ModUcom has released a new Telephone Gateway Card (TGC) designed to assist Public-Safety Answer Points (PSAPs) in their migration to NG911 operation by enabling new and existing ModUcom dispatch systems to interface with new digital VoIP telephone infrastructure.

It will be a number of years before the Next-Generation 911, or NG 911, standard transforms the PSAP landscape. The vision is for call-taking systems to receive text, video and other data formats from the public along with voice calls using an all-IP backbone. In the interim, there will still be a need for PSAPs to continue to handle analog calls, on both the E911 and administrative side, since local phone companies may delay migrating their systems to all IP.  ModUcom now has a seamless solution for both of these infrastructure connection methods.

ModUcom’s new TGC plays a key role in providing a voice connection using IP packets to transmit voice call data over private secure networks. In many cases, it can replace the costly analog interface between the ModUcom dispatch system and a VoIP PBX telephone system for administrative phone extensions. Previously PSAPs often had to maintain separate interface equipment that would convert administrative VoIP calls on their local PBX phone system to analog phone line calls.  Upcoming NG911 PSAPs may also have the need for conversion equipment to convert NG911 IP connections into analog CAMA trunk lines.  In many cases, this conversion equipment is no longer needed. ModUcom’s TGC incorporates that functionality and enables NG911 and Administrative VoIP calls over an IP connection that will travel over a PSAP’s Next-Generation 911 infrastructure.

ModUcom’s TGC provides an interface to either eight NG 911 emergency telephone calls or eight VoIP administrative phone line extensions. As the National Emergency Number Association (NENA) rolls out more specifications for NG 911, ModUcom plans to support them as the standards are finalized.

For the VoIP administrative phone extension interface, ModUcom has implemented a SIP VoIP interface that enables a direct IP connection to a VoIP-based PBX or a PBX that is capable of handling SIP phones. That means the conversion from analog to IP is no longer needed. The dispatcher has access to the following features: incoming call, outgoing call, incoming caller ID, DTMF touch-tone dialing for accessing voice menus, voicemail, hold function, transfer function and conferencing with other phone lines and radio channels present in the ModUcom system. These functions operate identically to the existing analog phone card user interface so ModUcom customers can mix-and-match a combination of analog and IP interfaces in a system, as their needs require. 

Police, fire and other emergency personnel must often perform their jobs in rugged terrain and jurisdictions that cover miles and miles of sparsely populated regions, making critical radio communications challenging.

While public-safety agencies have high-power fixed transmitters with adequate receivers and antennas, the lower power mobile units used by first responders can't always be heard well by dispatchers at the dispatch center. In cases where there are multiple base station receivers, dispatchers are likely to pick up transmissions from several different receiving sites, especially if those sites are located on various mountaintops and first responders are trying to transmit from the valley below. The incoming audio heard by the dispatcher is often a mix of static and multiple receive audio sources at the same time. This often results in poor quality field unit audio being heard by the dispatcher.

The public-safety vendor community has solved this problem by implementing what is called a Voting Comparator system that is capable of automatically selecting the best receive signal by combining radio channels located at multiple sites into one voting group. When audio is received from one or more sites in a voting group, the system chooses the best quality audio from the receiving channels and presents the audio to the dispatchers.

Most voting systems, however, come in the form of expensive external equipment. ModUcom has implemented the system as a standard, built-in internal feature in ModUcom’s latest version of its E911/Radio Dispatch Control System. The voter function is a software feature in every dual-radio channel card, and it’s a feature that is offered for free to ModUcom’s customers. External voting systems can cost as much as $60,000 in some cases.

ModUcom’s voting feature incorporates sophisticated digital signal processor algorithms to provide precise and fast voting operation and supports Status Tone and E-lead receiver status inputs. The voting function can also be used to automatically steerthe dispatcher responding transmit audio to the site that was last voted. This automatic Steering selection can provide quick and accurate transmitter site routing when seconds count.

While not all of ModUcom’s customers require voting systems today, this built-in free feature offers public safety a future-proof product that can be deployed in areas where voting may be required in the future.

ModUcom recently introduced the Ultra-Com IP25 product that supports the P25 DFSI. The system's standard features include the following features for the dispatcher:  Unit ID, Call Queue Display, voice Encryption, Call Alert, Radio Check, Radio Monitor, Radio Inhibit/Un-Inhibit, Unit-to-Unit Call, Status Query, Short Message, Talk Groups, Radio Frequency Control, Emergency Call, Voting indication and control, Digital/Analog mode, Radio Patch, Phone Patch and Phone Conference.. It is capable of encrypting voice audio using the AES, DES and TDES encryption methods with multiple authentication keys.

These new features that are included in the P25 Digital Fixed Station Interface add significant value for public-safety operations. This conventional P25 radio solution is ideal for agencies operating smaller systems that in the past may have purchased expensive proprietary trunked radio systems with just a few channels in order to support certain features such as encryption, unit ID and multiple talk groups. The open, non-proprietary nature of P25 radio equipment allows agencies to mix and match radios from multiple manufacturers instead of being locked in to one manufacturer's expensive product line.

ModUcom has completed compatibility testing of the P25 Digital Fixed Station Interface with a number of radio manufacturers and will continue work with new companies as they develop their DFSI interface.

P25 equipment compliance testing is now in full swing. The Department of Homeland Security established a program called the P25 Compliance Assessment Program (CAP), a voluntary program managed by the National Institute of Standards and Technology’s (NIST) Office of Law Enforcement Standards in partnership with a coalition of emergency agencies and communications equipment manufactures. The CAP program requires that manufacturers’ radios be tested for performance and interoperability using labs set up via an objective assessment process. P25 equipment suppliers are then required to release a summary of their test reports and declare they are compliant with the P25 standard based on that testing.  The U.S. Department of the Interior also has a P25 testing laboratory for testing P25 compatibility among manufacturers of P25 radio and dispatch equipment.