Abstract:
The present invention relates to a transmission method and system for groupcast message and a storage medium accessible by electronic devices applicable to a first electronic device transmitting a groupcast message to a plurality of remote second electronic devices. The method comprises steps of: acquiring a piece of communication quality information for each said second electronic device and each said piece of communication quality information representing the connection quality between each said second electronic device and nearby devices; the first electronic device selecting one of the plurality of second electronic devices as a broadcast transmitter according to the plurality pieces of communication quality information; the first electronic device transmitting the groupcast message to the broadcast transmitter; and the broadcast transmitter transmitting a broadcast message to the plurality of second electronic devices. Thereby, transmission of a groupcast message to the second electronic devices can be ensured without adding extra transmission cost.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to communication, and particularly to a transmission method and system for groupcast message to a plurality of remote electronic devices, and to a storage medium accessible by electronic devices. 
       BACKGROUND OF THE INVENTION 
       [0002]    As the Internet is developing rapidly, the technology of Internet of Things (IoT) attracts attention increasingly and is applied to various fields in people&#39;s everyday lives. 
         [0003]    The IoT is a network based the Internet and enabling physical entities therein having networking capability to communicate with one another. In the IoT, each physical entity can be accessed or manipulated through the network. Equipment, machines, and articles can be managed and manipulated concentrically via the IoT. Its application range is very extensive, such as smart living environment, health and medical, and burglarproof applications. 
         [0004]    The methods for manipulating physical entities in the IoT can be categorized into two types. The first is to command the physical entities to be manipulated directly. If the client commands a physical entity inside the IoT, direct manipulation is an easily achievable method. Nonetheless, as the client is at a remote site and wishes to manipulate the physical entity in the IoT, the manipulation command needs to be delivered via the network media. If the physical entity is disposed nearby the network media, the manipulation command submitted by the client can certainly be delivered smoothly. Unfortunately, if the physical entity is disposed so remote to the network media that the manipulation command cannot be delivered via the network media, the second type of method should be adopted for delivering the manipulation command. 
         [0005]    The second type of method for manipulating physical entities in the IoT is to transmit groupcast messages containing manipulation command to all the physical entities in the IoT. This transmission method is that the client&#39;s electronic device selects randomly a physically entity in the IoT and transmits a groupcast message containing a manipulation command to the selected physical entity through the network media. Then the physical entity transmits the manipulation command to the other physical entities. 
         [0006]    Nonetheless, according to this type of method, a physical entity in the IoT is selected randomly as the transmitter of the groupcast message. Under random selection, if the selected physical entity has inferior connection quality, errors in the groupcast message might result during the transmission process owing to the bad connection quality. In order to make sure the groupcast message is received by the selected physical entity, mechanisms such as the fault detection, the error correction, and the re-transmission of the groupcast message must be included when this method is applied, resulting in extra costs. In some severe cases, because the groupcast messages are re-transmitted continuously, the groupcast messages are jammed between the network media and the transmitter, disabling the groupcast message to be delivered with certainty. 
         [0007]    Accordingly, how to transmit a groupcast message to a physical entity in the IoT with certainty without increasing extra transmission costs has become a major subject in the present day. 
       SUMMARY 
       [0008]    An objective of the present invention is to provide a transmission method and system for groupcast message and a storage medium accessible by electronic devices, which can transmit groupcast messages to remote electronic devices without increasing extra transmission costs. 
         [0009]    In order to achieve the above objective and efficacy, according to an embodiment of the present invention, a transmission method for groupcast message is disclosed and applicable to a first electronic device transmitting a groupcast message to a plurality of remote second electronic devices. The method comprises steps of: acquiring a piece of communication quality information for each said second electronic device and each said piece of communication quality information representing the connection quality between each said second electronic device and nearby devices; the first electronic device selecting one of the plurality of second electronic devices as a broadcast transmitter according to the plurality pieces of communication quality information; the first electronic device transmitting the groupcast message to the broadcast transmitter; and the broadcast transmitter transmitting a broadcast message to the plurality of second electronic devices. 
         [0010]    Furthermore, according to another embodiment of the present invention, a transmission system for groupcast message is disclosed and applicable to transmitting a groupcast message to a plurality of remote second electronic devices. The transmission system comprises a first electronic device and a plurality of second electronic devices. The first electronic device transmits a groupcast message. Each said second electronic device includes a piece of communication quality information representing the connection quality between each said second electronic device and nearby devices. The first electronic device selects one of the plurality of second electronic devices as a broadcast transmitter according to the plurality pieces of communication quality information. The first electronic device transmits the groupcast message to the broadcast transmitter. The broadcast transmitter transmits a broadcast message to the plurality of second electronic devices. 
         [0011]    Moreover, according another embodiment of the present invention, a storage medium accessible by electronic devices is disclosed. A program is stored in the storage medium accessible by electronic devices and used for executing a transmission method for groupcast message. The method is applicable to a first electronic device transmitting a groupcast message to a plurality of remote second electronic devices. The method comprises steps of: acquiring a piece of communication quality information for each of said plurality of second electronic devices and each said piece of communication quality information representing the connection quality between each of said plurality of said second electronic devices and nearby devices; the first electronic device selecting one of the plurality of second electronic devices as a broadcast transmitter according to the plurality pieces of communication quality information; the first electronic device transmitting the groupcast message to the broadcast transmitter; and the broadcast transmitter transmitting a broadcast message to the plurality of second electronic devices. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1A  shows a schematic diagram of the first electronic device acquiring the information of each second electronic device via the medium according to the first embodiment of the present invention; 
           [0013]      FIG. 1B  shows a schematic diagram of the first electronic device acquiring the information of each second electronic device via the medium according to the second embodiment of the present invention; 
           [0014]      FIG. 1C  shows a schematic diagram of the transmission method for groupcast message according to the first embodiment of the present invention; 
           [0015]      FIG. 2  shows a flowchart of the transmission method for groupcast message according to the first embodiment of the present invention; 
           [0016]      FIG. 3  shows a schematic diagram of defining groups according to an embodiment of the present invention; 
           [0017]      FIG. 4A  shows a schematic diagram of the transmission system for groupcast message according to the second embodiment of the present invention; 
           [0018]      FIG. 4B to 4D  show schematic diagrams of the transmission method for groupcast message according to the second embodiment of the present invention; and 
           [0019]      FIG. 5  shows a flowchart of the transmission method for groupcast message according to the second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    In order to make the structure and characteristics as well as the effectiveness of the present invention to be further understood and recognized, the detailed description of the present invention is provided as follows along with embodiments and accompanying figures. 
         [0021]    Please refer to  FIG. 1A . As shown in the figure, the present embodiment provides a transmission system for groupcast message  1 , which comprises a first electronic device  10 , a medium  30 , and a plurality of second electronic devices  50 . According to the present embodiment, the first electronic device  10  and the plurality of second electronic devices  50  transmit information via the medium  30 . 
         [0022]    The first electronic device  10  according to the present embodiment includes a smartphone, a personal digital assistant (PDA), a tablet computer, a notebook computer, a desktop computer, or other electronic devices capable of transmitting information. 
         [0023]    The plurality of second electronic devices  50  according to the present invention include smartphones, PDAs, tablet computers, notebook computers, desktop computers, webcams, smart plugs, or other electronic devices capable of transmitting information. In addition, each of the plurality of second electronic devices  50  includes a connecting unit, respectively and is capable of connecting to one another through the respective connecting unit. The connecting unit includes infrared, Bluetooth, ZigBee, Wi-Fi, or physical networks. 
         [0024]    The medium  30  according to the present embodiment includes a router, a switch, a hub, a cloud server, a relay, or other media capable of network transmission. 
         [0025]    The transmission system  1  according to the present embodiment is used in transmitting a groupcast message to a plurality of second electronic devices  50  by the first electronic device  10  for controlling or configuring the plurality of second electronic devices  50  or transmitting data to the plurality of second electronic devices  50 . For example, the first electronic device  10  according to the present embodiment is a smartphone while the plurality of second electronic devices  50  are smart appliances. When a user operates the first electronic device  10  and transmits a control signal to the plurality of second electronic devices  50 , the signal can be transmitted using the transmission method and system  1  for groupcast message disclosed in the present embodiment. 
         [0026]    Please refer to  FIGS. 1A, 1B, 1C, 2 . As shown in the figures, when the transmission system  1  according to the present embodiment operates, the step ST 1  is first executed for defining the plurality of second electronic device  50  as at least one group. According to the present embodiment, the plurality of second electronic devices  50  are configured to the same group. According to another embodiment of the present invention, the plurality of second electronic devices  50  are defined to multiple groups. As shown in  FIG. 3 , each group includes at least one second electronic device  50 . The second electronic devices in the same group can transmit information to one another; the electronic devices  50  in different groups can also transmit information. The first electronic device can transmit a groupcast message to one of the groups or a plurality of groups. As shown in  FIG. 3 , the group  51  and the group  52  are groups including a plurality of second electronic devices  50 . On the other hand, the group  53  is a groups including only one second electronic device  50 . 
         [0027]    After the step ST 1  is finished, the step ST 3  is executed, in which the first electronic device  10  acquires the communication quality information of each of said plurality of second electronic devices  50  via the medium  30 . The communication quality information represents the connection quality between each said second electronic device  50  and a nearby device, which includes another second electronic device  50  and the medium  30 . The communication quality information includes the received signal strength indicator (RSSI) or the signal to noise ratio (SNR), representing the transmission intensity of the second electronic device  50 . Each said second electronic device  50 , as shown in  FIG. 1A , can transmit the respective communication quality information to the first electronic device  10  through the medium  30 . Alternatively, as shown in  FIG. 1B , the first electronic device  50  assigns one of the plurality of second electronic devices  50  or the medium  30  as a relay terminal. Each said second electronic device  50  transmits respective communication quality information to the relay terminal. Then the relay terminal transmits the plurality pieces of communication quality information to the first electronic device  10 . 
         [0028]    Please refer again to  FIG. 2 . The step ST  5  is executed, in which the first electronic device  10  selects one of the plurality of second electronic devices  50  as the broadcast transmitter. The method by which the first electronic device  10  selects the broadcast transmitter is to select the second electronic device  50  having the best connection quality as the broadcast transmitter according to the respective communication quality information of the plurality of second electronic devices  50 . Besides, according to another embodiment of the present invention, the first electronic device  10  sets a threshold value. When the communication quality information of a plurality of second electronic devices  50  exceeds the threshold value, a second electronic device  50  is selected randomly as the broadcast transmitter. Next, the step ST 7  is executed. As shown in  FIG. 1C , the first electronic device  10  transmits a groupcast message to the broadcast transmitter via the medium  30 . The broadcast transmitter receives the groupcast message. The groupcast message described above includes the control signal transmitted by the first electronic device  10 . The first electronic device  10  transmits the groupcast message to the broadcast transmitter based on TCP or UDP. 
         [0029]    Please refer again to  FIG. 2 . Finally, the step ST 9  is executed, in which the broadcast transmitter transmits a broadcast message according to the received groupcast message to the plurality of second electronic devices  50 , as shown in  FIG. 1C . The content of the broadcast message includes the groupcast message, namely, the control signal transmitted by the first electronic device  10 . According to the above, the present embodiment provides a transmission method and system for groupcast message. The second electronic device having the best connection quality or connection quality exceeding the threshold value is the broadcast transmitter. Thereby, the device having superior transmission quality is used for transmitted messages, and thus ensuring that the messages can be delivered to the plurality of second electronic devices  50 . 
         [0030]    Next, the transmission method for groupcast message according to another embodiment will be described. Please refer to  FIG. 4A . As shown in the figure, the embodiment provides another transmission system  2 , which comprises a first electronic device  10 , a medium  30 , a plurality of second electronic devices  501 ,  502 ,  503 ,  504 ,  505 . According to the present embodiment, the second electronic device  501  includes a neighborhood table  5011 , a neighborhood quantity  5013 , and a piece of communication quality information  5015 . The neighborhood table  5011  records the other second electronic devices nearby the second electronic device  501 . The neighborhood quantity represents the quantity of the other second electronic device nearby the second electronic device  501 . The communication quality information is the connection quality between the second electronic device  501  and the nearby devices, including the communication quality between the second electronic device  501  and the medium  30 . 
         [0031]    Please refer again to  FIG. 4A . The second electronic device  502  includes a neighborhood table  5021 , a neighborhood quantity  5023 , and a piece of communication quality information  5025 . The neighborhood table  5021  records the other second electronic devices nearby the second electronic device  502 . The neighborhood quantity  5023  represents the quantity of the other second electronic devices nearby the second electronic device  502 . The communication quality information  5025  is the connection quality between the second electronic devices  502  the nearby other electronic devices and includes the communication quality between the second electronic device  502  and the medium  30 . As the above description, the rest second electronic devices  503 ,  504 ,  505  also include neighboring tables  5031 ,  5041 ,  5051 , neighboring quantities  5033 ,  5043 ,  5053 , and communication quality information  5035 ,  5045 ,  5055 . Each of the above second electronic devices  501 ,  502 ,  503 ,  504 ,  505  searches the nearby devices (including the second electronic devices and the medium  30 ) at startup, records them in the respective neighboring table  5011 ,  5012 ,  5031 ,  5041 ,  5051 , and records the quantities of nearby devices. 
         [0032]    Please refer to  FIG. 5  as well as  FIGS. 4B-4D . When the transmission system  2  according to the present embodiment is operating, the step ST 21  is first executed for defining the plurality of second electronic devices  50  to at least one group. According to the present embodiment, the plurality of second electronic devices  501 ,  502 ,  503 ,  504 ,  505  belong to one group. 
         [0033]    After the step ST 21  is completed, the step ST 23  is executed, in which the first electronic device  10  acquires respective communication quality information  5015 ˜ 5055  and neighboring quantities  5013 ˜ 5053  of each of the second electronic devices  501 ,  502 ,  503 ,  504 ,  505 . Then the step ST  25  is executed, in which the first electronic device selects one of the plurality of second electronic devices  501 ,  502 ,  503 ,  504 ,  505  as the broadcast transmitter. The method by which the first electronic device  10  selects the broadcast transmitter is based on the respective communication quality information of each of the second electronic devices  501 ,  502 ,  503 ,  504 ,  505 . The one having the best connection quality is selected as the broadcast transmitter. According to the present embodiment, the communication quality information  5015 ˜ 5055  of the plurality of second electronic devices  501 ,  502 ,  503 ,  504 ,  505  is the RSSI having the values −55 dBm, −20 dBm, −40 dBm, −30 dBm, −25 dBm, respectively. The second electronic device  502  owns the best connection quality. Consequently, the first electronic device  10  selects the second electronic device  502  as the broadcast transmitter. 
         [0034]    In addition, the first electronic device  10  further selects the second electronic device having the most neighboring quantity according to the respective neighboring quantities  5012 ˜ 5053  of the plurality of second electronic devices  501 ,  502 ,  503 ,  504 ,  505  as another broadcast transmitter. According to the present embodiment, the neighboring quantities  5013 ˜ 5053  of the plurality of second electronic devices  501 ,  502 ,  503 ,  504 ,  505  are 2, 1, 1, 0, 3, respectively. Hence, the neighboring quantity  5053  of the second electronic device  505  is the most, meaning that the second electronic device  505  has the most nearby second electronic devices. Then, the first electronic device  10  selects the second electronic device  505  as the broadcast transmitter. 
         [0035]    Besides, the plurality of second electronic device may have no neighboring quantity, for example, when the second electronic device is placed at remote places such as the balcony or the roof. This means that this second electronic device cannot transmit information with the other electronic devices. In order to make sure that the broadcast signal is transmitted to each second electronic device, as shown in the step ST  25 , the first electronic device  10  further selects the second electronic device having no neighboring as another broadcast transmitter. According to the present embodiment, the first electronic device  10  further selects the second electronic device  504  as another broadcast transmitter. 
         [0036]    Please refer again to  FIG. 5 . Next, the step ST 27  is executed. As shown in  FIG. 4B , the first electronic device  10  transmits the groupcast message to the plurality of broadcast transmitters  502 ,  504 ,  505  via the medium  30 . The plurality of broadcast transmitters  502 ,  504 ,  505  receive the groupcast message. Finally, the step ST 29  is executed, in which the plurality of second electronic devices  502 ,  504 ,  505  (the broadcast transmitters) transmit a broadcast message according to the groupcast message. The content of the broadcast message includes the content of the groupcast message and the respective neighboring table of each of the broadcast transmitters. In other words, the broadcast message transmitted by the plurality of second electronic device  502 ,  504 ,  505  include the content of the groupcast message and the respective neighboring tables  5021 ,  5041 ,  5051 . The plurality of second electronic device  502 ,  504 ,  505  transmit the broadcast message according to the respective neighboring tables  5021 ,  5041 ,  5051 . As shown in  FIG. 4C , the second electronic device  502  transmits the broadcast message to the second electronic device  501  according to the neighboring table  5021 . The neighboring table  5041  of the second electronic device  504  does not record the nearby second electronic devices. Thereby, the second electronic device  504  does not transmit the broadcast message any longer. The broadcast transmitter  505  transmits the broadcast message to the second electronic devices  501 ,  502 ,  504  according to the neighboring table  5051 . 
         [0037]    Moreover, the plurality of second electronic devices having received the broadcast message will compare their own neighboring tables with those of the broadcast transmitters. When their own neighboring tables include the second electronic device not recorded in the neighboring tables of the broadcast transmitters, they will transmit the received broadcast message according to their own neighboring tables. As shown in  FIG. 4D , when the second electronic device  501  receives the broadcast messages transmitted by the plurality of second electronic devices  502 ,  505  (the broadcast transmitters), the second electronic device  501  compares the neighboring tables  5021 ,  5051  in the broadcast messages. According to the present embodiment, both the neighboring tables  5021 ,  5051  do not include the second electronic device  503  recorded in the neighboring table  5011  of the second electronic device  501 . Thereby, as shown in  FIG. 4D , the second electronic device  501  transmits the received broadcast message to the second electronic device  503  according to its own neighboring table  5011 , and thus ensuring that the broadcast can be transmitted to all second electronic devices. 
         [0038]    The transmission method for groupcast message according to the present invention can be implemented as a program and stored in a storage medium accessible by an electronic device. Thereby, after the electronic device reads the storage medium, the transmission method for groupcast message is executed. A computer accessible storage medium can be a read-only memory, a flash memory, a floppy disk. A hard disk, a compact disk, a USB flash drive, a magnetic tape, a network accessible database, or any other storage medium accessible by electronic devices well known to a personal having ordinary skill in the art. 
         [0039]    Accordingly, the present invention conforms to the legal requirements owing to its novelty, nonobviousness, and utility. However, the foregoing description is only embodiments of the present invention, not used to limit the scope and range of the present invention. Those equivalent changes or modifications made according to the shape, structure, feature, or spirit described in the claims of the present invention are included in the appended claims of the present invention.