Madison County Going Mototrbo

Zsneese

Member
Premium Subscriber
Joined
Dec 30, 2014
Messages
120
Location
Lavonia, Georgia
Watched the video from 8-3-20....As someone very familiar with Gunby Communications, Gunby Communications has been involved in zero discussions for this new Madison County radio system and was never asked to provide a priced proposal for a Kenwood Nexedge system as has been so stated. So not sure what the Director is referencing or the BOC looking at. Several years ago, GCI did provide a BUDGETARY ONLY estimate for Madison County to purchase their own multi-site Trunking System. Hopefully the BOC will follow through and publish a RFP with specifications and, contrary to what has been stated, learn there are several vendors close enough to service Madison County capable of providing a VHF Tier III trunking system if that is the system/technology they desire. Or perhaps look at Banks County, GA who purchased a 6 site Kenwood UHF NexEdge Trunking system with over 300 radios for less than 1 million.
If I'm not mistaken Kenwood/EFJ offers a Tier III simulcast solution which is why I mentioned that MCA isn't technically the only company that's able to provide the system they're looking for. I can see why they would want Tier III due to not having to license but half of the frequencies due to TDMA, not being locked to one brand (Tier III is an open standard but I'm sure Motorola proprietary features such as RAS or BP encryption would be enabled if Motorola got it to ensure only their equipment is compatible), and to work with their current XPR radios but it doesn't seem like enough research has been put into who all can provide this technology. I've used both Motorola and Kenwood equipment in a public safety environment and each brand has their strengths and weaknesses in their own way as far as design and UI but for the most part they all do the same thing when you ask it to. Personally, I'm not big on one brand or the other but I am big on a competitive and fair market without one single company monopolizing you. If a Kenwood offers a TIII solution, I'm sure it would be a fraction of the cost compared to /\/\ if it's anything like their other products and then they won't get the told that they're no longer supported and obsolete after about 8 years like the other NEGA counties on TRBO systems.
 
Last edited:

RRR

What?
Premium Subscriber
Joined
Dec 6, 2005
Messages
1,718
Yea, but it sure is hard for NXDN to compete with the 2 slots (2 channels) per frequency of Mototrbo, that NXDN does not have. Quite valuable for small to mid size areas
 

Experiment626

Member
Joined
Sep 30, 2015
Messages
28
Watched the video from 8-3-20 and learned that bids for Nexedge, TRBO, and P25 systems were taken from Gunby Communications, MCA, and Motorola Corprate. NXDN was thrown out due to no simulcast ability and P25 was too expensive so they said that TRBO was the only option in price range and with the features. They mentioned that the new VHF radios being purchased in the past couple of years are compatible with the new system so this means it is most likely a VHF Capacity Max/Tier III simulcast system with 3 sites being mentioned. It was explained that each department is purchasing its own "stock" in the system and the funding is already completely there. The only delay seems to be the legal processes of advertising and bidding it out even though only one local dealer (MCA) can provide said system (which technically isn't true). From listening it sounded like the P25 quote came in around $5 million while the TRBO quote came in at just a hair over $1 million. The video from tonight's meeting hasn't been posted yet so I'm unsure what all happened tonight.
I'd just like to throw in that NXDN does indeed support simulcast.

Here's what icom's website says.
 

kb4he

Member
Joined
Jul 16, 2015
Messages
7
Kenwood does support Nexedge simulcast in conventional systems only. Kenwood does not support Nexedge simulcast in their trunking systems. Kenwood does support DMR simulcast trunking and P25 simulcast trunking.

In reference to the 2 slot capability of DMR, 2 talkpaths per 12.5 Khz channel appears to be an advantage. However, loosing both talkpaths should a repeater be interfered with or fail is a disadvantage.

If you are purchasing Part 22 paired 30Khz channels to obtain clear spectrum, these paired frequencies can be divided into two 12.5Khz channels for DMR (4 talkpaths/4800bps) or four 6.25 Khz channels for Nexedge (4 talkpaths/3600bps). No advantage there.

If your getting your frequencies from the Part 90 pool frequencies It is much easier to obtain 6.25Khz channels than it is to obtain 12.5Khz channels.

While Nexedge does require twice as many repeaters( a disadvantage) , there is the inherent advantages of being less susceptible to interference (6.25Khz channels), lower bit rate (less symbols lost in weak signal conditions) no timing to worry about allowing more distance from the site (DMR has distance limitations due to TDMA timing) and the redundancy of having multiple repeaters (one repeater per talkpath).

Assume a three talkpath trunking system. (1 control channel, three talkpaths)
DMR requires two repeaters. 1 slot dedicated to control channel the other three slots dedicated to talk paths. Loose either repeater you will now have one talkpath or no talkpath depending on system design.

Nexedge requires four repeaters. 1 dedicated as primary control channel, 1 dedicated as dual function (control channel or talkpath) the other two function as talkpaths. Loose one repeater, you still have two functioning talkpaths. Loose the control channel repeater, the dual function repeater takes over and you still have two talkpaths.

Kenwood NX5000 series mobile/portables radios have a significant advantage over Motorola radios when it comes to interoperability.
Kenwood radios will support analog/Nexedge/DMR in a single radio.
Motorola radios will support analog/DMR only.
 

Experiment626

Member
Joined
Sep 30, 2015
Messages
28
Gotcha, makes sense I suppose. Not sure why a county of 28,000 thinks they need a multi-million dollar trunking radio system but what do I know.
 

MTS2000des

Member
Joined
Jul 12, 2008
Messages
3,469
Location
Cobb County, GA Stadium Crime Zone
Nexedge also offers real AES-256 encryption unlike Motorola who make it difficult for US customers to buy anything other than welfare grade ARC-4 based encryption, fine for school buses but easily compromised if one wants real comsec. NXDN also sounds way better than DMR, and Kenwood natively supports over the air aliasing.

If this agency is considering DMR, they really need to consider Nexedge for the reasons above and others. It's far secure from a network point to. Nexedge trunking means goodbye to cloned radios, hackers with ebay specials penetrating the system, and secure provisioning. ESN validation and secure system keys/software puts the brakes on the games played with outsiders trying to get access to the system.
 

kb4he

Member
Joined
Jul 16, 2015
Messages
7
Gotcha, makes sense I suppose. Not sure why a county of 28,000 thinks they need a multi-million dollar trunking radio system but what do I know.
The reasons to move from an analog system to a digital system are to numerous to discuss in a forum... A significant cost is the replacement of all non digital mobiles/portables. To achieve 95% portable coverage of a large area (county or larger) requires a multi-site system. Then there is the question of whether you only require outdoor coverage or indoor coverage. Residential indoor coverage is a totally different requirement than School indoor coverage or industrial indoor coverage as the construction materials are much different and greatly effect portable coverage.

Whether a multisite conventional system or a multi-site trunked system is determined by the number of talkgroups required. If all you require is one Fire talkgroup, one Sheriff talkgroup, one EMS talkgroup then a conventional system would be the recommended solution. Adding an additional talkgroup requires an additional repeater at each site.

If the departments have a need for multiple talkgroups, for example, Fire wants to have two talkgroups to simultaneously allow two incidents to be managed without having to share a talkgroup, or the Sheriff want to have a Patrol/Dispatch talkgroup, a CID talkgroup or a SRO talkgroup then a trunking system is the appropriate recommendation. With a Trunking system you could include your public works departments, Schools, or even each fire station can have their own private talkgroup. Adding a future talkgroup is in most cases a simple programming without the purchase of additional repeaters. If a additional repeater(s) are required to meet traffic loading, that equipment is to the benefit of all users not just the added user.

Since all users share the same infrastructure a properly designed trunking system with significant coverage overlap provides redundancy and resiliency which is critical for public safety users. With a conventional system and each user having its own repeater at each site, a failed site or failed repeater at that site will significantly affect the portable coverage of that user.
 

RRR

What?
Premium Subscriber
Joined
Dec 6, 2005
Messages
1,718
RAS on DMR takes care of the "cloned radio / ebay specials"

DMR = 2 repeaters = 4 talkpaths (unless trunked, then 3) There is that "if you lose one, you lose 2" yea true, if you have 2 arms, and you lose one, you still have 1. Masking the ability of DMR's double talkpaths with "what if you lose one" is a poor reason to try to debate NXDN is "better"

All this talk of 256 encryption, there are still a substantial amount of agencies / users that aren't interested in encryption, so moot point there.

And NXDN sounding better than DMR is an opinion. It depends on how it is set up, I have heard good and bad from both.
 

MTS2000des

Member
Joined
Jul 12, 2008
Messages
3,469
Location
Cobb County, GA Stadium Crime Zone
RAS on DMR takes care of the "cloned radio / ebay specials"
The RAS key can be compromised. Like the welfare encryption MSI insists on selling to DMR customers (unlike other vendors like Kenwood who offer real security of AES-256) is pathetic and based on 20 year old algo's that have been compromised by 15 year olds. Seriously. It is NOT security.
All this talk of 256 encryption, there are still a substantial amount of agencies / users that aren't interested in encryption, so moot point there.
If they want comsec, AES-256 or nothing. Still doesn't explain why the largest DMR vendor REFUSES to offer AES to it's customers (unless you are "special"). ASSuming agencies don't want encryption isn't moot. They shouldn't be held back from getting true comsec capability because some vendor wants to force the customers' hand into buying P25, which, while a purpose built public safety grade system, may be out of their price range. It's almost as if they're being told "well since your a poor piece of trash, this is all you get, or pound sand"
The fact that some special customers can get the AES-256 entitlement added is insulting.
 

RRR

What?
Premium Subscriber
Joined
Dec 6, 2005
Messages
1,718
Ok, I understand you have a disdain for Mototrbo. I get it.

But there are many agencies and users that find it to be wonderful.

Again, some don't want or need encryption, so yes, in those cases, it -is- a moot point.

NXDN has it's advantages as well, I agree. But let's consider the merits of each type of format before just flat downing it.
 

MTS2000des

Member
Joined
Jul 12, 2008
Messages
3,469
Location
Cobb County, GA Stadium Crime Zone
Ok, I understand you have a disdain for Mototrbo. I get it.
No, I disdain when agencies don't follow honest procurement and allow for open bidding. MotoTRBO is fine for school buses and non-safety of life communications. Sadly due to artificial limitations placed by the manufacturer, it lacks things that public safety users require like failsoft, talkgroup priority, site trunking, and industry standard robust encryption.
Again, some don't want or need encryption, so yes, in those cases, it -is- a moot point.
Did the RFP specifically exclude it? How do you know that Madison county does not want or need encryption? That is, after all, who we are talking about. If their RFP calls for the capability, than it should be AES-256 which, as I stated, some vendors do not offer as an option within the USA except to "certain customers" whereas it's openly available as an option on Nexedge.

Agencies who don't use due diligence and investigate all viable options don't do service to their taxpayers.
 

kb4he

Member
Joined
Jul 16, 2015
Messages
7
There has been no RFP published to date for Madison County. The Director solicited proposals from MCA and Motorola Solutions. MCA submitted a proposal for what has been stated to be a two site transmit, 1 site receive Motorola Capacity Max system and radio console positions for approximately $1 million. They currently have a (4) positions of Telex, I do not know how many or what brand was proposed. This price did not include any mobiles/portables. Those would be purchased separately by the various departments. The Motorola Solutions proposal was for a P25 system unknown sites/channels/frequency/ subscribers for approximately $5 million. According to the video of the August 3 BOC meeting, Gunby Communications submitted a proposal. Gunby Communications has not submitted any pricing proposal to Madison County other than a budgetary estimate for a multi-site trunking system and a FleetTalk proposal. Both were presented to the prior Director in the spring and summer of 2018 respectively. In the August 31 BOC meeting, the Director was directed to prepare and publish a RFP with specifications for the new radio system. The RFP is now with the county attorney for review and is expected to be made public in the next week or so. Whether encryption was part of either proposed system is unknown.
 

RRR

What?
Premium Subscriber
Joined
Dec 6, 2005
Messages
1,718
Basic privacy with a code of "1" would keep scanners out. Many times, that's really all some want, if that.

I appreciate your educated opinion. But remember, there are agencies that use Mototrbo and it works great for them, and the users love it. NXDN isn't necessarily designed for "public safety" either, but there are also agencies that love it too.

As always, YMMV. (y)
 

Zsneese

Member
Premium Subscriber
Joined
Dec 30, 2014
Messages
120
Location
Lavonia, Georgia
Seems like there is a lot of comparison between the two protocols so here is an interesting document of a fair comparison from Kenwood (who sells both DMR and NXDN systems). NXDN vs DMR White Paper The most interesting part is the fact that they both use the same vocoder at the same bitrate (when comparing to 4800 baud NXDN systems)
 

RRR

What?
Premium Subscriber
Joined
Dec 6, 2005
Messages
1,718
Kenwood really over-complicated their method of DMR.

I sure wouldn't want to have to set it up / program / maintain.

Motorola has DMR right. Kenwood has NXDN right.
 
Top