Police grapple with communications mandate

[Thunderbolt]

SANTA CRUZ, Calif. -- Just like televisions will stop working in 2009 without digital converter boxes, the radios used by police, firefighters and medics will go silent in 2013 without upgrades.

http://www.santacruzsentinel.com/ci_10879309

 

[BT202]

Narrowbanding of Public Safety Communications

Here in Oakland County, Michigan, every police, fire, EMS provider, and hospital will be switching over to the Open Sky system. It's really exciting technology. I can speak first hand as to how it works as I've been involved with the project for about the last 3 years. To date, five departments have made the transition, and three more will be added by the end of the year. I would anticipate all of Oakland County will be on the system by 2009.

The mandate of narrow banding drove the development of a 4-slot TDMA VOIP system that will allow 172 simultaneous conversations across the county; that's only using 43 (forty three) 800 MHz frequencies! Given the proliferation of wireless devices in our country, the FCC had to take some proactive steps to avoiding chaos in the very near future.


Pete
WWW.Glass-Cockpit.org

 

[red8]

Open Sky

Here in Oakland County, Michigan, every police, fire, EMS provider, and hospital will be switching over to the Open Sky system. It's really exciting technology. I can speak first hand as to how it works as I've been involved with the project for about the last 3 years. To date, five departments have made the transition, and three more will be added by the end of the year. I would anticipate all of Oakland County will be on the system by 2009.

The mandate of narrow banding drove the development of a 4-slot TDMA VOIP system that will allow 172 simultaneous conversations across the county; that's only using 43 (forty three) 800 MHz frequencies! Given the proliferation of wireless devices in our country, the FCC had to take some proactive steps to avoiding chaos in the very near future.


Pete
WWW.Glass-Cockpit.org

Hey Pete,
Answer this question, just how is the system going to Interop with the Michigan State System ? Because they are APCO- 25. And just about every other system in the state is on the Michigan system. in fact alot in the Detroit area.
red8

 

[BT202]

Open Sky and APCO-25

Hey Pete,
Answer this question, just how is the system going to Interop with the Michigan State System ? Because they are APCO- 25. And just about every other system in the state is on the Michigan system. in fact alot in the Detroit area.
red8

There is a hard patch between Oakland County's System and MPSCS. Every police car and prep in the county will have these talk groups installed in their radios.

I'm not sure if 'just about everybody else' is on the MPSCS system, but if that were the case it would be the shortcoming of the system. You see, the MPSCS is a simulcast system that only has 40 some frequencies. As a result, when somebody in Copper Harbor transmits, it denies the use of one talk path from someone in Flat Rock. So, there can only be a maximum of 40 or so simultaneous transmissions at one time on the state system. That's a problem. After a large storm or other disaster (G_d forbid!), I can see the state system getting overloaded very quickly.

The Open Sky system in Oakland County will accomodate 172 simultaneous conversations at one time.... just in Oakland County!!!! We also have talk groups in our INTEROP profile that allow communications with Warren and Southfield, too. Southfield, as you know, is an analog system. And yet, we can talk to them.

The real upside to Open Sky is the fact that it is NOT a simulcast system! It will function very much as wireless phone cells do. As you drive from one cell, you are picked up by another. The towers are also inter-connected by a data and fiber network that directs radio transmissions as needed throughout the county. Even if only one frequency were licensed to a given tower, just that 'cell' could accomodate four simultaneous conversations IN THAT CELL. Further, if the communications are strictly in one cell, it induces no extra load on the rest of the county's network.

Let's say we have a real nightmare scenario. A large commerical plane crash, let's say, in Royal Oak. Because the vast majority of those disaster relief operations would be taking place within two, maybe three 'cells', the communications in the rest of the county wouldn't be affected! Now, same scenario, but everybody in Michigan were on the MPSCS; those disaster communications would put an enormous load on the rest of the state's communications, from Three Rivers to Whitefish Point.


Have an incredible day!
Pete
WWW.Glass-Cockpit.Org