DALLAS, Oct. 13 /PRNewswire/ -- BearCom Wireless Worldwide has been selected as the installation and integration subcontractor for the South Central VA Health Care Network (VISN 16) -- a part of the Veterans Health Administration. The BearCom-provided equipment will become an integral part of this new communication system. This system is the first Project 25 digital simulcast system built and commissioned by an independent two-way radio distributor instead of a major radio manufacturer. Additionally, this two- part radio system is the first Project 25 digital multicast system to use Ethernet to transport audio, and is one of the first cases of true RF to IP analog to digital and back again.
VA Communications Project Manager, Dave Chagnon, was tasked with upgrading all two-way and one-way radio communication systems to narrow band operation by January 1, 2005. This is largely due to a federal mandate stating all government operations must use VHF narrowband frequencies by the year 2005 and UHF narrowband frequencies by 2007.
Mr. Chagnon chose TransTel Central of Norman, OK as the primary vendor. After completion of system design and site preparation construction, TransTel awarded BearCom with the bid to provide equipment and install the system.
Phase I of the project is staging. The BearCom headquarters in Dallas, Texas has served as the staging and simulation area for the individual sites. Infrastructure components are rack mounted so that the majority of finished equipment can be shipped all at once to reduce installation time at the sites.
Phase II consists of the actual installation of equipment at each site location, while Phase III is equipment optimization. After both of these phases are complete, the customer will inspect the system for acceptance, a 30-day test period will ensue, and removal of the old equipment will mark each site’s completion. Phase III is scheduled for completion by January 1, 2005.
The system consists of 39 Motorola Analog Quantar repeaters, which supply campus radio coverage for all non-public safety departments at each of the VISN’s 10 Medical Centers. The VA Police departments at each facility will be supplied with Motorola Project 25 Quantar repeaters with Digital Interface Units. Project 25 repeaters were chosen because of their maximum effectiveness at transmitting clear audio. All digital repeaters and associated equipment will be supplied with AES (Advanced Encryption Standard) encryption, the highest form of encryption available.
The hospitals will also receive a new paging system designed with redundant paging transmitters and an automatic cutover panel. This will insure that if one transmitter fails, radio transmissions will immediately switch over to the second transmitter via the cutover panel -- a piece of equipment that sits between the two racks of transmitters. This was essential, since the hospitals and E.R. personnel at each location rely on paging communications to treat their patients.
BearCom and TransTel have already successfully designed, staged, optimized and commissioned a new radio system at six of the sites. One of these sites (Central Arkansas Veterans Healthcare System located in Little Rock, Arkansas) is a two-site system which consists of three simulcast analog VHF channels, one simulcast VHF digital Project 25 channel with AES encryption, and one simulcast VHF paging channel.
Because it is a simulcast system, every radio transmission consists of two signals instead of one. Each analog Quantar repeater in the system is interfaced through a Harris channel bank to a Motorola DigiTac comparator. The Harris channel bank moves audio signals between locations, while the comparator chooses which of the two signals has better clarity. The comparator then feeds the selected audio back to the Quantar repeaters via the Harris channel bank.
System timing is controlled by both the Harris channel bank and Convex equalization / delay devices, which synchronize the two transmitted audio signals. Without this, the two separate transmissions would arrive at different times and sound garbled. Finally, the Project 25 digital Quantars feed V.24 (digitized audio) synchronous signals back to a Motorola AstroTac comparator for relay.
The paging system consists of a terminal sending pages to a controller. The Zetron model 600 controller was chosen because it uses a GPS time stamp, which controls the timing of the pages when they are sent to controllers at each site. The GPS timing ensures two signals will be synchronized within a millisecond of each other.
At each site, Vytek transmitters are used to send the pages simultaneously. Vytek also supplied an automatic cutover panel in the event there are problems with the main paging transmitter. If this happens the panel will cause a cutover to the backup-paging transmitter automatically.
In another example, BearCom and TransTel have also successfully designed, staged, optimized and commissioned a new radio system at a second site which is comprised of two locations, the VA Medical Center in Muskogee, Oklahoma and the VA outpatient clinic in Tulsa. The two-site system consists of two single-site analog VHF channels serving the support needs of the Muskogee Medical Center and one VHF digital Project 25 channel with AES encryption supporting the VA police at both locations.
The system consists of one single site redundant VHF paging channel, Quantar transmitters for the voice channels and Vytek transmitters for paging. The system provides connectivity to the VA personnel with multiple Zetron model 4010 consoles and Zetron model 284 remotes, just like the system installed at the Little Rock location.
What is different, however is the link between the two Quantar repeaters utilizes the VA Ethernet network, while maintaining the Project 25 signal in its native V.24 synchronous format. The benefit to this is being able to connect two repeaters through an existing network instead of paying monthly lease fees for an additional line. And, by preserving the native digital signal between the two repeaters, recovered audio quality remains the same regardless of which site the transmitting unit is located.
This two-part radio system is the first Project 25 digital multicast system using Ethernet to transport audio that has been built. It is also one of the first cases of true RF to IP convergence in the history of the industry. Now, instead of converting signals from analog to digital and back again (which can cause decreased clarity of the signal), it is possible to keep the signal digital the entire time of transmission, thus providing the maximum clarity.
BearCom Wireless Worldwide was founded in 1981 and today is a global provider of wireless communications equipment and tailored solutions. BearCom sells, rents and services a broad line of two-way radios, cellular telephones and wireless networking solutions. BearCom is the nation’s largest distributor of Motorola. For more information, contact your local BearCom branch today or visit http://www.bearcom.com/ .
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Contact: Tom Renick
(214) 765-7544
BearCom Wireless Worldwide
CONTACT: Tom Renick of BearCom Wireless Worldwide, +1-214-765-7544
Web site: http://www.bearcom.com/