As the broadcast industry continues to adapt to an all-digital workflow, the advent of IP-based systems has proliferated on almost every level, from capture and editing to distribution. One major area of broadcast where IP has not yet penetrated, however, is intercom. Most facilities still rely on existing, hard-wired, time-division multiplexing (TDM)-based architecture intercoms, which deliver dependable and quality performance but are expensive and difficult to extend into new or remote production areas. Until recently, delivering intercom capabilities over IP was not a viable option, simply because the audio quality was not good enough for broadcast purposes.
Yet the inherent cost-savings of delivering intercom over IP are an intriguing prospect, especially in the current economic environment. The flexibility of IP is also a draw, especially when broadcasters seek to upgrade their existing production and studio space through expansion into new areas of their current facilities or remote centers. The question then becomes: How can a broadcaster take advantage of the innate cost-savings in using its existing IP-based network to deliver intercom capabilities without sacrificing audio quality and the reliability of a traditional TDM-based intercom system?
Real-time intercom over IP
To address this situation, Clear-Com has recently acquired a different and advanced form of IP technology called I.V.Core (Instant-Voice Core), a set of building blocks and engines that enable real-time, dynamic and nonblocking intercom capabilities over standard IP networks. (See Figure 1.)
To date, I.V.Core is fully embedded into the company's Concert software-based intercom system, delivering audio-over-IP capabilities to new and traditional intercom systems. The associated hardware link is through the IVC-32, a 32-channel IP matrix card for the Eclipse Version 5.1 digital matrix system Median and Omega frames. The IVC-32 effectively connects Concert users on computers and Clear-Com V-Series IP panel users on a LAN or WAN to the existing, hard-wired intercom infrastructure.
This technology effectively expands the intercom footprint within a broadcast environment while addressing remote locations through an existing IP network and the Internet. For example, a remote production truck with Internet capabilities can actively access the intercom system back at the studio, or a creative team at the main office can link up to the studio while a production is in session. Armed with a laptop, USB headset (or embedded microphone and speaker) and a connection to the Internet, the computer screen now becomes a“soft panel” intercom system. This avenue opens up intercom communications to a wide range of users and locations, increasing productivity and allowing for more creative participation with a production.
I.V.Core is based on a decision-making engine that optimizes routing over standard networks, provides support for wideband codecs delivering high-quality audio, and features proprietary noise reduction and error recovery algorithms. Using AES 128-bit encryption for secure audio transmission, the system works over both wired and wireless packet-based networks such as the Internet.
While typical TDM-based and other IP systems simply mix or switch data, the I.V.Core bases its intelligent routing decisions on the audio needing to be routed, in effect making it an intelligent priority system. This maintains a low latency in the core while keeping control over network bandwidth. Only the active audio signal gets directed from source to destinations, allowing for efficient network-bandwidth utilizations that in turn permit the system to use wider-band codecs for a given system size. This is of great benefit to installed IP systems that are constantly bandwidth challenged through extensive traffic.
When combined with additional error recovery and noise reduction algorithms, the user can now experience high-clarity and low noise voice communication, even when using challenging connections such as the Internet, where IP-traffic priority is not guaranteed. With a client engine that sends and receives voice packets, the I.V.Core is capable of simultaneously handling several voice communications. It allows many clients to connect at the same time, forming a complete intercom network operating over standard IP. This technology can also scale much more effectively to higher numbers of users while maintaining a high tolerance to poorer quality or traffic-laden IP networks.
Current IP products are built using traditional and TDM-based connection protocols such as Session Initiation Protocol (SIP) or H.323. As a result, they do not adapt well to IP-connection problems such as Network Address Translation (NAT) and firewall traversal (present on most IP networks today because the nature of NAT is to hide an entire private address space behind a single IP address in, say, a more public space). The I.V.Core protocol uses only one IP connection port for linking all IP clients, simplifying the IT management while making audio (QoS) management possible by prioritizing audio packets in one IP port, making it a good choice for widely used NAT protocols. In addition, the protocol supports fixed IP and DHCP, offering more flexibility to the configuration.
Embedding the I.V.Core technology into intercom systems enables communication for broadcasters needing to expand intercom access into places where cabling may be cost-prohibitive. With the addition of a new high-density IP card for its Eclipse Matrix range, new users can now plug in to this new network from their IP-based, TDM-based intercom panels or Concert soft panel. The overall interoperability of the technology yields greater access by more users, enhancing creative flow and streamlining communications.
In this challenging financial environment, broadcasters are faced with mandated equipment and facility upgrades to meet the needs of the all-digital broadcast future, against a backdrop of dwindling resources. The I.V.Core technology, as expressed through the company's Concert Version 2.0 software and related hardware interfaces, addresses the broadcaster's need to restructure facilities and increase content production, while keeping a watchful eye on the bottom line.
Patrick Menard is director, worldwide sales, Concert, for Clear-Com Communication Systems.
