IP Codec Solutions From Vortex

Any old fool can send Audio over IP but there are many issues to overcome in keeping audio quality high and latency low.

The root of the problem is that IP and the Public Internet use packet-switched data and there is always the question as to whether packets get there in time, in the right order – if at all? The secret of success lies in using as little data as possible to provide the required quality on the basis that the less demanded of the connection, the more likely it is to get through. And if some of that data does not get through, the key is to make sure that it isn't missed whilst keeping delay to a minimum which is more difficult to achieve than it seems.

Vortex has been providing solutions that do this hard work for you, getting decent audio with low-delay even over the most difficult 4G/3G and satellite uplinks. Comrex ACCESS is the industry-standard when it comes to Outside Broadcast. Transporting audio is made easy via 3G/4G, WiFi or Ethernet and for robust connectivity, all connections can be utilised at the same time. The resourceful user interface provides an easy way for the user to connect calls as well as providing the technical team with all the options they need to make the best connection. Crosslock provides multi-streaming, intelligent Jitter Buffer Management, FEC and error masking offering unrivalled reliability over contended connections. The BRIC-Link II is a cut-down version of the ACCESS with fewer algorithms, but providing the same clever connection technology including Crosslock but at lower cost. Two desktop BRIC-Link IIs can be mounted in a 1U rack or when interfaced with our VX-4901 pushbutton panel, be used as an IP Intercom which provides 10 Quick-Dial connections.

Ease of connectivity is not forgotten and both BRIC-Link and ACCESS codecs are compatible with the Switchboard Server that acts as an address book, letting you to traverse NAT firewalls from both the front and back end allowing connections even between two mobile internet connections.

Vortex's new CallMe Click-and-Connect is an Internet Codec Service that lets stations put guests On-Air with high-quality audio without them having to have their own compatible codec or download special software, send round a reporter or have them come to the studio. It works with Comrex and other codecs and whilst the original idea was to get guests live, many use it for reporters as it works with browsers on mobiles also. As part of the CallMe setup, the Station gets its own web portal with its own station branding. We have an example on our web page which is a mock station called Ealing 104.8. The CallMe Link can be used by as many people as the station likes – there is no download – but of course, if there is only one back-end codec, there is only one-call-at-a-time and the subscription can be augmented to allow two or more simultaneous connections. Enterprise solutions are also available for stations that need large numbers of simultaneous connections.

It became obvious that some stations cannot afford to have full-featured Comrex and other codecs at their station and CallMe-TS (Studio Version) has been introduced as a low-cost studio back-end. It has no buttons but a web interface to set it up and for control. We then had requests to use two hardware CallMe-Ts as a low-cost way of using their Glensound ISDN mixers over IP but they needed some form of dialling – which is how CallMe-TS was born with two buttons on the front panel for quick preset dialling and a "drop" button to disconnect. It also has the browser interface for setup but users did not want to be forced to have a computer with them just to initiate a connection.

Our CallMe-T boxes are Audio Codecs (i.e. both directions), have balanced stereo audio in and out and provide Broadcast algorithms – Opus (15kHz low-delay), G.722 (7.5kHz low-delay) and G.711 (telephone algorithm) codecs.

For more information on how Vortex can help make Audio over IP easier for you, just head to www.vtx.co.uk, give us a call on 020 8579 2743 or just email [email protected] and we will get back to you right away.

This article is also available to read at BFV online as part of this issue's Audio feature here, page 36.

(JP/LM)