KR100802612B1 - Wireless interfacing apparatus and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for transmitting a high definition multimedia interface (hereinafter, referred to as HDMI) through a wireless interface. When the control information is included in a corresponding section while packetizing transmission signals within a predetermined section, the corresponding control is performed. The information is duplicated in the packet for the corresponding interval and a predetermined number of subsequent packets, and at least one of the packets including the corresponding control information is transmitted with the highest priority, thereby maximizing the possibility of normal transmission of the control information. It can be effected.

Description

Wireless interface device and method {WIRELESS INTERFACING APPARATUS AND METHOD THEREOF}

1 is an exemplary view showing a high definition multimedia interface (HDMI) connection configuration using a wireless.

2A to 2C are timing diagrams and data configuration diagrams showing standards of user electronic control (CEC).

3 is a signal processing conceptual diagram illustrating a packet transmission method for wireless data transmission.

4 is a block diagram of a wireless interface according to an embodiment of the present invention.

5 is a block diagram of a wireless communication device according to another embodiment of the present invention.

*** Explanation of symbols for main parts of drawing ***

10: first device 15: HDMI interface unit

17: HDMI connection part 20: first wireless communication device

25: HDMI interface unit 27: wireless communication unit

30: second device 35: HDMI interface unit

37: HDMI connection part 40: second wireless communication device

45: HDMI interface unit 47: wireless communication unit

210: HDMI interface 220: Packetizing unit

230: Priority queue 240: Scheduler

250: bandwidth evaluation unit 260: wireless communication unit physical layer

The present invention relates to a wireless interface device and method, and more particularly, to an apparatus and method for transmitting a high definition multimedia interface (hereinafter referred to as HDMI) through a wireless interface.

With the development of various multimedia broadcast receiving means, playback means and display means, interface related technologies are being developed to simplify the signal line connection between complex multimedia related devices and provide high quality information without loss.

Digital Video Interactive (DVI), which was developed for the connection between a computer and a display device and developed into a digital interface for connection between general multimedia devices, is widely used. HDMI, which is suitably developed, is becoming commercially available.

The HDMI is the first multimedia interface capable of transmitting uncompressed digital audio / video. The HDMI provides an interface between any audio / video source, set-top box and devices such as DVD players, monitors and digital TVs.

In addition, HDMI supports multichannel digital audio over a single cable, along with enhanced high-definition video, capable of transmitting all ATSC and HDTV and supporting 8-channel digital audio with sufficient bandwidth. Thus, when the user uses the HDMI, excellent and uncompressed high quality digital video and audio signals can be obtained. In addition, by supporting the Display Data Channel (DDC) defined in the underlying DVI to provide a function to check the relevant information including the type and resolution of the display.

In addition, the HDMI additionally connects display-related devices (for example, a display device, a set-top box, a multimedia playback device, a broadcast-related device, a video-related device, a sound-related device, etc.) to a network, and connects a desired device to an arbitrary device. A user electronic control (hereinafter referred to as CEC) for providing an additional signal for controlling is defined. By utilizing this, a network configuration of a simple multimedia-related device can be easily performed.

Recently, a wireless HDMI standard for providing the HDMI through a wired interface as well as a wired interface has been developed, and additional information / control signals such as the DDC and CEC should be transmitted even in the wireless HDMI scheme.

In the wired HDMI method, since the DDC or CEC information is transmitted through a stable wired parallel line (each piece of information uses a single bus), there is no need to worry about loss or change of the corresponding signal. In the case of information transmission through the environment, the CEC information related to the control of the device is lost compared to continuous video / audio (AV signal), and the user feels inconvenience when it is not transmitted normally. Therefore, when the HDMI interface is configured through a wireless interface, the stable transmission of the CEC information may be a problem to be solved.

As described above, an object of the present invention is to prevent transmission of control information that may be generated when an additional information for controlling a device is transmitted through a wireless interface together with a video / audio signal. It is an object of the present invention to provide a radio interface device and method for improving the possibility of stable delivery of a packet including control information by providing a packet including control information to a top queue of a priority queue.

Another object of the embodiment of the present invention is to packetize the transmission signals in a predetermined section, and when control information occurs in a predetermined section, the control information is included in the packets corresponding to the predetermined section after the corresponding section by overlapping the control information. It is an object of the present invention to provide a radio interface device and method that has realized the possibility of stable transmission.

Another object of the embodiment of the present invention is to packetize the transmission signals in a predetermined section while including control information in the corresponding section, the control information is included in the packet for the corresponding section and a predetermined number of subsequent packets, and the control information is It is an object of the present invention to provide a wireless interface device and method for maximizing the normal transmission possibility of the control information by transmitting at least one of the included packets with the highest priority.

Another object of an embodiment of the present invention is to packetize an HDMI interface signal for a predetermined interval and to transmit a section including CEC information with a higher priority, and to transmit subsequent CEC information having a smaller size than the entire HDMI interface signal. It is an object of the present invention to provide a radio interface device and method which increases the possibility of normal transmission of the CEC information by including a medium width.

Still another object of the present invention is to wirelessly transmit the packet after including the control signal for a predetermined period after the period in which the control information is generated, and the receiving side that receives the packet information including the control signal receives the packet. It is an object of the present invention to provide a radio interface device and a method in which subsequent duplicate packets are processed based on a serial number so that the same control is not repeated.

Still another object of the present invention is to wirelessly transmit the packet after including the control signal for a predetermined period after the period in which the control information is generated, and the receiving side that receives the packet information including the control signal receives the packet. It is an object of the present invention to provide a radio interface apparatus and method in which the same control is not repeated by ignoring subsequent control signals for a predetermined time after confirming stable reception.

In order to achieve the above object, an air interface device according to an embodiment of the present invention includes a priority queue for storing the packets to be transmitted in accordance with the priority; A packetizer which periodically packetizes the received audio / video information and a control signal and stores the received audio / video information in the priority queue at different priorities according to the presence or absence of the control signal; And a wireless communication unit configured to wirelessly transmit the packet stored in the priority queue based on the situation and priority of the wireless communication network.

The audio / video signal and control signal are provided via a high definition multimedia interface (HDMI), which is a user electronic control (CEC) signal.

In addition, the air interface device according to another embodiment of the present invention receives the audio / video and the control signal and periodically packetized, and if there is a control signal within the period is packetized by repeatedly including it in one or more subsequent periodic signals A packetizer; It includes a wireless communication unit for wirelessly transmitting a packet provided by the packetizer.

Also, the wireless interface device according to another embodiment of the present invention packetizes a video / audio signal and a CEC signal provided by a wired HDMI scheme for each fixed interval, and inserts it into one or more subsequent packets if a CEC signal is present. A packetization unit configured to prioritize and store a priority queue for increasing the priority of a signal including a CEC signal among the packetized information, and a packet having a high priority among packets stored in the priority queue according to a communication network state. A first wireless communication device having a wireless communication unit for wireless transmission; And a second wireless communication device for providing a video / audio signal and a CEC signal to the wired HDMI connected based on the packet received from the first wireless communication device.

In addition, the air interface device according to another embodiment of the present invention receives the audio / video and the control signal periodically packetized, and repeatedly included in one or more periodic signals subsequent to the period in which the control signal is present packet A first wireless communication device for transmitting and transmitting; And a second wireless communication device for determining the same control signal based on the sequence number of the packet when the control signal is included in the packet received from the first wireless communication device.

In addition, the air interface device according to another embodiment of the present invention receives the audio / video and the control signal periodically packetized, and repeatedly included in one or more periodic signals subsequent to the period in which the control signal is present packetized A first wireless communication device for transmitting by means of; And a second wireless communication device disregarding a control signal which is followed for a predetermined time when the control signal is included in the packet provided from the first wireless communication device.

In addition, the air interface method according to another embodiment of the present invention includes the steps of periodically packetizing while receiving the audio / video signal and the control signal; Packetizing the control signal by overlapping the control signal in one or more subsequent periods when the control signal is included in the packet period; Wirelessly transmitting the packetized information.

In addition, the air interface method according to another embodiment of the present invention includes the steps of periodically packetizing while receiving the audio / video signal and the control signal; If the control information is included in the packet information, adjusting the priority and storing the transmission signal in a transmission queue; And transmitting the wireless packet with a weighted value that is differential to the priority of the transmission queue based on the state of the wireless communication network.

Embodiments of the present invention as described above will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a method of connecting HDMI using wireless communication. As shown in FIG. 1, a first device and a second device supporting HDMI and a second device connected to each of the devices to wirelessly connect HDMI are shown. And first and second wireless communication devices 20, 40. The first and second devices 10 and 30 are multimedia related devices supporting HDMI, and are various multimedia related devices including a display device, a set top box, a multimedia playback device, an audio device, a broadcast receiving device, and the like. HDMI interface unit 15 and 35 for HDMI transmission and reception are included. The HDMI interface unit 25 corresponding to the HDMI interface unit 15 and 35 is also connected to the wireless communication devices 20 and 40 that are connected to the HDMI interface unit 15 and 35 of the devices 10 and 30 by wire. , 45 are respectively configured, and the audio / video information, the related information (DDC) and the control information (CEC) provided through the respective HDMI interface units 25 and 45 are packetized for transmission or packet information. Are wirelessly configured to configure audio / video information, related information (DDC) and control information (CEC), and then provide them to the HDMI interface parts 25 and 45 according to the HDMI interface standard. Consists of.

Accordingly, the wireless communication devices 20 and 40 are connected to the first and second devices 10 and 30 providing the wired HDMI interface, respectively, to packetize wired HDMI information and wirelessly transmit the wired HDMI information. This function is to receive and provide to the wired HDMI. In this case, the wired HDMI may be configured with parallel digital signal preferences to provide an audio / video signal, to provide a related information, and to provide a control signal. Is provided through. However, in order to convert the information into a wireless method using a serial communication channel, it is necessary to consider and provide information according to a communication band by appropriately processing information having a different transmission rate or communication method and different importance as described above.

In particular, the control information (CEC) provided by a user or provided by a specific device to another device to control a desired target device, although its transmission rate is small and the information is small, is important from the viewpoint of the user performing the operation. Should be considered higher than video / audio information or related information.

2A to 2C show the standard of the control information (CEC). As shown in FIG. 2A and FIG. 2C, the start bit as shown in FIG. 2A and the data bit as shown in FIG. 2B are shown. It is made up of bits. At least two CEC frames are gathered to form one unit of CEC information. The size of the CEC frame does not exceed 1 Kbyte, and one CEC frame is generally composed of 2 to 10 CEC frames. That is, it can be seen that the size of the actual CEC information is quite small. However, since the CEC is transmitted at a relatively low data rate as shown, a time of 20 ms or more is required to transmit one CEC frame, and a long time of 50 ms or more is required to transmit all the CEC information.

3 is a conceptual diagram illustrating a signal processing method for transmitting a wireless data. FIG. 3 illustrates a process of periodically packetizing HDMI signals provided in parallel and wirelessly transmitting them. In the illustrated case, a video / audio signal Bav provided during a certain section and information DDC information Bddc or CEC information Bcec that may be generated during the section are transmitted together with the video / audio signal Bav. And transmit it.

In the illustrated case, since the CEC information Bcec is generated along with the video / audio signal Bav in the first section T1, the information is present in the first packet P1 packetized therein, and the second section T2. Since the DDC information Bddc is generated together with the video / audio signal Bav, the information is present in the second packet P2 that packetizes it, and only the video / audio signal Bav is present in the third section T3. As such, only the above information exists in the third packet P3.

Since the CEC information Bcec represents one piece of CEC information, the CEC information may be composed of a plurality of CEC frames. Although the signal providing time is long, the size of the included information is very small (generally made up of several tens of bytes. Less than Kbyte).

That is, the size of each piece of information indicates that Bav is the largest, Bcec is the smallest, and Bddc is larger than Bcec and smaller than Bav (Bav> Bddc> Bcec).

The packets are generated at periodic time points a, b, and c, and they are sequentially wirelessly transmitted. Substantially, the bandwidth of the wireless channel transmitting the packet must be wide enough to transmit all the information provided through the HDMI. . Recently, since several Ghz bands are transmitted using several tens of Ghz bands (for example, 802.11n and 802.15.3c standards), the packet transmission time is substantially shorter than the actual HDMI reception time. There is room.

However, when the communication environment deteriorates such as the change of the communication environment and the occurrence of noise, the retransmission request is increased, and some of the information to be transmitted is lost or changed. In this case, the control signal CEC information It may also occur when a packet containing an A is lost or changed. In this case, the loss of CEC information, which may be a control command specified by the user, is much more in terms of the user's practical inconvenience than the video / audio information having real-time information or the DDC information that may be retransmitted by request between devices. This is a serious problem. For example, if a power off control command is transmitted to a predetermined device and a packet including the CEC information is lost, the corresponding device is not turned off. Therefore, the user must repeatedly provide the same command, thereby losing the reliability of the device or the wireless interface.

Therefore, even if CEC information important in terms of practical use of the user is transmitted through the air interface, it is necessary to ensure safe and reliable delivery of the CEC information.

4 shows a structure of an embodiment of the present invention, which enables the transmission of high priority CEC information with high priority.

Some components embedded in the wireless device shown in the drawing include an HDMI interface 210 for receiving wired HDMI information, a packetizer 220 for periodically packetizing information obtained through the HDMI interface 210, and the packetizer. The priority queue 230 includes a plurality of queues to store the packets in a queue according to the priority specified by the packetization, and the packets stored in the priority queue 230 are prioritized and the bandwidth evaluator ( A scheduler 240 for selecting a packet to be transmitted first based on the communication network state by 250 and a physical layer 260 of the wireless communication unit for substantially wirelessly transmitting the packet selected by the scheduler 240.

The priority queue 230 is composed of high priority queues 230-1 to low priority queues 230-n, and the packets stored in the queues are differentially ordered according to priority weights. Selected by 240. For example, when the network state is determined by the bandwidth evaluator 250, if the network state is not good, the packets stored in the high priority queue 230-1 are transmitted at high priority, and the low priority queue ( Packets stored at 230-m) are transmitted (or not transmitted) at low priority.

The packetizer 220 may store the packet in a higher priority queue when packetizing information including CEC information among packetization period information, which is stored in the highest priority queue 230-1. In some cases, a method of giving priority to a predetermined level or more than an actual priority of a corresponding packet may be applied.

FIG. 5 is a diagram for describing a redundant transmission scheme in a manner that can be used separately or together with the scheme illustrated in FIG. 4. When predetermined CEC information is detected in a specific section, as shown in FIG. It shows a method of transmitting by including in a packet for a plurality of intervals.

As illustrated, since the CEC information Bcec is generated together with the video / audio signal Bav in the first section T1, the information is present in the first packet P1 that packetizes it. In addition, since the DDC information Bddc is generated together with the video / audio signal Bav in the second section T2, the information is also present in the second packet P2 packetized therein, where the information occurs in the first section. Duplicate CEC information included. In the third section T3, only the video / audio signal Bav exists, but the third packet P3 includes the CEC information generated in the first section together with the above information. The duplication of the CEC information is performed on subsequent packets for a predetermined number of times, and it is preferable to use the method of including the CEC information in the information of the subsequent section and then packetizing it.

In addition, the packet period is preferably set to an integer multiple of the CEC frame length, which is a unit of the CEC information, to prevent loss of CEC information. More preferably, the packet period is longer than the maximum length of CEC information. CEC information can be transmitted.

For example, when calculating the success rate of one CEC information, the average packet loss rate in the CEC radio interval is called P _packetloss , the number of overlaps is called N _redundancy , and assuming that packet loss is independent The transmission success rate is improved by the ratio EnhRate.

When the above method is applied to the priority method shown in FIG. 4, when the CEC information is detected in the section including the CEC information, the corresponding packetizer is packetized by including the same CEC information at a predetermined number of times in the packet process in the subsequent section. The CEC containing packet is stored in a high priority queue. The scheduler for transmitting the packet stored in the priority queue performs the transmission according to the priority with different weights according to the state of the communication network. Of course, if the two methods are applied as described above, high transmission weight is given to the high priority. The probability of losing CEC information is greatly reduced.

Among the three types of methods described above, in case of performing redundant transmission, it is necessary to consider the reception method of the receiving wireless device. Whether the duplicated transmission of CEC information is determined as the same information or repeated reception of the same CEC information. You must decide whether or not to judge.

For example, if a user wants to repeatedly turn on / off a corresponding function by transmitting the same control command to a predetermined device, and if the same CEC information is repeatedly received by the redundant transmission, the packet is lost. It must be considered in a wireless environment where changes in the packet order and arrival can occur to distinguish the two cases.

In particular, since the CEC information should not be changed in consideration of the compatibility of the wireless HDMI interface and the wired HDMI interface, the present invention will solve this problem through two types of embodiments.

In other words, this method uses a discrimination method based on a unique number of a packet and a reception time of a CEC transmission. The distinguishing method based on the unique number of the packet is that when the receiving wireless device receives the packet including the CEC information, the same CEC information included in the packet up to a predetermined range before and after the unique number of the corresponding packet is By determining the information by the redundant transmission method to provide the CEC information to the wired HDMI interface connected only once. In this case, since abnormal CEC information may be received, a method of selecting corresponding CEC information may be applied when a plurality of CEC information matches. The predetermined range for determining the same CEC information may be determined by adding a margin based on a preset number of overlaps.

The method of using the reception time of the CEC transmission is determined that the CEC transmission will not be performed rapidly, and if the same CEC information is acquired until the first or several times (the same CEC information may be a reception error, it is excluded). For a certain time, the same CEC information is ignored. In this case, the CEC information is provided only once through the wired HDMI interface.

Although the above schemes may be applied in duplicate, even if only one type of scheme is applied, it is possible to distinguish the duplicate reception of CEC information by the redundant transmission scheme and the repeated reception of CEC information by repetitive selection of the user or the provision of the CEC information. For this purpose, there is no need to change the CEC information itself.

Although the above-described methods provide wireless HDMI that is fully compatible with the wired HDMI interface, it is possible to reliably transmit CEC information insensitive to changes in the wireless communication environment, thereby causing an inconvenience that users may experience. Will be prevented.

As described above, the air interface apparatus and method according to an embodiment of the present invention packetize the transmission signals within a predetermined interval and provides a packet including the control information to the highest queue of the priority queue, thereby including the control information. There is an effect that can improve the possibility of stable delivery of the packet.

In addition, the wireless interface device and method according to an embodiment of the present invention packetizes the transmission signals in a predetermined section, and if the control information occurs in the predetermined section, the control information is overlapped in packets corresponding to the predetermined section after the corresponding section. By doing so, there is an effect that can improve the stable transmission possibility of the control information included in the packet.

In addition, according to an embodiment of the present invention, when the control information is included in a corresponding section while packetizing transmission signals within a predetermined section, the control information is overlapped with the packet for the corresponding section and a predetermined number of subsequent packets. In addition, at least one of the packets including the corresponding control information is transmitted by giving the highest priority, thereby maximizing the possibility of normal transmission of the control information.

In addition, the wireless interface device and method according to an embodiment of the present invention packetizes the HDMI interface signal for each predetermined interval, and transmits a section including the CEC information with a higher priority, and has a smaller CEC than the entire HDMI interface signal. By including the information in the following section in a heavy width, it is possible to increase the probability of the normal transmission of the CEC information to ensure that the control command by the user is stably executed.

In addition, the wireless interface device and method according to an embodiment of the present invention includes the control signal overlapped with the control signal for a predetermined period after the period in which the control information is generated, and the receiving side receiving the packet information including the control signal By performing the process for the subsequent duplicate packet based on the serial number of the packet, there is an effect of not only transmitting the stable control command but also preventing the same control transmitted from being duplicated.

In addition, the wireless interface device and method according to an embodiment of the present invention includes the control signal overlapped with the control signal for a predetermined period after the period in which the control information is generated, and the receiving side receiving the packet information including the control signal After confirming the stable reception of the packet, it is possible to ignore subsequent control signals for a predetermined time, thereby preventing the same control from being repeated.

Claims (20)

A priority queue for storing packets to be transmitted according to priority; A packetizer which periodically packetizes the received audio / video information and a control signal and stores the audio / video information and the control signal in the priority queue at different priorities according to the presence or absence of the control signal; And a wireless communication unit configured to wirelessly transmit a packet stored in the priority queue based on a situation and priority of a wireless communication network. The method of claim 1, wherein the packetizing unit, And storing the packet including the control signal at the highest priority position of the priority queue. The method of claim 1, wherein the wireless communication unit, And an output ratio of the time priority of the priority queue according to the situation of the wireless communication network, and to transmit the contents of the high priority queue first. The method of claim 1, wherein the packetizing unit, And repeatedly inserting the control signal into at least one packet information for a subsequent period. delete delete The method of claim 1, wherein the audio / video information and the control signal, A wireless interface device provided via a high definition multimedia interface (HDMI), said control signal being a user electronic control (CEC) signal. A packetizer for packetizing the video / audio signal and the CEC signal provided by the wired HDMI method for each fixed section, and repeatedly inserting the CEC signal in at least one subsequent packet when the CEC signal exists, and the CEC signal among the packetized information. A first wireless communication device having a priority queue for increasing the priority of the received signal and storing the received signal; and a wireless communication unit for preferentially transmitting a packet having a higher priority among the packets stored in the priority queue according to the communication network state; ; And a second wireless communication device for providing a video / audio signal and a CEC signal to the wired HDMI connected based on the packet received from the first wireless communication device. The method of claim 8, wherein the second wireless communication device, When the CEC signal is included in the received packet, the same CEC signal is determined based on the sequence number of the packet, and provides the CEC signal through the wired HDMI connected only once. The method of claim 8, wherein the second wireless communication device, When the CEC signal is included in the received packet, the wireless interface device, characterized in that providing the received CEC signal via a wired HDMI connected, and ignores the CEC signal received in duplicate within a certain time. delete delete delete delete delete Packetizing periodically while receiving an audio / video signal and a control signal, and storing the packets at different priorities according to the presence or absence of the control signal; And wirelessly selecting the stored packet based on a situation and priority of a wireless communication network. The method of claim 16, wherein the storing step, And storing the packet including the control signal at the highest priority position. The method of claim 17, wherein the transmitting step, And among the stored signals, first transmit a signal having a high priority. The method of claim 17, wherein the storing step, And if the control signal is included in the signals of the packetizing period, inserting the control signal into subsequent at least one periodic signals. The method of claim 17, Receiving the wirelessly transmitted packet information and disregarding the same subsequent control signal based on the packet sequence number when the control signal is included in the corresponding packet.

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