Leaky Coax?

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DHkorn

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I have a couple of customers with properties that have areas in their buildings where cell phone communications (using any carrier) is spotty at best and impossable at worst. I have always been interested in helping them solve this problem.
Today I was told there is a solution with a product called 'leaky coax'. Just now I have found a few sites with information but I am really interested if anyone has expierience they could share?
Just what type of hardware goes on the end? And does it work?
Thanx
 
I have seen it work but cannot tell you many details.
The radios were mx80 Motorola?s in the 150mhz range, I think 5 or 6 watt, with a repeater on the premises.
I vaguely remember that Motorola was the supplier for the cable.
The cable was very thick like one inch diameter and looked like it had a helical outer shield under the outer coating.
My understanding is that it was VERY pricy.
But it did work in all the rooms that had it installed?underground with 3 foot thick reinforced concrete walls.
But the cable was run from floors 150 feet underground to150 feet above ground.
I think each run was terminated on both ends and was supported with special standoff.
 
Thanks

Thanks

Thanks for the quick response, I appreciate it. If I could ask, would that work with every carrier? Do you know where I could get application information for the system?
 
DK, the leaky coax you are referring to is a passive repeater. Basically a antenna mounted on top of a building, then a coax ran down a shaft of the building to the ground floor. The shield has holes or openings that allow RF energy to leak or pass through. Results range to fair to non-existent. If the radio is nearby, it should work, if not?

As far as which carriers they work with, they only works with two; the 850 MHz band (aka Celluar) and the 1900 Mhz (9aka PCS). In other words, they work with every carrier as they all carriers use the same frequency and technology in the two bands.
 
I know some people love buildings that have little or none of any type of cell reception... There was recently a court case about movie theaters putting in jamming devices, and I think by that publicity there has been recent rise in the previous interest in "cell free zones"... In many coffee shops here there are little signs at the register, and a few that will skip you in line if you're on the phone and trying to order.

Personally I would settle for a Bluetooth free zone - you cant tell if they are phsycotic, or talking to you or not.... - ANDROIDS!
 
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Leaky coax is (in my world, anyway) usually called a leaky feeder, with no relation to what the NEC thinks a feeder is :)

Do a google on leaky feeder cellular and you'll get lots of info. This technology is often used in tunnels and underground railways, it used to be for just FM radio and staff handy talkies, but now theres other applications.
 
I used to work for a cell company so be careful when putting a repeater up. The cell companies and the FCC will frown on it. If we tracked interference to a personal repeater, we asked that it be taken out of service, if the person did not comply, the FCC was involved and it was removed.

These devices can cause interference with the actual cell towers and the interference will be tracked down.
 
bmac, I think you are referring to an ACTIVE REPEATER aren't you? If so I agree with you.

I don't know if the FCC has much to say about a Passive Repeater since there are no recievers or amplifiers involved, just an antenna and coax.

Many Celluar Providers will install a micro-cell in high rise buildings, airports, etc in dead spots with high traffic volume. Catch is you have to be a subscriber to enjoy the benefit, or your company has to have a ROAMING agreement contract in place.
 
DHkorn said:
I have a couple of customers with properties that have areas in their buildings where cell phone communications (using any carrier) is spotty at best and impossable at worst. I have always been interested in helping them solve this problem.
Today I was told there is a solution with a product called 'leaky coax'. Just now I have found a few sites with information but I am really interested if anyone has expierience they could share?
Just what type of hardware goes on the end? And does it work?
Thanx
Click to expand...

Depending on who their cellphone provider is the provider may have their own in-building solution. We use Verizon and because of all the steel and data/voice cabling in our building cellphone signal is non-existent for any carrier. Verizon installed an in-building antenna system that eventually links up to an external antenna of somesort to allow us to have a cellphone signal in the building. This is an active system and not passive like the "leaky coax". However, if these are people with various cellphone providers it may not be as easy to get a real good solution.


dereckbc said:
I don't know if the FCC has much to say about a Passive Repeater since there are no recievers or amplifiers involved, just an antenna and coax.
Click to expand...

Being this passive antenna re-broadcasts a signal from the cellphone (transceiver) it infact is radiating a radio transmission which then could be regulated by the FCC.
 
After my last reply I got to thinking. I do believe that anything that causes interference, a amplifier, booster or anything else can be regulated by the FCC.

I remember a incident that we had trouble tracking down the interference and do not remember if it was a repeater or amplifier, but it was installed in a commercial building by a 3rd party vendor. This was causing problems with our signal in the area, not just in the building. We contacted the owner of the bldg and they refused to take it out of service, so we filed paperwork with the FCC (this was not me, just what we were told was happening, must ahve been lawyers) and this got the situation cleared in a hurry.

I do not have any hard evidence on this and I am trying to pull it frim my memory from the telcomm days.
 
bmac71 said:
These devices can cause interference with the actual cell towers and the interference will be tracked down.
Click to expand...
I was talking about an active repeater. Okay, let's suppose I wish to be compliant, and I call and complain that there is no signal in my home office. The provider sends out a couple of engineers who confirm that, in spite of being within two miles of three towers, there is indeed no signal around my home.

They have confirmed that they have no intention of doing anything about it. They advise me to look for another carrier, but will hold me to my service agreement. I wish to use my cell phone in the manner intended, without breaking any rules. If I am not allowed to take measures (that they should be paying for?) . . .

Suggestions?
 
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LarryFine,

I am not sure who your carrier is but as crazy as this sounds the fine print on the contract of the carrier I worked for specifically stated coverage is not guaranteed inside any building or structure. I had a hard time with this while working for them much less being a consumer. Pretty much if it don't work inside then the company does not have to do anything.

Now we did allow people out of their contract without fees if we sent out a tech that showed degraded signal in the area, NOT in the Home or Home office. Outside their home.

If indeed there is confirmation that there is no signal outside, around your home contact the company and speak to a manager & if the trouble ticket is on file that shows the tests and confirms the results, you can get out of your contract. Just mention every communications favorite initials "FCC". this will get their attentions real fast.

It may take a couple calls, but you can get out of the contract without penalty, you may be out equipment costs, but you should not be held to the contract.

Just my $.02.
 
bmac71 said:
Now we did allow people out of their contract without fees if we sent out a tech that showed degraded signal in the area, NOT in the Home or Home office. Outside their home.

It may take a couple calls, but you can get out of the contract without penalty, you may be out equipment costs, but you should not be held to the contract.
Click to expand...
The signal testing was indeed done outdoors, and the null area is two or three blocks long. There are three other phones on the same account, and the other three don't share the problem, so it's not so simple.
 
I see, that does make things more difficult. Another option and may or may not be feasible?? in your situation. This also sounds crazy, but if this is a fairly new number, get the number changed and see if this helps. I have done this and everything work great. Sounds crazy but for the strange reason I cannot explain this has worked and can clear problems that you are having. I will try to think of other options that we have used in the past and will pass them along. If you hang in there you will get the right tech that will correct your issue.
 
bmac71 said:
I used to work for a cell company so be careful when putting a repeater up. The cell companies and the FCC will frown on it. If we tracked interference to a personal repeater, we asked that it be taken out of service, if the person did not comply, the FCC was involved and it was removed.

These devices can cause interference with the actual cell towers and the interference will be tracked down.
Click to expand...

Intresting. Where I live the wireless companies install repeaters in the malls so their phones will work in their stores.
 
hmspe said:
Intresting. Where I live the wireless companies install repeaters in the malls so their phones will work in their stores.
Click to expand...
That is simple business economics. Putting in a repeater can cost up to $50K in equipment alone plus labor, monthly rents, and maintenance. That makes perfect since for thousands of revenue generating customers.

Now to add a repeater for one customer or a real cell site ($500K) for one or two customers is foolish. Just let them go to another competitor.
 
hmspe said:
Intresting. Where I live the wireless companies install repeaters in the malls so their phones will work in their stores.
Click to expand...



Correct "The wireless companies" install these repeaters in malls or other buildings, not individuals.

The wireless companies follow the FCC guidelines for this.
 
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