate of the wireless LAN may be increased, the number of retransmissions of the wireless LAN may be increased, and the transmission power may be increased.

  In addition, the communication control unit 154 of the streaming processing unit 150 transmits a power save mode control start notification to the display unit 130, the audio output unit 140, and the vibration unit 170 via the control unit 110. When the display unit 130 receives the power save mode control start notification, the display unit 130 displays an icon 134 indicating that control of the power save mode has started (see FIG. 3). Upon receiving the power save mode control start notification, the sound output unit 140 sounds a sound indicating that the power save mode control has started. When receiving the power save mode control start notification, the vibration unit 170 vibrates to indicate that control of the power save mode is started.

  The confirmation of the power save mode may be made by inquiring another block such as the WLAN communication unit 160, or the communication control unit 154 may hold the state of the power save mode.

  Even if the operation mode is “communication control function OFF mode” (communication control function OFF mode in step S2), the process may be continued depending on the control operation. Even if power saving control is not performed (NO in step S3), the processing may be continued. In that case, confirmation (S3) that it is operating in the power save mode may or may not be performed.

  In addition, the control of the power save mode at the start of streaming has been described for the case of performing the control operation with the minimum threshold value among the control operations when the threshold value is exceeded, but a separate control operation may be set. .

  Here, the state of the power save mode is a parameter controlled by control of the power save mode, such as power save mode operation / non-operation, voluntary PS-Poll packet transmission / non-transmission, and packet acquisition interval. Therefore, everything controlled in the power save mode is included.

  The control method of the display unit 130, the audio output unit 140, and the vibration unit 170 according to the power save mode control is not limited, and may be omitted. For example, the control of the display unit 130 may change the icon type or the color according to the control in the power save mode. Further, the color and shape of the icon indicating the electric field strength may be changed. The control of the audio output unit 140 may change the type of sound according to the control in the power save mode, or may sound the sound only once when the control in the power save mode is changed. The control of the vibration unit 170 may change the type of vibration according to the control in the power save mode, or may vibrate only once when the control in the power save mode is changed.

  Wireless LAN communication parameters are not limited to communication rate, number of retransmissions, and transmission power. In addition, the method for controlling the communication parameters of the wireless LAN is not limited and may be omitted.

[Operation during streaming]
The operations during streaming may be performed when the remaining amount of cache increases or when the remaining amount of cache decreases.

[Streaming: When the amount of remaining cache increases]
A case where the operation mode is “communication control function ON (fixed) mode 2”, the streaming is started, and the cache remaining amount is increased will be described as an example.

  The data acquisition unit 151 of the streaming processing unit 150 acquires the total amount of multimedia data to be acquired after transmitting the communication control start instruction, and starts streaming via the WLAN communication unit 160. The data acquisition unit 151 sequentially stores the acquired multimedia data in the storage unit 152 of the streaming processing unit 150. The multimedia processing unit 153 of the streaming processing unit 150 processes the multimedia data and outputs the data to the display unit 130 and the audio output unit 140 via the control unit 110 when data of a certain level or more is stored in the storage unit 152. . For example, a moving image is displayed on the display unit 130, and audio flows through the audio output unit 140. Note that the operations of the data acquisition unit 151 and the multimedia processing unit 153 may be anything.

  FIG. 9 is a flowchart showing an operation during streaming of the communication control unit 154 of the streaming processing unit 150. The operation during streaming is a loop process in calculating the remaining amount of cache, and the following processes are periodically performed between the loop start and end.

  While the power save mode is being controlled, processing is periodically performed at the cache remaining amount calculation cycle.

  In step S10, when the communication control unit 154 starts control of the power save mode, the remaining amount of cache is calculated from the amount of data stored in the storage unit 152 and the amount of data processed by the multimedia processing unit 153. Periodic difference is calculated periodically. The calculated difference data amount is called a cache remaining amount. Here, the case where the difference between the stored data amount (X) and the processed data amount (Y) is the ratio to the total data amount (Z) of the acquired multimedia data will be described as the cache remaining amount.

  FIG. 10 is a diagram for explaining an example of calculating the remaining amount of cache. FIG. 11 is a diagram illustrating a display example of the display unit 130 when calculating the remaining cache capacity.

  As shown in FIG. 3, the display screen 130 </ b> A of the display unit 130 includes a display area 131 for displaying data, an operation area 132, and a status display area 133 for remaining battery level, reception status, time, and the like. In 133, an icon 134 indicating that control of the power save mode has been started is displayed.

As shown by the arrows in FIG. 10, the storage unit 152 of the streaming processing unit 150 acquires the stored data amount (X), the multimedia processing unit 153 acquires the processed data amount (Y), and the data acquisition unit 151 acquires The total data amount (Z) to be output is output to the communication control unit 154. The communication control unit 154 calculates the remaining cache amount [%] by the following equation (1).
Cache remaining amount [%] = (X−Y) ÷ Z × 100 (1)

  For example, when the total data amount (Z) of the acquired multimedia data is 10 Mbytes, the stored data amount (X) is 2 Mbytes, and the processed data amount (Y) is 1 Mbytes, the cache remaining amount is 10%. As shown in FIG. 11, the remaining amount of cache is displayed in the operation area 132 of the display screen 130 </ b> A of the display unit 130 at the ratio of X, Y, and Z.

  Returning to the flow of FIG. 9, in step S11, the communication control unit 154 compares the currently calculated cache remaining amount with the previously calculated cache remaining amount, and whether or not the currently calculated cache remaining amount fluctuates across the threshold value. Is determined.

  If there is no fluctuation across the threshold, the process is terminated. When it fluctuates across the threshold value, the corresponding power save mode is controlled in step S12.

  FIG. 12 is a diagram for explaining a determination example 1 in a case where the remaining amount of cache has increased. FIG. 13 is a diagram showing a timing chart of the power save mode defined by IEEE 802.11.

  As shown in FIG. 12, the case where the previously calculated cache remaining amount (see the broken line ○ mark) reaches the currently calculated cache remaining amount (see the ● mark) across the threshold of 40% is taken as an example. When the remaining amount of cache increases from the start of streaming (the remaining amount of cache is 40% or less) and exceeds 40% (see the dotted line in FIG. 12), the communication control unit 154 instructs the control unit 110 to start the power save mode in step S12. To the WLAN communication unit 160. At this time, the threshold value of 20% is not applied because it is a threshold value when it falls below. When receiving the power save mode start instruction, the WLAN communication unit 160 starts the power save mode and starts intermittent reception (see FIG. 13). At this time, the WLAN communication unit 160 also controls the communication parameters of the wireless LAN. For example, the communication rate of the wireless LAN may be lowered, the number of times of retransmission of the wireless LAN may be reduced, and the transmission power may be lowered.

  In step S <b> 13, the communication control unit 154 transmits a power save mode control start notification to the display unit 130, the audio output unit 140, and the vibration unit 170 via the control unit 110. Upon receiving the power save mode control start notification, the display unit 130 displays an icon according to the power save mode control. When the audio output unit 140 receives the power save mode control change notification, the audio output unit 140 sounds a sound according to the control of the power save mode. When receiving the power save mode control change notification, the vibration unit 170 vibrates according to the control of the power save mode. At this time, the calculation of the remaining amount of cache may be averaged over a certain period of time or a certain number of times. The communication control unit 154 transmits a power save mode end instruction to the WLAN communication unit 160 via the control unit 110 when the remaining amount of cache is below a preset threshold value.

  The remaining cache amount is not particularly limited as long as it is a value calculated from the stored data amount and the processed data amount.

For example, instead of the equation (1), the remaining amount of cache is calculated as follows:
Difference between stored data amount (X) and processed data amount (Y): XY
-Ratio of stored data amount (X) and processed data amount (Y): X / Y or Y / X
A ratio of the data amount (X ′) stored in a certain time and the data amount processed (Y ′): X ′ ÷ Y ′ or Y ′ ÷ X ′
It may be. In addition, the calculation of the remaining amount of cache may be averaged over a certain period of time or a certain number of times.

  Next, a case where the remaining amount of cache further increases, for example, exceeds a threshold value of 60% will be described.

  FIG. 14 is a diagram for explaining a determination example 2 when the cache remaining amount increases. FIG. 15 is a diagram illustrating a timing chart example 1 when a PS-Poll packet is autonomously transmitted in the power save mode defined by IEEE 802.11.

  As shown in FIG. 14, a case where the previously calculated cache remaining amount (see the broken line ○ mark) reaches the currently calculated cache remaining amount (see the ● mark) across the threshold of 60% is taken as an example. When the remaining amount of cache increases further from the start of streaming (the remaining amount of cache is 60% or less) and exceeds the threshold value of 60%, the communication control unit 154 sends a received packet acquisition instruction together with a packet acquisition interval (= beacon cycle interval). The data is transmitted to the WLAN communication unit 160 via the control unit 110. When receiving the received packet acquisition instruction, the WLAN communication unit 160 autonomously periodically transmits PS-Poll packets at packet acquisition intervals as shown in FIG. At this time, the WLAN communication unit 160 transmits the beacon and the PS-Poll packet at a timing half the beacon reception timing. The control of the wireless LAN communication parameters is the same as described above. The same applies to the control of the display unit 130, the audio output unit 140, and the vibration unit 170.

  In addition, although the case where the packet acquisition interval is acquired from the communication control unit 154 together with the received packet acquisition instruction and the case where the timing of transmitting the PS-Poll packet affects the beacon have been described, the present invention is not limited thereto.

  Next, a case where the remaining amount of cache further increases, for example, exceeds a threshold value of 80% will be described.

  FIG. 16 is a diagram illustrating a timing chart example 2 in the case where the PS-Poll packet is autonomously transmitted in the power save mode stipulated by IEEE 802.11.

  If the remaining amount of the cache further increases and exceeds the threshold of 80%, the communication control unit 154 issues a packet acquisition interval change instruction together with a new packet acquisition interval (= 1/4 interval of the beacon period) via the control unit 110 to perform WLAN communication. To the unit 160. When receiving the packet acquisition interval change instruction, the WLAN communication unit 160 changes the transmission interval of the PS-Poll packet to a new packet acquisition interval as shown in FIG. At this time, if the beacon reception timing and the timing for transmitting the PS-Poll packet overlap, the WLAN communication unit 160 receives the beacon without transmitting the PS-Poll packet. The control of the wireless LAN communication parameters is the same as described above. The same applies to the control of the display unit 130, the audio output unit 140, and the vibration unit 170.

  Although the case where the PS-Poll packet is not transmitted when the reception timing of the beacon overlaps with the timing of transmitting the PS-Poll packet has been described, the present invention is not limited to this.

  The case where the remaining cache amount has increased in the operation during streaming has been described above. Hereinafter, a case where the cache remaining amount is reduced during the streaming operation will be described.

[Streaming: When the amount of cash remaining decreases]
A case will be described in which the operation mode is “communication control function ON (fixed) mode 2” and the cache remaining amount decreases after the cache remaining amount increases. The processing flowchart of the communication control unit 154 is the same as that in FIG.

  FIG. 17 is a diagram illustrating a determination example when the remaining amount of cache decreases.

  As shown in FIG. 17, the case where the previously calculated cache remaining amount (see the broken line ○ mark) is reduced to the currently calculated cache remaining amount (see the ● mark) across the threshold 20% is taken as an example. When the remaining amount of the cache decreases (below the remaining amount of cache 80% or more) and falls below 20%, the communication control unit 154 sends a power save mode end instruction to the WLAN communication unit 160 via the control unit 110. Send. At this time, the threshold value of 60% is a threshold value when it falls below, but the threshold value of 20% is lower and is not applied. When receiving the power save mode end instruction, the WLAN communication unit 160 ends the autonomous transmission of the PS-Poll packet and the power save mode, and ends the intermittent reception. The control of the wireless LAN communication parameters is the same as described above. The same applies to the control of the display unit 130, the audio output unit 140, and the vibration unit 170.

  Although the case where only one of the controls is performed when it fluctuates across a plurality of threshold values has been described, the present invention is not limited to this.

[End of streaming]
A case where multi-data acquisition is completed will be described.

  FIG. 18 is a flowchart showing the operation of the communication control unit 154 of the streaming processing unit 150 at the end of streaming.

  When the acquisition of all download multi-data is completed, the data acquisition unit 151 of the streaming processing unit 150 transmits a communication control end instruction to the communication control unit 154.

  In step S20, when receiving the communication control end instruction, the communication control unit 154 ends the control in the power save mode, and if necessary, the control for returning to the stored power save state and communication parameters before the control. The instruction is transmitted to the WLAN communication unit 160 via the control unit 110, and the process ends. When receiving the control instruction, the WLAN communication unit 160 changes the power save state and the communication parameter according to the control instruction.

  In step S <b> 21, the communication control unit 154 transmits a power save mode control end notification to the display unit 130, the audio output unit 140, and the vibration unit 170 via the control unit 110. When the display unit 130 receives the power save mode control end notification, the display unit 130 displays an icon indicating that the power save mode control is ended. When receiving the power save mode control end notification, the sound output unit 140 sounds a sound indicating that the power save mode control is ended. When receiving the power save mode control end notification, the vibration unit 170 vibrates to indicate that the power save mode control is ended.

  As described above in detail, according to the present embodiment, the communication control unit 154 of the streaming processing unit 150 performs the streaming process based on the data amounts from the data acquisition unit 151, the storage unit 152, and the multimedia processing unit 153. Calculates the remaining amount of data cache at the time and determines whether or not there is a real-time request, and controls the power save mode on / off, so whether or not the real-time request exists even when communication is started / disconnected and during communication Appropriate determination can be made, and power saving can be controlled according to the determination. Therefore, in the communication terminal device operating in the power save mode, packet delay can be prevented in communication that requires real-time characteristics such as voice and moving images.

  In the present embodiment, the calculated remaining cache amount is compared with a plurality of thresholds at a predetermined timing, and the presence / absence of a real-time request is determined based on the comparison result. By determining using the threshold value, frequent power save mode control can be avoided.

  Further, the communication terminal apparatus 100 has a plurality of operation modes as shown in FIG. 5 and determines the threshold value of the cache remaining amount according to the operation mode, thereby eliminating the need for the user to directly set the threshold value.

  As a control method of the power save mode, the power save can be controlled without adding a new function by controlling the start / end of the power save mode. For example, it is possible to eliminate the delay time due to power saving by determining that there is no real-time request when the remaining amount of cache falls below a certain threshold and ending the power saving mode. Further, when the cache remaining amount exceeds a certain threshold value, it is determined that there is a real-time request, and the power saving mode is started, so that power consumption can be reduced.

  In addition, when the streaming starts, the power save mode is terminated, so that it is not necessary to check the remaining amount of cache when starting the streaming.

  In the present embodiment, when communication terminal apparatus 100 is operating with the power save defined in IEEE 802.11, communication terminal apparatus 100 autonomously periodically transmits a PS-Poll packet, and in power save mode. As a control method, there is an effect that stepwise control can be performed by controlling the interval at which PS-Poll packets are transmitted. In this case, when the remaining amount of the cache falls below a certain threshold, the delay time due to power saving can be reduced by shortening the transmission cycle interval of the PS-Poll packet. Further, when the remaining amount of the cache exceeds a certain threshold value, the power consumption can be reduced by increasing the transmission cycle interval of PS-Poll. Further, by shortening the transmission cycle interval of the PS-Poll packet at the start of streaming, it is not necessary to check the remaining amount of cache at the start of streaming.

  Similarly, when the communication terminal device 100 is operating at the power save specified in IEEE802.11e / WiFi WMM-PS, the communication terminal device 100 autonomously periodically transmits QoS-null packets, and the power As a control method in the save mode, there is an effect that stepwise control can be performed by controlling the interval at which the QoS-null packet is transmitted. In this case, the delay time due to power saving can be reduced by shortening the transmission interval of the QoS-null packet when the remaining amount of the cache falls below a certain threshold. Further, when the cache remaining amount exceeds a certain threshold, the power consumption can be reduced by increasing the transmission interval of the QoS-null packet. Also, by shortening the transmission interval of QoS-null packets at the start of streaming, it is not necessary to check the remaining amount of cache at the start of streaming.

  In the present embodiment, when controlling the power save mode, the user can be informed intuitively of the presence / absence of a real-time request by notifying by sound, display, and / or vibration according to the presence / absence of the real-time request.

(Embodiment 2)
The second embodiment will be described taking an example in which the operation mode is “communication control function ON (optimization) mode”.

  The hardware configuration of the communication terminal device and the power save mode control system according to Embodiment 2 is the same as that shown in FIGS.

  FIG. 19 is a flowchart showing an operation during streaming of the communication control unit 154 of the streaming processing unit 150 of the communication terminal apparatus according to Embodiment 2 of the present invention.

  The operation during streaming shown in the flow of FIG. 19 is a loop process in the communication status acquisition cycle, and the following processes are periodically performed between the loop start end and the end.

  While the power save mode control is being performed, processing is periodically performed at the communication status acquisition cycle.

  In step S30, when the communication control unit 154 starts control of the power save mode, the communication control unit 154 periodically acquires a communication status at a communication status acquisition cycle.

  In step S31, the communication control unit 154 determines whether or not the acquired communication status has been changed. If the acquired communication status has not been changed, the process ends. When the acquired communication status is changed, the threshold is changed in step S32.

  FIG. 20 is a flowchart showing an operation during streaming of the communication control unit 154 of the streaming processing unit 150 of the communication terminal device according to the second embodiment.

  The operation during streaming shown in the flow of FIG. 20 is a loop process in a reproduction status acquisition cycle, and the following processes are periodically performed between the loop start end and the end.

  While the power save mode is being controlled, processing is performed periodically at the playback status acquisition cycle.

  In step S40, when the communication control unit 154 starts control in the power save mode, the communication control unit 154 periodically acquires the communication status at the playback status acquisition cycle.

  In step S41, the communication control unit 154 determines whether or not the acquired reproduction status has been changed. If the acquired playback status has not been changed, the process ends. When the acquired reproduction status is changed, the threshold is changed in step S42.

  FIG. 21 is a diagram illustrating a configuration example of threshold values according to the communication status. As shown in FIG. 21, the communication status is indicated by, for example, throughput, and the threshold values are 20 to 30% and 40 to 50% according to TCP (Transmission Control Protocol).

  The communication status is not limited to the above. For example, throughput, RSSI (Received Signal Strength Indicator) or SNR (Signal to Noise Ratio) of a wireless LAN beacon or received packet, or PER (Packet Error Rate) of a wireless LAN transmission packet And the number of discarded packets, the number of retransmissions of the wireless LAN packet, Ack, wireless LAN communication rate, wireless LAN beacon interval, wireless LAN DTIM cycle (Delivery Traffic Indication Message), and TCP window size.

  The reproduction status can be acquired from the change history of the number of stops and the remaining amount of cache.

  The relationship between the communication status acquisition cycle and the playback status acquisition cycle may be anything. It is preferable to calculate the cache when the threshold is changed.

  As described above, according to the present embodiment, the communication control unit 154 of the streaming processing unit 150 appropriately determines the presence / absence of a real-time request by controlling the threshold of the remaining amount of cache according to the communication state or the streaming reproduction state. can do.

  The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this.

  For example, the system configuration and the configuration of each device are not limited.

  In the present embodiment, the names of the communication terminal device, the power save mode control system, and the power save mode control method are used. However, this is for convenience of explanation, and the radio terminal device, the radio communication system, and the power save mode setting are used. Of course, it may be a method or the like.

  Further, the communication terminal device and the power saving mode control system, for example, the types of data acquisition units, the number thereof, and the connection method may be any.

  The power save mode control method described above is also realized by a program for causing the power save mode control method to function. This program is stored in a computer-readable recording medium.

  The communication terminal device, the power save mode control system, and the power save mode control method according to the present invention can be widely applied to a wireless communication system in which a communication terminal device and a wireless base station that configure a wireless LAN are connected. In addition, the present invention can be widely applied to portable electronic devices having a wireless communication function such as notebook personal computers and PDAs.

The figure which shows the structure of the communication terminal device and power save mode control system which concern on Embodiment 1 of this invention. Block diagram showing an internal configuration of the communication terminal apparatus according to the first embodiment The figure which shows the example of a display of the display part of the communication terminal device which concerns on this Embodiment 1. The figure which shows the structure of the streaming process part of the communication terminal device which concerns on this Embodiment 1. FIG. The figure which shows the structural example of the operation mode of the communication terminal device which concerns on this Embodiment 1. Timing chart of power saving mode defined in IEEE 802.11 of communication terminal apparatus according to Embodiment 1 The flowchart which shows the operation | movement at the time of the streaming start of the communication control part of the streaming process part of the communication terminal device which concerns on this Embodiment 1. FIG. Timing chart when power saving mode defined in IEEE 802.11 of communication terminal apparatus according to Embodiment 1 is terminated The flowchart which shows the operation | movement in the streaming of the communication control part of the streaming process part of the communication terminal device which concerns on this Embodiment 1. FIG. The figure explaining the example of calculation of the cash remaining amount of the communication terminal device which concerns on this Embodiment 1. The figure which shows the example of a display of the display part at the time of calculation of the cash remaining amount of the communication terminal device which concerns on this Embodiment 1. FIG. The figure explaining the example 1 of judgment when the cash remaining amount of the communication terminal device which concerns on this Embodiment 1 increases. Timing chart of power saving mode defined in IEEE 802.11 of communication terminal apparatus according to Embodiment 1 The figure explaining the example 2 of judgment when the cash remaining amount of the communication terminal device which concerns on this Embodiment 1 increases. Timing chart when PS-Poll packet is transmitted autonomously in power save mode defined by IEEE 802.11 of communication terminal apparatus according to Embodiment 1 Timing chart when PS-Poll packet is autonomously transmitted in power save mode defined in IEEE 802.11 of communication terminal apparatus according to Embodiment 1 The figure explaining the example of determination in case the cash remaining amount of the communication terminal device which concerns on this Embodiment 1 reduces. The flowchart which shows the operation | movement at the time of the end of streaming of the communication control part of the streaming process part of the communication terminal device which concerns on this Embodiment 1. FIG. The flowchart which shows the operation | movement in the streaming of the communication control part of the streaming process part of the communication terminal device which concerns on Embodiment 2 of this invention. The flowchart which shows the operation | movement in the streaming of the communication control part of the streaming process part of the communication terminal device which concerns on this Embodiment 2. FIG. The figure which shows the structural example of the threshold value according to the communication condition of the communication terminal device which concerns on this Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Communication terminal device 110 Control part 120 Key input part 130 Display part 140 Audio | voice output part 150 Streaming process part 151 Data acquisition part 152 Storage part 153 Multimedia processing part 154 Communication control part 154a Cache residual quantity calculation means 154b Real-time request determination means 154c Control unit 160 WLAN communication unit 170 Vibration unit 200 Access point (AP)
300 network 400 streaming server

Claims (21)

A communication terminal device operating in power save mode,
Cache remaining amount calculating means for calculating the remaining amount of cache of data at the time of streaming processing;
Real-time request determination means for determining the presence or absence of a real-time request based on the calculated remaining cache capacity;
A communication terminal device comprising: control means for controlling on / off of the power save mode according to the determined presence / absence of a real-time request.   The communication terminal apparatus according to claim 1, wherein the cache remaining amount calculating unit calculates a remaining amount of pseudo streaming cache using TCP.   The communication terminal apparatus according to claim 1, wherein the real-time request determination unit compares the calculated remaining cache amount with a plurality of thresholds at a predetermined timing, and determines whether there is a real-time request based on the comparison result.   The real-time request determination unit compares the currently calculated cache remaining amount with the previously calculated cache remaining amount, and determines whether there is a real-time request when the currently calculated cache remaining amount fluctuates across a predetermined threshold. Item 2. The communication terminal device according to Item 1. Have one or more operation modes of the communication control function,
The communication terminal apparatus according to claim 1, wherein the real-time request determination unit determines the threshold based on the operation mode. A communication status acquisition means for acquiring the communication status;
The communication terminal apparatus according to claim 1, wherein the real-time request determination unit determines the threshold based on the communication status. Provided with playback status acquisition means for acquiring the playback status of streaming,
The communication terminal apparatus according to claim 1, wherein the real-time request determination unit determines the threshold based on the reproduction status.   The communication terminal apparatus according to claim 1, wherein the control unit controls start / end of the power save mode. The real-time request determination means determines that there is no real-time request when the calculated remaining cache amount falls below a predetermined threshold,
The communication terminal apparatus according to claim 1, wherein the control unit ends the power save mode. The real-time request determination means determines that there is a real-time request when the calculated remaining cache amount exceeds a predetermined threshold,
The communication terminal apparatus according to claim 1, wherein the control unit starts the power save mode.   The communication terminal apparatus according to claim 1, wherein the control unit ends the power save mode when streaming is started.   When the control means is operating in the power save mode, it performs control to periodically transmit PS-Poll packets autonomously, and an interval to transmit the PS-Poll packets based on the calculated remaining cache capacity The communication terminal device according to claim 1 which controls a cycle.   The communication terminal apparatus according to claim 1, wherein the control means shortens the transmission cycle interval of the PS-Poll packet when the calculated remaining amount of cache falls below a predetermined threshold value.   The communication terminal apparatus according to claim 1, wherein the control means lengthens a transmission cycle interval of the PS-Poll packet when the calculated remaining amount of cache exceeds a predetermined threshold.   The communication terminal apparatus according to claim 1, wherein the control unit shortens a transmission cycle interval of the PS-Poll packet at the start of streaming.   When operating in the power save mode, the control means performs control to periodically transmit QoS-null packet packets autonomously and transmits the QoS-null packets based on the calculated remaining cache capacity. The communication terminal device according to claim 1, wherein the interval is controlled.   The communication terminal apparatus according to claim 1, wherein the control unit shortens the transmission interval of the QoS-null packet when the calculated remaining amount of cache falls below a predetermined threshold.   The communication terminal apparatus according to claim 1, wherein the control means lengthens a transmission interval of the QoS-null packet when the calculated remaining amount of cache exceeds a predetermined threshold.   The communication terminal apparatus according to claim 1, wherein the control unit shortens a transmission interval of the QoS-null packet at the start of streaming. A power save mode control system comprising a communication terminal device that operates in a power save mode, and a radio base station that performs radio communication with the communication terminal device,
The power saving mode control system, wherein the communication terminal device is the communication terminal device according to any one of claims 1 to 19. A power saving mode control method for a communication terminal device operating in a power saving mode,
Calculating the remaining amount of data cache during streaming processing;
Determining the presence or absence of a real-time request based on the calculated remaining cache capacity;
Controlling the on / off of the power save mode according to the determined presence / absence of a real-time request.

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