Hey there. I've been tasked by my company to help come up with ideas to link several repeater sites in my city together 3 sites to be exact. Each site will have 2 MTR 2000 UHF repeaters. For the sake of the description I will call them channels 1 and 2. Each repeater has its own pair of UHF freqs and PLs. I need to link these 3 sites in a way that will allow a portable at say site 1 on channel 1 to talk to either of the other sites on channel one. I also need a portable on channel 2 to be rebroadcast on all three channel 2 repeaters.
RF links including control stations and microwave links have already been ruled out for various reasons (all good ones too) so this will have to be linked either by phone or Internet IP protocol.
My best option so far is to put a pair of Zetron units at each site shat will allow the sites to be linked by phone lines. This meets all of my requirements however these things cost $1500 a piece and I'd need 6 (you do the math there) We may end up doing that any way however I wanted to know if you guys knew of another ways to do this.
Money as always is a factor but in this instance it will take a second place to functionality. We have not been told what the budget will be yet but I've been told "Money will not be a problem just find the best solution". So we have a lot of cash to mess with.
Are there any other ways to do this?
TIA for your help!
-RFN-
Linking Repeater Sites
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RFNebraska
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thebigphish
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RFNebraska
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Microwave was ruled out because we can't get a path and the end user doesn't want to rely on it for his link any way. Secure phone and T1 connections are already in place between these locations and they just trust them more for multi layer redundancy. Its the end users call there.
Now don't get me wrong I Love Microwave links
I just can't use them here!
As far as the money goes my main concern is not wasting cash. I am fine with spending it if I get an outstanding end result. My issue with the Zetron (and I can't for the life of me remember the Model number. I'll get it first thing in the morning) is the fact that its overkill for our purposes. Its got all kinds of bells and whistles and we would only use it for its most basic function.
Man, I sure made that sound confusing as heck. Sorry about that guys.
I did locate a company that makes VoIP Links. http://www.criticalrf.com/
I'll talk to them in the morning too.
Can I make this any more confusing?
-RFN-
Now don't get me wrong I Love Microwave links
I just can't use them here!As far as the money goes my main concern is not wasting cash. I am fine with spending it if I get an outstanding end result. My issue with the Zetron (and I can't for the life of me remember the Model number. I'll get it first thing in the morning) is the fact that its overkill for our purposes. Its got all kinds of bells and whistles and we would only use it for its most basic function.
Man, I sure made that sound confusing as heck. Sorry about that guys.
I did locate a company that makes VoIP Links. http://www.criticalrf.com/
I'll talk to them in the morning too.
Can I make this any more confusing?
-RFN-
The best set-up IMHO is to use a JPS voter system at a central site for each channel you want to link-up.
Here let me explain:
You have site A with rptr 1 and 2, site 2 with rptr 1 and 2, and site 3 with rptr 1 and 2.
Now pick a site as your main site (for this example we will call it site A.)
Get a JPS voter (which uses signal to noise voting and does not need a status tone) and install it at site A. Now run telco lines from Site B and C for the Repeater Rx side to Site A. Connect the repeater rx side of A, B, and C to the voter.
Then run the output of the voter to the Repeater Tx side to A, and run it also out on telco lines to Site B and C.
Therefore when someone keys up on site A it will go into the voter and be sent back out to all the sites.
However, you can not have the sites on the same freq or PL as this will not solve simulcast issues.
You can does this for both channels at each site.
If you have more questions please e-mail or PM me.
Here let me explain:
You have site A with rptr 1 and 2, site 2 with rptr 1 and 2, and site 3 with rptr 1 and 2.
Now pick a site as your main site (for this example we will call it site A.)
Get a JPS voter (which uses signal to noise voting and does not need a status tone) and install it at site A. Now run telco lines from Site B and C for the Repeater Rx side to Site A. Connect the repeater rx side of A, B, and C to the voter.
Then run the output of the voter to the Repeater Tx side to A, and run it also out on telco lines to Site B and C.
Therefore when someone keys up on site A it will go into the voter and be sent back out to all the sites.
However, you can not have the sites on the same freq or PL as this will not solve simulcast issues.
You can does this for both channels at each site.
If you have more questions please e-mail or PM me.
" ah the fatman made a funny!" - Stewie from the family guy.
I went to the doctor and all he did was just suck blood. Never go to Dr Acula - M. Hedberg
I went to the doctor and all he did was just suck blood. Never go to Dr Acula - M. Hedberg
That makes no sense.
Worried about microwave links but will consider VoIp?
VoIP is the LEAST "durable" linking method.
That said, if you do have T1 connectivity, get cards for the channel banks they use, and use the above mentioned JPS voters.
Or it seems to me 4 wire and E & M paralled up on 66 blocks would be cheap.
The real problem is gonna be simulcast if the three tx are all on the same freq.
More info needed here, there may not be an easy (cheap) solution.
Worried about microwave links but will consider VoIp?
VoIP is the LEAST "durable" linking method.
That said, if you do have T1 connectivity, get cards for the channel banks they use, and use the above mentioned JPS voters.
Or it seems to me 4 wire and E & M paralled up on 66 blocks would be cheap.
The real problem is gonna be simulcast if the three tx are all on the same freq.
More info needed here, there may not be an easy (cheap) solution.
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RFNebraska
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n9upc,
OK, so let me see if I follow you. We are using a Voter as more of an audio junction than a voter. when one receiver hears a proper signal it will be sent via the phone line to the other 2 transmitters and also retransmitted via the local transmitter. How would I need to configure the Voter and the MTR to make that work. Could this be passed in a 2-wire tone remote style?
Since I am running 2 MTR 2000s at each site I'd assume I'd need 2 voters. Would this be correct. I have not worked with that particular unit however I just pulled up the specs up on it from there site.
How much dose one of those bad boys run (cost)?
-RFN-
OK, so let me see if I follow you. We are using a Voter as more of an audio junction than a voter. when one receiver hears a proper signal it will be sent via the phone line to the other 2 transmitters and also retransmitted via the local transmitter. How would I need to configure the Voter and the MTR to make that work. Could this be passed in a 2-wire tone remote style?
Since I am running 2 MTR 2000s at each site I'd assume I'd need 2 voters. Would this be correct. I have not worked with that particular unit however I just pulled up the specs up on it from there site.
How much dose one of those bad boys run (cost)?
-RFN-
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RFNebraska
- Posts: 16
- Joined: Tue Feb 15, 2005 5:10 pm
The end user is a major financial intuition and the three sites are major outpost sites in this area. They have highly reliable dedicated secure internet links with all three of these sites that we are able to use. These Lines are highly reliable and very redundant. They already use these for internal data transactions between sites.PETNRDX wrote:That makes no sense.
Worried about microwave links but will consider VoIp?
VoIP is the LEAST "durable" linking method.
That said, if you do have T1 connectivity, get cards for the channel banks they use, and use the above mentioned JPS voters.
Or it seems to me 4 wire and E & M paralled up on 66 blocks would be cheap.
The real problem is gonna be simulcast if the three tx are all on the same freq.
More info needed here, there may not be an easy (cheap) solution.
As to your simulcast question, it will not be a problem as all three sites have 2 repeater pairs.
-RFN-
So what you are saying is that there are six repeater pairs?
If so, then it sounds like you want to "parallel" each repeater at each site to the same "channel" at the other two sites, but they would not be on the same RF freq.
Still not going to be any simple solution.
Still sounds like the JPS voter would be good.
If so, then it sounds like you want to "parallel" each repeater at each site to the same "channel" at the other two sites, but they would not be on the same RF freq.
Still not going to be any simple solution.
Still sounds like the JPS voter would be good.
A few years back I did this for some off-shore oil rigs...similar set-up with each rig having an MTR2000 with it's own repeater pair.
There was already existing microwave links in place, in your case you'll use the T1 line.
What I did was take the board out of an MC1000 tone remote & put it into a Hammond enclosure I sourced. I placed a terminal strip & power switch on one side of the box, and a power & "link" led on the other. I interfaced it to the MTR2000 as follows:
When a portable on rig "A" keys up, the MTR of course repeats the audio locally, while also providing a COR output on J5 (forget which pin at the moment & don't have my notes in front of me). I use this COR to 'key' the MC1000 board, through a transistor circuit to provide an active low, as the output of the COR on the MTR is active high (unless you have the wildcard option in the MTR).
I then take the RX wireline output & wire it into the MC1000 tx audio circuit, at the handset mic input. So what happens is the MC1000 is taking the local "rig A" audio & routing it through the board, giving on the output the audio PLUS high & low level guard tone.
This output is then fed into the microwave link, and on the other end at "rig B" is fed into the MTR2000 TX wireline input. The MTR sees high & low level guard tone so of course it keys up & transmits the audio throughout "rig B".
There's another modified MC1000 board on "rig B" to do the same job when that MTR is keyed locally by a portable, sending the audio back to "rig A" in the same fashion.
I believe they are using Nortel audio bridges to route the "audio + guardtone" into several microwave links to achieve multiple site simulcast.
With a little playing with the microwave channel bank audio levels, there's no discernable difference between "local" & "remote" audio. It's been running about 4 years without a glitch.
I originally got the idea when looking at a Vega linking product which seemed to me to be the same thing...a modified tone remote board set-up.
Todd
There was already existing microwave links in place, in your case you'll use the T1 line.
What I did was take the board out of an MC1000 tone remote & put it into a Hammond enclosure I sourced. I placed a terminal strip & power switch on one side of the box, and a power & "link" led on the other. I interfaced it to the MTR2000 as follows:
When a portable on rig "A" keys up, the MTR of course repeats the audio locally, while also providing a COR output on J5 (forget which pin at the moment & don't have my notes in front of me). I use this COR to 'key' the MC1000 board, through a transistor circuit to provide an active low, as the output of the COR on the MTR is active high (unless you have the wildcard option in the MTR).
I then take the RX wireline output & wire it into the MC1000 tx audio circuit, at the handset mic input. So what happens is the MC1000 is taking the local "rig A" audio & routing it through the board, giving on the output the audio PLUS high & low level guard tone.
This output is then fed into the microwave link, and on the other end at "rig B" is fed into the MTR2000 TX wireline input. The MTR sees high & low level guard tone so of course it keys up & transmits the audio throughout "rig B".
There's another modified MC1000 board on "rig B" to do the same job when that MTR is keyed locally by a portable, sending the audio back to "rig A" in the same fashion.
I believe they are using Nortel audio bridges to route the "audio + guardtone" into several microwave links to achieve multiple site simulcast.
With a little playing with the microwave channel bank audio levels, there's no discernable difference between "local" & "remote" audio. It's been running about 4 years without a glitch.
I originally got the idea when looking at a Vega linking product which seemed to me to be the same thing...a modified tone remote board set-up.
Todd
No trees were harmed in the posting of this message...however an extraordinarily large number of electrons were horribly inconvenienced.
Welcome to the /\/\achine.
Welcome to the /\/\achine.
Check this link, This system is the best I have ever seen for multi-site systems. http://www.bridgecomsystems.com/TL-NET.html
Linking
There is information missing from the original poster. There are many ways to deal with this. Wavetar pointed out analog based transport. But in my circles, there isn't anything transport related that is still analog. And how to do this over the T1, ooops... DS1 link if it is digital? Someone else mentioned a channel bank which might be hanging on the DS1, but we weren't told. And to make VOIP work properly and reliably, you require reserved or prioritized (QoS and VLAN) segregation on the bridging equipment. Internet is a loose term... that implies public broadband. The banks would never go for that. And public broadband is often asymetrical (one dirction is slower than the other). But on a DS1 that is HDSL, or better still, fibre transport point to point, you would be OK, barring any "backhoe fades".
You have to consider the initial capital outlay, and any recurring costs. If the existing DS1 has spare capacity, or is already transporting IP with a DS1 to Ethernet switch, you are on your way to a VOIP solution. If you have to lease 4-wire circuits from the phone company, there will be another monthly cost and you have already identified the Zetron device and its costs.
Personally, I like to look forward and futureproof my installation. Build in some IP transport on that DS1 if you can. Then put VOIP on it.
Two companies to have a look at for this purpose:
http://www.optimatele.com/ and their TLAN product. Note this has excellent site alarm capabilities with its RIO product. No doubt your bank can also place any other IP services on this. I use this product to deliver VOIP site phone service to over a hundred remote tower sites (along with site alarms, power plant monitoring, channel bank craft port, etc). Segregation is using VLAN tagging. Lastly, this product has a ring protect mode which will keep you going if one of the hops fails.
http://www.sycamorenet.com/products/net ... /dnx1u.asp from what was Eastern Research, now Sycamore Networks. I don't use this product but it is similar to TLAN. There are also products from ADTRAN and many others.
Bottom line, with IP and Ethernet jacks, you can usually cover many separate applications for a lot less money that the traditional solutions. With the right approach, reliability can be engineered into the system.
RF Dude
You have to consider the initial capital outlay, and any recurring costs. If the existing DS1 has spare capacity, or is already transporting IP with a DS1 to Ethernet switch, you are on your way to a VOIP solution. If you have to lease 4-wire circuits from the phone company, there will be another monthly cost and you have already identified the Zetron device and its costs.
Personally, I like to look forward and futureproof my installation. Build in some IP transport on that DS1 if you can. Then put VOIP on it.
Two companies to have a look at for this purpose:
http://www.optimatele.com/ and their TLAN product. Note this has excellent site alarm capabilities with its RIO product. No doubt your bank can also place any other IP services on this. I use this product to deliver VOIP site phone service to over a hundred remote tower sites (along with site alarms, power plant monitoring, channel bank craft port, etc). Segregation is using VLAN tagging. Lastly, this product has a ring protect mode which will keep you going if one of the hops fails.
http://www.sycamorenet.com/products/net ... /dnx1u.asp from what was Eastern Research, now Sycamore Networks. I don't use this product but it is similar to TLAN. There are also products from ADTRAN and many others.
Bottom line, with IP and Ethernet jacks, you can usually cover many separate applications for a lot less money that the traditional solutions. With the right approach, reliability can be engineered into the system.
RF Dude
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/\/\y 2 cents
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I have developed (2) ways to interconect either your Simplex base stations, conventional repeaters, a trunked takgroup, or all trunked talkgroups in a system. I sell them in kit form, or we can build it for you Really it comes down to what another poster said - About how much outlay you have budgeted or available for the project and what packet network to you have avilable or within budget.
First, I have worked tirelessly to create new ways to have reliable radio comms over just about any packet switched connection. Single channel repeaters, a trunked talkgroup, or simplex base can be linked no problem reliably 24/7 with as little as a 33.6 dialup and pentium 120 PC. On a DSL or Cable you can have somewhere around 35 or so repeaters/bases linked w/o a hitch. QOS is not really an issue and I can go into detail about how we manage that if anyone wants to know details.
I have also worked hard on creating ways to link entire trunking systems / panels over the internet with software that is freely available. Our cards or standalone boxes (not free) can be installed and used to link the following systems anywhere in the world: SmartZone, PassPORT LTR, LTR (Trident TNT), EDACS, iDEN, ESAS, SmartNet AMSS, MPT 1327, and various other cellular equipment. They also have the ability to interconnect these systems with great resilency across a DSL/Cable/Satellite conenction of 256K or greater. Have many PassPORT owners who finally can make some $ rather than pay for channelized T-1's. A few months ago we connected an iDEN site on wheels to an ISC just for kicks over satellite.
These are all things I think folks on the board could benefit from learning about, since it can allow a mere mortal to build some very nice wide area systems.
Steve
First, I have worked tirelessly to create new ways to have reliable radio comms over just about any packet switched connection. Single channel repeaters, a trunked talkgroup, or simplex base can be linked no problem reliably 24/7 with as little as a 33.6 dialup and pentium 120 PC. On a DSL or Cable you can have somewhere around 35 or so repeaters/bases linked w/o a hitch. QOS is not really an issue and I can go into detail about how we manage that if anyone wants to know details.
I have also worked hard on creating ways to link entire trunking systems / panels over the internet with software that is freely available. Our cards or standalone boxes (not free) can be installed and used to link the following systems anywhere in the world: SmartZone, PassPORT LTR, LTR (Trident TNT), EDACS, iDEN, ESAS, SmartNet AMSS, MPT 1327, and various other cellular equipment. They also have the ability to interconnect these systems with great resilency across a DSL/Cable/Satellite conenction of 256K or greater. Have many PassPORT owners who finally can make some $ rather than pay for channelized T-1's. A few months ago we connected an iDEN site on wheels to an ISC just for kicks over satellite.
These are all things I think folks on the board could benefit from learning about, since it can allow a mere mortal to build some very nice wide area systems.
Steve
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WB5ITT
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Re: Linking Repeater Sites
Are Freq 1 and 2 the same across the system? Actually doesnt matter....I did such a thing once before with telco single dry pairs between sites and using some SCC signaling cards...but they are out of biz IIRC now....You would have to order a PLPA circuit (2w audio grade) multidrop to go to the three sites....(one PLPA ckt for each channel)....the Telco can bridge the ckts together and keep the audio levels at -10dbm nomimal..which you would use as the reference 5kHz deviation..getting the sites to key up requires an external interface to give you a Signaling Tone down the line to the others sites...I used 2175Hz on the SSC cards but any tone will do between 1000 and 3200 usually...you DO need to notch it out from rcv output before hitting the phone line so rcv audio doesnt interfer...think of this as a multipoint tone remote...each rptr being a "console" keying the other TWO rptrs up at the other sites and vice versa...RFNebraska wrote:Hey there. I've been tasked by my company to help come up with ideas to link several repeater sites in my city together 3 sites to be exact. Each site will have 2 MTR 2000 UHF repeaters. For the sake of the description I will call them channels 1 and 2. Each repeater has its own pair of UHF freqs and PLs. I need to link these 3 sites in a way that will allow a portable at say site 1 on channel 1 to talk to either of the other sites on channel one. I also need a portable on channel 2 to be rebroadcast on all three channel 2 repeaters.
RF links including control stations and microwave links have already been ruled out for various reasons (all good ones too) so this will have to be linked either by phone or Internet IP protocol.
My best option so far is to put a pair of Zetron units at each site shat will allow the sites to be linked by phone lines. This meets all of my requirements however these things cost $1500 a piece and I'd need 6 (you do the math there) We may end up doing that any way however I wanted to know if you guys knew of another ways to do this.
Money as always is a factor but in this instance it will take a second place to functionality. We have not been told what the budget will be yet but I've been told "Money will not be a problem just find the best solution". So we have a lot of cash to mess with.
Are there any other ways to do this?
TIA for your help!
-RFN-
Dont need a voter...this would allow a mobile or HT on channel 1 to travel and never change freq, etc...but if you have any overlap, you may want to change PL tones so all 3 sites use different tones from each other (Site 1 uses 100Hz, Site 2 110.9, etc) on both channels.....but that will take 6 programmed "channels" on radios..