Milwaukee's future OpenSky system
- Thread starter newald
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izz
Member
I don't see how. The Police and Fire Departments combined use 24 frequencies and other city services use about a dozen more.
mikey60
Member
OpenSky is supposed to support up to 4 simultanious conversations on a 25Khz wide channel through the use of TDMA. In theory that would mean that with 24 frequencies, it could be possible to have 96 concurrent conversations occuring.
How realistic this is I don't really know. Oakland County Michigan has been trying to get their OpenSky system on line now for quite some time, and from what I've heard, there are very few people on the system thus far. Time estimates that I've seen said the system should be fully implemented by now.
I don't know of any fully functional OpenSky systems yet. Maybe other people do.
Mike
How realistic this is I don't really know. Oakland County Michigan has been trying to get their OpenSky system on line now for quite some time, and from what I've heard, there are very few people on the system thus far. Time estimates that I've seen said the system should be fully implemented by now.
I don't know of any fully functional OpenSky systems yet. Maybe other people do.
Mike
izz
Member
According to RR trunked database the OpenSky system in Milwaukee with 2/3 of the county's population will use only 9 frequencies, while the county's trunked motorola system uses 15 frequencies. If the county needs 15 frequencies, how would they squeeze all city departments onto a 9 frequency trunked system?
mikey60
Member
Ok, 9 frequencies, times 4 simultanious users per frequency (assuming 25 Khz channel) would be similar to 36 frequencies on a motorola trunked system (although motorola is limited to 28 on a single site).
Now if they are using 12.5Khz channels, the Opensky system allows 2 simultanious conversations per frequency, so it would be similar to 18 frequencies.
Now none of this includes the addition of non-voice traffic which would reduce the capacity of the system as far as voice traffic is concerned.
This is my understanding of Opensky. It may or may not be 100% accurate, and depending on the design of the system, the same conversations may occur on multiple frequencies at the same time, which would also reduce the capacity.
Mike
Now if they are using 12.5Khz channels, the Opensky system allows 2 simultanious conversations per frequency, so it would be similar to 18 frequencies.
Now none of this includes the addition of non-voice traffic which would reduce the capacity of the system as far as voice traffic is concerned.
This is my understanding of Opensky. It may or may not be 100% accurate, and depending on the design of the system, the same conversations may occur on multiple frequencies at the same time, which would also reduce the capacity.
Mike
izz
Member
Thanks for the info 
I understand OpenSky more now than I did before, but I'm going to miss listening to the Milwaukee Police when they make the move.
I understand OpenSky more now than I did before, but I'm going to miss listening to the Milwaukee Police when they make the move.
mikey60
Member
I hear ya...
My county is in the process of building an Opensky system as well. Reports are that it's running behind schedule but I can't find the document that I read that from now.
Mike
My county is in the process of building an Opensky system as well. Reports are that it's running behind schedule but I can't find the document that I read that from now.
Mike
Anyone know why the FCC doesn't have any record of the frequencies listed in the RR trunked database?
866.0375
866.2375
866.6125
867.1500
867.1875
867.9000
868.5000
868.8125
868.9875
Also two frequencies, 866.6125 and 867.1500 are already licensed to the Sheboygan County trunked system. The southern most tower near Random Lake is only 26 miles from the Milwaukee city limits. Won't these trunking systems interfere with each other?
866.0375
866.2375
866.6125
867.1500
867.1875
867.9000
868.5000
868.8125
868.9875
Also two frequencies, 866.6125 and 867.1500 are already licensed to the Sheboygan County trunked system. The southern most tower near Random Lake is only 26 miles from the Milwaukee city limits. Won't these trunking systems interfere with each other?
HowD
Member
OpenSky
Is there any receiver that will allow one to listen to OpenSky comms?
Is there any receiver that will allow one to listen to OpenSky comms?
GlacierClipper
Member
HowD
Member
Really?
So, one must purchase an OpenSky radio? (Or were you joking?)
So, one must purchase an OpenSky radio? (Or were you joking?)
GlacierClipper
Member
They want to be the first one on the list to have Opensky up and running.
That gives the Politicians something to bragg about and capturing the spotlight.
Taxpayers $$$ at work.
Sames as "Money Talks and BS walks"!
That gives the Politicians something to bragg about and capturing the spotlight.
Taxpayers $$$ at work.
Sames as "Money Talks and BS walks"!
nslt204
Member
Tonight 1/9/07 at 10 pm Milwaukee Channel 4 WTMJ is doing an investigative report on the so far failing Open Sky system in Milwaukee.
They are looking at the cost overruns as well as how late the system is in being built.
www.touchtmj4.com is the stations web site
They are looking at the cost overruns as well as how late the system is in being built.
www.touchtmj4.com is the stations web site
Just out of curiosity, how much does MACOM stand to lose if this project gets axed/fails?
wiradio
Member
- Joined
- Feb 2, 2005
- Messages
- 63
I wonder if future commercial scanners will include the OpenSky protocol, as well as APCO P25 Phase II (when specifications are decided) in the scanner protocol stack? Dream on for a few more years ... and while dreaming, may as well add iDEN to the stack, too ...
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JGP
Member
Anything is possible, but I'm not counting on it in my life time.bc780l said:
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