Internet Protocol Intercom Systems: A New Trend in Justice Facilities


Traditionally, intercom systems in the correctional setting have been analog-based switching and voice delivery. They offer very little in the form of management and/or control of voice intelligibility.

In addition, complicated relay switching systems had to be designed to accommodate different control points and multiple voice paths. Intercoms and paging speakers were often installed utilizing the same amplifiers and a balance of volume had to be created when trying to communicate with a dayroom versus a single cell. This variance in spaces and lack of control create an environment in which it is difficult to achieve good sound quality and voice intelligibility.

A somewhat new trend has begun toward Internet Protocol-based systems, which have been popping up in video surveillance, door control and other secure-environment systems in the correctional market.

As Internet Protocol-based systems continue to mature and gain functionality, a close look must be given to the added capabilities that may benefit an organization. We have seen the digital and network video recorders become a mainstay in the security industry. In an effort to standardize on a single communications philosophy, convergence of security and telecommunications has driven the need for all systems to communicate on a more global level. As the Internet has demonstrated, IP is the protocol to achieve this desired communications strategy.

IP-based intercom systems have increased in popularity and decreased in cost. For several years voice over IP (VoIP) systems have been utilized in telecommunications applications. Recently companies have developed intercom systems based on the same principles, transmitting VoIP and providing digitally managed switching.

IP intercom systems have additional features that go beyond the traditional systems. Keep in mind that the features will vary from manufacturer to manufacturer.

Management and Control

IP-based intercom systems have the ability to provide control of intercom stations on a case-by-case basis.

Volume levels can be adjusted with certain ranges to help make up for less than desirable acoustic environments, such as housing cells. Individual selection of volume levels, speakers for dayroom communication and cell intercoms can be set at the optimum level for the specific application.

In addition to the control possibilities, there is a capability to manage where calls are routed, either after a period of no answer, or on a time basis. This allows call management to transfer a call to a different control point in the event a control center is busy answering something more critical, or has been de-manned during a third shift.

Priority can also be given to specific stations, which allows interruption of calls or an alert to be issued. This can create an emergency call system that will enable officers to receive an alarm and hear what is happening in a particular location. An immediate camera call-up and recording of both voice and video can be accomplished by tying the systems together.

Logging of all calls and recording based upon events can also easily be accomplished. This added voice record and log of the call time and date, as well as response/answer times can be crucial to effective management. Recording the audio portion of an event can sometimes help determine what actually took place during an incident. This can be extremely valuable to forensic investigation of incidents that occur in a facility.

IP-based systems often utilize standard networking architecture and devices. The same type of switch used to transfer data on your facility local area or wide area networks can be used to transmit voice. This enables transfer of voice to remote areas within a facility or outside the facility. By utilizing the same networking infrastructure, the addition of intercom over IP (IoIP) to your facility can be simplified. The possibilities of wireless and fiber optic integration make the IP solution potentially unlimited in both capacity and distance.

The systems are also capable of self-monitoring. In the event that a component is not operational, the system will alert either the operator or a management computer to the failed device.

As other systems migrate to IP, integration between systems will become less complicated, which in turn should make the dreaded start-up of a new facility less of the burden it has traditionally been. In addition, the system integrators, which are responsible for making everything work together, should have an easier job of achieving operational compatibility.

Some manufacturers offer systems with interfaces to existing analog systems that make the migration or upgrades more cost effective by negating the need to replace legacy systems and the intercom stations themselves — a great alternative when adding on to an existing facility.

The Case for IP-Based systems:

  • High quality audio over Ethernet, wireless and fiber 
  • Easy expansion to hundreds of stations 
  • Seamless connection over LANs and worldwide WANs 
  • Remote listening, paging and transfer capability 
  • PC-based or stand-alone operation
  • Integrated access control, video surveillance, duress and perimeter system operation
  • Fast deployment, easy maintenance and flexible configuration

Michael Havens is a systems designer for the correctional and civic markets, and has experience with programmable logic controllers, locking controls, alarm reporting and access controls, intercommunications, CCTV/MATV/CATV, PC-based controls, perimeter intrusion detection, duress and fire alarms, and uninterruptible power supply systems.