Patent Publication Number: US-2019173614-A1

Title: Wireless communication method and communication terminal device using the same

Description:
This application claims the benefit of Taiwan application Serial No. 106142574, filed Dec. 5, 2017, the entirety of which is hereby incorporated by reference herein. 
     TECHNICAL FIELD 
     The disclosure relates to a wireless communication method and a communication terminal device using the same. 
     BACKGROUND 
     As the service quality of network streaming improves, how to satisfy the demand of low latency and high transmission rate in wireless communication is one of the issues to be solved in the industry. 
     WiFi is one of wireless communication protocols and is widely used. WiFi may support multicast, that is, every access point (AP) may provide wireless transmission service to multiple user equipments. However, in order to serve a user equipment whose location is farther, an AP may decrease the transmission rate for all user equipments. The bandwidth may also be insufficient because the AP establishes connections with too many user equipments, such that the data transmission rate fails to be increased. 
     SUMMARY 
     The disclosure is directed to a wireless communication method and a communication terminal device using the same. According to embodiments of the disclosure, establishing connection with a wireless transmitting device is not required for the communication terminal device to perform data transmission. The communication terminal device may obtain, by a way of sniffing, the radio signal which is transmitted from the wireless transmitting device to a dummy wireless receiving device, and capture the packet therein. The communication terminal device may filter the captured packet through a specific condition to obtain the data payload required by the communication terminal device. Since the communication terminal device does not need to establish a connection with the wireless transmitting device, and the communication terminal device sniffs the radio signal which is transmitted by the wireless transmitting device instead, the communication terminal device does not occupy the transmission bandwidth of the wireless transmitting device. In addition, according to the error rate of the decoded data payload, the communication terminal device may also report an error correcting information to the server, such that the wireless transmitting device may adjust the error correction mechanism to decrease the data error rate. 
     According to one aspect of the disclosure, a wireless communication of a communication terminal device is provided. The wireless communication method includes the following steps. The communication terminal device sniffs a radio signal and captures a packet from the radio signal. The communication terminal device determines whether the packet meets a source condition or not. The source condition includes that the packet contains a specific transmitter address corresponding to a wireless transmitting device and a specific receiver address corresponding to a wireless receiving device. The communication terminal device determines whether the packet meets a data condition or not if the packet meets the source condition. The data condition includes that the packet contains a specific packet type. The communication terminal device extracts a data payload from the packet if the packet meets the data condition. The communication terminal device determines whether a data error rate of the data payload is greater than a tolerable value or not. The communication terminal device sends an error correcting information to a server if the error rate of the data payload is greater than the tolerable value, such that the server provides an error correction parameter for updating a forward error correction coding scheme to the wireless transmitting device. 
     According to another aspect of the disclosure, a communication terminal device is provided. The communication terminal device includes a transmission interface and a processing circuit. The transmission interface sniffs a radio signal and captures a packet from the radio signal. The processing circuit is coupled to the transmission interface and is configured to perform the following steps. Determining whether the packet meets a source condition or not. The source condition includes that the packet contains a specific transmitter address corresponding to a wireless transmitting device and a specific receiver address corresponding to a wireless receiving device. Determining whether the packet meets a data condition or not if the packet meets the source condition. The data condition includes that the packet contains a specific packet type. Extracting a data payload from the packet if the packet meets the data condition. Determining whether a data error rate of the data payload is greater than a tolerable value or not. Sending an error correcting information to a server if the error rate of the data payload is greater than the tolerable value, such that the server provides an error correction parameter for updating a forward error correction coding scheme to the wireless transmitting device. 
     For better understanding to above and other aspects of the disclosure, exemplary embodiments are illustrated herein below with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exemplary block diagram of a wireless communication system according to an embodiment of the disclosure. 
         FIG. 2  shows an exemplary flowchart of a wireless communication method according to an embodiment of the disclosure. 
         FIG. 3  shows an exemplary architectural diagram of the wireless communication system according to an embodiment of the disclosure. 
         FIG. 4  shows an exemplary sequence diagram of the wireless communication method according to an embodiment of the disclosure. 
         FIG. 5  shows a flowchart of the wireless communication method according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an exemplary block diagram of a wireless communication system according to an embodiment of the disclosure. The wireless communication system includes a wireless terminal device  100 , a wireless transmitting device  120 , a wireless receiving device  140 , and a server  160 . 
     The wireless transmitting device  120 , for example, is an access point (AP) or a wireless transmitter. The wireless transmitting device  120  has a transmitter address (for example, an internet protocol (IP) address of the wireless transmitting device). The wireless transmitting device  120  may receive a streaming data from the server  160 , and then transmit the streaming data to the wireless receiving device  140  using a form of a radio signal. The wireless transmitting device  120  and the wireless receiving device  140  may communicate with each other using WiFi protocol or other wireless communication protocols, such as Bluetooth, ZigBee, etc. 
     The server  160 , for example, is a providing node of the streaming data in a cloud network. The wireless receiving device  140 , for example, is a wireless receiver. The wireless receiving device  140  has a receiver address (for example, an IP address of the wireless receiving device  140 ). According to embodiments of the disclosure, the wireless receiving device  140  may be deemed a dummy receiver, with the purpose of being a target for the wireless transmitting device  120  to transmit a packet. In an embodiment, the wireless transmitting device  120  and the wireless receiving device  140  are placed independently, and a distance between the wireless transmitting device  120  and the wireless receiving device  140  is less than or equal to 1 meter. The reason for this placement is described in the following. In general, a data transmission rate of the wireless transmitting device  120  would be adjusted dynamically according to the distance of the receiving terminal. That is to say, if the distance of the receiving terminal is nearer, the wireless transmitting device  120  would transmit with a higher data transmission rate. In order that the wireless transmitting device  120  may transmit packets with a fixed relative high data transmission rate, the wireless receiving device  140  may be disposed near the wireless transmitting device  120 , for example (but not limited to), within 1 meter. In another embodiment, the wireless transmitting device  120  and the wireless receiving device  140  may also be integrated in the same equipment. 
     The communication terminal device  100 , for example, is a user equipment such as a personal computer, a mobile phone, a laptop computer, a wearable device with virtual reality (VR)/augmented reality (AR), etc. According to the embodiment of  FIG. 1 , the wireless terminal device  100  includes a transmission interface  102 , a driving unit  104 , a tunneling unit  106 , a packet processing unit  108 , and an interference coordinating unit  110 . 
     The transmission interface  102 , for example, is a network adapter or a wireless transceiver, capable of transmitting and/or receiving the radio signal. 
     The driving unit  104 , the tunneling unit  106 , the packet processing unit  108 , and the interference coordinating unit  110  may be implemented in a processing circuit, by ways of software (for example, a program, one or more instructions, data, one or more files, etc.), hardware (for example, a logic circuit), or a combination thereof. The processing circuit is coupled to the transmission interface  102 , and is configured to be capable of performing the wireless communication method in embodiments of the disclosure. The processing circuit, for example, may be implemented by a microcontroller, a microprocessor, a digital signal processor, an application specific integrated circuit (ASIC), a digital logic circuit, a field programmable gate array (FPGA), or other hardware components with operating and processing functions. 
     When the wireless transmitting device  120  transmits a packet to the wireless receiving device  140 , the communication terminal device  100  may sniff, through the transmission interface  102 , the radio signal transmitted by the wireless transmitting device  120  to obtain the packet in the radio signal. During this process, the communication terminal device  100  does not need to establish a connection (for example, association) with the wireless transmitting device  120 . Instead, the communication terminal device  100  passively sniffs the radio signal transmitted from the wireless transmitting device  120 . For the wireless transmitting device  120 , the transmitting target of the packet, wherein the packet is transmitted by the communication terminal device  100 , is the wireless receiving device  140 , not the communication terminal device  100 . 
     The driving unit  104  is configured to control the operation(s) of the transmission interface  102 . For example, the driving unit  104  is a driver of the transmission interface  102 . The tunneling unit  106  may capture the packet from the transmission interface  102  and provide the packet to an upper layer, which is the packet processing unit  108 , to process. In other words, the tunneling unit  106  may build a tunneling channel which is from the transmission interface  102  and to the packet processing unit  108 . In an embodiment, the tunneling unit  106  may be realized by libpcap function on Linux platform. 
     The packet processing unit  108  may filter the packet to obtain data, for example, video data, required by the communication terminal device  100 . When the packet processing unit  108  determines that a data error rate of a data payload is greater than a tolerable value, the packet processing unit  108  may also return an error correcting information to the remote server  160 , such that the server  160  may enable the wireless transmitting device  120  to adjust an error correction mechanism of the wireless transmitting device  120 . The error correction mechanism, for example, is forward error correction (FEC) $ mechanism. In an embodiment, the packet processing unit  108  may be implemented in a hardware abstract middleware layer. The related operations of the packet processing unit  108  would be described with appropriate reference to the  FIG. 2 . 
     The interference coordinating unit  110  may adjust a receiving frequency band of the communication terminal device  100 , so as to adjust the transmission interface  102  and the driving unit  104  to receive packets in transmitting frequency band of the wireless transmitting device  120 . In this way, the signal interference to the communication terminal device  100 , which may be induced by nearby wireless transmitting devices (for example, nearby APs), may be decreased. In an embodiment, the communication terminal device  100  does not include the interference coordinating unit  110 . 
       FIG. 2  shows an exemplary flowchart of a wireless communication method according to an embodiment of the disclosure. The wireless communication method may be implemented, for example, by the wireless terminal device  100  in  FIG. 1 . The wireless communication method may also be implemented by an electronic device which includes a transmission interface and a processing circuit. For easy to understand, the wireless terminal device  100  is taken as an example in the following description. 
     In the step S 202 , the communication terminal device  100  sniffs a radio signal through the transmission interface  102  and captures a packet from the radio signal. 
     In the step S 204 , the packet processing unit  108  determines whether the packet meets a source condition or not. If affirmative, the step S 206  is executed. In the step S 206 , the packet processing unit  108  further determines whether the packet meets a data condition or not. If it is determined to be negative in the step S 204 , the step S 208  is executed. In the step S 208 , the packet processing unit  108  will discard the packet. After the step S 208 , the process may return to the step S 202 . 
     In an embodiment, the source condition includes that the received packet contains the transmitter address corresponding to the wireless transmitting device  120  and the receiver address corresponding to the wireless receiving device  140 . 
     If the determined result is affirmative in the step S 206 , the packet processing unit  108  will extract the data payload from the packet in the step S 210 . Otherwise, the packet processing unit  108  will discard the packet in the step S 208 . In an embodiment, the data condition includes that the received packet contains a specific packet type. 
     In an embodiment, the step S 206  may be implemented, for example, as follows. The packet processing unit  108  obtains a packet type from a header of the packet and determines whether the packet type meets the specific packet type or not. In detail, the header of the packet may include a packet type field which is used to indicate a type of information carried in the packet. The packet type may include a re-transmitted packet, a magic packet, a beacon, a data packet, etc. Since the communication terminal device  100  wants to obtain data provided by the server  160  from the wireless transmitting device  120 , the communication terminal device  100  may configure the specific packet type in the data condition to be “data packet” type. According to the configuration, if the packet received by the communication terminal device  100  is a beacon, the communication terminal device  100  will discard the packet. On the contrary, if the packet received by the communication terminal device  100  is a data packet, the communication terminal device  100  extracts the data payload therein. 
     In the step S 212 , the packet processing unit  108  performs an FEC decoding on the data payload. In the step S 214 , the packet processing unit  108  calculates a data error rate occurred in the FEC decoding. For example, the data error rate may be obtained by calculating an FEC error rate of an accumulated amount of received packets. In the step S 216 , the packet processing unit  108  provides the data payload to an application layer. 
     In the step S 218 , the packet processing unit  108  determines whether the data error rate of the data payload is greater than a tolerable value or not. If affirmative, it means that the configuration of a correction mechanism (for example, FEC) may be too loose. In the step S 220 , the communication terminal device  100  will send an error correcting information to the server  160  through the transmission interface  102 , such that the server  160  may provide an error correction parameter, which is for updating an FEC coding scheme, to the wireless transmitting device  120 , in order that the wireless transmitting device  120  may adopt a stricter configuration of FEC. For example, the configuration of FEC is adjusted from ¼ FEC to ½ FEC. On the other hand, the server  160  may also provide the update error correction parameter to the communication terminal device  100 , such that the communication terminal device  100  and the wireless transmitting device  120  may update FEC parameters synchronously. After the step S 220  is executed, the process may returns to the step S 202  to continue sniffing radio signals. 
     If it is determined to be negative in the step S 218 , it means that the data error rate of the data payload is not greater than the tolerable value, and the process will returns to the step S 202 . 
       FIG. 3  shows an exemplary architectural diagram of the wireless communication system according to an embodiment of the disclosure. In the example of  FIG. 3 , the wireless communication system include four communication terminal devices  100 , three wireless transmitting devices  120 , a wireless receiving device  140 , a server  160 , a gateway  320 , and three video source devices  340 . 
     In this example, the communication terminal device(s)  100 , for example, is a VR helmet. The wireless transmitting device(s)  120 , for example, is a WiFi AP. The wireless receiving device  140 , for example, is a laptop computer. The video source device(s)  340 , for example, is an omnidirectional camera. It should be noted that the example is used to describe the disclosure, not to limit the disclosure. The number, the type, and the configuration of the device(s) mentioned above may be adjusted according to different application environments. 
     The video source device(s)  340  may provide the extracted video data to the server  160 . The wireless transmitting device(s)  120  may connect to the server  160  which is in the cloud network through the gateway  320  to obtain the video data from the video source device(s)  340 . The wireless transmitting device(s)  120  may transmit the obtained video data to the wireless receiving device(s)  140  by a wireless mechanism. The wireless receiving device  140  is disposed near the wireless transmitting device  120 , for example, within 1 meter. The wireless transmitting device  120  and the wireless receiving device  140  may also be integrated in the same equipment. 
     The communication terminal device(s)  100  is in the signal coverage of the wireless transmitting device(s)  120 . When the wireless transmitting device(s)  120  transmits the packet to the wireless receiving device  140 , the communication terminal device(s)  100  may sniff the radio signal transmitted by the wireless transmitting device(s)  120  and capture the packet therein, so as to obtain the video data which is from the video source device(s)  340 . In this way, the communication terminal device(s)  100  may obtain the video data without establishing the connection with the wireless transmitting device(s)  120 . 
       FIG. 4  shows an exemplary sequence diagram of the wireless communication method according to an embodiment of the disclosure. 
     In the step S 402 , the server  160  provides the streaming data (for example, video stream) and the FEC error correction parameter to the wireless transmitting device  120 . 
     In the step S 404 , the communication terminal device  100  sends a request to the server  160 , such that the server  160  may return the transmitter address of the wireless transmitting device  120  and the receiver address of the wireless receiving device  140 , as shown in the step S 406 . According to the transmitter address and the receiver address provided by the server  160 , the communication terminal device  100  may determine the packet source to be listened. 
     In the step S 408 , the wireless transmitting device  120  transmits the packet to the wireless receiving device  140  by a wireless mechanism. During this process, the communication terminal device  100  also listens to, through the propagating medium (for example, the air) of the ratio signal, the radio signal transmitted by the wireless transmitting device  120  and captures the packet therein. 
     In the step S 410 , the communication terminal device  100  may process the captured packet as shown in  FIG. 2 . The captured packet should meet the source condition and the data condition for the captured packet to be deemed a data packet which the communication terminal device  100  wants to acquire. The specific transmitter address and the specific receiver address used as the source condition may be the transmitter address of the wireless transmitting device  120  (for example, IP address of the wireless transmitting device  120 ) and the receiver address of the wireless receiving device  140  (for example, IP address of the wireless receiving device  140 ) provided by the server  160  in the step S 406 . 
     In the step S 412 , although the communication terminal device  100  determines that the packet meets the source condition and the data condition, but if the data error rate of the data payload (the data payload is extracted from the packet) is greater than the tolerable value, the communication terminal device  100  will report the error correcting information to the server  160 . 
     In the step S 414 , in response to the error correcting information, the server  160  provides the error correction parameter, which is used to update the FEC coding scheme, to the wireless transmitting device  120 , such that the wireless transmitting device  120  may adopt a stricter FEC code to decrease the data error rate. 
     The person skilled in the art should understand that the order of the steps mentioned in embodiments of the disclosure may be, except mentioned especially, rearranged according to real-life situations, and that the steps may be executed at the same time or partly at the same time. 
       FIG. 5  shows a flowchart of the wireless communication method according to an embodiment of the disclosure. The wireless communication method may be implemented, for example, by the wireless terminal device  100  in  FIG. 1 . The wireless communication method may also be implemented by the electronic device which includes the transmission interface and the processing circuit. For easy to understand, the wireless terminal device  100  is taken as an example in the following description. 
     In the step S 502 , the communication terminal device  100  sniffs the radio signal and captures the packet from the radio signal. 
     In the step S 504 , the communication terminal device determines whether the packet meets the source condition or not. The source condition, for example, includes that the packet contains the specific transmitter address corresponding to the wireless transmitting device and the specific receiver address corresponding to the wireless receiving device. 
     If it is determined to be affirmative in the step S 504 , the step S 506  is executed. In the step S 506 , the communication terminal device  100  determines whether the packet meets the data condition or not. The data condition, for example, includes that the packet contains the specific packet type. Otherwise, if it is determined to be negative in the step S 504 , the step S 508  is executed. In the step S 508 , the communication terminal device  100  will discard the packet. After the step S 508  is executed, the process will return to the step S 502 . 
     If the packet meets the data condition, the communication terminal device  100  will extract the data payload from the packet in the step S 510 . Otherwise, if the packet does not meet the data condition, the step S 508  is executed and the packet is discarded. 
     In the step S 512 , the communication terminal device  100  determines whether the data error rate of the data payload, after FEC decoding is performed, is greater than the tolerable value or not. If it is determined to be affirmative in the step S 512 , the step S 514  is executed. In the step S 514 , the communication terminal device  100  will send the error correcting information to the server  160 , such that the server  160  may provide the error correction parameter, which is for updating FEC coding scheme, to the wireless transmitting device  120 . If it is determined to be negative in the step S 512 , the process will returns to the step S 502 . 
     To sum up, a wireless communication method and a communication terminal device using the wireless communication method are provided in the disclosure. According to embodiments of the disclosure, establishing the connection with the wireless transmitting device is not required for the communication terminal device to perform data transmission. The communication terminal device may capture, by a way of sniffing, the radio signal which is transmitted from the wireless transmitting device to a dummy wireless receiving device, and capture the packet therein. The communication terminal device may filter the captured packet through a specific condition to obtain the data payload required by the communication terminal device. Since the communication terminal device does not need to establish the connection with the wireless transmitting device, and the communication terminal device sniffs the radio signal which is transmitted by the wireless transmitting device instead, the communication terminal device does not occupy the transmission bandwidth of the wireless transmitting device. In addition, according to the error rate of the decoded data payload, the communication terminal device may also report the error correcting information to the server, such that the wireless transmitting device may adjust the error correction mechanism to decrease the data error rate. 
     The specification and the above embodiments are considered as examples of the disclosure only, not to limit the disclosure. It will be apparent to those skilled in the art to make various modifications and variations to the disclosed embodiments without departing from the spirit and the scope of the disclosure. The scope of the disclosure is indicated by the following claims and their equivalents.