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  #41 (permalink)  
Old 10-30-2012, 11:57 PM
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Originally Posted by crazynova View Post
It sounds like LVMPD will try to get Harris to foot the bill for a switch to P25, keep Open Sky for data (the MDTs run great with OpenSky), and hope to not eat anymore money. IMHO, Harris needs to stop trying to sell OpenSky for anything other than data only, and make it right for their customers who bought this train wreck of a radio system.
It's interesting that it works fine for data but not voice. I guess it has something to do with the different amount of data being transferred for each function. Or perhaps the OpenSky voice codec/CAI/whatever is inherently flaky.

Speaking to your last sentence, I would think that first responder agencies would be extremely reluctant to buy something like OpenSky strictly for data in this day and age. If you're not going to go with a proven system like a standard P25 network, you might as well push right through to LTE (so long as someone can deliver appropriately with that platform).

I'd like to see salesmen stop trying to push their own finicky proprietary systems on the basis of nobody being able to scan it, it being "state of the art" (for their company and their company alone), etc. OpenSky IMO is kind of like the digital radio Yaesu is trying to push on hams currently, with no compatibility with anything but other Yaesu radios. All that going with a proprietary system ensures is that you are wed to that vendor for the life of that system with no "out" to be had.
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  #42 (permalink)  
Old 10-31-2012, 10:08 AM
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From what I heard the data on the computers weren't running "great," just the voice problems were more obvious.

Last edited by bikinjohn; 10-31-2012 at 10:11 AM..
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  #43 (permalink)  
Old 10-31-2012, 1:12 PM
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Originally Posted by garys View Post
What I wonder is why, with all of these failures, anyone opts to buy such a system? Has anyone anywhere successfully built an Open Sky system?
A bigger question - why are there failures?

Before I vested out, I was reviewing various technologies to replace a deficient VHF system with an eye toward creating a large region-wide multi-user radio platform which couldn't be done considering the available channels in VHF. M/A-Comm (then) came out and presented a very compelling case for OpenSky. Here's my recollection of the high points:

1) 4 slot TDMA. This means that one repeater can carry 4 conversations within a 20 kHz channelspace. That one repeater equals the capacity of 4 separate P25 Phase 1 repeaters. 4 slot TDMA is essentially the same concept as TETRA, which has proven itself around the world and is just now beginning to have the intellectual property strangle hold taken off it in North America. That 1 repeater with 4 simultaneous conversation capability should be mathematically equivalent to an old 5 channel SmartNet trunked radio system.

2) Picosites. If I have a problem area, as long as I have connectivity and power, I can light it up with a very small unit bolted to a utility pole with an antenna on it. We wouldn't have to potentially spend on the order of several million dollars to construct and equip a full-blown site.

3) Retrocompatibility to P25 and analog on defined frequencies. Not everyone wants OS, so the stuff can be retrocompatible on mutual aid and interoperability channels. TETRA products currently are not (which is why some vocal factions within public safety have pushed back on it).

4) Forward-looking technology. P25 phase 1 got old before it had a good grasp of proliferation. The goombas who were working on it dilly-dallied and kept milking the various funding sources for R&D on something that should have been completed in 1/5 of the time (my own opinion). I was concerned about concentrating on 12.5 kHz efficiency while everyone else is looking at 6.25, and didn't want something that the sun was setting on before it ever left the box.

5) An automatic mobile repeater scheme which used the vehicle radio as a voice path into the scene and a voice path into the radio system. If your radio bonked out of the system, it could be programmed (if the vehicle's equipped) to connect with the vehicle and go through it seamlessly.

All of these things were really nifty and four of us sat in the room thinking 'This is great! But if it's great, why isn't it taking root? It can't all be name recognition because of the other company.' And each of us read/knew about the PSP and Lancaster stories. And later on, we knew the NYS collapse was coming. Around the same time, I got to "play with" OS. I was able to speak with someone on the other end. To me, it sounded like Nextel iDEN. So, it worked, even though it's not necessarily my definition of robust audio quality and I would have to strain to use it all day. But someone younger who has grown up around compressed digital (read: crappy) audio might think it's fine.

At the end of the story, we decided on P25, not because we didn't like the concept of TDMA, and not because we thought P25 (or its leading manufacturer) was great, but because grant monies would probably be contingent on its compatibility and because there was something... buggy... here.

Now, I am dying to know exactly why this stuff doesn't work as originally portrayed. It HAS TO be something, and someone (maybe not in our group) HAS TO know. There is no good reason for it not to be working, unless there is some kind of deficiency.

And, yes, I don't think 19.2 kbps data makes sense anymore, considering file sizes and other bloat we've come to accept (but it was really, really fast back when we had VME or VAX computers and programmers prided themselves in their economically efficient coding abilities).

(Disclaimer: I don't currently have any financial or employment interest in any communications system manufacturer.)
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  #44 (permalink)  
Old 10-31-2012, 1:56 PM
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P25 2 slot TDMA fits in a 12.5 kHz channel. A pair of these gives you four talk paths inside 25 kHz. The only downside is the 9600 bps control channel which is kept for backwards compatibility.

Opensky comes in 2 flavors - 4 slot and the newer 2 slot. Most of the problems reported seem to be with the older 4 slot version on 851 MHz.

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Now, I am dying to know exactly why this stuff doesn't work as originally portrayed. It HAS TO be something, and someone (maybe not in our group) HAS TO know. There is no good reason for it not to be working, unless there is some kind of deficiency.
I'd like to know that too.
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Old 10-31-2012, 2:58 PM
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Originally Posted by Unitrunker View Post
P25 2 slot TDMA fits in a 12.5 kHz channel. A pair of these gives you four talk paths inside 25 kHz. The only downside is the 9600 bps control channel which is kept for backwards compatibility.

Opensky comes in 2 flavors - 4 slot and the newer 2 slot. Most of the problems reported seem to be with the older 4 slot version on 851 MHz.

I'd like to know that too.
The control channel concept is a waste of spectrum (in my opinion). This could have been done with embedded signaling, but I think this was an attempt to tie back to Project 16.

I am seeing NXDN being combined at 3.125 kHz off center frequency to produce two FDMA talkpaths in a 12.5 kHz channelspace to be competitive with DMR, but co-locating two immediately adjacent TDMA base stations will produce a number of out-of-band-emission problems making the 2 repeater/ 2 slot solution impractical - at least at this time. AND, it's paying for 2 base stations which effectively doubles the expense if enough isolation could be achieved to make it practical, as opposed to one base station running 4-slot.

The other things about P25 phase 2 are that it's being deployed as a trunked technology, and it's infrastructure dependent. It's not currently a 6.25 kHz migration for conventional systems and its simplex solution is phase 1.

It's not a big deal adding waveforms in today's software defined subscriber units, but there are still isolation requirements in fixed-end architecture.
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  #46 (permalink)  
Old 10-31-2012, 3:35 PM
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Originally Posted by crazynova View Post
This isn't a very popular opinion, but look at the other side - all radio traffic is still recorded and saved. If a large scale incident occurs, it will be evidence in court. It is also still monitored and controlled by the FCC, meaning cops don't just go saying whatever they want. Radio discipline is still there, at least with a department as large as LVMPD, so trying to get away with things isn't the reason for being encrypted.
Popular or not, it's one of the tenets our nation was founded on. Distrust of large government was very popular with the founders based on the actions of the British government back then. Large scale or not, the public should have the right to monitor the doings of their public servants.

The FCC will monitor (or review) tapes if there is a complaint, but I doubt that they have the manpower to listen to all of the radio systems operating in the US. Of course, if the radio traffic is encrypted, the public can't monitor it. It's probably cost prohibitive for an individual citizen to request either a transcript or unencrypted copy of all of the radio traffic.

I'll stop now as this is probably outside the topic of this thread and drifts into political commentary which I don't mean to do.
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  #47 (permalink)  
Old 10-31-2012, 6:15 PM
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Originally Posted by 16b View Post
So is anybody keeping score on how many ClosedSky systems have been scrapped or aren't working the way they were intended/designed/promised to work?

Something about trying the same thing over and over again and expecting different results...
I wonder how the OpenSky systems are holding up in Broken Arrow, OK and Naperville, IL? Unless I've missed something, it doesn't seem like there's been too many complaints from either one (yet).
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  #48 (permalink)  
Old 10-31-2012, 8:32 PM
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Originally Posted by PVPD730 View Post
I wonder how the OpenSky systems are holding up in Broken Arrow, OK and Naperville, IL? Unless I've missed something, it doesn't seem like there's been too many complaints from either one (yet).
This past spring I made an inquiry with a family member that is a Broken Arrow PD officer. He was not happy with OS as regards coverage issues. He was left without the ability to get backup on some calls. He said this and other issues have been communicated to the new chief by multiple officers and the FOP. The chief promised to review the radio system. I am not aware of any other developments but I may be able to make further inquiries if he comes to Thanksgiving.
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  #49 (permalink)  
Old 11-01-2012, 4:50 AM
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Post KLAS-TV 8's news story on this topic.

Here is KLAS-TV 8's news story on this topic.
Police Scrapping $42M Communications System - 8 News NOW

From what I understand that studier sound is common on Open Sky (broken sky) systems. I don't understand why if Project 25, P25 is better and all, why OS & OS2 users don't just move to P25?

And one more thing CCFD, and NLVPD are on the SNACC Moto. 800mhz system, why did LVMPD (metro)
not just make the switch to SNACC? I do know that LVMPD radios have access to the NSRS right now, and that both SNACC, and NSRS will make the move over to P25 some day. So I think that Metro should just stay on NSRS until they make the move to P25. You know metro would not be $42M in the hole right now if it was not for this Desert broken sky "system".

Thank you for letting me rant.

My name is Paul by the way nice to "meet" all of you.
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  #50 (permalink)  
Old 11-01-2012, 6:15 PM
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are they back on vhf yet
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  #51 (permalink)  
Old 11-01-2012, 10:46 PM
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Originally Posted by bikinjohn View Post
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From what I heard the data on the computers weren't running "great," just the voice problems were more obvious.
I heard and witnessed the Computers were just as bad but, worst case you wait a few seconds longer before you get the response. The dead spots for voice were the same for data
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Old 11-02-2012, 3:40 AM
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Wouldn't it have been easier to modernize the VHF system, or move to a modern, analog (non trunked, etc) system?

Cops got by, much more safe, before all these fancy radio systems were implemented.
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  #53 (permalink)  
Old 11-02-2012, 12:38 PM
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Which is, from what I have heard, OpenSky was orignally intended to do. After all these very public failures, I don't understand why Harris is still marketing the system.
Harris doesn't market the OpenSky product for public safety from what I have been told. They inherited it when they bought M/A Comm. They've been fighting with it ever since. My understanding is OpenSky was was originally designed for utilities and commercial use, not public safety. How it was every sold to public safety is beyond me.

Watch what happens. I'll bet that they keep OpenSky for data portion, but that Harris comes up with a wiz-bang deal for their P25 trunked system that LVMPD accepts...

Last edited by car5le; 11-02-2012 at 12:40 PM..
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  #54 (permalink)  
Old 11-02-2012, 2:12 PM
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Here is a local Florida article that references this...

Las Vegas police drop OpenSky; West Palm still undecided on police radios | West Palm Beat blog | The Palm Beach Post
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  #55 (permalink)  
Old 11-02-2012, 3:46 PM
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I can understand the desire to not just throw away a system you paid great heaping piles of cash for, but to keep (and end up maintaining) an entire trunked radio system strictly for data, while erecting a replacement trunked radio system for voice, just boggles my mind.
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Old 11-02-2012, 6:04 PM
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I can understand the desire to not just throw away a system you paid great heaping piles of cash for, but to keep (and end up maintaining) an entire trunked radio system strictly for data, while erecting a replacement trunked radio system for voice, just boggles my mind.
Well from the contractual side, did the city ever officially accept the system in its current state? If so they are screwed. But if they didn't and if they had a sharp attorney developing the boiler plate, there would be a performance bond in place for the entire amount of the system. If the vendor is found in default of the contract, which in this case they might be, then the city could get the entire amout back plus damages.

This really depends on whether or not they officially accepted it or not, and only someone from the inside can fill in the details.
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Old 11-02-2012, 6:06 PM
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My understanding is OpenSky was was originally designed for utilities and commercial use, not public safety.
It was actually designed for either FedEx or UPS as a data system. It was an after thought to utilize it for VoIP.
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Old 11-02-2012, 10:52 PM
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Originally Posted by PaulSuperman View Post
Here is KLAS-TV 8's news story on this topic.
Police Scrapping $42M Communications System - 8 News NOW

From what I understand that studier sound is common on Open Sky (broken sky) systems. I don't understand why if Project 25, P25 is better and all, why OS & OS2 users don't just move to P25?

And one more thing CCFD, and NLVPD are on the SNACC Moto. 800mhz system, why did LVMPD (metro)
not just make the switch to SNACC? I do know that LVMPD radios have access to the NSRS right now, and that both SNACC, and NSRS will make the move over to P25 some day. So I think that Metro should just stay on NSRS until they make the move to P25. You know metro would not be $42M in the hole right now if it was not for this Desert broken sky "system".

Thank you for letting me rant.

My name is Paul by the way nice to "meet" all of you.
CCFD, LVFR, NLVPD & FD, HPD & FD, BCPD & FD, CCSDPD and all the Henderson, Boulder City, Las Vegas and North Las Vegas Marshals, are all on SNACC, which encompasses almost every agency in Clark County with the exception of Mesquite PD, UNLVPD (Which is on NSRS with UNR PD), Hoover Dam PD (Federal) and DPS (Includes NHP & Capitol PD which are on the NSRS).

I was not aware Metro had access to the NSRS? I know they have a channel (Or two, IDK) that are patched through to SNACC so I would guess they have the same for NSRS, but I don't think they can just use the NSRS, especially given how many channels Metro uses on a regular basis (So discounting the Tactical & Car to Car channels).
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Old 11-03-2012, 2:02 AM
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It was actually designed for either FedEx or UPS as a data system. It was an after thought to utilize it for VoIP.
I have heard UPS, But I might be wrong.
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Old 11-03-2012, 3:50 AM
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I agree because they have EDACS capable radios which they can use on the NSRS
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