Why isn't Nextel / iDen used in public safety?

[N_Jay]

As a digital encoding method, Motorola seems to consider iDEN obsolete. That would mean no support or upgrades. Another excellent reason not to START using it now.

Where did you get this information?

Last I heard Moto was supporting iDEN until the iDEN carriers stop buying it.

 

[N_Jay]

. . . . iDen is simply a coding method, . . . .

iDEN is a bit more than "coding method", it is a complete system platform.

 

[N4DES]

WiDEN is GPRS concepts on iDEN Channels. It does not require continous spectrum (except maybe to avoid interferring, but reular iDEN does that just fine.

Not according to the engineering documents that I have read that states its specific that it requires a minimum of 50KHz or 2 channels back to back.

 

[N4DES]

iDEN does have some fall back modes that can be designed into a system.

It is not a standard feature like it is in commercial and public safety systems.

If there are it wasn't stated in the documents that I have read. I'll see if I can dig them back out and look again, but that was one of the factors that we were looking at when we were debating on deploying a private mobile data system. Being we couldn't find any we didn't proceed any further.

 

[N_Jay]

Not according to the engineering documents that I have read that states its specific that it requires a minimum of 50KHz or 2 channels back to back.

Interesting.

Wonder what they are doing?

 

[N_Jay]

If there are it wasn't stated in the documents that I have read. I'll see if I can dig them back out and look again, but that was one of the factors that we were looking at when we were debating on deploying a private mobile data system. Being we couldn't find any we didn't proceed any further.

ISO, Isolated Site Operation, is one that comes to mind.

A system design could also incorporate other redundancy and failure mitigation methods.
I think Southern-Link used some of these features.

 

[b52hbuff]

So given all of the 'negative' comments about Nextel. I wonder if the operations folks at WDW are going to see any problems with their Nextel radios? Hopefully, they'll see enough that they'd go back to motorola?

I know that a lot of Theme Park Ops aren't 'mission critical'. But monorails and medical dispatch operations are just as 'critical' as public safety systems...

 

[PhilBurks]

Mozilla hit a critical point yesterday and is 100% correct. Motorola never designed it as a PS network. It was built around a GSM structure. The GSM structure never considered the system management things that all major operators have grown to expect and use. Things like:

• Selective Radio Inhibit
• Dynamic Reqrouping
• Selector Lock
• Storm Plans
• Radio Trace
• Status Message
• Emergency Priority
• and the list goes on.

It's not that it couldn't happen on iDEN, and its not that creative ways couldn't be found to make hte system do some of these things. It just wasn't part of the 'build contract'. To ask Motorola to add these things.... ain't gonna happen with the P25 push going on. And, you got to know that Motorola, Ma-Com, etal, are all on to the next generation systems that will work faster, better and bigger.

I THUROUGHLY believe in iDEN as a backup plan, as others have suggested. I'm a BIG plan 'B' guy. Also, I had always heard from the beat guys that they didn't like iDEN because the phones weren't heavy enough! In a pinch, apparently some have used their XTS's as weapons of persuasion!

 

[nd5y]

Not according to the engineering documents that I have read that states its specific that it requires a minimum of 50KHz or 2 channels back to back.

Do they really mean 2 RF channels or 2 time slots?

 

[N_Jay]

Do they really mean 2 RF channels or 2 time slots?

Multiple time slots makes more sense, but I would need the whole sentence or paragraph to be sure.

 

[N4DES]

Do they really mean 2 RF channels or 2 time slots?

2 RF channels

 

[N_Jay]

2 RF channels

Would love to learn more about this.

 

[mkewman]

I had an experiance the other day that proved that Nextel should not be used by PS:

I live in a dorm on a college campus. The Campus Police use 800 mhz conventional, have a handheld connected with local pd, and a nextel.

when it's after buisness hours, they forward all the calls to the CP hotline to the officers nextel.

There was a fire alarm that went off in one of the dorm buildings, and the protocol is that when an alarm goes off, campus police is to respond to see if it's an actual alarm and needs response, then contacts proper authorities using the local pd's radio system with his handheld.

Well, it was about 1am, and since it's a small school, there's only one officer from midnight to 3am. he was in a building that doesn't get Nextel Reception. So the Head RA kept calling and calling and calling, and couldn't get thru. 15 minutes after the alarm went off, i thought "hmm... it's interesting that no authorities have shown up... considering that fire alarms are often autodial the authorities unless they've been shut off within a small amount of time (it was still going off 15 minutes later) anywho, i decided to call 911 with my cell phone and have them send someone, they said that it's the college security's jurisdiction, and i said that they haven't responded, so the dispatcher called him using the local pd's radio system, and he responded.

later come to find out that his nextel didn't get reception, but a conventional radio did.

moral of the story (if this even made any sense) use conventional or trunking, don't use a POS nextel.

 

[suttles1972]

[ Nobody has yet been able to cover a single STATE reliably, although Motorola has apparently gotten very close in Florida (after M/A-Com dropped the ball). But "very close" is not the ultimate goal in public safety, either.[/QUOTE]

I most say that South Carolina's SCANA is indeed a superb statewide system. It covers the borders of North Carolina, Florida, Georgia and the coast.

 

[N4DES]

http://en.wikipedia.org/wiki/IDEN

In order to provide high data rates for packet data, Nextel started to develop a 2.5G technology called WiDEN.

WiDEN is a planned expansion on the iDEN system, where instead of using a normal 25 kHz channel for packet data, it will encompass 4 carriers (100 kHz) into one channel. This would have allowed download speeds of 96 kbit/s, which is comparable to the average CDMA2000 speeds from American competitors Sprint and Verizon.

and this is one of the iDEN documents that we reviewed:

https://idenonline.motorola.com/ideveloper/pdf/techover.pdf#search='iDEN'

 

[Al42]

I most say that South Carolina's SCANA is indeed a superb statewide system. It covers the borders of North Carolina, Florida, Georgia and the coast.

But does it cover all the ground in South Carolina? Covering just the borders doesn't do much good.

 

[FireCop]

SCANA/Palmetto 800

The South Carolina system isn't iDEN. It is a Motorola Type II combination analog & digital. It think it covers close to 100% of the state.

 

[nozzle75]

PS Communications

First of all, it seems there are several topics/questions. As for SC's Palmetto 800 (Formerly SCANA) system, it does cover most of the state. No system provides 100% coverage 100% of the time. In fact, most RFP's call for 90-95% coverage. You can see more about Palmetto 800 at www.cio.sc.gov to learn more. It is built on the Motorola Type II Smartzone technology.

As for NEXTEL, NEXTEL provides an alternative means of communication for public safety with the addition of Public Safety Priority Dispatch where NEXTEL gives priority to public safety units. The system will actually "bump" another lower priority user off of the system to free up a dispatch channel. Remember, we aren't talking about primary communications. NEXTEL doesn't meet the NFPA 1220 Standard for Fire Department Communications; for that matter, most public safety system fail to meet the standard. In my experience, NEXTEL offers a great solution for command and control functions to help ease the traffic on normal dispatch channels. If the NEXTEL system doesn't work, go back to your existing system.

There has also been some discussion regarding interoperability as well. The sad truth is, if we're waiting to provide interoperability with radio equipment, we're too late. Interoperability starts with planning and lots of it. It starts with email, phone calls, and (My favorite) working lunches with other agencies. There has to be communication verbally between agencies and controlling parties before the disaster hits. Granted, there should be a common platform to operate on. How many of you have the National Public Safety Tactical Channels in your radios? We're talking about channels authorized by the FCC in Low Band, VHF, UHF, (Soon 700Mhz), and 800Mhz that do not require a license for portable and mobile stations?

Finally, having spent time in Louisiann after Katrina, the common platform has to exist and i don't beleive it is P25. P25 greatly limited range and penetration in simplex mode. P25 is an excellent standard so long as you have the infrastructure to support it. We didn't, and subsequently reprogrammed all of the radios to analog mode. Remember, just beacuse you've never faced a huge national disaster, doesn't mean that you won't. Be prepared. As for NEXTEL, we had two-way/dispatch capabilities so long as we had NEXTEL service. Often times, we couldn't call out on the telephone side, but almost always made contact through PTT. Imagine that, NEXTEL survived when a lot of PS systems failed.

Matthew

 

[N_Jay]

http://en.wikipedia.org/wiki/IDEN

In order to provide high data rates for packet data, Nextel started to develop a 2.5G technology called WiDEN.

WiDEN is a planned expansion on the iDEN system, where instead of using a normal 25 kHz channel for packet data, it will encompass 4 carriers (100 kHz) into one channel. This would have allowed download speeds of 96 kbit/s, which is comparable to the average CDMA2000 speeds from American competitors Sprint and Verizon.

and this is one of the iDEN documents that we reviewed:

https://idenonline.motorola.com/ideveloper/pdf/techover.pdf#search='iDEN'

Not that I don't trust wikipedia (after all, it is as reliable as any other information on the internet), can you show me an iDEN document that talks about combining channels rather than time slots?

 

[Seadoo]

In answer to the original posters question. Iden is a much stronger encrypted technology and can be used for public saftey. The reason I think that it is not used by PS is because most public saftey agencies use the type II Motorola format and interopperbility with surrounding PS agencies would be a problem because the equiptment is different, hense you cannot use a type II radio on a Iden system, so no mutuial aid support would be possible except by a patch which would defeat the purpose. All equiptment would need to be swapped out and at this point Type II equiptment is the better bang for the buck. That is just my guess on the subject. Iden is by the way a TDMA type system like the common cellphone systems..