453.9125?

[CT22]

I agree that copper is expensive but its a fix for now. I just received an estimate for running coppper to a three site voting system as well... odd!

Anyway, some of the timing issues could be easily solved by using some of the infrastructure already in place at some sites (CSP, Cellular Providers, etc). I know of a few towns using CSP space right now.

 

[dittrimd]

You are right, the State Police or more accurately the Department of Public Safety have been very open to other public safety agencies using the microwave backbone, tower space and building space. To that end DPS and the State Police have been excellent partners in public safety communicaitons. Without their assistance many public safety agencies would have a much more difficult time making thier new radio systems a reality.

The big problem is on sites that are not owned by the State Police or DPS. On these other tower sites there are instances where over the years anytime anyone put a radio on the tower they added an antenna. This has left little space available for other users. If new users would like to utilize a tower that has little or no room the new user is faced with paying for the enginnering and installation of a combiner system in addition to the radio. They must also get agreement from the tower user and the radio owners who are not always the same organization. It creates a tough situation and one that does not have a clear solution. Tower sites especially ones that are in good locations are a valuable resource for public safety. In this day an age when getting new towers built is neither economical or popluar with the general public we begin to realize just how valuable they really are.

Mark

 

[PJH]

Yeah, SBC rates for the leased lines can kill ya, but MW doesn't have to be expensive and doesn't require that much in service. As long as its PM'd once in awhile, life is good.

You can even run in the unlicensed spectum for most applications. Biggest problem with MW are making sure you have a good path. If you have that, MW is the way to go.

Right now we are looking at an IP based approach for 6 tower sites, but I think that's getting things a little too complicated. We have the fiber to do it, but the MW has been so reliable and we control it, why wait hours for a service tech from the telco when we can hit the shelter and trouble shoot (and hit reset) and have things working in 20 mins?

BTW: I am using old ass Motorola Starpoints and never had a problem. My newest MDS digital link though gives me headaches all the time (damn -110db RX alarms!)...but usually with the power supplies. Like the box, like the features but something I would not buy again (not that I really had a choice the first time....) Each dish is carrying at least 10 channels, some 14. Can't beat free! Only reoccuring costs is electricity and the PM.

Simucast is a nice way to go, but is expensive as mentioned. GPS clocks are cheap, but its the high stability osc's that cost the mega cash in order to have that a nice tight signal. Things have to be perfect, the but the results are outstanding. That's my current project...getting the county on a six or seven site simucast conventional or VHF trunked. Either option is expensive, just the 2nd one is more....but would take care of quite a bit of problems. Its just getting the elders to open the wallets.

 

[dittrimd]

PJH,

What county are you talking about? The only county that I know of in Connecticut that is operating on VHF is Litchfield County. They have a simulcast system out there that seems to serve them well. They also utilize the state police microwave system as well. TN looked for one VHF frequency in high power and was unable to find anything so I would be surprised if you were looking for new VHF RF. That experience was almost as painful as looking for UHF. I would be curious to know what county is looking at a VHF system of any type. I know for TN I have pretty much resigned myself to analog UHF simulcast. Many departments do not have trunking radios and have recently made large purchases of new radios. Hard to ask them to purchase new radios yet again. Right now the biggest problem is finding a couple of UHF pairs that I can license through out the county on high power. Forget the cost issues it's the RF that is the killer.

Also for short hops a spread spectrum MW system would be ok since the chance of interference would be minimal. For longer hops you really should look at the licensed route especially for public safety to ensure secure and safe communications. I just priced up a 1/2 spread spectrum 5 gig Harris system with 48 channels, some T1 and some Telco circuts with hot standby for 157K installed. We looked at the 5.9 Gig lincesed route but because we were only going 1/2 mile we did not need to look any further. As for my next hop of 4 miles we are going 5.9 licensed. These are only 12 channel hops which are around 75 ot 80 K.

Mark

 

[PJH]

Ouch. I feel your pain. Right now I am out on a job in the Western Catskills of NY. Its a challenge...you think CT politics are bad, you haven't seen anything with the way NY works!

I think the lowest tower is at around 1800ft and the tallest high point is about 2400ft. With that, we hear EVERYBODY. We were just able to convert EMS (VHF) to PL access (prior was DTMF into the comm center...and it left all the towers open) and Fire is lowband WITHOUT PL at the moment (on the comm center side). Routinely we hear Central MA, Cromwell, most of Long Island and NJ/PA. It took over years of fighting to get PL's.

Right now we are running a 2GHz backbone. It works for us. I am working on getting a voter installed so there is less guessing at which tower to use (all manual select right now). The Orbacomm console looks nice 21st century, but everything behind it is 1970's.

We have the million dollar data center, but the GE Master base stations. As you can see, the MDS takes up a lot less than the starpoints, but the starpoints are rock solid (for those who have never seen them).

 

[dittrimd]

I need to clarify my comments in an earlier post in which I commented about tower management. The Connecticut State Police and the Department of Public Safety do a phenomenal job of operating and maintaining their very large statewide system. They also are very receptive to other public safety entities utilitzing their tower space, radio room space and MW backbone. My comments were not directed at this system in anyway.

The main problem I was addressing were the NON-State police sites we have tried to access. Sites that have great location but little space available particularly with respect to tower space for new antennae. My opinion looking at how these towers have evolved over the years is that no one looked at the big picture. If someone had a radio they asked the tower owner and they were given space. They would put up an antenna and isntall their radio and were in business. Now these towers have little to no space and if another party wants to add a radio they have to look at combining. This cost money to engineer a system that will work and you need to have agreement with the radio owners you are going to affect as well as the tower owner. It makes the process much more difficult and adds cost.

I hope this clears up any confusion from my earlier post.

Mark

 

[PJH]

Have you tried any of the former Long Lines MW sites? Most of the towers in the area haven't been really touched by cell or LMR...and if they are in the right spots, but may be a good alternative. American Tower owns many, but I understand that they have also sold off a few. They are the 8xxxx site numbers on their website.

Ones off the top of my head that haven't been bogged down are in Durham (dual towers - lots of ticks in the spring), Bald Hill (also a CSP/NU site) etc. John Tom Hill is pretty saturated... That's where you get those RF headaches.