Abstract:
Provided is a data transmission system of providing preambles of different classes according to a characteristic of a terminal. A terminal having constraints on using a power with respect to a data reception may receive only a preamble of a particular class and thus decrease a power consumption. A general terminal may receive preambles of plural classes and quickly receive data.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Application No. 10-2010-0029983, filed on Apr. 1, 2010, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
     BACKGROUND 
     1. Field 
     The following description relates to a mobile communication field, and more particularly, to a preamble structure of transmitting preambles of different classes. 
     2. Description of Related Art 
     A reception apparatus may receive data from a transmission apparatus. In general, the reception apparatus may be unaware of when the transmission apparatus transmits data. In cases in which the reception apparatus waits for data to be transmitted from the transmission apparatus at all times, the reception apparatus may use a significantly great amount of power to receive the data. Accordingly, in an idle state, the reception apparatus may periodically monitor whether the transmission apparatus has transmitted data. Only when the transmission apparatus transmits the data may the reception apparatus shift from the idle state to an active state and receive the data. 
     For the above operation, the transmission apparatus may include a preamble within a frame to transmit the data. In the idle status, the reception apparatus may periodically attempt a detection of the preamble that may have been transmitted from the transmission apparatus. When the reception apparatus succeeds in detecting the preamble, the reception apparatus determines that data is ready to be transmitted from the transmission apparatus, and thus may shift from the idle state to the active state to receive the data. 
     Conventional systems and methods use power inefficiently. 
     SUMMARY 
     In one general aspect, there is provided a transmission apparatus, including: a first preamble transmitter configured to transmit a first preamble and first data to a first reception apparatus, the first reception apparatus being configured to receive the first data, depending on whether the first preamble is detected, and a second preamble transmitter configured to transmit a second preamble and second data to the first reception apparatus and a second reception apparatus, the first reception apparatus and the second reception apparatus being configured to receive the second data, depending on whether the second preamble is detected. 
     In the transmission apparatus, a length of the first preamble is an integer multiple of a length of the second preamble. 
     In the transmission apparatus, the second preamble transmitter is further configured to repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     In the transmission apparatus, the second reception apparatus is configured to be supplied with a power using a battery. 
     In another general aspect, there is provided a reception apparatus, including: a receiver configured to receive, from a transmission apparatus, a signal including a first preamble or a second preamble, a control signal receiver configured to receive a control signal, a first preamble detector configured to detect the first preamble, and a second preamble detector configured to detect the second preamble, wherein the control signal receiver is further configured to activate the first preamble detector or the second preamble detector, according to the control signal, and wherein, in response to the first preamble or the second preamble being detected, the receiver is further configured to receive data from the transmission apparatus. 
     In the reception apparatus, a length of the first preamble is an integer multiple of a length of the second preamble. 
     In another general aspect, there is provided a reception apparatus, including: a preamble detector configured to detect a first preamble or a second preamble, received from a transmission apparatus, and a receiver configured to receive data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected, wherein a second reception apparatus is configured to: detect the second preamble received from the transmission apparatus, and receive second data from the transmission apparatus, depending on whether the second preamble is detected. 
     In the reception apparatus, a length of the first preamble is an integer multiple of a length of the second preamble. 
     In the reception apparatus, the transmission apparatus is further configured to repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     In another general aspect, there is provided a reception apparatus, including: a detector configured to detect a first preamble received from a transmission apparatus, and a receiver configured to receive data from the transmission apparatus, depending on whether the first preamble is detected, wherein a second reception apparatus is configured to: detect the first preamble or a second preamble received from the transmission, and receive second data from the transmission apparatus, depending on whether the second preamble is detected. 
     In the reception apparatus, a length of the first preamble is an integer multiple of a length of the second preamble. 
     In another general aspect, there is provided a transmission method, including: transmitting a first preamble and first data to a first reception apparatus, the first data being received by the first reception apparatus, depending on whether the first preamble is detected, and transmitting a second preamble and second data to the first reception apparatus and a second reception apparatus, the second data is received by the first reception apparatus or the second reception apparatus, depending on whether the second preamble is detected. 
     In the transmission method, a length of the first preamble is an integer multiple of a length of the second preamble. 
     In the transmission method, the transmitting of the second preamble includes repeatedly transmitting the second preamble during a time interval in which the first preamble is transmitted. 
     In another general aspect, there is provided a reception method, including: receiving, from a transmission apparatus, a signal including a first preamble or a second preamble, receiving a control signal, detecting the first preamble or the second preamble, according to the control signal, and receiving data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected. 
     In the reception method, a length of the first preamble is an integer multiple of a length of the second preamble. 
     In another general aspect, there is provided a reception method, including: detecting a first preamble or a second preamble, received from a transmission apparatus, and receiving data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected, wherein a reception apparatus: detects the second preamble received from the transmission apparatus, and receives second data from the transmission apparatus, depending on whether the second preamble is detected. 
     In another general aspect, there is provided a reception method, including: detecting a first preamble received from a transmission apparatus, and receiving data from the transmission apparatus, depending on whether the first preamble is detected, wherein a second reception apparatus detects the first preamble or a second preamble received from the transmission apparatus, and receives second data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected. 
     In another general aspect, there is provided a reception apparatus, including: a preamble detector configured to detect a first preamble or a second preamble, received from a transmission apparatus, a receiver configured to receive data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected, and a reception unit configured to: detect the second preamble received from the transmission apparatus, and receive second data from the transmission apparatus, depending on whether the second preamble is detected. 
     In the reception apparatus, a length of the first preamble is an integer multiple of a length of the second preamble. 
     In the reception apparatus, the transmission apparatus is further configured to repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     In another general aspect, there is provided a reception apparatus, including: a detector configured to detect a first preamble received from a transmission apparatus, and a receiver configured to receive data from the transmission apparatus, depending on whether the first preamble is detected, and a reception unit configured to: detect the first preamble or a second preamble received from the transmission, and receive second data from the transmission apparatus, depending on whether the second preamble is detected. 
     In the reception apparatus, a length of the first preamble may be an integer multiple of a length of the second preamble. 
     In another general aspect, there is provided a reception method, including: detecting a first preamble received from a transmission apparatus, receiving data from the transmission apparatus, depending on whether the first preamble is detected, detecting, by a reception unit, the first preamble or a second preamble received from the transmission apparatus, and receiving, by the reception unit, second data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected. 
     A non-transitory computer-readable medium may include a program for instructing a computer to perform any of the above methods. 
     Other features and aspects may be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram to describe an example of a method of transmitting and receiving data using a multi-class preamble structure. 
         FIG. 2  is a diagram illustrating an example of multiple preambles. 
         FIG. 3  is a diagram illustrating an example of each reception apparatus receiving a first preamble. 
         FIG. 4  is a diagram illustrating an example of each reception apparatus receiving a second preamble. 
         FIG. 5  is a diagram illustrating an example of a transmission apparatus. 
         FIG. 6  is a diagram illustrating an example of a reception apparatus. 
         FIG. 7  is a diagram illustrating another example of a reception apparatus. 
         FIG. 8  is a diagram illustrating still another example of a reception apparatus. 
         FIG. 9  is a diagram illustrating an example of a data transmission method. 
         FIG. 10  is a diagram illustrating an example of a data reception method. 
         FIG. 11  is a diagram illustrating another example of a data reception method. 
     
    
    
     Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION 
     The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be suggested to those of ordinary skill in the art. The progression of processing steps and/or operations described is an example; however, the sequence of steps and/or operations is not limited to that set forth herein and may be changed as is known in the art, with the exception of steps and/or operations necessarily occurring in a certain order. Also, description of well-known functions and constructions may be omitted for increased clarity and conciseness. 
       FIG. 1  illustrates a diagram to describe an example of a method of transmitting and receiving data using a multi-class preamble structure. 
     According to an embodiment, a transmission apparatus (e.g., transmission apparatus  500  in the example of  FIG. 5 , below) may transmit, to a reception apparatus (e.g., first reception apparatus  540  or second reception apparatus  550  in the example of  FIG. 5 , below), a data frame containing data. In an idle state, the reception apparatus may detect a preamble included in the data frame. In response to the reception apparatus succeeding in a detection of the preamble, the reception apparatus may determine data is being transmitted from the transmission apparatus. In response to the data not being transmitted from the transmission apparatus, the reception apparatus may maintain the idle state and decrease a power communication. Conversely, in response to the data being transmitted from the transmission apparatus, the reception apparatus may shift from the idle state to an active state to receive the data. 
     The transmission apparatus may transmit data to a plurality of reception apparatuses having different characteristics (e.g., first reception apparatus  540  or second reception apparatus  550  in the example of  FIG. 5 , below). For example, a first reception apparatus may be stably supplied with a power from a power socket, and the like. The first reception apparatus may receive data without a limitation on the power. A second reception apparatus may be supplied with the power using a battery, and the like. The second reception apparatus may have some constraints on receiving the data due to a limitation of the power. 
     The transmission apparatus may transmit different preambles designed based on characteristics of the respective reception apparatuses. Each of the reception apparatuses may detect a portion of or all of the preambles based on corresponding characteristics. For example, the first reception apparatus may detect both a first preamble and a second preamble. For example, the first reception apparatus, which may not be affected by the power limitation, may detect all the preambles, and may quickly receive data from the transmission apparatus. The second reception apparatus, which may be affected by the power limitation, may detect only the second preamble, and may effectively receive data. 
     Referring to  FIG. 1 , a transmission apparatus may transmit, to a second reception apparatus, data frames  111  and  121  containing first preambles  110  and  120 , and a data frame  131  containing a second preamble  130 . In this instance, the second reception apparatus may not detect the first preambles  110  and  120 , and thus may not receive data included in the data frames  111  and  121  containing the first preambles  110  and  120 . The second reception apparatus may detect the second preamble  130 , and thus may receive data  140  included in the data frame  131  containing the second preamble  130 . 
     According to another embodiment, a first reception apparatus may detect only a first preamble, and may receive data from a transmission apparatus. A second reception apparatus may detect only a second preamble and receive data from the transmission apparatus. 
       FIG. 2  illustrates an example of multiple preambles. 
     Referring to  FIG. 2 , a first preamble may be repeatedly transmitted during every first time interval  220 . A second preamble may be repeatedly transmitted during every second time interval  231  or  232 . A transmission apparatus may transmit all of the first preamble and the second preamble. Each of reception apparatuses may receive a preamble corresponding to a characteristic of a corresponding reception apparatus. 
     A length of the first time interval  220  may be different from a length of the second time interval  231  or  232 . As shown in  FIG. 2 , the first time interval  220  may be an integer multiple of the second time interval  231  or  232 . 
     A first reception apparatus may receive preambles repeated during every first time interval  220 . Referring to  FIG. 2 , the first reception apparatus may receive the first preamble and the second preamble repeated during every first time interval  220 . 
     A second reception apparatus may receive preambles repeated during every second time interval  231  or  232 . Referring to  FIG. 2 , the second reception apparatus may receive the second preamble repeated during every second time interval  231  or  232 . However, the second reception apparatus may not receive the first preamble. 
       FIG. 3  illustrates an example of each reception apparatus receiving a first preamble. 
     A first reception apparatus may detect the first preamble by correlating a first correlation signal with a signal received from a transmission apparatus. A length of the first correlation signal may be the same as a length of a first time interval. For example, in response to the length of the first correlation signal being the same as a length of the first preamble, the first reception apparatus may detect preambles repeated during every first time interval. 
     Referring to  FIG. 3 , the first reception apparatus may detect the first preamble after the first preamble is repeated twice. 
     A second reception apparatus may detect a second preamble by correlating a second correlation signal with the signal received from the transmission apparatus. A length of the second correlation signal may be the same as a length of a second time interval. For example, in response to the length of the second correlation signal being the same as a length of the second preamble, the second reception apparatus may detect preambles repeated during every second time interval. 
     However, in response to the length of the first preamble being an integer multiple of the length of the second correlation signal, the second reception apparatus may not detect the first preamble. Referring to  FIG. 3 , the second reception apparatus may not detect the first preamble. 
       FIG. 4  illustrates an example of each reception apparatus receiving a second preamble. 
     The second preamble may be repeated during every second time interval. A length of a first time interval may be an integer multiple of a length of the second time interval. Accordingly, in response to an integer number of second preambles being combined, the second preamble may be repeated during every first time interval. Accordingly, in  FIG. 4 , a first reception apparatus may detect the second preamble after the first time interval is repeated twice, using a first correlation signal. 
     A second reception apparatus may detect the second preamble after the second time interval is repeated twice. 
       FIGS. 3 and 4  illustrate examples in which each reception apparatus may receive the preambles of  FIG. 2 . The first reception apparatus may receive both the first preamble and the second preamble. The second reception apparatus may receive only the second preamble. 
       FIG. 5  illustrates an example of a transmission apparatus  500 . 
     The transmission apparatus  500  may include a first preamble transmitter  510 , a control signal transmitter  520 , and a second preamble transmitter  530 . 
     The first preamble transmitter  510  may transmit, to a first reception apparatus  540 , a first preamble detectable by the first reception apparatus  540 . 
     The second preamble transmitter  530  may transmit, to a second reception apparatus  550 , a second preamble detectable by the second reception apparatus  550 . 
     The first preamble transmitter  510  may transmit the first preamble to the second reception apparatus  550 , and the second preamble transmitter  530  may transmit the second preamble to the first reception apparatus  540 . In one example, even though the second reception apparatus  550  may not detect the first preamble, the first reception apparatus  540  may detect the second preamble. 
     A length of the first preamble may be an integer multiple of the second preamble. 
     The first reception apparatus  540  may denote a reception apparatus that may be stably supplied with a power from a power socket, and the like. The second reception apparatus  550  may denote a reception apparatus that may be supplied with the power using a battery, and the like. In one example, the first reception apparatus  540  may receive data without a limitation on the power, and the second reception apparatus  550  may have some constraints on receiving the data due to a limitation of the power. 
     As described above, the first reception apparatus  540  may detect both the first preamble and the second preamble. In response to the first reception apparatus  540  receiving data, the power may be unlimited and thus the first reception apparatus  540  may attempt a detection of the first preamble or the second preamble during every time interval in which the first preamble or the second preamble is transmitted. In response to the first reception apparatus  540  succeeding in a preamble detection, the first reception apparatus  540  may determine data is to be transmitted from the transmission apparatus  500 . Accordingly, the first reception apparatus  540  may shift from an idle state to an active state, and may receive data from the transmission apparatus  500 . 
     The second reception apparatus  550  may detect only the second preamble. The second reception apparatus  550  may attempt a detection of the second preamble during every time interval in which the second preamble is transmitted. The second reception apparatus  550  may attempt the detection of only the second preamble, and thus may decrease a power consumption compared to the first reception apparatus  540 . In response to the second reception apparatus  550  succeeding in the detection of the second preamble, the second reception apparatus  550  may determine data is to be transmitted from the transmission apparatus  500 . Accordingly, the second reception apparatus  550  may shift from the idle state to the active state and receive data from the transmission apparatus  500 . 
     The control signal transmitter  520  may transmit a control signal to each of the first reception apparatus  540  and the second reception apparatus  550 . Each of the first reception apparatus  540  and the second reception apparatus  550  may detect both the first preamble and the second preamble, or may detect only the first preamble according to the control signal. 
       FIG. 6  illustrates an example of a reception apparatus  600 . 
     The reception apparatus  600  may include a receiver  610 , a control signal receiver  620 , a first preamble detector  630 , and a second preamble detector  640 . 
     The receiver  610  may receive, from a transmission apparatus  650 , a signal containing a first preamble or a second preamble. 
     The control signal receiver  620  may receive a control signal from an upper layer. The control signal may include information associated with a preamble to be detected by the reception apparatus  600 . 
     The first preamble detector  630  may detect the first preamble. 
     The second preamble detector  640  may detect the second preamble. 
     In response to the reception apparatus  600  being in an idle state, the control signal receiver  620  may decrease a power consumption of the reception apparatus  600  by inactivating the first preamble detector  630  and the second preamble detector  640 , and by cutting off the power. 
     The transmission apparatus  650  may designate a preamble to be received by the reception apparatus  600 , using the control signal. The transmission apparatus  650  may transmit the control signal to the reception apparatus  600 . The upper layer of the reception apparatus  600  may recognize the control signal. The control signal receiver  620  may receive the control signal from the upper layer. 
     The control signal receiver  620  may activate the first preamble detector  630  or the second preamble detector  640  according to the control signal. For example, in response to the control signal indicating, e.g., that “the reception apparatus  600  needs to detect the first preamble,” the control signal receiver  620  may activate the first preamble detector  630  during a time interval in which the first preamble is transmitted. As the second preamble detector  640  may not activate, and only the first preamble detector  630  may be activated, a power consumption of the reception apparatus  600  may decrease. 
     In response to the control signal indicating that “the reception apparatus  600  needs to detect the second preamble,” the control signal receiver  620  may decrease the power consumption by activating only the second preamble detector  640 . 
     A length of the first preamble may be an integer multiple of a length of the second preamble. In one example, the first preamble detector  630  may detect the first preamble as well as the second preamble. 
       FIG. 7  illustrates another example of a reception apparatus  700 . 
     The reception apparatus  700  may include a receiver  710 , a first preamble detector  720 , a second preamble detector  730 , and a multiplexer (MUX)  740 . 
     The receiver  710  may receive, from a transmission apparatus  750 , a signal containing a first preamble or a second preamble. 
     The first preamble detector  720  may detect the first preamble included in the received signal. In response to the first preamble being included in the received signal, the first preamble detector  720  may succeed in a detection of the first preamble. 
     The second preamble detector  730  may detect the second preamble included in the received signal. In response to the second preamble being included in the received signal, the second preamble detector  730  may succeed in a detection of the second preamble. 
     The MUX  740  may select one of an output of the first preamble detector  720  and an output of the second preamble detector  730 , according to the control signal. 
     For example, the received signal may include the first preamble, and the first preamble detector  720  may detect the first preamble. In one example, the MUX  740  may select the output of the first preamble detector  720 , according to the control signal. 
     The received signal may include the second preamble, and the second preamble detector  730  may detect the second preamble. In one example, the MUX  740  may select the output of the second preamble detector  730 . 
       FIG. 8  illustrates still another example of a reception apparatus  800 . 
     The reception apparatus  800  may include a preamble detector  810  and a receiver  820 . 
     The reception apparatus  800  may operate to detect both a first preamble and a second preamble, or may operate to detect only the second preamble. 
     1) In response to the reception apparatus  800  operating to detect both the first preamble and the second preamble: 
     The preamble detector  810  may detect the first preamble or the second preamble received from a transmission apparatus  830 . The second preamble may be a preamble detectable by both the reception apparatus  800  and a second reception apparatus  840 , and the first preamble may be a preamble detectable by only the reception apparatus  800 . 
     A length of the first preamble may be an integer multiple of a length of the second preamble. In one example, the transmission apparatus  830  may repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     The receiver  820  may receive data from the transmission apparatus  830 , depending on whether the first preamble or the second preamble is detected. In response to the preamble detector  810  succeeding in a detection of the first preamble or the second preamble, the receiver  820  may receive data from the transmission apparatus  830 . 
     The second reception apparatus  840  may detect the first preamble received from the transmission apparatus  830 . In response to the second reception apparatus  840  succeeding in the detection of the first preamble, the second reception apparatus  840  may receive second data from the transmission apparatus  830 . 
     2) In response to the reception apparatus  800  operating to detect only the first preamble: 
     The preamble detector  810  may detect the second preamble received from the transmission apparatus  830 . The second preamble may be a preamble detectable by both the reception apparatus  800  and the second reception apparatus  840 . The first preamble may be a preamble detectable by only the reception apparatus  800 . 
     A length of the first preamble may be an integer multiple of a length of the second preamble. In one example, the transmission apparatus  830  may repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     The receiver  820  may receive data from the transmission apparatus  830 , depending on whether the first preamble is detected. In response to the preamble detector  810  succeeding in a detection of the first preamble, the receiver  820  may receive data from the transmission apparatus  830 . 
     The second reception apparatus  840  may detect the first preamble or the second preamble received from the transmission apparatus  830 . In response to the second reception apparatus  840  succeeding in the detection of the first preamble or the second preamble, the second reception apparatus  840  may receive second data from the transmission apparatus  830 . 
       FIG. 9  illustrates an example of a data transmission method. 
     In operation  910 , a transmission apparatus, e.g., transmission apparatus  500  in  FIG. 5 , may transmit a first preamble and first data to a first reception apparatus, e.g., first reception apparatus  540  in  FIG. 5 . 
     In operation  920 , the transmission apparatus may transmit a second preamble and second data to the first reception apparatus and to a second reception apparatus, e.g., second reception apparatus  550  in  FIG. 5 . 
     The second preamble may be a preamble detectable by both the first reception apparatus and the second reception apparatus. The first preamble may be a preamble detectable only by the first reception apparatus. A length of the first preamble may be an integer multiple of a length of the second preamble. 
     The transmission apparatus may repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     The first reception apparatus may detect both the first preamble and the second preamble. In response to the first reception apparatus succeeding in a detection of the first preamble, the first reception apparatus may receive the first data. In response to the first reception apparatus succeeding in a detection of the second preamble, the first reception apparatus may receive the second data. 
     The second reception apparatus may detect the second preamble. In response to the second reception apparatus succeeding in the detection of the second preamble, the second reception apparatus may receive the second data. 
     The first reception apparatus may denote a reception apparatus that may be stably supplied with a power from a power socket, and the like. The second reception apparatus may denote a reception apparatus that may be supplied with the power using a battery and the like. In one example, the first reception apparatus may receive data without a limitation on the power, and the second reception apparatus may have some constraints on receiving the data due to a limitation of the power. 
     The second reception apparatus may operate only during a time interval in which the second preamble is transmitted, and thus may decrease a power consumption in receiving data. 
       FIG. 10  illustrates an example of a data reception method. 
     In operation  1010 , a reception apparatus may receive, from a transmission apparatus, a signal containing a first preamble or a second preamble. 
     The first preamble may be a preamble detectable by only the first reception apparatus, and the second preamble may be a preamble detectable by the first reception apparatus and the second reception apparatus. A length of the first preamble may be an integer multiple of a length of the second preamble. The transmission apparatus may repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     In operation  1020 , the reception apparatus may receive a control signal from the transmission apparatus. The control signal may include information associated with a preamble to be received by the reception apparatus. 
     In operation  1030 , the reception apparatus may detect the first preamble or the second preamble according to the control signal. 
     The control signal may include information associated with one of the first preamble and the second preamble. The reception apparatus may detect only one of the first preamble and the second preamble according to the control signal. The reception apparatus may include a first preamble detector to detect the first preamble and a second preamble detector to detect the second preamble. The reception apparatus may decrease a power consumption by inactivating one of the first preamble detector and the second preamble detector according to the control signal. 
     In operation  1040 , the reception apparatus may receive data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected. 
       FIG. 11  illustrates another example of a data reception method. 
     In operation  1110 , a reception apparatus may detect a first preamble or a second preamble received from a transmission apparatus. 
     The second preamble may be a preamble detectable by both the reception apparatus and a second reception apparatus, and the first preamble may be a preamble detectable by only the reception apparatus. 
     A length of the first preamble may be an integer multiple of a length of the second preamble. The transmission apparatus may repeatedly transmit the second preamble during a time interval in which the first preamble is transmitted. 
     In operation  1110 , the second reception apparatus may detect the second preamble. 
     In operation  1120 , the reception apparatus may receive data from the transmission apparatus, depending on whether the first preamble or the second preamble is detected. In response to the reception apparatus succeeding in a detection of the first preamble, or in response to the reception apparatus succeeding in a detection of the second preamble, the reception apparatus may receive data from the transmission apparatus. 
     In response to the second reception apparatus succeeding in the detection of the second preamble, the second reception apparatus may receive data from the transmission apparatus. 
     The second reception apparatus may operate to detect the second preamble only during a time interval in which the second preamble is transmitted, and may not operate during a time interval in which the first preamble is transmitted. Accordingly, in response to receiving data, it may be possible to decrease a power consumption with respect to a data reception. 
     According to embodiments, it may be possible to decrease a power consumption of a reception apparatus in an idle state. 
     According to embodiments, it may be possible to increase a standby time of a reception apparatus. 
     It should be appreciated that any of the above devices may perform any of the above methods, as consistent with the above disclosure. 
     The processes, functions, methods and/or software described above may be recorded, stored, or fixed in one or more computer-readable storage media that includes program instructions to be implemented by a computer to cause a processor to execute or perform the program instructions. The media may also include, alone or in combination with the program instructions, data files, data structures, and the like. The media and program instructions may be those specially designed and constructed, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable media include magnetic media, such as hard disks, floppy disks, and magnetic tape; optical media such as CD-ROM disks and DVDs; magneto-optical media, such as optical disks; and hardware devices that are specially configured to store and perform program instructions, such as read-only memory (ROM), random access memory (RAM), flash memory, and the like. Examples of program instructions include machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations and methods described above, or vice versa. In addition, a computer-readable storage medium may be distributed among computer systems connected through a network and computer-readable codes or program instructions may be stored and executed in a decentralized manner. 
     As a non-exhaustive illustration only, the device described herein may refer to mobile devices such as a cellular phone, a personal digital assistant (PDA), a digital camera, a portable game console, and an MP3 player, a portable/personal multimedia player (PMP), a handheld e-book, a portable tablet and/or laptop PC, a global positioning system (GPS) navigation, and devices such as a desktop PC, a high definition television (HDTV), an optical disc player, a setup and/or set top box, and the like consistent with that disclosed herein. 
     A computing system or a computer may include a microprocessor that is electrically connected with a bus, a user interface, and a memory controller. It may further include a flash memory device. The flash memory device may store N-bit data via the memory controller. The N-bit data is processed or will be processed by the microprocessor and N may be 1 or an integer greater than 1. Where the computing system or computer is a mobile apparatus, a battery may be additionally provided to supply operation voltage of the computing system or computer. 
     It will be apparent to those of ordinary skill in the art that the computing system or computer may further include an application chipset, a camera image processor (CIS), a mobile Dynamic Random Access Memory (DRAM), and the like. The memory controller and the flash memory device may constitute a solid state drive/disk (SSD) that uses a non-volatile memory to store data. 
     A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.