we've got a VIC (very important customer) within 100 m and roughly perpendicular of overhead high voltage distribution lines leading to the substation about 1 km away.
Our shot is roughly perpendicular to the overhead lines and roughly 4 km.
AP is RB532A+SR2+MaxRad Omni. CPE is subject to NDA, but compatible.
If you've had success in this environment, please advise and we'll do our best quid pro quo (return the favor somehow).
kind regards/ldv
I don't think you'll have a problem. I've only had EMI problems in the electrical closets of hotels (they always want their network equip in the same room as 300+ circuit breakers).
I've got several customers (not WISP customers, just computer/networking) right by a substation with high voltage lines leading in, substation that powers my entire line, and I have no problems accessing their wireless from outdoors near the substation. I haven't tried through the substation, as its kind of big, but...
Also, the wireless link for the schools goes right through those same lines a few miles earlier. No issues.
Just my experiences, your milage may vary.
I've got several customers (not WISP customers, just computer/networking) right by a substation with high voltage lines leading in, substation that powers my entire line, and I have no problems accessing their wireless from outdoors near the substation. I haven't tried through the substation, as its kind of big, but...
Also, the wireless link for the schools goes right through those same lines a few miles earlier. No issues.
Just my experiences, your milage may vary.
I have established such a link of 6 km for one of my customer . In the middle there is a 33Kv Power Station and high voltage wires just in the RF Path.
I had some issues in 2.4 Ghz like sudden increase in noise sometimes.
After checking with spectrum analyser i got some weird reading in 2.4 Ghz but not always.
Then i had to change it to 5.8 Ghz and now it is working good.
Can someone explain the phenomena of 2.4 Ghz from electrical wires ??
Maybe the signal is not from the electrical line but i did not find any other wireless installations in that ares.
I had some issues in 2.4 Ghz like sudden increase in noise sometimes.
After checking with spectrum analyser i got some weird reading in 2.4 Ghz but not always.
Then i had to change it to 5.8 Ghz and now it is working good.
Can someone explain the phenomena of 2.4 Ghz from electrical wires ??
Maybe the signal is not from the electrical line but i did not find any other wireless installations in that ares.
The problem is load dependant, but I've not had problems with lines themselves.
The hotel installs in electrical closets worked until some high amperage device (elevator, AC, etc) turned on. In one location, it didn't bother 2.4GHz at all, but made the main router unstable. That took some time to track down and shield. The problem seemed to stem from the fact they left the breaker boxes open often, and some just weren't shielded well enough to start with on some older buildings.
In another location I moved the AP, completely re-engineered the links. It seems the lines themselves didn't cause problems, even running next to the power to the elevator, water heater, AC, etc, but anywhere there was a link the connection, breaker boxes, power switches, relays, etc.
The hotel installs in electrical closets worked until some high amperage device (elevator, AC, etc) turned on. In one location, it didn't bother 2.4GHz at all, but made the main router unstable. That took some time to track down and shield. The problem seemed to stem from the fact they left the breaker boxes open often, and some just weren't shielded well enough to start with on some older buildings.
In another location I moved the AP, completely re-engineered the links. It seems the lines themselves didn't cause problems, even running next to the power to the elevator, water heater, AC, etc, but anywhere there was a link the connection, breaker boxes, power switches, relays, etc.
Power lines should not adversly affect wireless.
You may find that in some cases the power cables can act as an amplifier.
In these strange cases you will find that the aim of the client antenna is best several degrees out from straight line to the tower (AP).
Edit:
Also consider this:
Octaves of 60Hz (North America) drop 3dB for each.
How many octaves till you reach 2.4GHz.
The frequency seperation is such that there will be no effect.
You may find that in some cases the power cables can act as an amplifier.
In these strange cases you will find that the aim of the client antenna is best several degrees out from straight line to the tower (AP).
Edit:
Also consider this:
Octaves of 60Hz (North America) drop 3dB for each.
How many octaves till you reach 2.4GHz.
The frequency seperation is such that there will be no effect.
This reminds me of a joke I first heard in college about 40 years ago:Power lines should not adversly affect wireless.
You may find that in some cases the power cables can act as an amplifier.
In these strange cases you will find that the aim of the client antenna is best several degrees out from straight line to the tower (AP).
Edit:
Also consider this:
Octaves of 60Hz (North America) drop 3dB for each.
How many octaves till you reach 2.4GHz.
The frequency seperation is such that there will be no effect.
Situation: department chairman was interviewing two candidates for a position; candidate 1 was a mathematician, candidate 2 was a physicist.
The department chairman suggested that that the winner would be the one who could successfully invite a coed located two meters away to go for a coffee, but first, they had to follow his rules; both agreed.
The department chairman then said the only rule was to approach the coed by halving the distance between them on each step.
The mathematician interrupted the department chairman and said "That's impossible! Half of any distance is > 0, so I would never reach the coed.
The physicist said "I can get there for all practical purposes."
The diff between expected (-61 dBm) and actual (-84 dBm) has an explanation.
rgds/ldv
rgds/ldv
maybe your power lines are acting in the exact way line mine. I tried to increase/decrease the height of my towers but still i was facing issues.This reminds me of a joke I first heard in college about 40 years ago:Power lines should not adversly affect wireless.
You may find that in some cases the power cables can act as an amplifier.
In these strange cases you will find that the aim of the client antenna is best several degrees out from straight line to the tower (AP).
Edit:
Also consider this:
Octaves of 60Hz (North America) drop 3dB for each.
How many octaves till you reach 2.4GHz.
The frequency seperation is such that there will be no effect.
Situation: department chairman was interviewing two candidates for a position; candidate 1 was a mathematician, candidate 2 was a physicist.
The department chairman suggested that that the winner would be the one who could successfully invite a coed located two meters away to go for a coffee, but first, they had to follow his rules; both agreed.
The department chairman then said the only rule was to approach the coed by halving the distance between them on each step.
The mathematician interrupted the department chairman and said "That's impossible! Half of any distance is > 0, so I would never reach the coed.
The physicist said "I can get there for all practical purposes."
The diff between expected (-61 dBm) and actual (-84 dBm) has an explanation.
rgds/ldv
rgds/ldv
The link was fine when there is no data flow. but as soon as data flow started the link signal dropped considerably sometimes locking out the AP.
FYI : This problem was not faced in Mikrotik. That is another hardware/firmware which 0ldman knows very well
Re: have you had success within 100 m of high voltage lines?
I live almost under 6 x 400KV power lines and do a lot of wireless networking.. Havent had any issues except for being zapped very oftenwe've got a VIC (very important customer) within 100 m and roughly perpendicular of overhead high voltage distribution lines leading to the substation about 1 km away.
Our shot is roughly perpendicular to the overhead lines and roughly 4 km.
AP is RB532A+SR2+MaxRad Omni. CPE is subject to NDA, but compatible.
If you've had success in this environment, please advise and we'll do our best quid pro quo (return the favor somehow).
kind regards/ldv
/Henrik
i put a 90 degree sector, 17dbi on a utility pole, which also had a long metal conduit feeding electrical to several trailors....
SR2, radio, tried 3 other radios, no work, nothing. laptop clients can never connect..cards shows a -75-90 noise floor on every channel (when its really -98 here).
We then had a 900mhz link from here to another site with electrical pole...link barely works....fluctuates ALOT..5-30 CCQ gernerally..teriible noise floor on all 900mhz channels.
we now ALWAYS stay away from electrical pole....they KILL wifi in our expericec..maby its all less than 2.4ghz only as some ppl pointed out.
but there is our experience...and that all we need.
SR2, radio, tried 3 other radios, no work, nothing. laptop clients can never connect..cards shows a -75-90 noise floor on every channel (when its really -98 here).
We then had a 900mhz link from here to another site with electrical pole...link barely works....fluctuates ALOT..5-30 CCQ gernerally..teriible noise floor on all 900mhz channels.
we now ALWAYS stay away from electrical pole....they KILL wifi in our expericec..maby its all less than 2.4ghz only as some ppl pointed out.
but there is our experience...and that all we need.
Assuming quite a few FEMA trailers, FEMA (or its vendor for power) is not likely to bring in 240 V service to such an area, therefore the distribution point prolly involves transformers.theses are at fema trailer parks..no transf. but high voltage feeds to transformers or some kind of distribution point, 30ft below on ground.
this feed is like the a big version of what you normally see on the side of a house where the power feed comes in.
I could be wrong about this, but to deny the 1/r^2 law is tantamount to saying you can't spell physics. It doesn't have to cause interference at 2.4 GHz or whatever frequency, but rather it has to excite your board to failure.
Part of this could be housing of the board and grounding of the board. e.g., just take the ground off and see what happens (would you routinely run without a ground?).
Then imagine the "floating" ground in the presence of all that electrical energy. AFAIK, we're dealing in microvolts at the antenna output and to say a 7200 V or 14,400 V line can't impress enough voltage to cause a board to fail a critical task at 30' would require some fairly good electrical engineer's calculations IMHO, not to mention confirming measurements.
We routinely sit atop coop power poles on a member's property say 50 yards/meters from the transformer and don't have a problem unless we're trying to shoot through the high voltage lines 50 meters/yards away, further away if the power lines are primary voltage.
rgds/ldv
i can say this:
at these many fema sites we do...its like 100-250 trailers..small temp housing, close together.
there will be a point where the city power comes, big lines, Bunch of Large cylindrical Transformers, up on the poles on poles, a meter is all that is on the ground....from the large transformer setup, lines run large pilings, that have large metal pipe type conduit that take the wires to the ground (this pilings, is where we have our equipment mounts around the park), on the ground where there is a G.E. box the size of say 65% of a refrigerator.
that box then serves 20-40 tailors, a single 120v 30A (YES 30!) weatherproof/outdoor plug, that the trailer then plugs into and gets it power..
wanted to explain as many electricans ive talked to say this is a failrly strange electrical setup. many also say those piling to piling wires are most likly. running 480v ...maybe 240
eitherway..if mouting either a Pac WIreless 12db 120degee OR 17db 90 degree antenna on the side of the piling, where the metal conduit is running, the setup is useless.. The TX is about 50% what it should be and the RX is trash.. noise floor various, but -75 to -88.
maybe 120v is really bad for 2.4
at these many fema sites we do...its like 100-250 trailers..small temp housing, close together.
there will be a point where the city power comes, big lines, Bunch of Large cylindrical Transformers, up on the poles on poles, a meter is all that is on the ground....from the large transformer setup, lines run large pilings, that have large metal pipe type conduit that take the wires to the ground (this pilings, is where we have our equipment mounts around the park), on the ground where there is a G.E. box the size of say 65% of a refrigerator.
that box then serves 20-40 tailors, a single 120v 30A (YES 30!) weatherproof/outdoor plug, that the trailer then plugs into and gets it power..
wanted to explain as many electricans ive talked to say this is a failrly strange electrical setup. many also say those piling to piling wires are most likly. running 480v ...maybe 240
eitherway..if mouting either a Pac WIreless 12db 120degee OR 17db 90 degree antenna on the side of the piling, where the metal conduit is running, the setup is useless.. The TX is about 50% what it should be and the RX is trash.. noise floor various, but -75 to -88.
maybe 120v is really bad for 2.4
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