Friday, September 05, 2014

Acquiring Studio Quality ISDN BRI Audio Lines

By: John Shepler

ISDN BRI has been the gold standard for audio connections between studios, film production companies, and radio station broadcast locations. One problem is that ISDN BRI service has been getting more expensive and harder to find as of late. In some areas, the old faithful telephone companies have simply refused to provision new ISDN BRI lines. Does that mean you are out of luck for your voice over work or remote broadcasts? Not anymore.

Find ISDN BRI service now.New BRI Service, Not Telco
What’s new is the arrival of a nationwide ISDN BRI line service provided by a company in the audio production business, not the telephone companies. Truth be told, ISDN BRI isn’t a very important service for telcos. It has very specialized uses. Phone companies would really like to phase it out so they can concentrate on higher volume products. In some areas, they are already not accepting orders for moves, adds or changes.

Alternative Approaches
So where does that leave people who’s livelihood depends on high quality audio service connections? One approach is to record the program material and then transport it as you would any other file using the Internet. That’s preserves the quality but is hardly real-time. Another approach is to go with the flow and move to IP network services. These include private lines and the Internet. Private lines give you the quality and immediacy you need, but only go between designated locations. The Internet can be found everywhere, but performance for real-time audio can leave a lot to be desired.

ISDN BRI Still Best
The best option is to stick with a winner, ISDN BRI, but get the service from a nationwide provider, not the local phone company. Source Elements, a major player in the professional audio field, is now offering ISDN BRI service as a complement to their IP Audio and other services.

ISDN BRI is so desirable because it provides an industry accepted method of connecting live audio at high quality between any two facilities that are set up for the service. It’s a dial-up service that works something like your POTS phone line. You dial the ISDN number of the location you want to connect with. Terminal equipment at each end make the connection and you have an FM broadcast quality link for the duration of the call.

BRI For Voice Acting
A very popular use for iSDN BRI is in the voice acting or voiceover business. Professional announcers and actors can voice their lines without having to be present in the recording studio. This includes ADR or “looping” for film recording. What’s required is an ISDN BRI connection at each end along with a CODEC (CODer/DECoder) to handle to analog to digital to analog conversions. Standard microphones and control boards can generate the audio feed to the CODEC.

How It Works
You might think of ISDN BRI as a really high quality phone line. In fact, it is. ISDN stands for Integrated Services Data Network. It uses the switched circuit architecture of the public telephone system and standard twisted pair telephone wiring. Each ISDN line has a telephone number that can be called by any other ISDN line.

What’s different is the signal being transported. Instead of analog currents, ISDN is a digital format. There are two versions: BRI and PRI. BRI stands for Basic Rate Interface. It consists of 2 “B” or bearer channels and one “D” or delta channel. The bearer channels carry the digital audio. The D channel is used for system signaling. The bearer channels can be used separately at 64 Kbps each or bonded together for a 128 Kbps channel. Two bonded channels plus compression such as AAC or MP3 delivers studio quality microphone vocals.

Bidirectional and Low Latency
It should be noted that ISDN circuits are bi-directional. That’s a big selling point for audio work. A voice actor can be delivering lines through a microphone and receiving direction from the studio through headphones without the disturbing latency or time delay that plagues Internet services. ISDN is not a shared bandwidth service, so there is no such thing as network congestion causing dropouts in the signal.

You might recognize ISDNs larger service, PRI or Primary Rate Interface, as the telephone trunking standard used by many PBX business telephone systems. It is organized the same as BRI, but has 23 B channels and one D channel to support 23 simultaneous telephone calls. PRI is likely to be around for many years to come, although it is being challenged by SIP Trunks as a telephone transport technology.

How to Acquire New ISDN BRI Service
Do you have an audio application such as having a voiceover or voice acting business, a radio station with need for high quality remote broadcasts or studio to transmitter link, or a production studio that needs to connect with talent and other studios? If so, ISDN BRI may still be your connection of choice. Get a quote on competitive ISDN BRI service for your particular location now.

Click to check pricing and features or get support from a Telarus product specialist.

Follow Telexplainer on Twitter