Patent Publication Number: US-2015085825-A1

Title: Communication apparatus and control method

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2013-196157, filed on Sep. 20, 2013; the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a communication apparatus and a control method. 
     BACKGROUND 
     Scarcity of the frequency band of a wireless wide area network has become problematic. Thus, off-load traffic to a wireless LAN where high-speed communication can be performed targeting for small areas is sought. However, there are problems such as not being able to smoothly perform communication through a wireless LAN, and increasing power consumption by the use of a wireless LAN. Hence, users continue to download high-volume information using a wireless wide area network. 
     In addition, services where high-volume information (moving images, etc.) is downloaded through a network and users view the information have become popular. Since it takes time to download such high-volume information, there is a technique for downloading in advance information that suits user&#39;s preferences. In addition, as a storage apparatus having a communication function, an SD card in which a wireless LAN and a NAND flash memory are contained in one package is proliferated. By inserting the card into a digital camera, digital images saved in the card can be automatically uploaded to a photo sharing website. In addition, the card is preset to establish a connection to a public wireless LAN. Thus, a user can use wireless LAN communication without performing complex settings. 
     However, normally, a chip having a wireless LAN function such as that described above increases in its power consumption when operating at all times. Hence, there is demand for a control method that can efficiently connect to and disconnect from a network while suppressing power consumption. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating the functional configuration and hardware configuration of a communication apparatus of an embodiment; 
         FIG. 2  is a flowchart illustrating the flow of the process of establishing a connection and obtaining information by the communication apparatus of the embodiment; 
         FIG. 3  is a sequence diagram of a process related to sharing of network information between wireless communicators, in the communication apparatus of the embodiment; 
         FIG. 4  is a sequence diagram of a process related to sharing of network information between the wireless communicators, in the communication apparatus of the embodiment; 
         FIG. 5  is a flowchart illustrating the flow of the process of establishing a connection and obtaining information by a communication apparatus of a second embodiment; 
         FIG. 6  is a flowchart illustrating the flow of the process of establishing a connection and obtaining information by the communication apparatus of the second embodiment; 
         FIG. 7  is a block diagram illustrating the functional configuration and hardware configuration of a communication apparatus of a modification of the embodiment; 
         FIG. 8  is a sequence diagram of a process performed between communicators to resume obtaining of information obtained by the communication apparatus of the modification of the embodiment; 
         FIGS. 9A to 9C  are sequence diagrams of the process of obtaining information in a storage of the communication apparatus from a processor, in the communication apparatus of the modification of the embodiment; and 
         FIG. 10  is a sequence diagram of the process of obtaining information in the storage of the communication apparatus from the processor, in the communication apparatus of the modification of the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     According to an embodiment, a communication apparatus includes a first wireless communicator, a storage, and a controller. The first wireless communicator establishes a wireless connection to a network. The storage stores therein data. The controller causes the first wireless communicator to establish a connection to the network when a determination value satisfies a connection condition. The determination value is characterized by at least one of operating conditions, positional information, communication conditions, and communication quality of the communication apparatus. The controller causes the first wireless communicator to obtain information through the network and store the information in the storage or further transmit the information stored in the storage through the network when the determination value satisfies an obtaining condition. The controller disconnects the connection between the first wireless communicator and the network when the determination value satisfies a disconnection condition. 
     First Embodiment 
     A first embodiment in which a communication apparatus of the present invention is embodied will be described below with reference to the drawings.  FIG. 1  is a block diagram illustrating a state in which a communication apparatus  100  and an external apparatus  200  are connected to each other, and illustrating the functional configurations of the communication apparatus  100  and the external apparatus  200 . The communication apparatus  100  is assumed to be hardware having a wireless communication function, e.g., a card-type wireless LAN card, a wireless connection module for smartphones, or a chipset. The external apparatus  200  includes a processor  101  and a wireless communicator  110 . The communication apparatus  100  includes a controller  102 , a storage  103 , and a wireless communicator  104 . Since the communication apparatus  100  operates independently of the processor  101  of the external apparatus  200 , processes required for communication such as a TCP/IP stack and a network application are also performed by the controller  102 . The storage  103  is a storage composed of, for example, a NAND flash memory, and saves information obtained through the wireless communicator  104 , etc. The wireless communicator  104  implements wireless communication compliant with, for example, IEEE 802.11n. Note that, though not illustrated in the configuration of  FIG. 1 , a communication interface may be provided in addition to the wireless communicator  104 . Likewise, a storage other than the storage  103  may be provided. 
       FIG. 2  illustrates the flow of the operation of the communication apparatus  100  performed by the controller  102 . When a process starts by receiving an instruction from the processor  101 , the controller  102  turns on the power to the wireless communicator  104  (step S 202 ). At this time, when the wireless communicator  104  is not in a power-off state, but is just transitioned to a low power consumption state (so-called sleep state), the controller  102  performs the process of allowing the wireless communicator  104  to return to a normal operating state, instead of performing a power operation. In addition, when the controller  102  can perform a power operation by itself, the controller  102  performs the power operation, but if a process by the processor  101  is required, the controller  102  requests the processor  101  for power-on, and the processor  101  performs a power operation. 
     When the wireless communicator  104  starts operating, a search for a connectable network starts (step S 203 ). This is performed by receiving a beacon frame which is transmitted by a neighboring wireless LAN access point. The controller  102  determines whether a connectable network has been detected (step S 204 ). If a connectable network has been detected (S 204 : YES), the controller  102  establishes a connection to the target network through the wireless communicator  104  (step S 206 ). This is done by performing a series of processes defined in IEEE 802.11. Note that information required for the connection (SSID, user name, password, etc.) may be already preset, or a user may be required to input such information through some kind of interface, or such information may be obtained from an external device by some kind of means. 
     On the other hand, if a connectable network has not been found (S 204 : No), the controller  102  goes into standby for a fixed period of time (step S 205 ), and then performs a search again through the wireless communicator  104 . At this time, if the number of times the controller  102  has failed to find a connectable network reaches a predetermined number of times, the controller  102  may stop a search and transition to step S 211  to turn off the power. 
     When the controller  102  has been able to establish a connection to the network, the controller  102  starts obtaining of desired information from a connected server, etc., through the network (step S 207 ). A communication protocol used at this time is, for example, HTTP (in the caser of a web page, etc.) or IMAP (in the case of electronic mail). It is assumed that information (e.g., a URI) that identifies information to be obtained is notified to the controller  102  in advance or is saved in the storage  103 . The number of pieces of such information is not limited to one and may be plural. 
     During obtaining of information, the controller  102  stores in the storage  103  desired information among information received by the wireless communicator  104 , and checks whether a wireless communication disconnection condition is met (step S 208 ). The check process is performed, for example, every fixed period of time. If the disconnection condition is met (S 209 : YES), when information is being transferred, the controller  102  interrupts the transfer and withdraws from the network (step S 210 ). Note that, when information is not being transferred, the controller  102  simply withdraws from the network. Thereafter, the controller  102  turns off the power to the wireless communicator  104  (step S 211 ) and ends the process. Note that, when the wireless communicator  104  supports a low power consumption state, the controller  102  may allow the wireless communicator  104  to transition to a sleep state, instead of turning off the power. When the controller  102  can perform a power-off process by itself, the controller  102  performs the power-off process. When the power-off process requires control by the processor  101 , the controller  102  requests the processor  101  for power-off, and the processor  101  controls the power to the wireless communicator  104 . Note that at this time the controller  102  may request the wireless communicator  110  to search for a network. By doing so, even if the wireless communicator  104  is in an off state or a low power consumption state, by the wireless communicator  110  searching for a network instead and sharing network information having been found, the wireless communicator  104  can promptly return to a network-connected state when placed in a power-on state. 
     In the above-described process, when the power is turned on, a connection to a network is automatically established and downloading of predetermined data starts, and thus, a wireless connection can be easily established. In addition, when a disconnection condition such as completion of downloading of information has been met, the power to the wireless communicator  104  is turned off, and thus, power more than necessary is not consumed. 
     For the disconnection condition at step S 208 , a condition for normal time and a condition for abnormal time are considered. The condition for normal time is that “all processes to be performed have been completed”. The condition for abnormal time is considered to be, for example, operating information such as “a beacon from an access point has not been able to be received”, “the remaining battery level falls below a threshold value”, or “the number of terminals connected to an access point exceeds a preset threshold value”, communication conditions such as “the strength of a radio wave received falls below a threshold value”, “the throughput for obtaining information falls below a threshold value”, “the packet loss rate exceeds a threshold value”, or “the frame error rate exceeds a threshold value”, or positional information such as “the apparatus has moved (movement has been detected by an acceleration sensor or the like, which is not illustrated, or a value obtained from the GPS has changed)” or “the apparatus has moved away from an access point (the distance from an access point which is determined by some kind of positioning technique is greater than a preset threshold value)”. Note that these disconnection conditions may be saved in the storage  103  or may be stored in another storage which is not illustrated. In addition, since a determination result is expected to change over time, a determination process may be repeatedly performed taking into consideration the degree of importance of information to be obtained, the remaining battery level, etc. Namely, these disconnection conditions and connection conditions are set depending on whether a determination value characterized by at least one of operating conditions, positional information, communication conditions, and communication quality satisfies a predetermined condition. 
     It has been described that at step S 210 , if communication is being performed when the disconnection condition has been met, the communication is interrupted and then the controller  102  withdraws from the network. At this time, the communication may be simply interrupted; however, in that case, obtained information cannot be utilized later. Hence, information required to resume obtaining of information may be saved as resume information upon interruption; and when the power is turned on again, resumption may be performed using the resume information. The information saved upon interruption includes the identifier of information being obtained and the size of obtained information. The information may be saved in the storage  103 , or may be passed to the processor  101  and saved in another storage (not illustrated) managed by the processor  101 , or may be saved in both of the storages. When the information is saved in the storage of the processor  101 , by the processor  101  notifying of the saved information together with a power-on instruction, the controller  102  can resume obtaining of information. 
     Note that when the disconnection condition in the controller  102  is a condition for normal time (e.g., completion of obtaining of information), simply only disconnection from the network and power control are performed without generating resume information. 
     Next, cooperation between the wireless communicator  110  and the wireless communicator  104  will be described. The wireless communicator  110  is, unlike the wireless communicator  104  controlled by the controller  102 , a wireless communication interface controlled by the processor  101 . It is assumed that the communication scheme is compatible with the wireless communicator  104 . An example thereof includes a wireless communication interface compliant with IEEE 802.11n. Note that, as a communication scheme different than that of the wireless communicator  104 , LTE, etc., may be adopted. Note that in the following description, “active” indicates an operating state with the power turned on, and “inactive” indicates a power-off state. Note also that “sleep state” indicates a low-power state with the power turned on. 
     First, the case is assumed in which the wireless communicator  104  is active and the wireless communicator  110  is also active. When both of the wireless communicator  104  and the wireless communicator  110  are active, the wireless communicators basically operate independently of each other. The explanation of the controller  102 , the storage  103 , and the wireless communicator  104  is the same as the above-described explanation. Note that the wireless communicator  104  and the wireless communicator  110  may operate in cooperation with each other and, for example, one of the interfaces may intensively perform a network search, etc. 
     Next, the case is assumed in which the wireless communicator  104  is active and the wireless communicator  110  is inactive. When the wireless communicator  104  is active and the wireless communicator  110  is inactive, the controller  102  searches for a connectable network, using the wireless communicator  104 . 
     Next, the case is assumed in which the wireless communicator  104  is inactive and the wireless communicator  110  is active. When the wireless communicator  104  is inactive and the wireless communicator  110  is active, the controller  102  searches for a network to which the wireless communicator  104  can establish a connection, using information obtained from the processor  101 . 
     The processor  101  can know a neighboring wireless LAN access point through the wireless communicator  110 . When the wireless communicator  104  is inactive, the controller  102  requests the processor  101  to share information collected through the wireless communicator  110 . In response to the request, the processor  101  shares the collected information with the controller  102 . The controller  102  can resume operation by two methods. The first method is detecting whether there is a connectable network, by directly referring to the shared information. The second method is that the processor  101  detects a network to which the controller  102  can establish a connection and which is shared in advance, and notifies the controller  102  of the network using an interrupt signal, etc. Note that when a plurality of candidates is shared as connectable networks, a connection destination may not be able to be identified only by an interrupt signal. In that case, a connection destination is notified using a storage, another signal line, etc. 
     By the above-described operation, two wireless communicators do not operate only to detect a connectable network. Thus, a connectable network can be detected with an increase in power consumption suppressed. 
     The flow of the above-described operation of sharing information between the wireless communicators will be described using  FIG. 3 .  FIG. 3  illustrates three phases, i.e., a state in which the wireless communicator  104  is in operation, a state in which the wireless communicator  110  searches for a connectable network using shared information, and a state in which a connectable network has been found and thus the wireless communicator  104  has become active again. In an intermediate state in which a search is performed, the wireless communicator  110  is not operating (a thick portion indicates “on” and a thin portion indicates “off”). In the drawing, every time information is shared, it is checked whether a connection can be established; however, the check does not necessarily need to be performed every time and may be performed intermittently. At that time, the controller  102  may transition to a low power consumption state between check processes. 
     Finally, when both of the wireless communicator  104  and the wireless communicator  110  are inactive, either one of the wireless communicators periodically becomes active, and detects a network to which the wireless communicator  104  can establish a connection. At this time, a wireless communicator to be used is determined by the processor  101 . When the wireless communicator  104  is inactive, as described above, the processor  101  receives a request from the controller  102  to share information. When, under such circumstances, the wireless communicator  110  is inactive, the processor  101  causes one of the wireless communicators to be active periodically. When the wireless communicator  104  is caused to be active, the above-described process for when the wireless communicator  104  is active is performed. Note that, when a connectable network has not been found, the wireless communicator  104  stops its operation, going into an inactive state. In addition, at the time point when the wireless communicator  104  is caused to be active, a request to cancel the sharing of information is transmitted to the processor  101 . Likewise, at the time point when the wireless communicator  104  is caused to be inactive, a request to share information is issued again. When the wireless communicator  110  is caused to be active, operation is performed by the method for when only the wireless communicator  110  is active. After going into a state where collected information can be shared, the wireless communicator  110  goes into an inactive state again. A series of operations are as illustrated in  FIG. 4 . 
     Information to be shared through the processor  101  when the wireless communicator  104  is inactive and the wireless communicator  110  is active is, for example, as follows: 
     MAC address: a MAC address that identifies an access point 
     SSID: an identifier that identifies a wireless network provided by the access point 
     Channel: a channel used by the access point 
     Speed information: communication speed supported by the access point 
     Security information: an authentication/encryption scheme used when connecting to the access point 
     RSSI: strength of a signal received from the access point 
     In addition to such a method in which specific information is thus shared by interpreting a received beacon frame, a beacon frame received by the wireless communicator  110  may be shared as it is. In addition, to connect to an operating access point without including an SSID in a beacon, the SSID of an access point desired to be connected may be included in an information sharing request. At that time, the processor  101  actively checks whether there is an access point having the specified SSID, and shares the result of the check with the controller  102 . 
     By thus sharing obtained information between the wireless communicators, the operation of the wireless communicator  104  can be resumed while suppressing power consumption. 
     Second Embodiment 
     In the first embodiment, when a wireless communicator  104  detects a connectable network, the wireless communicator  104  establishes a connection to the network, and when the wireless communicator  104  establishes a connection to the network, the wireless communicator  104  immediately obtains preset information. On the other hand, in the present embodiment, a connection is established only when a predetermined condition is satisfied. In addition, even if a connection is being established, only when a predetermined condition is satisfied, obtaining of information starts. 
     In the present embodiment, in a processor  101 , a control application operates that has the function of minutely controlling the conditions for a connection and obtaining of information, in addition to the function of controlling the overall operation of the apparatus. A storage  103  saves various conditions for controlling the execution timing of a connection and obtaining of information. In addition, the storage  103  may have the function as a temporary storage (working memory) of a controller  102 . The controller  102  has, in addition to the functions described in the first embodiment, the function of controlling the timing of a connection to a network by a wireless communicator  104  and the timing of obtaining of information using the wireless communicator  104 , according to an instruction from the control application operating in the processor  101  and the conditions saved in the storage  103 . 
       FIG. 5  is a flowchart of the operation of the controller  102  in the present embodiment. A determination about a connection to a network and processes related thereto (S 702  to S 706 ) and a determination about obtaining of information and processes related thereto (S 707  to S 709 ) are added to the flowchart in the first embodiment which is illustrated in  FIG. 2 . A flowchart of a determination about connection conditions and obtaining conditions is illustrated in  FIG. 6 . In  FIG. 5 , it is assumed that one or more conditions are stored in the storage  103 . In addition, it is assumed that an instruction from the processor  101  is also stored in the storage  103 . Note that these pieces of various information may be stored in a storage different than the storage  103 . 
     First, the controller  102  determines whether the connection conditions are met (step S 702 ). If the connection conditions are met (step S 703 : Yes), the controller  102  determines whether the power to the wireless communicator  104  is turned on. If not turned on, the controller  102  turns on the power (step S 705 ). Then, the controller  102  establishes a connection to a network through the wireless communicator  104  (step S 706 ). When a connection is established to the network, the controller  102  checks whether the information obtaining conditions have been met (step S 707 ). If the information obtaining conditions have been met (step S 708 : Yes), the controller  102  performs the above-described processes at and after step S 207 . If the information obtaining conditions are not met (step S 708 : No), the controller  102  disconnects from the network (step S 709 ) and ends the process. 
     As described previously, an instruction from the processor  101  is obtained by various methods. For example, it is possible to use a method in which an instruction is obtained by accessing a register of the processor  101  where the content of the instruction is stored, and a method in which an instruction is obtained as a signal on a signal line provided between the processor  101  and the controller  102 . In addition, in the flowchart of  FIG. 6 , when all conditions stored in the storage  103  are satisfied, it is determined to be “met”; however, when, for example, a logical OR between conditions is formed, all conditions do not necessarily need to be determined. 
     Next, the process of determining whether the connection conditions have been met will be described. As illustrated in  FIG. 6 , the controller  102  first determines whether unchecked connection conditions to be checked remain in the storage  103  (step S 802 ). If connection conditions remain (step S 802 : Yes), the controller  102  selects one of the unchecked connection conditions (step S 804 ). Then, the controller  102  checks, for the selected connection condition, whether information required for the determination is available (step S 805 ). This is to check whether, when information on a sensor, etc., is required for the condition determination, those pieces of information have been able to be appropriately obtained. For example, when the connection condition includes positional information, it is checked whether positional information with appropriate accuracy has been able to be obtained, and when the connection condition includes a movement condition, it is checked whether the value of an acceleration sensor has been able to be obtained. Note that items that are continuously measured substantially routinely in the wireless communicator  104 , such as an RSSI value from an expected connection destination and remaining battery level, are determined at this step to be available. 
     If it is determined that information is not sufficiently available for the connection condition determination (step S 805 : No), the controller  102  collects information required for the determination (step S 806 ). As described previously, the information may be obtained using various types of sensors. Note that the case of requiring a connection to a wide area network which is not illustrated is also considered depending on the type of information (e.g., base station information of a wide area network). 
     Then, the controller  102  determines whether the connection condition has been met (step S 807 ). If it is determined that the connection condition has been met (step S 807 : Yes), the controller  102  returns to step S 802  to make a determination about the next connection condition. On the other hand, if it is determined that the connection condition is not met (step S 807 : No), the controller  102  determines that the connection conditions are not met, and thus, ends the process (step S 808 ). 
     Then, when all connection conditions are determined to be met and thus there is no more unchecked connection condition (step S 802 : No), finally, the controller  102  determines that the connection conditions have been met (step S 803 ), and thus, performs the process of establishing a connection to a network. Note that although the above shows the process related to the connection condition determination, the same processing procedure can also be used for the obtaining conditions by replacing the connection conditions with the obtaining conditions. Note, however, that the number of pieces of information required for the determination increases compared to the case of the connection determination. For example, the information is considered to be throughput and delay between the apparatus and an assumed communication counterpart, communication time estimated from the throughput, current time, current position, movement conditions, the degree of congestion at a connected wireless LAN access point, SSID, an IP address identifying a connected network, an IP address of the communication counterpart, remaining battery level, and an URL (domain) to be obtained. To obtain these pieces of information, at step S 806 , a necessary process is performed. For example, when throughput and delay are required, a connection is established to a communication counterpart, and the throughput and delay thereof are measured. For the degree of congestion at a wireless LAN access point, for example, there are considered a method in which the degree of congestion is directly obtained from the access point, and a method in which the degree of congestion is obtained by inquiring a management server of a telecommunications carrier. Note that assuming, for example, the case in which it is difficult to establish a connection to the actual communication counterpart, measurement may be performed with a server that is prepared in advance. For other information, too, likewise, in the case of obtaining the current time, synchronization is achieved with a time server, and in the case of obtaining the current position, the position is measured using the GPS, etc. 
     A measurement method is not limited to one type, and a plurality of measurements may be continuously performed, or a plurality of measurements may be simultaneously performed. Alternatively, necessary information may be listed in advance, and after obtaining those pieces of information at a time, a determination may be performed. Furthermore, in  FIG. 6 , these pieces of information are collected as part of the connection determination and the information obtaining determination, but may be collected independently. Furthermore, a series of information may be collected by proxy by a management server that manages a wireless LAN network or a wireless wide area network, etc., and the apparatus may obtain the series of information. 
     The controller  102  performs a series of determination processes such as those described above, and the processor  101  may control the conditions for the processes. For example, an application that adds or deletes a determination condition, temporarily invalidates a condition, and checks or overwrites a determination result may be operated. 
     (Modification) 
     Next, a modification for the case will be described in which, when interruption occurs in the middle of obtaining information by a communication apparatus  100 , a wireless communicator  110  resumes obtaining of information using resume information. Although in the first embodiment resume information is stored in a storage  103  of a communication apparatus  100 , the resume information also needs to be stored in a second storage  203  of an external apparatus  200  illustrated in  FIG. 7 . Specifically, a processor  101  continues obtaining of information, based on resume information notified from a controller  102 . The controller  102  interrupts obtaining of information being performed, organizes the obtaining conditions in resume information, and shares the resume information with the processor  101 . Then, the processor  101  stores the resume information, etc., in the second storage  203 . 
       FIG. 8  illustrates an operation sequence of an example case in which obtaining of information by a wireless communicator  104  is interrupted, and a wireless communicator  110  takes over obtaining of information, and then again, the wireless communicator  104  resumes obtaining. A thick-frame portion in  FIG. 8  indicates “being operated” and a thin-line portion indicates “being stopped” or “power-saving state”. 
     If the controller  102  determines that obtaining of information through the wireless communicator  104  is not in an appropriate state (step S 1001 ), the controller  102  performs a disconnection process and generates resume information (step S 1002 ). The generated resume information is saved in a storage  103  (step S 1003 ) and is shared with the processor  101  and is also saved in the second storage  203  (step S 1004 ). After sharing the information, the controller  102  may perform control to reduce the power consumption of the entire apparatus by turning off the power to the controller  102  and the wireless communicator  104  (step S 1005 ). 
     The processor  101  checks the updated resume information (step S 1006 ) and checks whether an obtaining condition for information to be obtained is met (step S 1007 ). If not met, the processor  101  does not perform obtaining using the wireless communicator  110 . The processor  101  goes into standby or transitions to a low power consumption state. Note, however, that as described above, a search for a connectable wireless LAN access point, etc., may be performed. 
     If the connection condition has been met, the processor  101  requests the wireless communicator  110  to obtain information (step S 1018 ), and the wireless communicator  110  establishes a connection to a communication counterpart to obtain information (step S 1009 ). The processor  101  stores the obtained information in the second storage  203  (steps S 1010  and S 1011 ). In the sequence of  FIG. 8 , the obtained information is temporarily saved in the second storage  203 , and when a disconnection process is performed (steps S 1012  and S 1013 ), the controller  101  puts together and organizes the obtained information and writes the information in the second storage  203 . On the other hand, the information may be directly saved in the storage  103  (in that case, since the information is saved through the controller  102 , the controller  102  needs to be appropriately in operation). 
     When a disconnection condition is met in the processor  101 , the processor  101  generates resume information (steps S 1014  and S 1015 ), and the resume information is saved in the second storage  203  and the storage  103 , and is thereby shared with the controller  102  (step S 1016 ). Note that, when the power to the controller  102  and the storage  103  is turned off upon sharing, the power is turned on in advance. The processor  101  notifies the controller  102  that the resume information has been updated (step S 1017 ). When the controller  102  confirms the update to the resume information (step S 1018 ), the controller  102  refers to the resume information (step S 1019 ) and activates the wireless communicator  104  (step S 1020 ) to resume an information obtaining process (step S 1021 ). 
     In the case of the above-described modification, pieces of information obtained by different wireless communicators are put together and shared as resume information. By this, communication can be performed using a plurality of wireless communicators without a user being aware of it. 
     In addition, instead of the process of obtaining information, the flow of a process for the case of using obtained information between the external apparatus  200  and the communication apparatus  100  will be described.  FIGS. 9A to 9C  illustrate the operation sequences of each component. In the drawing, a process starts assuming that information is stored in the storage  103  and the processor  101  uses the information. 
       FIG. 9A  illustrates the case in which simply the processor  101  refers to information in the storage  103 . When the processor  101  issues a reference request (step S 901 ), the controller  102  interprets the reference request and sends to the storage  103  a request to refer to desired information (step S 902 ). At that time, if the controller  102  has transitioned to a sleep state or the power to the storage  103  is turned off, the controller  102  recovers by a signal from the processor  101 , or a current is allowed to pass through the storage  103  by the controller  102  upon referring (step S 903 ). The controller  102  reads from the storage  103  information for which the reference request is issued (step S 904 ) and passes the information to the processor  101  (step S 905 ). Then, the processor  101  performs some kind of process (step S 906 ). As a result, the information may be presented to a user of the apparatus or may be stored again in the storage  103 , etc. 
     Note that the reference request can be implemented in various forms. For example, it is assumed that the controller  102  performs control such that the storage  103  can be referred to by the processor  101 , as some kind of file system. In that case, the reference request is a file access request, and information serving as a response is returned as the content of a file. In addition, for example, the reference request may be an information obtaining request from the processor  101  to the controller  102  which is described in other embodiments. In this case, information is obtained through the wireless communicator  104  in the above-described embodiments. However, in  FIG. 9B , it can be checked by processes at steps S 907  and S 908  that target information is saved in the storage  103 , and thus, the operation of returning the target information to the processor  101  without communicating with an external server through a wireless network is performed. 
     In addition, as illustrated in  FIG. 9C , when the processor  101  issues a request as an information obtaining request, the controller  102  may check whether information is saved in the storage  103  (step S 907 ), and if saved, the controller  102  may check whether the information is the latest information (step S 910  to S 914 ). In this case, the case is illustrated in which the result of the check reveals that the latest information is saved in the storage  103 . If not saved, the controller  102  obtains the latest information before turning off the power to the wireless communicator  104  and inactivating the wireless communicator  104 . The obtaining process is performed in accordance with the previously described methods in the embodiments. 
     In a series of operations described here, the case is considered in which, when information is obtained from the storage  103 , some information has not been able to be obtained. In that case, the process of obtaining unobtained information may be performed according to the previously described embodiments. At that time, the processor  101  may be notified of the fact that information is being obtained. On the other hand, when information has a missing portion, a process may be performed considering that the storage  103  does not have corresponding information. 
       FIG. 10  is a sequence diagram for a modification of the case in which the process of obtaining additional information is added by the wireless communicator  110 . For example, there is a possibility that a decryption key required to obtain original information, etc., may be distributed through a different path than that for obtained information. To handle such a case, the processor  101  having obtained information from the storage  103  checks whether additional information is required (step S 920 ). If it is determined that additional information is required, the processor  101  obtains the information using a communication means appropriate for acquiring the information (steps S 921  to S 923 ). Note that at step S 920  in  FIG. 10  it is determined that the information needs to be obtained using the wireless communicator  110 , and thus, the wireless communicator  110  is activated to obtain the information. Note that this information for making a determination may be included in the information obtained from the storage  103  or may be programmed in advance. Alternatively, the user may set the information for making a determination as occasion arises. 
     In addition to a decryption key, examples in which the present modification can be applied are considered to include obtaining of supplemental information to be additionally displayed on an already obtained moving image, and notifying an external server of the current location information of the apparatus by the wireless communicator  110  and checking whether there is information related to the current location information. Furthermore, the step of checking whether the obtained information is the latest information may also be performed by the method described here. Note that how to handle additionally obtained information is not limited here. The information may be saved in the storage  103  and then reused at timing at which the information is referred to next time, or the saved additional information may be provided with a period of validity so as to be reused during a fixed period of time, or the information may be discarded after use and obtained without fail. 
     The previously described embodiments of the present invention describe the case of obtaining information. However, the present invention can also be applied to the case of transmitting information to a network. At that time, information accumulated in a storage is transmitted to a network, according to a URL specified in advance. 
     The communication apparatuses  100  of the above-described embodiments have a hardware configuration including, for example, a control apparatus such as a CPU, storage apparatuses such as a ROM (Read Only Memory) and a RAM, and external storage apparatuses such as an HDD and a CD drive apparatus. 
     Programs executed by the communication apparatuses  100  of the above-described embodiments are provided by being recorded in a computer-readable recording medium, such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk), in an installable or executable format file. 
     Alternatively, the programs of the above-described embodiments may be configured to be provided by being stored on a computer connected to a network such as the Internet, and downloaded via the network. Alternatively, the programs executed by the communication apparatuses  100  of the above-described embodiments may be configured to be provided or distributed via a network such as the Internet. 
     Alternatively, the programs of the above-described embodiments may be configured to be provided by being pre-installed in a ROM, etc. 
     In addition, the programs executed by the communication apparatuses  100  of the above-described embodiments have a module configuration including the above-described units. In the actual hardware, a CPU (processor) reads a program from the storage medium and executes the program, by which the units are loaded onto a main storage apparatus and created on the main storage apparatus. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.