Last updated
Tieline Technology
Private company
Industry Broadcasting
FoundersRod Henderson, John Gouteff
ProductsBroadcast IP audio codec
Website http://www.tieline.com

Tieline Technology has offices in Indianapolis in the United States (Tieline America LLC) and in Perth, Western Australia (Tieline Pty Ltd). The company has a wide and established distribution network throughout Europe, the Americas and Australasia. Tieline develops a range of broadcast audio codecs that are sold to television and radio networks around the globe. All Tieline codecs are IP codecs, ISDN codecs, POTS codecs, GSM codecs, X.21 codecs and satellite-capable (IP and ISDN) codecs.

Indianapolis State capital and consolidated city-county in the United States

Indianapolis, often shortened to Indy, is the state capital and most populous city of the U.S. state of Indiana and the seat of Marion County. According to 2017 estimates from the U.S. Census Bureau, the consolidated population of Indianapolis and Marion County was 872,680. The "balance" population, which excludes semi-autonomous municipalities in Marion County, was 863,002. It is the 17th most populous city in the U.S. The Indianapolis metropolitan area is the 34th most populous metropolitan statistical area in the U.S., with 2,028,614 residents. Its combined statistical area ranks 27th, with a population of 2,411,086. Indianapolis covers 368 square miles (950 km2), making it the 16th largest city by land area in the U.S.

IP codecs are used to send video or audio signals over an IP network such as the Internet. The initials "IP" here stand for "Internet Protocol", while the term "codec" is short for "encoder/decoder" or "compressor/decompressor".

A POTS codec is a type of audio coder-decoder (codec) that uses digital signal processing to transmit audio digitally over standard telephone lines at a higher level of audio quality than the telephone line would normally provide in its analog mode. The POTS codec is one of a family of broadcast codecs differentiated by the type of telecommunications circuit used for transmission. The ISDN codec, which instead uses ISDN lines, and the IP codec which uses private or public IP networks are also common.


Broadcasters use these codecs for remote broadcasts (outside broadcasting), for audio distribution between studios and for studio/transmitter link (STL) applications. Tieline codecs are Session Initiation Protocol (SIP) compatible and Tieline and ten other codec manufacturers have successfully tested IP Interoperability using SIP to connect according to EBU N/ACIP tech 3326 specifications relating to sending audio over IP.

In broadcast engineering, a remote broadcast is broadcasting done from a location away from a formal television studio and is considered an electronic field production (EFP). A remote pickup unit (RPU) is usually used to transmit the audio and/or video back to the television station, where it joins the normal airchain. Other methods include satellite trucks, production trucks and even regular telephone lines if necessary.

Outside broadcasting Remote production of television or radio programmes

Outside broadcasting (OB) is the electronic field production (EFP) of television or radio programmes from a mobile remote broadcast television studio. Professional video camera and microphone signals come into the production truck for processing, recording and possibly transmission.

The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, and terminating real-time sessions that include voice, video and messaging applications. SIP is used for signaling and controlling multimedia communication sessions in applications of Internet telephony for voice and video calls, in private IP telephone systems, in instant messaging over Internet Protocol (IP) networks as well as mobile phone calling over LTE (VoLTE).


The company was founded in 1981 by John Gouteff and Rod Henderson. In 1981 Television Communications Pty Ltd formed to import and distribute broadcast audio and video products into the Western Australian market. During the next 14 years, TVC achieved major installations into most Television stations, private video organizations and government departments. TVC also developed and manufactured a range of video switching and distribution products.

In 1995 TVC became Audio Video Communications (AVC). The growing range of video products expanded heavily into audio products including radio Broadcast Mixing consoles, signal measurement, conversion, and amplification products, which it sold throughout Australasia.

In 1998 AVC identified a growing market for digital audio codecs required to deliver live, studio quality audio over narrow band networks such as analogue telephone and ISDN links. AVC developed a family of world class digital POTS codecs and ISDN codecs. These were branded under the name Tieline and between 1998 and 2001 AVC developed a global distribution network spanning the Americas, Europe, UK, Africa, Asia, Middle East and Australasia.

An audio codec is a codec that encodes or decodes audio.

The first audio codec produced was a POTS codec called the Patriot, which was the first in the world able to send 15 kHz CD quality audio over a regular phone line. The company won numerous awards for its codec range and became better known to its customers for the brand Tieline than its name AVC. In 2002, having successfully secured www.tieline.com and relevant trademarks, AVC became Tieline Technology.

The company now focuses on [1] IP audio codec solutions that include broadcasting over wireless 3G, 4G and 5G cellular broadband networks and can multicast and multiple unicast audio streams across all types of IP audio networks. [2] In 2010 Tieline became the first company to create an IP audio codec application called Report-IT to run on the Apple Inc. iPhone. The application is used for live broadcasting and recording interviews and sending them to a remote studio via file transfer. In 2012 the application became so popular with broadcasters, with over 10,000 downloads, that the company released an Android version of the application for smartphone users. There have been tens of thousands of downloads of Report-IT since its release. In December 2012 the company announced the integration of the Opus codec into Report-IT and Genie, Merlin, Bridge-IT and ViA IP audio codecs for interoperability. [3]

An IP audio codec is used to send broadcast-quality audio over IP from remote locations to radio and television studios around the globe. A codec that uses Internet Protocol (IP) may be used in remote broadcasts, as studio/transmitter links (STLs) or for studio-to-studio audio distribution. IP audio codecs use audio compression algorithms to send high fidelity audio over both wired broadband IP networks and wireless 3G, 3.5G, 4G and 5G cellular broadband networks.

3G, short for third generation, is the third generation of wireless mobile telecommunications technology. It is the upgrade for 2G and 2.5G GPRS networks, for faster data transfer speed. This is based on a set of standards used for mobile devices and mobile telecommunications use services and networks that comply with the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union. 3G finds application in wireless voice telephony, mobile Internet access, fixed wireless Internet access, video calls and mobile TV.

4G is the fourth generation of broadband cellular network technology, succeeding 3G. A 4G system must provide capabilities defined by ITU in IMT Advanced. Potential and current applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D television.

IP audio broadcasting and SIP (session initiation protocol)

Tieline being used in a transmission at the National Stadium of Brasilia Mane Garrincha, Brazil. Tieline in Brasilia.jpg
Tieline being used in a transmission at the National Stadium of Brasilia Mane Garrincha, Brazil.

Tieline Technology has committed considerable resources to educating television and radio broadcasters about IP audio generally, broadcasting IP audio over [4] wireless IP audio technologies, as well as how to reliably send internet IP audio over Ethernet. [5] The company has worked closely with the EBU, broadcasters and IP codec manufacturers to introduce broadcast standards for audio interoperability over IP according to [6] EBU N/ACIP Tech 3329. [7] The integration of Session Initiation Protocol (SIP) into IP codecs has been central to achieving this objective and Tieline codecs were amongst the first to trial and integrate SIP reliably.

Audio-via-IP Experts Group

Tieline Technology was a member of the Audio-via-IP Experts Group as a technology provider advising on the interoperability of audio codecs when broadcasting IP audio. [8] Tieline and other Group members collaborated on interoperability when developing new audio over IP enhancements and made recommendations to the European Broadcasting Union regarding IP audio codec standards.

Broadcasting distribution of audio and video content to a dispersed audience via any audio or visual mass communications medium

Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum, in a one-to-many model. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and receivers. Before this, all forms of electronic communication were one-to-one, with the message intended for a single recipient. The term broadcasting evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as early as 1898.

European Broadcasting Union alliance of public service media entities

The European Broadcasting Union is an alliance of public service media organisations, established on 12 February 1950. The organisation is made up of 116 member organisations in 56 countries, and 34 associate members from a further 21 countries. It is best known for producing the Eurovision Song Contest. It also hosted debates between candidates for the European Commission presidency for the 2014 and 2019 parliamentary elections but is unrelated to the European Union itself.

Tieline Research

Tieline Research is one of the Tieline group of companies and it developed the Tieline audio codec range and has also developed proprietary audio and video management systems for broadcast and surveillance industries around the world.

SMD Assembly

SMD Assembly is one of the Tieline group of companies and provides precision Surface Mount Device assembly services. It uses the latest surface-mount technology equipment to create printed circuit boards (PCBs) to military specifications.

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A video codec is an electronic circuit or software that compresses or decompresses digital video. It converts uncompressed video to a compressed format or vice versa. In the context of video compression, "codec" is a concatenation of "encoder" and "decoder"—a device that only compresses is typically called an encoder, and one that only decompresses is a decoder.

Ericsson Television, formerly Tandberg Television, is a company providing MPEG-4 AVC, MPEG-2 and HEVC encoding decoding and control solutions, plus stream processing, packaging, network adaption and related products, for Contribution & Distribution (C+D), IPTV, Cable, DTT, Satellite DTH and OTT.

IBM Sametime is a client–server application and middleware platform that provides real-time, unified communications and collaboration for enterprises. Those capabilities include presence information, enterprise instant messaging, web conferencing, community collaboration, and telephony capabilities and integration. It is sold by the Lotus Software division of IBM.

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A video server is a computer-based device that is dedicated to delivering video. Video servers are used in a number of applications, and often have additional functions and capabilities that address the needs of particular applications. For example, video servers used in security, surveillance and inspection applications typically are designed to capture video from one or more cameras and deliver the video via a computer network. In video production and broadcast applications, a video server may have the ability to record and play recorded video, and to deliver many video streams simultaneously.

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The International Multimedia Telecommunications Consortium (IMTC) is an organization consisting of several companies interested in real-time, rich-media communications. Rich media includes voice and one-way data and one-way video. Members of this community include Internet application developers and service providers, teleconferencing hardware and software suppliers and service providers, telecommunications service providers and equipment vendors, end users, educational institutions, government agencies and non-profit corporations. On July 28, 2014 IMTC and the Unified Communications Interoperability Forum (UCIF) merged into one consortium. The UCI Forum defined interoperability profiles and certification tests, implementation guidelines, and best practices for interoperability between UC products and existing applications.

The Telos Alliance is an American corporation manufacturing audio products primarily for broadcast stations. Headquartered in Cleveland, Ohio, USA, the company is divided into six divisions:

Audio over IP (AoIP) is the distribution of digital audio across an IP network such as the Internet. It is being used increasingly to provide high-quality audio feeds over long distances. The application is also known as audio contribution over IP (ACIP) in reference to the programming contributions made by field reporters and remote events. Audio quality and latency are key issues for contribution links.

Wideband audio, also known as wideband voice or HD voice, is high definition voice quality for telephony audio, contrasted with standard digital telephony "toll quality". It extends the frequency range of audio signals transmitted over telephone lines, resulting in higher quality speech. The range of the human voice extends from 80 Hz to 14 kHz but traditional, voiceband or narrowband telephone calls limit audio frequencies to the range of 300 Hz to 3.4 kHz. Wideband audio relaxes the bandwidth limitation and transmits in the audio frequency range of 50 Hz to 7 kHz or even up to 22 kHz. In addition, some wideband codecs may use a higher audio bit depth of 16-bits to encode samples, also resulting in much better voice quality.

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AES67 is a technical standard for audio over IP and audio over Ethernet (AoE) interoperability. The standard was developed by the Audio Engineering Society and first published in September 2013. It is a layer 3 protocol suite based on existing standards and is designed to allow interoperability between various IP-based audio networking systems such as RAVENNA, Livewire, Q-LAN and Dante.

ipDTL is an IP codec running in a Web-browser and used for remote broadcasts in television and radio, as well as voice-over. It is a replacement for classic ISDN audio codecs, with which it has backward compatibility. It is also capable of video transmissions and can be used in the field with some mobile devices.

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  1. Kovacs, Bob, "AoIP Grows Up and Sprouts Legs", "Radio World Magazine", 12th Feb, 2009.
  2. Eldorado Recording Services, http://eldorec.com/eldoblog/2010/4/19/nab-wrapup-yellowtec-intellimix-tieline-report-it-live.html, 19 April 2010.
  3. "Tieline Integrates OPUS into Report-IT and IP codecs". Radio Magazine. 2012-12-18. Archived from the original on 2013-05-09. Retrieved 2012-12-18.
  4. Mcland, Paul J., "Tieline Sees the Power in Wireless", "Radio World Magazine", 4 July 2007.
  5. Davies, Glenn, "IP Broadcasting and Session Initiation Protocol", "Radio (magazine)", June 1st, 2008.
  6. EBU Audio Contribution over IP
  7. Scherrer, Chriss, Editor , "Establishing a SIP Connection", "Radio (magazine)", June 1st, 2008.
  8. Radio World Magazine, , "Tieline Ties with Audio-IP Group", 17th Jan, 2008.