About Voice over Internet Protocol
Voice over Internet Protocol (VoIP) is a broad, emerging technology area that allows for the transmission of real-time voice services through Internet Protocol (IP)-based networks. The use of IP networks as the transport mechanism enables significant flexibility in call placement options, device addressing, and device placement.
Additional flexibility is achieved because devices can connect by directly addressing each other over any network; with VoIP, there is no need for the burdensome switching, routing, and billing infrastructures that are typically used for telephone services. In fact, the use of IP-based networks enables voice transport between any two devices connected to the network—provided the security policies allow access and VoIP has been implemented in an interoperable manner.
Due to these advantages, public safety radio manufacturers have begun to implement VoIP in the bridges, consoles, radios, and other equipment that form a radio system’s infrastructure.
Public Safety VoIP Working Group
As manufacturers have begun implementing VoIP in their products, confusion has been growing around the use of the technology in public safety communications. To address this problem, the U.S. Department of Homeland Security (DHS) and the U.S. Department of Commerce (DOC) gathered key stakeholders from the public safety and industry communities to form a working group. Led by DHS’s Office for Interoperability and Compatibility and DOC’s Public Safety Communications Research Program, the Public Safety VoIP Working Group works to define and clarify the expectations for VoIP in the public safety environment.
Public Safety VoIP Working Group Fact Sheet
VoIP Interfaces
By limiting discussions to agency-to-agency communications, working group members were able to develop a list of nine application areas in which VoIP could improve public safety communications. Each of these application areas occurs as an interface, or connection, between pieces of communications equipment. The practitioners participating in the VoIP Working Group selected the following five VoIP interfaces as their current priorities:
- Radio System Interface – an interface that enables VoIP communication to radio system infrastructure
- Dispatch Interface – an interface to a dispatch console
- End Unit (Software Device) Interface – an interface that allows a network-connected computing device to connect into a radio system using a software implementation
- Radio Site Interface – an interface to a base station or similar device
- Bridging Systems Enhanced Interface – additional functions of the BSI Core Profile, an interface between bridging or gateway devices
Guiding Principles
After identifying potential VoIP interfaces, the Working Group developed a number of general principles for VoIP-based public safety communications systems. Systems must meet these guidelines to ensure acceptance within the public safety community. These requirements specify that each VoIP interface is:
- Compatible and interchangeable
- Reliable
- Affordable
- Scalable
- Manageable
In addition, the Working Group required all VoIP interfaces to include a common security framework, possess a minimum set of standards and features, and leverage commercial off-the-shelf products.
Implementation Profiles
Given the need for standardized implementations, the Working Group is producing specifications, or implementation profiles, for each of the potential VoIP interfaces. The first interface addressed by the Working Group was the Bridging Systems Interface.
VoIP Plugfest and Roundtable Meetings
The Working Group held its first Roundtable discussion in August 2006 to discuss VoIP’s strengths and limitations, to define the requirements for its effective use, and to recognize the need for VoIP specifications. The VoIP Roundtables gather practitioner, Federal, and industry representatives to discuss VoIP priorities and work face-to-face on Implementation Profiles.
The first Plugfest, held in November 2007, brought together industry representatives to test their radio equipment using the Working Group’s BSI Core Implementation Profile. There have since been additional Plugfests to test and accept the BSI Core Profile.
Click here to access the VoIP Plugfest and Roundtable Meeting Reports.
For more information on upcoming meetings, please contact VoIP_Working_Group@sra.com.
Related Links