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What is a fixed station


WRPA445
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Good question. In the Part 90 world a fixed station is primarily used for data transmissions between two points. Fixed stations are usually used for automatic reporting of fluid levels in storage tanks, river levels and the like. They are primarily one way transmissions but they can also be two way such as the control station sending a command to open a valve or flip a switch.

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You ask a valid question that is not easily found in the FCC documents GMRS folks are familiar with. I have never been able to read its full official definition in the FCC’s own language to this day, except that which they put in the part 95 rules. I have tried extensively to find more.

Here is the understanding that I have developed over nearly 20 years.

A “fixed” station is a permanently installed station that communicates solely with another permanently installed “fixed” station. Fixed stations never communication with base, mobile, or HT stations which are normally used to communicate with other like stations. Then you may ask, what is heck is left? Well, in effect one can think of them almost like radio links that are used to communicate between two repeater towers, perhaps for control purposes, or perhaps for point-to-point repeater linking using highly directional antennas (imagine complementary aimed microwave dishes). I suspect there may be another scenario or two where it would be applicable also.

I understand that there is limited use of, and need for, “Fixed” stations in GMRS, but the language remains because of it’s historical and legacy significance, and perhaps an edge case need.

If anyone reading this has a link to an official FCC document or legal precedent that further clarifies this, perhaps from another service, I and others would be eternally grateful.


Michael
WRHS965
KE8PLM

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eCFR Title 47, Chapter I, Subchapter D, 95.303: Definitions
"Fixed station. A station at a fixed location that directly communicates with other fixed stations only."

Agreed. Yep, that is the lame definition in part 95. It is nearly equivalent to Webster giving the official definition of ‘House’ as ‘a House.“. Somewhere else in the FCC legal language I have to believe lives a better definition or legal precedent-setting example.

Absent further definition, it could be said that five HT used solely for communication between each other are ‘fixed’ stations, as are two cups and a string carried by kids walking down the street.


Michael
WRHS965
KE8PLM
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45 minutes ago, tweiss3 said:

eCFR Title 47, Chapter I, Subchapter D, 95.303: Definitions

"Fixed station. A station at a fixed location that directly communicates with other fixed stations only."

Well that's clear as mud.  In 47 CFR 95.1767(a)(2) I was wondering why it's restricted to 15W.  Sounds like a fixed station is used for data communication for a SCADA (Supervisory control and data acquisition) system.

John

WRPA445

 

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9 minutes ago, mbrun said:


Agreed. Yep, that is the lame definition in part 95. It is nearly equivalent to Webster giving the official definition of ‘House’ as ‘a House.“. Somewhere else in the FCC legal language I have to believe lives a better definition or legal precedent-setting example.

Absent further definition, it could be said that five HT used solely for communication between each other are ‘fixed’ stations, as are two cups and a string carried by kids walking down the street.


Michael
WRHS965
KE8PLM

Well since there are so many limitations on what is not permitted on GMRS, I am guessing the only use for fixed stations in GMRS would be RF Links between repeater. Essentially use another repeater on the same site at 15 watts max on a different pair with a Yagi pointed at the other repeater site, creating a wide area repeater network without IP or any other infrastructure.

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In the Part90 world - and in the world of FCC Licensing, I think you'll find the FCC's answer:

An FB2 is a repeater. FB is a Simplex base  - aka a Base Station in the techspeak of older (now mostly dead) Technicians.  They would also refer to the downlink frequency (or lower frequency in the repeater pair) as the "Base" - with the uplink frequency referred to as the "Mobile Transmit".

When those older techs talked about a mobile radio in a tray - often located at a business office or dispatch center - it was always a Control Station - and sometimes a Fixed Base -  which is referred to as an FX1 in the FCC Licensing database. It was NEVER referred to as a Base Station - except by Salespeople, who would always get corrected by the older techs. You might be able to get away with saying it was a Base - but never a Base Station. 

To them, a Fixed Base was a non-movable radio which transmitted on the uplink frequency to operate a Repeater. A Base radio that operates in Simplex to any other unit on the lower side frequency (462.xxx for GMRS) was also a Fixed Base Station. That is consistent with the definitions I was taught.

I was also taught that it used to be illegal for a Fixed Base to talk to another Fixed Base. People went to great lengths to make high power radios "mobile" in order to meet the definition of an MO mobile designation. Not sure when it changed - but I'd guess early 80's with deregulation.

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3 hours ago, WRPA445 said:

Well that's clear as mud.  In 47 CFR 95.1767(a)(2) I was wondering why it's restricted to 15W.  Sounds like a fixed station is used for data communication for a SCADA (Supervisory control and data acquisition) system.

John

WRPA445

 

I think that’s probably correct, telemetry stations with grandfathered licenses for the fixed stations rather than the individual licenses that are issued for GMRS users.

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