[Title] INFORMATION PROCESSING DEVICE, COMMUNICATION SYSTEM, INFORMATION PROCESSING METHOD, AND PROGRAM [Technical Field) [0001] The present technology relates to an information processing device. More particularly, the technology relates to an information processing device, a communication system, and an information processing method for transmitting and receiving data using 1-1ireless communication, as 1-1ell as to a program for causing a computer to execute the information processing method. [Background Art) [0002) There exist 1·1ireless communication techniques for transmitting and receiving data using wireless communication. For example, there have been proposed communication methods for transmitting and receiving data between information processing devices using a \•fireless local area net>fork (LAN) . [0003] Where data is transmitted and received using the \•fireless LAN, the device of the transmission source receives a confirmation of reception (e.g., Acknmfledgement (ACK)) l.l. . 2 SP363097 from the device of the transmission destination. This allows the source device to ascertain that reception of the transmitted data by the destination device is completed. Also, receiving the confirmation of the reception enables the source device to discard from its buffer the data that was transmitted to the destination device. [0004] The Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard discloses frame aggregation techniques for aggregating multiple items of data and transmitting the aggregated data in a single burst. For data transmission sequences of the frame aggregation, techniques are provided to identify the data to be retransmitted upon receipt of a single confirmation of reception (Block ACK (BACK)) for multiple data items transmitted. [0005] In recent years, techniques have been proposed for transmitting data in a single burst to multiple destination devices (e.g., techniques of frame aggregation for multiple users). Also proposed are techniques for applying the multi-user frame aggregation techniques to multiple-input multiple-output (MIMO) techniques. The techniques are then used to multiplex 3 SP363097 signals by multiplying by a coefficient each of multiple antenna elements addressed to multiple users. [0006] Also proposed are sequences in which a non-delivery notification (Negative Acknowledgement (NACK)) identifying undelivered data is exchanged on a stably connected transmission network (e.g., a wired transmission network) . [0007) For example, there is proposed a technique (e.g., see PTL 1) for returning NACK so as to have the transmitted data retransmitted if the data transmission from the transmission source to the transmission destination fails. [Citation List) [Patent Literature] [0008) [ PTL 1) JP 2005-260939 A [Summary) [Technical Problems] [0009) According to the above-mentioned existing techniques, the source device recognizes that data reception is complete upon receipt of a confirmation of reception (ACK) . Thus if a confirmation of reception (ACK) has yet to be 4 SP363097 received, the source device retransmits the data to the destination device in accordance with a predetermined procedure. However, where the source device does not receive the confirmation of reception (ACK) even if the destination device has received the data correctly, the source device starts retransmitting the data. [0010] As another example, if BACK including multiple data items is not received through frame aggregation, it might happen that all data items that have been correctly received by the destination device are retransmitted by the source device. In this case, the unnecessary data retransmission needlessly occupies 1·1ireless transmission paths for an extended period of time, potentially making it difficult to efficiently use the wireless transmission paths. [0011] If the non-delivery notification (NACK) is in use but the source device does not receive it, the data involved is discarded. Thus if the source device fails to receive the non-delivery notification (NACK) that was nevertheless transmitted by the destination device, the data is discarded. This raises the possibility that the data may never reach the destination device. [0012] 5 SP363097 The multi-user frame aggregation techniques involve getting the source device to transmit a request for confirmation of reception (BACK request) to each of multiple destination devices after transmitting data thereto so that the source device 1·1ill receive a confirmation of reception (ACK) from each destination device. The source device needs to receive the confirmation of reception (ACK) following every data transmission. This can prolong the time required to collect the confirmations of reception from multiple destination devices, which potentially makes it difficult to efficiently use the wireless transmission paths. [0013] Also according to the above-described existing techniques, the non-delivery notification (NACK) is used as a retransmission request. The retransmission request is continued until the device of the data transmission source receives ACK signifying successful data reception. This prolongs the time required for data transmission and reception, Hhich potentially makes it difficult to efficiently use the Hireless transmission paths. [0014] The present technology has been conceived in vie11 of the above circumstances. An object of the technology is therefore to use Hireless transmission paths efficiently. 6 SP363097 [Solution to Problems] [0015] The present technology has been devised to solve the above problems. According to a first aspect of the present technology, there are provided an information processing device, an information processing method for use 1·1i th the device, and a program for causing a computer to execute the method, the information processing device including a control section configured in such a manner that if data destined for the own device is received from another device and if there exists undelivered data in the data, the control section transmits a retransmission request for the data to the other device and that if there exists no undelivered data in the data, the control section performs control not to transmit a confirmation of reception. This provides an effect such that if data destined for the 01·m device is received from another device and if there exists undelivered data in the data, a retransmission request for the data is transmitted to the other device and that if there exists no undelivered data in the data, a confirmation of reception is not transmitted. [ 00 16] Also according to the first aspect, if there exists the undelivered data, the control section may transmit a 7 SP363097 retransmission request for the undelivered data to the other device. This provides an effect of transmitting the retransmission request for the undelivered data to the other device if there exists the undelivered data. [0017] Also according to the first aspect, if first undelivered data constituting the undelivered data corresponding to the retransmission request is not transmitted from the other device following the transmission of the retransmission request, if nevi data destined for the own device is received from the other device, and if there exists undelivered data in the ne11 data, the control section may transmit to the other device a retransmission request for the ne1·1 data including information about the first undelivered data. This provides an effect such that if the undelivered data (first undelivered data) corresponding to the retransmission request following its transmission is not transmitted from the other device, if new data destined for the m·m device is received from the other device, and if there exists undelivered data in the ne1-1 data, a retransmission request for the new data including information about the first undelivered data is transmitted to the other device. [0018] Also according to the first aspect, the data destined for 8 SP363097 the mm device may have multiple data items combined by the other device to make up aggregated data. If there exists undelivered data in the aggregated data, the control section may transmit a retransmission request for part or all of the aggregated data to the other device. This provides an effect such that if there exists undelivered data in the aggregated data, a retransmission request for part or all of the aggregated data is transmitted to the other device. [0019] Also according to the first aspect, the data destined for the m·m device may have multiple data items combined by the other device to make up aggregated data. The aggregated data may be destined for multiple devices including the information processing device. This provides an effect such that multiple data items making up the aggregated data and destined for multiple devices are received thereby. [0020] Also according to the first aspect, the control section may set a timing for transmitting the retransmission request to the other device in a manner backing off from a transmission timing of the retransmission request communicated from the other device. This provides an effect of setting the timing for transmitting the 9 SP363097 retransmission request to the other device in a manner backing off from the transmission timing of the retransmission request communicated from the other device. [0021] Also according to the first aspect, even if a reception buffer section configured to hold data destined for the mm device does not have at least a predetermined free space, the control section may perform control to transmit the retransmission request to the other device. This provides an effect of transmitting the retransmission request to the other device even if the reception buffer section for holding data destined for the ovm device does not have at least a predetermined free space. [0022] Also according to the first aspect, the control section may perform the control after verifying that the data destined for the own device is transmitted from the other device following exchange of a transmission request and a confirmation of transmission 1·1i th the other device. This provides an effect of performing the control after verifying that the data destined for the m·m device is transmitted from the other device following exchange of a transmission request and a confirmation of transmission with the other device. 11 10 SP363097 [0023] According to a second aspect of the present technology, there are provided an information processing device, an information processing method for use with the device, and a program for causing a computer to execute the method, the information processing device including a control section configured in such a manner that if aggregated data combining multiple data items is transmitted to a destination device and if a retransmission request for the aggregated data is received from the destination device, the control section performs control to collectively transmit undelivered data in the data items corresponding to the retransmission request to the device. This provides an effect such that if aggregated data is transmitted to the destination device and if a retransmission request for the aggregated data is received from the destination device, the undelivered data in the data items corresponding to the retransmission request are collectively transmitted to the device. [0024] Also according to the second aspect, the control section may set a transmission timing of the retransmission request to be transmitted from the device if undelivered data exists in the aggregated data, the control section 11 SP363097 communicating the transmission timing to the device using a transmission request to be transmitted to the device before the transmission of the aggregated data. This provides an effect of setting the transmission timing of the retransmission request and communicating the transmission timing to the device using a transmission request before the transmission of the aggregated data. [0025] Also according to the second aspect, in transmitting the aggregated data to multiple devices, the control section may set the transmission timing of the retransmission request to be transmitted from the devices if there exists undelivered data in the aggregated data, on the basis of a number fewer than the number of the devices. This provides an effect such that ~~hich a predetermined retransmission count is to be reached1 in consideration of a possible failure to receive a retransmission request (NAQ) from the destination device. That is, the source device may hold the transmitted data over a predetermined time period established on the basis of the retransmission request {NAQ) transmission timing. This implements a communication protocol that provides an opportunity of receiving multiple retransmission requests (NAQ) after 1·1hich the retained data is discarded. [0243) Given the frame aggregation techniques for permitting multiple devices to request retransmission, the sequences of retransmission requests are used by these destination rl q 87 SP363097 devices to return retransmission requests (NAQ) to the source device during a predetermined time interval. [0244] Specifically, the source device sets aside a time period in which to arrange multiple retransmission request (NAQ) return timings. Each of the destination devices sets its mm retransmission request (NAQ) return timing in a manner randomly backing off from the last return timing, and returns a retransmission request (NAQ) accordingly to the source device. [0245] The retransmission request (NAQ) return timing may be arranged to be Nithin a variable back-off range that reflects the number of the destination devices involved. That is, where numerous destination devices are involved, more transmission opportunities may be provided. [0246] In view of the possibility that multiple retransmission requests may collide Nith each other, the source device may retransmit all data upon detecting a signal whose reception field intensity exceeds a predetermined level at a predetermined retransmission request return timing. [0247] As described above, the embodiment of the present technology realizes a wireless communication method for 88 SP363097 performing retransmission control 1·1i thout recourse to the confirmation of reception. That is, 1·1here multiple data items are transmitted through frame aggregation, the destination device does not terminate its sequence by returning a confirmation of reception (ACK) upon receipt of the transmitted data. Where there exists undelivered data following the data reception, the destination device returns a retransmission request (NAQ) at a predetermined timing (time interval). If all data is received, the destination device does not return a retransmission request (NAQ). Upon elapse of a predetermined time period, the source device discards the data from its transmission buffer section. [0248) If use is made of the communication sequences for aggregation destined for multiple devices, there are provided timings for the source device to receive multiple retransmission requests (NAQ) . This makes it possible to efficiently receive retransmission requests (NAQ) from the multiple destination devices. [0249) As described above, this embodiment allows the confirmation of reception (ACK) to be omitted following the data transmission if the status of transmission paths is satisfactory. This shortens the time required to 89 SP363097 return ACK and enables Hireless transmission paths to be utilized efficiently. [0250] In the transmission of aggregated data, the confirmation of reception (ACK) is not returned. This prevents all data from being retransmitted redundantly upon failure to receive the confirmation of reception (ACK) . This practice improves the efficiency of transmission path utilization. [0251] Where continuously aggregated data items are transmitted, the information about the data to be retransmitted may be described collectively in a retransmission request (NAQ). This simplifies the processing related to retransmission control. [0252] With the transmitted data retained over a predetermined time period in \·lhich retransmission may take place, the data can be retransmitted even if the reception of a retransmission request fails. [0253] Where aggregated data items are transmitted to multiple devices, there is no need to make a BACK request to each device or to exchange BACK individually thereHith for confirmation of reception. The time required for the 90 SP363097 exchange is thus unnecessary, Hhich improves the efficiency of transmission path utilization. [0254] In returning a retransmission request (NAQ) for the aggregated data destined for multiple devices, each destination device may set its back-off time relative to the retransmission request (NAQ) return timing. This allo11s multiple destination devices to return their retransmission requests (NAQ) appropriately. [0255] If retransmission requests (NAQ) overlap 11ith one another 11hen returned, the source device may retransmit all data. In this manner, the source device can perform retransmission effectively 11ithout retransmitting the undelivered data to specific individual devices. [ 0256] On the basis of the Duration information included in the retransmission request (NAQ), peripheral devices may set the netl-1ork allocation vector (NAV) in a manner preventing the retransmitted data items from colliding vii th each other 11hile being received. [0257] The dedicated frame type and frame subtype for identifying retransmission requests (NAQ) are provided. This enables the data exchanging sequence for returning 91 SP363097 only the undelivered data retransmission request (NAQ) to coexist 1dth the existing data exchanging sequence for returning the confirmation of reception (ACK) . [0258] There are provided the frame types and subframe types for identifying ne1·1 RTS and CTS frames apart from the existing RTS and CTS frames. This makes it possible to apply the communication protocol of this embodiment to existing Hireless systems. [0259] The information processing device 100 embodying the present technology may be used in conjunction 1·1ith devices in diverse fields. For example, the information processing device 100 may be used in Hireless devices employed on board a vehicle (e.g., car navigation system, smartphone). As another example, the information processing device 100 may be used in learning devices (e.g., tablet terminals) employed in the field of education. As a further example, the information processing device 100 may be used in \·Tireless devices employed in the field of agriculture (e.g., terminals of a cattle management system) Likewise, the information processing device 100 may be used in \·Tireless devices employed in such fields as sports and medical care. [0260] u !1 92 SP363097 2. Applications The technology of the present disclosure may be applied to diverse products. For example, the information processing device 100 may be realized in the form of mobile terminals such as smartphones, tablet personal computers (PCs), laptop PCs, mobile game terminals, or digital cameras; fixed terminals such as TV sets, printers, digital scanners, or network storage; or onboard terminals such as car navigation systems. The information processing device 100 may also be realized as machine type communication (MTC} terminals that perform machine-to-machine (MZM) communication, such as smart meters, automatic vending machines, remote monitoring devices, or point-of-sale (POS) terminals. The information processing device 100 may further be realized in the form of a wireless communication module (e.g., an integrated circuit module made up of a single die) to be mounted in the above-mentioned terminals. [ 02 61] Alternatively, the information processing device 100 may be realized as a wireless LAN access point (also known as a 1-lireless base station) that may or may not be provided with a router function. As another alternative, the information processing device 100 may be realized as a mobile wireless LAN router. As a further alternative, the 93 SP363097 information processing device 100 may be a 1·1ireless communication module (e.g., an integrated circuit module made up of a single die) to be mounted in such equipment, [0262] 2-1, First Application Fig. 21 is a block diagram depicting a schematic configuration example of a smartphone 900 to which the technology of the present disclosure may be applied. The smartphone 900 includes a processor 901, a memory 902, storage 903, an external connection interface 904, a camera 906, sensors 907, a microphone 908, an input device 909, a display device 910, speakers 911, a wireless communication interface 913, an antenna S\·litch 914, an antenna 915, a bus 917, a battery 918, and an auxiliary controller 919, [0263] The processor 901 may be a central processing unit (CPU) or a system on chip (SoC) , The processor 901 controls the functions of the application layer and other layers of the smartphone 900. The memory 902 includes a random access memory (RAM) and a read-only memory (ROM) for storing data and the programs to be executed by the processor 901. The storage 903 may include storage media such as a semiconductor memory or a hard disk, The external connection interface 904 is an interface that L _ ; 94 SP363097 connects an external device such as a memory card or a Universal Serial Bus (USB) device with the smartphone 900. [0264] The camera 906 may have imaging elements such as chargecoupled devices (CCD) or complementary metal oxide semiconductors (CMOS) for generating captured images. The sensors 907 may include a group of sensors such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor, for example. The microphone 908 converts the sound input to the smartphone 900 into an audio signal. The input device 909 includes a touch sensor that detects touches on a screen of the display device 910, a keypad, a keyboard, buttons, or switches for example, and receives operations or information input from the user. The display device 910 has a screen such as a liquid crystal display (LCD) or an organic lightemitting diode (OLED) display that displays images output from the smartphone 900. The speakers 911 convert an audio signal output from the smartphone 900 into sound. [0265] The wireless communication interface 913 performs wireless communication by supporting at least one of the vlireless LAN standards such as IEEE 802 .11a, IEEE 802 .11b, IEEE 802.11g, IEEE 802.11n, IEEE 802.11ac, and IEEE 802.11ad. In infrastructure mode, the wireless 95 SP363097 communication interface 913 can communicate 1·1ith another device via a Hireless LAN access point. In direct communication mode such as ad-hoc mode or Wi-Fi Direct mode, the wireless communication interface 913 can communicate directly Hi th another device. In Wi -Fi Direct mode, unlike in ad-hoc mode, one of the tHo communicating terminals acts as an access point. Communication takes place directly bet11een these terminals. Typically, the Hireless communication interface 913 may include a baseband processor, a radio frequency (RF) circuit, and a po>~er amplifier. The Hireless communication interface 913 may be a one-chip module that integrates a memory for storing a communication control program, a processor for executing the program, and related circuits. In addition to the 1·1ireless LAN system, the 1·1ireless communication interface 913 may support other types of 11ireless communication systems such as near-field communication, close proximity communication system, or cellular communication. The antenna sl'li tch 914 S~>li tches the connection points of the antenna 915 to which to connect multiple circuits (e.g., for different wireless communication systems) included in the 1-1ireless communication interface 913. The antenna 915 has one or multiple antenna elements (e.g., those that make up a MIMO antenna), and is used by the Hireless communication 96 SP363097 interface 913 for transmitting and receiving wireless signals. [0266] The example in Fig. 21 is not limitative of how the smartphone 900 is configured. Alternatively, the smartphone 900 may have multiple antennas (e.g., one for wireless LAN, one for the close proximity communication system, etc.) . In this case, the antenna s1·li tch 914 may be omitted from the configuration of the smartphone 900. [0267] The bus 917 interconnects the processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensors 907, microphone 908, input device 909, display device 910, speakers 911, wireless communication interface 913, and auxiliary controller 919. The battery 918 supplies power to the blocks of the smartphone 900 depicted in Fig. 21 via feeder lines indicated partially by broken lines in the drawing. The auxiliary controller 919 activates minimal functions of the smartphone 900 in sleep mode, for example. [0268] In the smartphone 900 depicted in Fig. 21, the communication control section 240 discussed above with reference to Fig. 2 may be implemented using the 1·lireless communication interface 913. At least part of the above97 SP363097 described functions may be implemented using the processor 901 or auxiliary controller 919. [0269) The smartphone 900 may operate as a wireless access point (software AP) by getting the processor 901 to execute the access point function on the application level. Alternatively, the 1•lireless communication interface 913 may include a wireless access point function. [ 027 0 l 2-2. Second Application Fig. 22 is a block diagram depicting a schematic configuration example of a car navigation system 920 to which the technology of the present disclosure may be applied. The car navigation system 920 includes a processor 921, a memory 922, a global positioning system (GPS) module 924, sensors 925, a data interface 926, a content player 927, a storage medium interface 928, an input device 929, a display device 930, speakers 931, a v1ireless communication interface 933, an antenna switch 934, an antenna 935, and a battery 938. [0271) The processor 921 may be a CPU or an SoC, for example, which controls the navigation function and other functions of the car navigation system 920. The memory 922 includes a RAM and a ROM for storing data and the 98 SP363097 programs to be executed by the processor 921. [ 0272] The GPS module 924 measures the position of the car navigation system 920 (e.g., in latitude, longitude, and altitude) using GPS signals received from GPS satellites. The sensors 925 may include a group of sensors such as a gyro sensor, a geomagnetic sensor, and an atmospheric pressure sensor. The data interface 926 is connected for example to an onboard netl·10rk 941 via a terminal, not depicted, and acquires data such as velocity data generated on the side of the vehicle. [0273] The content player 927 reproduces content stored on a storage medium (e.g., CD or DVD) loaded into the storage medium interface 928. The input device 929 includes a touch sensor that detects touches on a screen of the display device 930, buttons, or Sl·litches for example, and receives operations or information input from the user. The display device 930 has a screen such as an LCD or an OLEO display that displays images from the navigation function or from the content being reproduced. The speakers 931 output sound from the navigation function or from the content being reproduced. [0274] The 1-lireless communication interface 933 performs 99 SP363097 wireless communication by supporting at least one of the wireless LAN standards such as IEEE 802.11a, IEEE 802.llb, IEEE 802.llg, IEEE 802.11n, IEEE 802.llac, and IEEE 802.llad. In infrastructure mode, the wireless communication interface 933 can communicate with another device via a 1·1ireless LAN access point. In direct communication mode such as ad-hoc mode or l'li-Fi Direct mode, the wireless communication interface 933 can communicate directly with another device. Typically, the wireless communication interface 933 may include a baseband processor, an RF circuit, and a po•1er amplifier. The wireless communication interface 933 may be a onechip module that integrates a memory for storing a communication control program, a processor for executing the program, and related circuits. In addition to the wireless LAN system, the wireless communication interface 933 may support other types of •1ireless communication systems such as near-field communication, close proximity communication system, or cellular communication. The antenna switch 934 switches the connection points of the antenna 935 to 1•1hich to connect multiple circuits included in the wireless communication interface 933. The antenna 935 has one or multiple antenna elements and is used by the 1•1ireless communication interface 933 for transmitting and receiving wireless signals. 100 SP363097 [0275] The example in Fig. 22 is not limitative of hm·1 the car navigation system 920 is configured. Alternatively, the car navigation system 920 may have multiple antennas. In this case, the antenna switch 934 may be omitted from the configuration of the car navigation system 920. [0276] The battery 938 supplies power to the blocks of the car navigation system 920 depicted in Fig. 22 via feeder lines indicated partially by broken lines in the drawing. The battery 938 further stores power fed from the side of the vehicle. [0277] In the car navigation system 920 depicted in Fig. 22, the communication control section 240 discussed above with reference to Fig. 2 may be implemented using the wireless communication interface 933. At least part of the abovedescribed functions may be implemented using the processor 921. [ 027 8] The 1·1ireless communication interface 933 may operate as the above-described information processing device 100, providing wireless connection to the terminal held by the user riding in the vehicle. [0279] :-i 101 SP363097 The technology of the present disclosure may be implemented in the form of an onboard system (or vehicle) 940 including at least one block of the above-described car navigation system 920, the onboard net1-10rk 941, and a vehicle-side module 942. The vehicle-side module 942 generates vehicle-side data such as engine revolutions or failure information and outputs the generated data onto the onboard network 941. [ 0280] 2-3. Third Application Fig. 23 is a block diagram depicting a schematic configuration example of a wireless access point 950 to which the technology of the present disclosure may be applied. The wireless access point 950 includes a controller 951, a memory 952, an input device 954, a display device 955, a network interface 957, a wireless communication interface 963, an antenna switch 964, and an antenna 965. [0281] The controller 951 may be a CPU or a digital signal processor (DSP), for example. The controller 951 activates the diverse functions of the Internet Protocol (IP) layer and upper layers of the v1ireless access point 950 (e.g., access restriction, routing, encryption, firewall, and log management) . The memory 952 includes a 102 SP363097 RAM and a ROM and stores the programs to be executed by the controller 951 as well as various control data (e.g., terminal list, routing table, encryption keys, security settings, and logs). [0282] The input device 954 includes buttons or s1·1i tches for example, and receives operations made by the user. The display device 955 includes LED lamps displaying the operating status of the 1dreless access point 950. [0283] The net>Jork interface 957 is a wired communication interface for connecting the >lireless access point 950 to a ''ired communication network 958. The network interface 957 may include multiple connection terminals. The 1dred communication network 958 may be a LAN such as the Ethernet (registered trademark) or a >lide area network (WAN) . [0284] The wireless communication interface 963 supports at least one of the wireless LAN standards such as IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11n, IEEE 802 .11ac, and IEEE 802 .11ad. The 1·1ireless communication interface 963 acting as an access point provides wireless connection for nearby terminals. Typically, the 1·1ireless communication interface 963 may include a baseband li n 103 SP363097 processor, an RF circuit, and a poHer amplifier. The Hireless communication interface 963 may be a one-chip module that integrates a memory for storing a communication control program, a processor for executing the program, and related circuits. The antenna s1·1i tch 964 s1·1itches the connection points of the antenna 965 to Hhich to connect multiple circuits included in the Hireless communication interface 963. The antenna 965 has one or multiple antenna elements and is used by the Hireless communication interface 963 for transmitting and receiving wireless signals. [0285] In the wireless access point 950 depicted in Fig. 23, the communication control section 240 discussed above l·li th reference to Fig. 2 may be implemented using the v1ireless communication interface 963. At least part of the abovedescribed functions may be implemented using the controller 951. [0286] The embodiments described above are merely examples in which the present technology may be implemented. The particulars of the embodiments correspond basically to the inventive matters claimed in the appended claims. Likewise, the inventive matters named in the appended claims correspond basically to the particulars of the .,f.,j 104 SP363097 embodiments with the same names in the foregoing description of the preferred embodiments of the present technology. H01·1ever, these embodiments and other examples are not limitative of the present technology that may also be implemented using various modifications and alterations of the embodiments so far as they are within the scope of the appended claims. [0287] The procedures discussed above in connection 1oith the embodiments may be construed as constituting a method having a series of such procedures. Also, the procedures may be construed as forming a program for causing a computer to execute a series of such procedures, or as constituting a recording medium storing such a program. The recording medium may be a Compact Disc (CD), a MiniDisc (MD), a Digital Versatile Disc (DVD), a memory card, or a Blu-ray Disc (registered trademark), for example. [0288] The advantageous effects mentioned in this description are only examples and not limitative of the present disclosure. Further advantages will become apparent from a reading of the present disclosure. [0289] The present technology may be configured preferably as 105 SP363097 follows. ( 1) An information processing device including: a control section configured in such a manner that if data destined for the own device is received from another device and if there exists undelivered data in the data, the control section transmits a retransmission request for the data to the other device and that if there exists no undelivered data in the data, the control section performs control not to transmit a confirmation of reception. (2) The information processing device as stated in paragraph (1) above in l·lhich, if there exists the undelivered data, the control section transmits a retransmission request for the undelivered data to the other device. ( 3) The information processing device as stated in paragraph (1) above in which, if first undelivered data constituting the undelivered data corresponding to the retransmission request is not transmitted from the other device following the transmission of the retransmission request, if new data destined for the mm device is received from the other device, and if there exists undelivered data in the new data, the control section 106 SP363097 transmits to the other device a retransmission request for the new data including information about the first undelivered data. ( 4) The information processing device as stated in any one of paragraphs (1) to (3) above, in which the data destined for the 01om device has multiple data items combined by the other device to make up aggregated data, and if there exists undelivered data in the aggregated data, the control section transmits a retransmission request for part or all of the aggregated data to the other device. (5) The information processing device as stated in any one of paragraphs (1) to (4) above, in \