Calvert County has implemented their communications system "rebanding" effort. This is a process that moves the county trunked "walky-talky" system to a different set of frequencies. This is due to an interference problem that was noted as occuring a number of years ago.
Rebanding - The RadioReference Wiki is a link to a comprehensive explanation of the issue, what scanners are affected, where to get scanner software updates (if available), which scanners WON'T need an update, etc. etc.
Here is a excerpt of the technical explanation of the situation:
When the 800 MHz band was originally created, two segments of the spectrum were set aside for Cellular Telephone (mobile and base). Public Safety was later assigned a block of frequencies, and "SMR" (community repeater), "ESMR" (Nextel), and public safety services were allowed on the remainder of frequencies. However, unlike in other bands where licensee types were allocated to contiguous blocks of frequencies, in the 800 MHz band Public Safety, SMR, and ESMR services were all mixed together. During the 1980's and 90's, Nextel created a nation-wide network by buying up thousands of individual licenses for frequencies between 851-866 MHz.
A Brief History of Mobile Comms and Trunking
Public Safety systems are not operated for profit, and typically use a "high site" architecture, where a few base stations with power output in the 100-200 watt range are located on tall buildings and hill tops. This results in lower signal strength over a wide coverage area. Nextel and other ESMR systems use a "low site" or cellular type architecture, with many base stations installed on 1-3 story buildings and 30-50 ft monopoles to create high signal density and greater user capacity over their coverage area. These ESMR sites transmit continuously with ERP of as much as 1000 watts. The presence of these sites, and the RF energy they generate in close proximity to public safety operations, causes radios used by public safety to lose contact with their more distant base stations.
APCO Project 39
In the late 1990's, the FCC was forced to acknowledge that there was a problem. The number of interference complaints to public safety were rising, and the popularity of the ESMR services that were primarily blamed for the interference was also rising, with no end in sight. Something had to be done. The FCC solicited input from the various users groups to determine the best course of action. After many hearings, replies, counter-replies, and conferences, the FCC issued a Report and Order directing the "rebanding" of the 800 MHz spectrum. The result of rebanding will relocate NPSPAC, the contiguous block of frequencies reserved for Public Safety, and create a separate contiguous block reserved for high power ESMR operations, primarily Nextel.
When the 800 MHz band was originally created, two segments of the spectrum were set aside for Cellular Telephone (mobile and base). Public Safety was later assigned a block of frequencies, and "SMR" (community repeater), "ESMR" (Nextel), and public safety services were allowed on the remainder of frequencies. However, unlike in other bands where licensee types were allocated to contiguous blocks of frequencies, in the 800 MHz band Public Safety, SMR, and ESMR services were all mixed together. During the 1980's and 90's, Nextel created a nation-wide network by buying up thousands of individual licenses for frequencies between 851-866 MHz.
A Brief History of Mobile Comms and Trunking
Public Safety systems are not operated for profit, and typically use a "high site" architecture, where a few base stations with power output in the 100-200 watt range are located on tall buildings and hill tops. This results in lower signal strength over a wide coverage area. Nextel and other ESMR systems use a "low site" or cellular type architecture, with many base stations installed on 1-3 story buildings and 30-50 ft monopoles to create high signal density and greater user capacity over their coverage area. These ESMR sites transmit continuously with ERP of as much as 1000 watts. The presence of these sites, and the RF energy they generate in close proximity to public safety operations, causes radios used by public safety to lose contact with their more distant base stations.
APCO Project 39
In the late 1990's, the FCC was forced to acknowledge that there was a problem. The number of interference complaints to public safety were rising, and the popularity of the ESMR services that were primarily blamed for the interference was also rising, with no end in sight. Something had to be done. The FCC solicited input from the various users groups to determine the best course of action. After many hearings, replies, counter-replies, and conferences, the FCC issued a Report and Order directing the "rebanding" of the 800 MHz spectrum. The result of rebanding will relocate NPSPAC, the contiguous block of frequencies reserved for Public Safety, and create a separate contiguous block reserved for high power ESMR operations, primarily Nextel.
What does rebanding actually do?
(To keep it simple, only the output or base station side is described below. Since all 800 MHz channels are paired, the input or mobile side will be similarly reorganized as shown in the graphic.)
Before rebanding, Public Safety, Business/Industrial, SMR and ESMR's both operate in the 851-861 MHz range. ESMR has exclusive use of the 861-866 MHz range, and Public Safety has exclusive use of the 866-869 MHz range.
During rebanding the following will occur:
All licensees with channels between 866-869 MHz (NPSPAC) must relocate to equivalent channels between 851-854.
All licensees other than ESMRs with channels between 851-854 MHz must relocate to equivalent channels between 854-862.
Nextel and other ESMR operators must relinquish all channels below 862 MHz. The FCC has required Nextel to vacate all its channels in the band from 854-854.5 nationwide as soon as possible to provide additional spectrum for Public Safety needs.
Public Safety has exclusive access to all vacated Nextel channels for 3 years, after which they are open to all eligible users.
After rebanding, Public Safety and Critical Infrastructure will have exclusive use of 851-854 MHz. ESMR systems (primarily Nextel) will have exclusive use of 862-869 MHz range, and public safety, business/industrial users, and low-power SMR's will share the 854-862 MHz spectrum. 860-861 MHz is designated as an "Expansion Band", and 861-862 MHz is designated as a "Guard Band". No licensees other than ESMR are required to relocate to channels above 860 MHz.
Rebanding - The RadioReference Wiki is a link to a comprehensive explanation of the issue, what scanners are affected, where to get scanner software updates (if available), which scanners WON'T need an update, etc. etc.
Here is a excerpt of the technical explanation of the situation:
When the 800 MHz band was originally created, two segments of the spectrum were set aside for Cellular Telephone (mobile and base). Public Safety was later assigned a block of frequencies, and "SMR" (community repeater), "ESMR" (Nextel), and public safety services were allowed on the remainder of frequencies. However, unlike in other bands where licensee types were allocated to contiguous blocks of frequencies, in the 800 MHz band Public Safety, SMR, and ESMR services were all mixed together. During the 1980's and 90's, Nextel created a nation-wide network by buying up thousands of individual licenses for frequencies between 851-866 MHz.
A Brief History of Mobile Comms and Trunking
Public Safety systems are not operated for profit, and typically use a "high site" architecture, where a few base stations with power output in the 100-200 watt range are located on tall buildings and hill tops. This results in lower signal strength over a wide coverage area. Nextel and other ESMR systems use a "low site" or cellular type architecture, with many base stations installed on 1-3 story buildings and 30-50 ft monopoles to create high signal density and greater user capacity over their coverage area. These ESMR sites transmit continuously with ERP of as much as 1000 watts. The presence of these sites, and the RF energy they generate in close proximity to public safety operations, causes radios used by public safety to lose contact with their more distant base stations.
APCO Project 39
In the late 1990's, the FCC was forced to acknowledge that there was a problem. The number of interference complaints to public safety were rising, and the popularity of the ESMR services that were primarily blamed for the interference was also rising, with no end in sight. Something had to be done. The FCC solicited input from the various users groups to determine the best course of action. After many hearings, replies, counter-replies, and conferences, the FCC issued a Report and Order directing the "rebanding" of the 800 MHz spectrum. The result of rebanding will relocate NPSPAC, the contiguous block of frequencies reserved for Public Safety, and create a separate contiguous block reserved for high power ESMR operations, primarily Nextel.
When the 800 MHz band was originally created, two segments of the spectrum were set aside for Cellular Telephone (mobile and base). Public Safety was later assigned a block of frequencies, and "SMR" (community repeater), "ESMR" (Nextel), and public safety services were allowed on the remainder of frequencies. However, unlike in other bands where licensee types were allocated to contiguous blocks of frequencies, in the 800 MHz band Public Safety, SMR, and ESMR services were all mixed together. During the 1980's and 90's, Nextel created a nation-wide network by buying up thousands of individual licenses for frequencies between 851-866 MHz.
A Brief History of Mobile Comms and Trunking
Public Safety systems are not operated for profit, and typically use a "high site" architecture, where a few base stations with power output in the 100-200 watt range are located on tall buildings and hill tops. This results in lower signal strength over a wide coverage area. Nextel and other ESMR systems use a "low site" or cellular type architecture, with many base stations installed on 1-3 story buildings and 30-50 ft monopoles to create high signal density and greater user capacity over their coverage area. These ESMR sites transmit continuously with ERP of as much as 1000 watts. The presence of these sites, and the RF energy they generate in close proximity to public safety operations, causes radios used by public safety to lose contact with their more distant base stations.
APCO Project 39
In the late 1990's, the FCC was forced to acknowledge that there was a problem. The number of interference complaints to public safety were rising, and the popularity of the ESMR services that were primarily blamed for the interference was also rising, with no end in sight. Something had to be done. The FCC solicited input from the various users groups to determine the best course of action. After many hearings, replies, counter-replies, and conferences, the FCC issued a Report and Order directing the "rebanding" of the 800 MHz spectrum. The result of rebanding will relocate NPSPAC, the contiguous block of frequencies reserved for Public Safety, and create a separate contiguous block reserved for high power ESMR operations, primarily Nextel.
What does rebanding actually do?
(To keep it simple, only the output or base station side is described below. Since all 800 MHz channels are paired, the input or mobile side will be similarly reorganized as shown in the graphic.)
Before rebanding, Public Safety, Business/Industrial, SMR and ESMR's both operate in the 851-861 MHz range. ESMR has exclusive use of the 861-866 MHz range, and Public Safety has exclusive use of the 866-869 MHz range.
During rebanding the following will occur:
All licensees with channels between 866-869 MHz (NPSPAC) must relocate to equivalent channels between 851-854.
All licensees other than ESMRs with channels between 851-854 MHz must relocate to equivalent channels between 854-862.
Nextel and other ESMR operators must relinquish all channels below 862 MHz. The FCC has required Nextel to vacate all its channels in the band from 854-854.5 nationwide as soon as possible to provide additional spectrum for Public Safety needs.
Public Safety has exclusive access to all vacated Nextel channels for 3 years, after which they are open to all eligible users.
After rebanding, Public Safety and Critical Infrastructure will have exclusive use of 851-854 MHz. ESMR systems (primarily Nextel) will have exclusive use of 862-869 MHz range, and public safety, business/industrial users, and low-power SMR's will share the 854-862 MHz spectrum. 860-861 MHz is designated as an "Expansion Band", and 861-862 MHz is designated as a "Guard Band". No licensees other than ESMR are required to relocate to channels above 860 MHz.
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