BR102016002235A2 - SYSTEM AND METHOD OF TRANSMISSION AND RECEPTION OF ANALOG SIGNALS USING WIRELESS DATA NETWORKS CONNECTED IN SMART DEVICES - Google Patents

Abstract

Summary of the Invention The system and method of transmitting and receiving multichannel analog signals using wireless data networks connected to smart devices within the field of electronics results in a method that provides the plurality of receivers with a or more simultaneous media and interface, and may use headset-type transponders, either by cable or any other wireless connection. provides an innovative system capable of providing users of smartdevices by receiving an analog signal (eg audio), transmitted and received in environments where they have wi-fi infrastructure. The invention provides a system for transmitting one or more simultaneous communication means by means of a wireless transmission system (wi-fi) which can transmit one or more analog channels (eg audio) simultaneously to one or more recipients. (receivers) capable of receiving wifi or any other wireless connection. The invention provides use for the following applications: audio transmission at events, avoiding the use of auxiliary equipment, if not the smartdevices themselves; transmission of multi-language lectures, the language can be chosen directly in smartdevice; lecture transmission in a high noise environment; audio streaming in games and simulators so that end users choose which audio channel to use. The system is advantageous, for example, for providing multi-event audio transmission in which the receiver can choose which event to listen to through his smartdevice.

Description

"MULTI-CHANNEL ANALOG SIGNAL TRANSMISSION AND RECEIVING SYSTEM AND METHOD USING WIRELESS DATA NETWORKS CONNECTED IN SMARTDEVICES" FIELD OF THE INVENTION

[001] The invention consists of a system and method of distribution of analog channels (eg audio), by means of signal distribution via wireless communication (WI-FI), based on the use of Smartdevices (eg SmartPhones). , SmartWatch, Tablets, etc.) as receivers and by application servers that will provide audio channels or any other signal, in environments that require multiple simultaneous channels without channel limiting, allowing one or more end users without limit end users using their receivers can choose which channel to play directly on their Smartdevices.

TECHNICAL STATE

[002] Currently it is possible to find several multichannel communication systems applied indoors (lectures, events, etc.) that has the principle of broadcasting the FM radio in order to distribute to the various users of the system through Broadcasting technology using FM receivers. analog

[003] Broadcasting systems in AM or FM are capable of transmitting one or more audio channels simultaneously, but channel selection depends on the frequency bands available in the environment and the number of channels is limited to the capacity of the radio Transmitter / Receiver. select the broadcast channels.

[004] The disadvantage of current indoor broadcasting systems is that the organizer needs to make the receiving equipment available to each user (receiver), hampering logistics and limiting listeners' capacity to the limited number of available equipment.

[005] Another disadvantage is that for indoor environments where radio frequency noise is present, interference and signal overlap can occur which impacts reception quality. [006] Finally, current AM / FM Radio multichannel audio transmission systems have channel limiting, due to the technological restriction of the multiplexing of radio channels and their transmission band. DESCRIPTION OF THE FIGURES

[007] Figure 1 illustrates the arrangement of system elements.

[008] Figure 2 illustrates the communication between Web Server components with the system administrator, Smartdevices and Streaming Server.

[009] Figure 3 illustrates an example of communication between Web and Streaming Servers with Smartdevice.

[411] Figure 4 illustrates the process between the capture of the analog signal until its reproduction by the receivers.

[012] Figure 5 illustrates the visualization of the application in Smartdevice by the end user.

[013] Figure 6 illustrates the network infrastructure required to distribute audio to Receivers.

DETAILED DESCRIPTION

[014] The method has the function of capturing multiple audio signals and its purpose is to distribute them to Smartdevices via wireless network. The main components of the system are represented in Figure 1.

[015] The method and system presented differently from current systems, which capture and distribute audio in a purely analog form, such as AM and FM radio transmitters among others, and reduce the space and logistics of radio equipment (transmitters and receivers) currently used. The system allows the use of cheaper devices to receive audio. Within the electronics field, audio receivers are Smartdevices (smartphones, smartwatch tablets, etc.).

[016] Figure 1 is a high level block diagram showing the main components of the system. Audio inputs 101A and 101B can be any independent analog signals with no input limits (eg audio), need to be converted to digital. As audio sources, we can cite an event with simultaneous translation, where the speaker and the various translators speaking in microphones are the audio inputs of the system represented in elements 101.

[017] In an event with simultaneous translation, it is very important for the listener to receive audio as quickly as possible without major delays between the speaker's speech and the listener's reception.

[018] We call latency or delay the time between audio capture and its receipt by the listener. Latency is a measure of the relationship, which represents the time between the start of an event and when its effects are perceived. Audio Latency is the time interval between when and when the signal is captured and when it is played.

[019] The delay between the analog input signals in set 101 and the wireless digital reception by Smartdevice 104 must be as short as possible. The Method and the system developed are based on a combination of using low latency audio protocols and codecs represented in element 106 and a local Wireless Network at 103, such as a WI-FI Network.

[020] Between items 101 and 106, an analog to digital audio signal conversion is required through an analog-to-digital converter (ADC), this process has a delay.

[021] The system ADC may be the server 100 sound card, or the audio may be pre-captured and mixed by a soundboard and be digitally passed directly to server 100.

[022] In item 106 the digital audio signal may need to be converted back to a more efficient format. In some cases ADC may have hardware coding support for these more efficient codecs, avoiding delay of the second audio conversion. Broadcasting audio over the WIFI network represented by 103 also contributes to system latency.

[023] An audio codec is a program responsible for converting an analog audio signal into digital form that can be stored and reproduced by a computer. The receiving device uses the same codec to convert digital audio to analog signal again for playback. There are several types of codecs with different quality and conversion speed. The choice of system codec should take into account the type of audio to be transmitted (voice or music), the amount of data bandwidth required for storage and transmission, and conversion delay.

[024] PCM (Pulse-code modulation) codec is supported natively on all ADCs, resulting in minimal conversion delay, but its digital representation is very large and this is a problem in its transmission over network 103, because it occupies too much. transmission bandwidth by limiting the number of Smartdevices that can receive audio simultaneously.

[025] For network audio transmission, other codecs such as MP2 (MPEG-2 Audio Layer II) and Opus are recommended. 2 MP2 is one of the most widely used codecs for broadcasting audio over Ethernet and internet networks, some ADCs support MP2 conversion natively. Opus is one of the fastest and most optimized codecs for voice and audio transmission over the network. Many Voice over IP (VolP) systems use the Opus codec because it has low delay, good audio compression and good sound quality optimized for voice.

[026] The system is managed remotely by as many administrators as needed represented by pool 102 who have the responsibility to register all Smartdevices that will be allowed to use system 100.

[027] By the method developed, the moment Smartdevice 104 attempts to connect to the system, it will send information to server 105 for authentication. Only after this authentication will the user have access to the audio.

[028] The web server can also block access to audio streams 101 through access control policies. For example, in an event where users need to be registered in advance, only those who have an authentication login and password will be able to access the service through 104 devices. In another situation, audio can be made available to any user who connects to the network. , through Smartdevices, without the need for login and password authentication.

[029] The network infrastructure at 103 contains the elements necessary to distribute data from the streaming and web servers to the connected Smart Equipment. This infrastructure is basically made up of a wireless local area network. One or more Wireless Access Points or routers are distributed throughout the environment in which the audio will be distributed or may be moving in cases where the event is mobile, where both the speaker and listeners are moving during the event, such as presentation. of a factory process or museum, etc.

[030] Figure 2 illustrates the operation of the Web Server, which is responsible for user authentication and management. To use the system it is necessary for the user to use an Intelligent Equipment, represented by element 202 of the figure, and be previously registered. Registration is performed by system administrators using a device (notebook, desktop, etc.) to communicate with the Web Server. The administrator along with the communication device is represented in element 201. There may be one or more administrators who, through the "management interface" represented in 204, will register the users, which will be stored in element 206.

[031] In the developed method, for Smartdevice authentication in the system, element 205 is used. This element, called "Authentication API", where API is the acronym for Application Programmig Interface. Applications, which in turn communicates with data stored in element 206, previously registered by element 201 using the interface represented in 204, and returns the result of authentication. If the user has permission to use the system, he will be released to listen to the stream reproduced by element 207. Otherwise, a message stating the request status will be displayed at 202.

In the system developed, all communications between elements 201 and 202 with elements 204, 205, 206 and 207 will necessarily use a local wireless network, such as a WI-FI network, represented by element 203.

[033] Figure 3 illustrates an example of communication between Web and Streaming Servers with the Smartdevice application. To initiate communication between elements 304 and 301 and 302, they must be inserted in a local Wireless Network, such as the WIFI network represented by element 303.

[034] In the system developed, to connect to network 303, Smartdevice 304 will require authentication via a key / password (eg WPA2-PSK) as it is a wireless network such as WI-FI for access. in a closed / restricted place. Depending on the environment the WIFI network can also be opened and without password, so just the 304 element just connect to it. Element 301 and 302 may connect to element 303 via a wired network because it is inserted in the same physical structure, but nothing prevents using the wireless network such as WI-FI for the same purpose.

[035] After the connection between elements 304 and 303 is established, Smartdevice 304 authenticates with element 301 through a token / user and a key, the token / user must be previously registered in element 301 in its database. data and the key must be unique for element identification 304, a key that can be generically generated by the administrator using the management interface. As an example, an email and a unique identification key (uid) can be used as a token / user and key.

[036] In the method developed, upon authentication and communication between elements 304 and 301, element 301 queries the available audio channels in element 302 and returns to element 304 the transmission channels to which access is allowed. Selecting the channels available on element 304 starts playback by streaming audio from element 302 to element 304.

[037] In the event of loss of communication between elements 301 and 304, streaming is interrupted, and communication must be reestablished to continue transmission; when communication is restored between elements 301 and 304, streaming will resume automatically. from the previously selected channel before loss of communication.

[038] In the developed method, lost streaming information between elements 301 and 304, during the process of re-establishing communication or during transmission, is discarded in order to maintain real-time streaming, improve transmission performance and reduce the delay between input audio on element 302 and output audio from element 304.

[039] Figure 4 shows the audio signal flow through the system. Analog signal 401 is captured through any audio source, which may be a microphone for example. The analog signal, before it can be used, is digitized by the ADC 402, which may be the server sound card. In some situations the system input audio can be digitally generated, represented by element 407. In this case it does not need to pass through ADC 402 directly entering element 403, as an example, a digital piano that transfers the direct sound can be cited. to the system through a physical interface or other audio stream from the internet.

[040] Element 403 is an encoder responsible for encoding sound in a format optimized for Intelligent Equipment.

[041] Not all Smartdevices can play all digital audio formats, and some formats take up a lot of data transfer bandwidth on the network, and this can result in a poor user experience.

[042] The System is based on the use of the wireless network represented by 405. For example, in the WIFI network it is important to take into account that packet loss can be a problem. At frequencies used by the system, other devices may be using the same frequency which may cause interference.

[043] A codec that has low transfer bandwidth utilization at 403 can compensate for packet loss from the 405 wireless network. For real-time voice transfer, the system must achieve the same quality as a VolP system, with a low encoding delay codec and low data transfer rate.

[044] All audio codecs have a transfer rate measured in kbps (kbits per second); when Smartdevice 406 establishes a connection with element 404, transmission of encoded audio encoder 403 begins; It now consumes the transfer rate requested by the codec from the network. The more users are listening to audio, the higher the overall bandwidth consumption available on the media. The system utilizes Quality of Service QoS and Smartdevice bandwidth limiting to avoid interference problems and raise overall audio quality.

The straming protocol represented in element 404 is responsible for organizing the sending of 403 encoded digital audio packets to Smartdevices 406. In practice, most often element 404 represents a set of protocols. There are several protocols that can be used such as Real-time Transport Protocol (RTP), Real Time Streaming Protocol (RTSP), Session Initiation Protocol (SIP), and Session Description Protocol (SDP). RTSP, for example, serves to negotiate and control the transfer of multimedia (in this case audio) between the server and Smartdevice, whereas RTP is responsible for transferring audio data for playback.

[046] Wireless Network 405 is responsible for transmitting audio data over the physical medium. The target devices of the System are Smartdevices, the Wireless Network uses Access Points (AP) to distribute the electromagnetic signal with the data. One or more APs can be attached to the system to support an increasing number of concurrent Smartdevices.

[047] Streaming user 406 is a Smartdevice, such as a smartphone. It must be able to connect to the 405 Wireless network, communicate and initiate the transmission session with 404 element, decode the sound data in a reverse process to encoder 403 and finally convert the digital signal to analog and play it back.

[048] Figure 5 is a high level block diagram that illustrates the visualization of the application in Smartdevice by the end user (listener).

[049] To gain access to the application, Smartdevice must first connect to a local wireless network, such as a WIFI network, and will also authenticate to the application as directed by the system administrator previously registered with the web server.

[050] After the connection and authentication in the application that is represented by the element 500 is established, the available audio channels are consulted and returns in the Smartdevice main screen which audios are available. These audios are represented in the figure by the 501A, 501B, 501C elements, where the end user will be able to choose which audio to listen to and simply select from his Smartdevice the option of the available 501A, 501B, 501C elements.

[051] Depending on the environment in which audio is played, the use of a headset represented by the 502 element may be required for better listening to all end users. The headset can connect to Smartdevice via cable or wirelessly, such as a Bluetooth connection.

[052] Figure 6 shows the arrangement of physical elements in a closed environment 600 of the described system. The Access Points (APs) represented by the 601 elements have two limitations that must be taken into account when configuring the wireless network. These limitations correspond to a limited coverage area and a maximum limit of concurrent Smartdevices that can be managed. Because of this, APs need to be distributed across the environment to cover the largest possible area of the total.

Claims (3)

1- Method for transmitting and receiving multichannel audio signals using Wireless Networks connected to Smartdevices for indoors. The Method can be used in combination or individually. It is characterized by: Method that allows the extraction and selection of channels of audio transmitted over a wireless data network independently by choosing the channel to be selected on the receiver (Smartdevice). 2- Method of transmitting and receiving multichannel audio signals using Wireless Networks connected to Smartdevices for indoors. The Method can be used in combination or individually. It is characterized by: Method that allows the receiver to be positioned in different points within a given environment represented at 600, allowing the receiver to move without the incoming audio channel having any interference or clipping. 3- The system for transmission and reception of multichannel audio signals using Wireless Networks connected to Smartdevices for indoors. The System can be used in combination or individually. It is characterized by: a System that allows the transmission of audio signals. synchronously from the various input audio signals with no delay between the input audio channels relative to the inputs.