[Letter of Provisional Authorization] [pdf]
PURPOSE
It is not always practical for a public safety radio system to have 100% coverage. This is especially true inside buildings in which different construction materials can block or attenuate radio signals. It would be cost prohibitive as well as almost impossible to get FCC licensing for a system to cover inside all buildings. There is a statewide public safety coverage requirement stated in the Washington Administrative Code(WAC). There is also local fire codes and requirements that must be followed. In order to reach this requirement, the most common solution is a Bi Directional Amplifier(BDA).
A BDA can take a usable received signal outside from a radio tower site and via antennas installed inside the building, amplify and distribute that signal throughout a building. It is also able to take the relatively low signal from a portable radio and amplify that signal to send to a radio tower site.
SNO911 SCOPE
SNO911 is responsible for verifying that any installed BDA using the Snohomish County 911 radio frequencies does not interfere or cause harm with the SNO911 public safety radio system. SNO911 is not responsible for verifying that the radio system coverage meets the requirements of the WAC or Authority Having Jurisdiction(AHJ).
AUTHORIZATION PROCEDURE
The vender will conduct testing to verify if a BDA is required. A Letter of Final Authorization will not be issued if it is discovered that a BDA is not necessary for the building.
The vender will fill out the Letter of Provisional Authorization(LOPA) and email it to This email address is being protected from spambots. You need JavaScript enabled to view it..
SNO911 will review the document and will return a signed version of the LOPA with donor site and azimuth information
Vender will verify that the donor signal level received from the site noted in the LOPA is sufficient and will contact This email address is being protected from spambots. You need JavaScript enabled to view it. if it is not. If not, SNO911 will issue a new LOPA with a different site and azimuth ad this verification will be repeated until a site with sufficient donor signal is determined.
Once donor site is finalized, the Vendor will complete the installation per AHJ requirements. The BDA is not to have the uplink portion activated until uplink tests have been completed by SNO911.
When installation is complete, the vendor will contact SNO911 at This email address is being protected from spambots. You need JavaScript enabled to view it. requesting to schedule uplink testing. A minimum of 72 hours advance notice is required although there is no schedule guarantee. As much advance notice as possible is requested.
A SNO911 representative will schedule uplink testing with the vendor.
After uplink testing is complete and it is determined that the BDA causes no interference or harmful effect to the SNO911 radios system, a signed Letter of Final authorization will be emailed to the vendor.
For any questions or support please contact: This email address is being protected from spambots. You need JavaScript enabled to view it.