The New Mobile Broadcast via AoIP

April 1, 2012


IP remote setup

Before ISDN, remote broadcasts involved quite a bit of work. With ISDN, they were considerably easier. Now with access to the public Internet just about everywhere, carrying out a remote is easier than ever. Last month we talked about STL over IP (nailed-up connections). This month we're shifting gears and focusing on temporary connections. We're going to cover hand-held devices, then small portables, and finally we'll look at devices you'd put in a road case or remote truck.

Using a mobile phone app

Comrex Arc

Comrex Arc


The first "device" we'll look at is simply an app from Comrex that works on specific Android phones. It's called ARC (Access Reporter Codec). Yes, the phone you may already have is the hardware you need for a remote. Like other Android apps, this one works via the touchscreen; it allows you to use 3G, 4G or Wi-Fi to connect to an Access or Comrex Bric-link (running firmware 2.7.1 or higher). The codec is G.722, which according to Comrex provides 7kHz of full-duplex, low-delay audio. ARC has two modes of operation: registered, which uses a SIP account on each end, and unregistered, which can simply use an IP address to connect to an Access or Bric-Link. Comrex has a list of Android phones that work, but recommends the Google Nexus 1. In any case, the phone has to be running Android version 2.1 and must contain a processor running at least 1GHz.

Now if you are totally committed to the iPhone you can still use Comrex for remotes at the far end. Comrex recommends using a SIP softphone client for iPhone called Media5 Fone. (This is a third-party app not written by Comrex.) With this app, you'll need two SIP accounts because Media5 Fone only works in registered mode. Again, you'll need to be running version 2.7.1 or better on your Access or Bric-link on the far end.

Tieline Mic Adapter

Tieline Mic Adapter


Tieline has a neat application for iPhone called Report-IT, and it can be used in one of two ways. You can record an interview with the microphone in the iPhone itself, and then trim heads and tails via its touchscreen display, or you can edit using a compatible app. You can then upload the file to an FTP server, using WAV or AAC-LD formats (20kHz of bandwidth). Your studio then retrieves the file from the fileserver for playback. Alternatively, live remotes using the mic in the iPhone, can be delivered via 3G or Wi-Fi. Another option is to use the Tieline Mic Adapter for iPhone4. This connects an outboard microphone and headphones to the iPhone. According to Tieline, live remotes will have 15kHz of audio bandwidth, and of course you'll need a compatible Tieline codec at the far end.

For Android devotees, there is some good news: There will be an Android version of Report-IT coming out soon, with the same features already discussed. Tieline expects to have the app available for download in time for the 2012 NAB Show.

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AEQ Broadcast Phoenix Lite

AEQ Broadcast Phoenix Lite


AEQ also has an app called Phoenix Lite that allows the user to establish a full-duplex audio connection between an AEQ Phoenix (located back at the studio) or other N/ACIP compatible codecs, and an iPhone (and soon Android). It comes with a wide variety of algorithms: M2, AAC, AAC-HE, AAC-HEV2, G.711, G.722, and ULCC, running on speeds between 44.1 and 384kb/s. It also simultaneous records and plays audio, and can playback files in the midst of live audio transmission (the classic wrap-around).

Using a small portable codec

Many of the same players that made equipment based on POTS codecs are now making replacements for that legacy equipment - replacing the phone line part with Ethernet, Wi-Fi, or cell network connections.

Musicam Road Warrior

Musicam Road Warrior


Perhaps you're just warming up to the idea of IP for remotes, and you're not ready to give up ISDN just yet; in that case you might consider the Road Warrior from Musicam. Not only does the Road Warrior have an Ethernet port, but a built-in ISDN terminal adaptor as well. IP and ISDN can be used simultaneously if desired. This device supports MPEG1/2 LayerII/III, G711/G722, PCM, AAC (optional), and Apt-x (optional). Road Warrior comes in two versions: LC, which has two mic/line inputs and another line level in; or the XL, which has four mic/line level inputs. Both have line-level balanced auxiliary outs in addition to headphone outs: two for LX, four for XL. The XL has a USB port for a 3G modem. The IP codec has a test tool that allows the user to check the bandwidth, delay and jitter in the IP connection, so that the user can optimize the streaming parameters, such as the jitter buffer depth, and frame size. While the setup can be saved as a pre-set, the device is completely configurable via its built-in Web interface as well. The studio end of this link would be another Musicam device, such as the Suprima.

Barix Exstreamer 1000

Barix Exstreamer 1000


Another brand that is become familiar to more and more broadcast engineers is Barix. While Barix sells separate encoders and decoders (Instreamer and Exstreamer respectively) they also offer a full-duplex unit known as the Exstreamer 1000. This device features both analog and AES ins/outs along with contact closures (four relays in both directions). You would make use of the Exstreamer 1000 with a separate mixing system; so if you have a tried and true remote mixer that you can't live without, this may be the way to go. It's important to note that the configuration of the device must be done with a Web browser, so make sure you have something that can run a browser while you are in the field.

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Comrex Access Portable

Comrex Access Portable


Comrex has a long history in this category and the Access portable, while not a new product, continues getting new features added as time goes along. It's a full-duplex codec, with one line/mic level input, and a headphone mixer built-in. While it has an integral Ethernet connector, it also has a cardbus slot and a USB port that will fit various specific modems that will communicate via POTS, Wi-Fi (802.11b, g or n), Wimax, 3G and 4G (LTE). On the far end you would have another Access, either a portable or a rack mount unit. (If you use the POTS modem, Access is backward-compatible with legacy Comrex POTS codecs (except for Hotline).) By the way, when using that cardbus slot or USB port, you can make use of the Ethernet connection for Internet sharing. Network interfaces can be set for static IP addresses or set to use DHCP. The Access portable also has a built-in Web browser, so that you can log-in to access points as necessary. Access comes with the Comrex BRIC algorithms, and MPEG4/AAC algorithms. Another option is the five-channel mixer, which plugs in to the side of the Access portable, and gives you an additional five mic/line level inputs, and an additional five headphone outputs as well.

Tieline Commander G3

Tieline Commander G3


Another option for a small, portable remote device is the Tieline G3 Commander field unit. This device has two mic/line level inputs along with a single unbalanced input (RCA connector); it has two balanced outputs, and one unbalanced (RCA) out. It has built-in headphone mixing, with the separate headphone outputs. Via plug-in modules that go in to an expansion slot, you can communicate (in a full-duplex fashion) via IP, 3G, ISDN, X.21, and even BGAN (for satellite uplinking). IP interfaces can be configured for static IP or DHCP. A new plug-in module just being introduced is for 4G (USB style) modems. The far-end device back at your studio HQ would be another Tieline Commander. The Commander comes with the Tieline Music and MusicPlus algorithms in addition to G.711, G.722 and MPEG layer II. According to Tieline, the MusicPlus algorithm will provide 20kHz of stereo audio capability with data rates as low as 96kb/s. You also get the free Tieline Toolbox PC software configuration and control software, offering configuration, audio routing and input control of your local and remote codec.

Aeta Audio Scoopy

Aeta Audio Scoopy


While considering different manufacturers for a field unit, you may want to take a look at Scoopy from Aeta. This device has three mic/line inputs (with built-in limiters); two headphone outs and two line outs. As with the other devices we've talked about, it has multiple interfaces: Ethernet, ISDN and POTS. It has an integrated antenna for GSM, or UMTS, or 3g+, and it also has a card expansion slot, and a USB port for other modems such as WiMax or 4G/LTE. It will communicate with other devices via G.711 or G.722, and its N/ACIP compliant. (Typically on the far end you would have another Aeta codec, such as the Scoop 4+.) Other algorithms are MPEG layer 2, AAC, CELP and 4SB ADPCM. Last but not least, you can do recording and simple editing right on the device itself.

Road case or remote truck

It may be time to remove legacy ISDN codecs from road cases and remote broadcast vehicles, and to replace them (or at the very least, supplement them) with AoIP codecs of some flavor.

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Telos Z/IP One

Telos Z/IP One


The evolution of the Telos Zephyr has produced the Z/IP One, a single rack-unit, full-duplex codec. This device has two mic/line level balanced inputs and two balanced (analog) outputs. For communications, it has two integral Ethernet connections; one can be used for streaming, while the other is used for control purposes with its built-in Web browser (it can also be configured via its front panel.) The codec supports Livewire. Additionally the unit is supplied with a Wi-Fi stick, and you can plug a 3G modem in to its USB port. A feature that Telos calls ACT (agile connection technology) senses network conditions and dynamically adapts the codec performance to provide the best audio. There is an 8-bit parallel GPIO port for signaling and control, along with an RS-232 channel. The Z/IP One has a large set of codecs available: AAC-ELD, AAC-HE, AAC-LD, MPEG Layer 2, MPEG 4 AAC LC, MPEG 2 AAC LC, G.711, G.722 and linear PCM. On the far end, you would have another Z/IP One.

Worldcast Systems APT Horizon NextGen

Worldcast Systems APT Horizon NextGen


Worldcast (APT) has a line of IP codecs, and the one we'll look at is the Horizon NextGen. This is a single rack-unit, full-duplex codec, two channels in and out, available via line-level balanced or AES-3. (Another Worldcast codec would be on the far end.) It has two integral Ethernet ports; one can be used for streaming, and the other for control (using the Worldcast GUI or a browser). Alternatively, there is an option called SureStream, which allows the user to set-up two simultaneous independent IP streams that can be configured go out on a per-port basis, or together on the same port (either one). Both Ethernet ports can be configured for static IP or set for DHCP. Included algorithms are Enhanced apt-X (16 and 24-bit) and linear PCM (16, 20, 24-bit). Optionally, MPEG 4 AAC HEv1/2, MPEG AAC LC, MPEG 4 AAC LD are also available. GPIO consists of four optically isolated inputs, and four relay outputs. An RS-232 path is also available for the transmission of ancillary data. There aren't any front panel controls, so you will need to have a device that can run a browser along with you when you use this device.

Musicam Suprima

Musicam Suprima


Musicam offers the Suprima, a 1RU full-duplex codec. (Another compatible Musicam codec would be on the far end.) This device supports two channels of audio, with line-level balanced inputs and outputs (along with AES versions of each on a db9 connector). It has an integral Ethernet connector used for streaming as well as control (via embedded Web server). Coding algorithms supported are MUSICAM MPEG1/2 Layer II/III, MPEG2/4 AAC LC, MPEG4 AAC LD, MPEG4 AAC-HE, Standard & Enhanced apt-X, G.722, G.711, and uncompressed PCM. GPIO provisioning allows for up to seven contact closures; serial data is supported when using either apt-X or MPEG algorithms. Like the Musicam Road Warrior I mentioned earlier, this codec can communicate via ISDN, as well as X.21 or even V.35; so it might be a good choice if you want to segue into IP from ISDN, instead of going cold turkey.

I keep hearing stories about how some phone companies, in various parts of the country, are no longer accepting ISDN orders. Here in New York, Verizon still does, but the writing is on the wall. No matter where you are, and no matter what your local phone company supports today, tomorrow could easily see a big change.


Resources

AETA Audio Systems
AEQ Broadcast
Barix
Comrex
Musicam USA
Telos Systems
Tieline Technology
Worldcast Systems APT


Irwin is transmission systems supervisor for Clear Channel NYC and chief engineer of WKTU, New York. Contact him at doug@dougirwin.net.



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