Audio over IP devices System description Ed 2.0

Transcription

1 Equitel Network Audio Audio over IP devices System description Ed 2.0

2 This document contains the description and some application notes for the ENA devices. Equipos De Telecomunicación Optoelectrónicos, S.A. Zaragoza, July Ed 2.0

3 ENA devices: System description Index Chapter 1 : Introduction... 1 Chapter 2 : Functionality Audio source types for decoders Encoder audio stream types Audio layers in decoders Audio switching in decoders Digital I/Os Paging consoles E495 and E497 usage... 6 Chapter 3 : Application examples Hotel Chain store 1: Using ICEcast streams Chain store 2: Using File uploading Healthcare center using IP phones School Chapter 4 : Software ENA devices: System description i

4 Chapter 1: Introduction The EQUITEL audio over IP devices family allows the transmission and reception of music channels and audio messages over IP, using standard IP network hardware. These devices provide a unified solution for transmitting audio signals such as background music, advertising and informational messages, to one or more destinations. By supporting multiple protocols and encoders, these devices are indicated in broadcasting applications, VoIP and Internet radio. In addition to leveraging existing infrastructure and devices such as SIP phones. The encoder (E421) sends audio input through the Ethernet network. This process is known as "streaming". Streams can also be generated by other devices, like a PC running an application or a SIP phone. The E495 and E497 desktop microphone consoles can also send vocal messages to the decoders for paging applications. If more than one of these devices are used, they intercommunicate to avoid message collisions. Decoders (E411, E413 or E415) can receive selected channels (i.e. "streams") from the network and convert it back to an analog audio signal. Mixer (E417), besides the same features than the decoders, includes the option to use audio coming from files stored in a USB memory or analog signals in its MIC or LINE inputs. The selection of the actual stream, local file or analog signal to be played is made based on a powerful but very easy to configure priority schema. The figure shows a schematic of this family of devices usage: Figure 1: EQUITEL Audio over IP devices usage schema ENA devices: System description Page 1

5 The members of the family are: E411 - Decoder Stereo output in line level (RCA) and headphones. To be used with an external amplifier. E413 - Decoder with digital I/O Same features as E411 including two digital inputs and outputs for external devices control. Digital outputs can be used to switch ON/OFF the external amplifier. E415 - Amplified decoder Same as E413 and includes a high quality 25W audio amplifier. Amplified output can be configured in mono or stereo. Line-out output can be used simultaneously. E417 - Decoder / Mixer With the same characteristics as E415, it can also play sound from files stored in an external USB memory and from its analog inputs. Ideal to mix external background sources with local messages. E421 - Encoder Line and microphone level inputs for analog encoding. USB input for audio files streaming. Digital inputs for audio encoding triggering. E495 - Paging console 12 configurable keys Microphone or pre-recorded messages. Up to 10 units can be used simultaneously, with busy zone indication. E497 - Paging console 24 configurable keys Microphone or pre-recorded messages. Up to 10 units can be used simultaneously, with busy zone indication. ENA devices: System description Page 2

6 Chapter 2: Functionality 2.1 Audio source types for decoders Decoders can play sound coming from several source types: RTP: Audio streams coming from E321 encoders, computer applications or other devices, in the RTP format as defined in RFC The RTP can be received also in multicast mode. So, many decoders can play the same RTP stream without extra bandwidth consumption. The allowable payload formats are: o o RTP/SIP 1 : G711-A: (64 kb/s, vocal quality) PCM16, 1 channel (mono), Hz (music medium quality) Audio streams coming from a standard SIP phone or PBX. The audio codec used is G711-A. The decoder has an internal SIP agent that can be registered in an SIP PBX and acts as a standard extension accepting calls. Also, can be configured in peer-to-peer (P2P) mode if not PBX is used to accept calls directly from phones. When a call is received, is automatically answered and the audio is sent to the output if no other higher priority channel is being played. SHOUTcast / ICEcast 2 : High quality audio streams coming from local or internet servers (internet radios). The device connects to the configured URL to acquire the compressed audio stream. The audio can be sent in any of the following formats: o MP3 up to 192 kb/s o o AAC+ up to 192 kb/s Ogg-Vorbis up to 192 kb/s Audio files (in E417 only): The E417 can decode and play audio files stored in an USB mass storage device. The allowable formats are: o MP3 up to 320 kb/s (Fixed bit rate) Analog inputs (in E417 only): The E417 has two analog inputs (microphone and line-in) than can be sent directly to the output. Each input can be assigned only to one of the possible audio sources. See next point for more information. 1 SIP is the most widely used protocol nowadays for session establishing in VoIP telephony. It is defined in RFC SHOUTcast and ICEcast are both standards used to transmit sound through Internet. There are many public radios in Internet using these protocols, and is quite easy to create a proprietary radio using one ICEcast server provided by an ISE (Internet Services Provider). ENA devices: System description Page 3

7 2.2 Encoder audio stream types The decoder E421 can generate these types of stream: RTP: Analog audio inputs can be coded an streamed in the RTP format as defined in RFC 3550, in unicast or multicast mode up to 5 different destinations (i.e. multi-unicast). The streaming can be triggered by one of the input contacts change. The allowable formats are: o o ICEcast: G711-A: (64 kb/s, vocal quality) PCM16, 1 channel (mono), Hz (music medium quality) The analog line input or MP3 files in the USB can be streamed to an ICEcast server in MP3 format to create an internet radio. 2.3 Audio layers in decoders Decoders can accept up to 10 simultaneous sources or channels, grouped in three categories or audio layers : Background music: The purpose of this layer is to be used for the ambience sound. Is the lowest priority layer and accepts up to 6 sources (channels). The allowable source types for this layer are: RTP, SHOUTcast / ICEcast, Audio files (in continuous playlist mode) and the Analog inputs. The selection of the channel to be played can be made manually with the web server of the device or through an external application in a computer or mobile device. It is also possible to allow the device to automatically change the channel being played if there are no data to decode (for instance, a break-down in the connection to an internet radio). The playing of a channel of this layer can be interrupted by the presence of audio in one channel of the other two layers. Advertisements: This is the layer used to play advertisements. It accepts up to 3 channels, each one with its own priority level. Allowable source types are: RTP, RTP/SIP, Audio files (in periodic playlist mode) and the analog inputs. Audio in this layer can interrupt the audio in the Background Music one and can be interrupted by audio in the Emergency layer. Emergency: This is the highest priority layer and accepts only one channel. It is commonly used in PA systems for evacuation or emergency messages. The allowable source types for this layer are: RTP, RTP/SIP and the Analog inputs. ENA devices: System description Page 4

8 Source type July Ed.2.0 This is a summary of the allowable source types in each of the audio layers: Background music Audio layers Advertisements Emergency RTP SIP/RTP SHOUTcast / ICEcast Audio files (E417) Analog inputs (E417) 2.4 Audio switching in decoders Only one of the 10 possible channels can be played at a time. The device chooses which one must be played analyzing their status (active/inactive), the assigned priorities and the user selection (only for the Background Music layer channels). The activation of each channel depends on the source type configured for it: For the RTP audio streams, the channel becomes active when there is data present during more than 70 ms and becomes inactive when there is no data for more than 1 second. When the audio comes from an SIP phone, the channel becomes active or inactive attending to the SIP protocol. When the call is established, the channel is activated. When the call is ended, the channel is deactivated. SHOUTcast or ICEcast sources are activated when the connection with the configured server can be established. If the connection fails, the source is deactivated. Sources based on local files for the advertisement layer are activated by a time scheduling. When used for the background music layer, they are always active, being played continuously in a loop mode if the channel is selected. Analog inputs used for the Advertisements or Emergency layers are activated by one of the digital inputs in the device. When used for background music, they are always active. Each one of the analog inputs can be assigned only to one input channel. 2.5 Digital I/Os The E413, E415 and E417 models have two digital inputs and outputs. Inputs, in the E417, can be used to activate the analog audio sources. In the E413 and E415 models can only be used with an external application to read sensors status, etc. Digital outputs can be used for activation of external devices (i.e. an amplifier, a light, etc.) when one (or more) of the input channels are being played. In the E421 encoder, the digital inputs can be used to trigger the emitting of the audio stream to selected targets when the RTP format is used. ENA devices: System description Page 5

9 2.6 Paging consoles E495 and E497 usage Both E495 and E497 are desktop microphone consoles to be used in paging applications in conjunction with the ENA family decoders. These devices have 12 or 24 keys that can be configured in different ways to send live messages or prerecorded ones to the decoders. Messages can be sent simultaneously to various decoders, either in multicast or multi-unicast. This grouping (zoning) is made very easily in the console using its integrated web server configuration. If several E495 and E497 devices are used in a system, when one is sending audio, it informs the others about the destinations (decoders) it is using. So, the others E495 or E497 in the system disable the emission to that destinations and inform to the user by means of a red light in the correspondent key, which becomes blocked. This allows to have several paging control points in a very easy, safe and economic way. The console E495 or E497 has two working modes: 1. Multiple selection mode: In this mode some keys are configured as zone selection keys. Each key is assigned to a decoder, a group of decoders or a multicast address. When the key is pressed, it alternatively enables or disables the emission to the configured decoders, which is indicated by its led in green or off respectively. Other keys can be configured to send live messages ( TALK key) or pre-recorded ones. When the user wants to send a message, first has to select the desired destinations and then push and maintain the TALK or desired pre-recorded message key. If other console in the system is sending audio to a decoder that is assigned to a zone selection key, its led becomes red to indicate that the decoder is busy and no audio can be sent to it. 2. Single selection mode: In this mode, all the keys are configured in the same way. Each key is associated with a destination, group of destinations or multicast address and a source, than can be the microphone or a prerecorded message. When the user want to send audio to a specific zone, simply pushes and maintains the correspondent button while the message is being sent. In this mode, the sending zones are defined in the configuration and the user can t combine them. As in the other working mode, if other consoles are sending audio to destinations associated to configured keys, the led turns red and the key is disabled. ENA devices: System description Page 6

10 Chapter 3: Application examples In this chapter we will show some application examples to illustrate the different possibilities of the devices. The intention is to give some ideas to the reader of how the devices can be used to add functionalities to the audio systems that would be more difficult and expensive in a standard analog installation. Real life projects surely will require a mix of the configurations proposed here. But, if the basic ideas are properly understood, there will be no problem to apply the correct configuration in each case. If you have a project in mind using these devices and need help to find the better solution for it, just contact us at support@equitel.es 3.1 Hotel Let s suppose we have to deploy an audio over IP solution for a hotel with these requirements: Distribution of emergency messages to all hotel zones. Distribution of ambient music to all the hotel zones, including rooms, with possibility to select different music in each zone. Guests will be able to control the ambient music in its room, selecting it from a variety of proposed stations. In the restaurant the audio system may be used for the live music played in events. In the conference room the audio system may be used for the local microphones. This is the schema of the proposed solution: Figure 2: Installation in a Hotel ENA devices: System description Page 7

11 Reception desk: At the reception desk, there is E495 or E497 console used for the emergency and paging messages to be sent to all the building. The console is configured to send messages to the EM layer channel. As this channel has maximum priority, this messages will be decoded and played over any other audio they were playing. Here we have also a computer running the management software with these characteristics 3 : Rooms: Generates several ICEcast streams, based on local files, for the BGM channels. Communicates with the App running in the guest s smartphones to grant or deny permissions and to control the decoders in the rooms for the music selection. Sends pre-recorded or live messages to specific zones using the AD channels. Keeps control of the status of all the devices in the network. In each room, there is an E415 decoder connected to the loudspeaker(s) in the ceiling. These decoders have the EM channel configured to decode the multicast RTP stream generated by the E421 encoder in the reception desk for emergency and evacuation messages. The 6 BGM channels are configured to decode the ICEcast streams served by the management software. The selection of the channel to be decoded and the output volume is made through a mobile application that guests can download 4. Hall and corridors: An E411 decoder is connected to an external amplifier connected to all the speakers needed to cover all the space in each zone. If the power of the E415 internal amplifier is enough, it can be used instead of the E411 and the external amplifier. In these zones, as in all the decoders, the EM channel is configured to decode the multicast RTP stream generated by the E421 encoder in the reception desktop. In specific zones, the AD channels are configured to decode the RTP streams generated by the management application. This can be used for people localization, announcements to tourists groups about buses departures, etc. Restaurant and conference room: Both zones need an E417 mixer because it is able to use the local analog audio inputs. The analog input is connected to a local audio mixer which adapts and mixes all signals coming from the microphones, instruments, etc. to be amplified locally. This signal is used as one of the BGM channels, which can be activated when needed. If no local audio is to be played, the other BGM channels are used to play ambient music sent from the management software as ICEcast streams or to play files stored in an USB memory. And, as in the rest of the zones, the EM channel is used for the emergency and evacuation messages sent from the reception desk. 3 Management application can be as complex as needed. We show here only a few possibilities for this example. EQUITEL provides by free all the information and support needed to create this applications and also can create them based on specific requirements. 4 As with the management software, EQUITEL will provide support to create this kind of applications or can create them for a specific project. EQUITEL provides by free a basic application but, for most cases, it will be a better solution to create a specific one for each project. ENA devices: System description Page 8

12 3.2 Chain store 1: Using ICEcast streams. In this example, we will imagine a brand with stores spread all over the country, or even over the world, that want to control the ambient music and advertisements being played in all the shops. The schema of the proposed solution is this: Figure 3: Chain store sound distribution using ICEcast streams In this example, the audio distribution is based on the use of an ICECast server provided by any of the numerous ISP that offer this service 5. In the central, one or more ICEcast source streams are generated by software and / or using E421 encoders. These streams are sent to the ICEcast server that sent them to all the decoders (i.e. stores). For instance, you can generate different streams with different music styles and mixed advertisements for different types of store, zones, countries, etc. For small shops E415 can be used, if the output power of its internal amplifier is enough. For lager shops, the E411 and an external amplifier is the solution. In both cases, the decoder is configured to play one or more of the ICEcast streams. The selection of the actual stream to play and the output volume can be made with a mobile application. In very simple cases, where only a stream is decoded in each shop, you can use the E411 and an external amplifier and the volume control is done with the amplifier knob. 5 ISPs (Internet Services Providers) offer ICEcast streaming at different costs, depending on the number of receivers, audio quality and timetable required. On the other hand, many of the providers that offer this service, also include a software (usually by free) to create the audio stream from audio files uploaded to the server. ENA devices: System description Page 9

13 3.3 Chain store 2: Using File uploading. In this example we have a similar chain store but the contents, instead of being generated in almost real-time as in the example above, are sent off-line. Let's see the proposed solution: Figure 4: Chain store sound distribution using file synchronization Here, the E417 decoders are used to play the sound files sent by the central computer by night. The application in the central allows building the different playlists for background music and announcements for the different shops. These playlists are synchronized with the decoders in the shops sequentially by night when needed. This way, the required bandwidth on the Internet connection of the central is very low. In the shops, a PTT microphone can be connected to the E417 for local messages. The control of the device in each store can be made using a mobile device (i.e. a tablet) with an application. This is a very simple way to have a controlled music and advertisements content in all the shops. ENA devices: System description Page 10

14 3.4 Healthcare center using IP phones. In this case we will suppose a healthcare center with several doctor offices, each one with its own waiting room, and common spaces as the hall, the corridors, etc. The center has also a IP telephony 6 system and each office has its own IP phone: The project requirements are: Figure 5: Healthcare sound distribution Background music in common zones and waiting rooms. Vocal messages can be sent from admissions desk to selected zones. Each doctor can send vocal messages to call patients to his waiting room. The solution for this project could be the following: In the technical room, we install a computer with the software for background music generation and devices control 7. From the software, several background music channels are generated for the different zones. All the ENA receivers are configured to be registered in the SIP PBX as a telephone extension. Also, in the PBX groups of extensions can be configured to make simultaneous calls (i.e. paging to a zone). 6 For compatibility with the ENA devices, the IP telephony system must use the SIP protocol 7 Our ENALite application can be used for this purpose. ENA devices: System description Page 11

15 When a doctor wants to call the next patient to enter the office, he just picks up the phone and calls the extension corresponding to his waiting room. Then the audio sent from the phone is decoded and played by the E415 in the room In the same way, from the admissions desk, they can pick up the phone and call to a specific extension or a group to send messages that will be decoded and played in each decoder. ENA devices: System description Page 12

16 3.5 School For this example, we we ll suppose a school with an existent LAN network where we must deploy the PA system: Figure 6: School PA example In each classroom we install a E415 and a loudspeaker. If the output power of the E415 s internal amplifier of the E415 isn t enough, we may use the E411 and an external amplifier as shown for the Gym, sports pavilion etc. In the yard, we will install an E411 with an external amplifier and a 100V line of speakers. For the auditorium, we use an E417 inserted between the mixer and the amplifier of the local audio system. In normal state, the mixer output is sent to the amplifier but if any message comes from the network with greater priority, the decoder will switch to play this message instead. In the lodge and the director s office, we install two E495 or E497 microphone consoles to emit voice messages to the different zones. As both consoles are intercommunicated, when a zone is in use by one, the another disables it. Finally, we can install somewhere a computer with a software to: Monitor the status of the receivers and consoles. Generate background music channels and to control its playing in certain zones. Generate scheduled advertisements: begin / end of class etc. Generate fire or evacuation alarms (there must be any device in the system capable to send a command to the computer to trigger the messages)... ENA devices: System description Page 13

17 Chapter 4: Software In some applications, the ENA family of devices can be used without any other software, but in other cases specific software is needed, as shown in the above examples. EQUITEL provides, by free, the application ENALite to control small installations with these features: Can control up to 10 decoders. Allow grouping the decoders in zones to sent same messages. It can generate up to 6 ICEcast streams for background music. These streams can be published using a local ICEcast server installed with the application, or any other. Generate up to 15 RTP streams for advertisements, using the computer microphone or audio files. Each stream is sent to a specific configured zone. Generate a RTP stream for the emergency channel using the computer microphone or pre-recorded messages. The destination zone of the stream is chosen when used. Figure 7: ENALite application Also, we have created the sample application ENAControl for Android, which allows controlling all the decoders in a LAN using the WIFI access. These applications are created not only to be used installations, but as examples to help developers to build their own ones for specific projects. For those projects where an application with specific characteristics is needed, EQUITEL can offer to create the application or, to give the information and support needed to create it. In this information, the source code of the above mentioned applications is included. In case you are interested in any of these solutions, please contact us at support@equitel.es. ENA devices: System description Page 14