May 2014 Inbox
Wednesday, May 14, 2014 | Comments

Following are comments we’ve received from readers about recent online and print news and articles. If you’d like to comment on an article, email edit@RRMediaGroup.com.

In response to “Users, Vendors Still See Value in Analog” from May 27

Editor:

I am in agreement with the vendors still wanting to continue analog. As anyone that uses digital radio now and digital cellular users will attest to, digital radios give clear communications but will instantly drop off with no warning either because of a lack of signal or multipath that destroys the digital signal. At least with analog, all radios are compatible, and you have an audible warning with a noisy signal that you are getting a weaker signal or distorted signal and can have the party repeat the last transmission or you can move to get a better signal.

In public safety, communications is important and having good communications instantly go to no communications is just not in our interest. I have been using a multisite digital system and am frustrated with the instant drop of signal and the delay in acquiring another site to continue the conversation.

I am in Washington state with many hills and trees, and this UHF digital system doesn’t work as well as the UHF analog systems I used previously. On the plus side, I must say the audio quality of the digital radio system is excellent — when there is a signal.

Gerald Marsh
Peninsula Communications
Washington State

 

Editor:

I work in a rural area in Washington state surrounded on one side by the Olympic Mountains, with Canada in clear view and around a terrain that includes some deep valleys and many trees.

We have just finished an analog simulcast system using Harris Synchrocast, three JPS Raytheon comparators, and Motorola Solutions base stations on hi-band VHF and UHF spectrum. The system is working well, and we have no plans in the near future to change to any form of digital modulation.

During testing it was discovered that the multipath that seems to reflect off the mountains to the southwest is unforgiving to digital modulation. While it might be possible to build new sites closer to these mountains and use directional antenna systems, the cost of such a venture would be enormous and difficult under current budgets to maintain.

As well, at a time when technology in the field is becoming more advanced, it seems that finding technicians that understand what modulation actually is, as well as any other constraint of the industry has become more difficult due to the lack of schooling, mentoring and interest these days.

The cons of digital seem to outweigh any pros. At least with analog you know when someone is trying to talk. Having my officers in a situation where the radios simply don't react is not an option. Static at least tells them to reposition and lets them know that someone is trying to talk.

There will always be a need for analog and some of us refuse to go without kicking and screaming.

Christopher Palmer
Greentree Communications
Washington State



 

In response to “Analog Still King for Many Users,” in the May issue

Editor:

I just read your article in MissionCritical Communications. Very interesting comments.

I'm Victor Sanora, engineering manager from Epcom/Syscom. We are major distributors in Central and South America for two-way radio systems, and we've been promoting a lot of digital technologies.

I think the main problem with digital systems is interoperability. Systems must be multivendor to grow. Very few people would like to get stuck with only one brand.

Another interesting thing that I found is the National Public Safety Telecommunications Council (NPSTC) comment. There is one technology that interacts easily with analog systems and that’s NXDN. Unlike Digital Mobile Radio (DMR) that only scans between analog and digital, NXDN truly receives both modes on the same channel and answers back the same way it receives. I think NXDN has practically the same performance as Project 25 (P25) Phase 1 but at nearly half price.

I know analog audio is unique and it is very hard for digital technologies to even get close to that quality, but still, users have good options for migrating to digital without giving up functionality.

Victor A. Sanora M.
Syscom

 


 

In response to “Zetron Console Uses CSSI in P25 Phase 2 Network” from May 14

Editor:

You will now see the price drop with the Motorola Solutions MCC7500 and MCC7100 series of consoles. In Colorado I have seen a six-position basic console system sell for more than $1 million and some sell for as little as $550,000, so you know there is some price gouging going on here.

Manufacturer’s Rep
Denver

 


 

In response to “What’s the Best Path Forward for T-Band Users?” from May 14

Editor:

Well, the last paragraph of this article says it all! This is a move to change the T-band spectrum to a system that has not been widely popular. Constant system-busies during peak usage continues to plague the Motorola systems because of lack of spectrum, and there are those who want to load it even more? Not only that, our pubic-safety users on the 700/800 MHz spectrum have nowhere to go many times during peak usage. They can't even go to a talkaround channel for short-range use at a scene because the interoperability systems don't have that feature.

Because I planned well ahead knowing this would happen, I kept the T-band channels and some of the VHF permanently patched to the interoperability channels. It was not met well with some of the department heads that believed the interoperability mantra after spending millions to go backwards. It was however met with great appreciation when the users realized that they were able to switch back to a channel that didn't have system busies and didn't sound like they were squeezing their noses when receiving transmissions from others.

For a few years now we have been training for an incident command system (ICS) format, and an ICS operation when run effectively and properly doesn’t allow for their field units to go on their own "mission" to communicate with others and lose contact with their evolving situation and command with them. How many lives will it take to get the point across?

It's not like we have the billions to throw out the window to support this boondoggle. I have noted that these systems are the best for those who profit from them and never be subjected to their use. Wake up folks! Leave T-band alone and move to put the VHF spectrum back to wideband.

If you think this is an angry letter, it actually is not. It has been prepared by someone using something that just doesn’t exist much anymore — reality and common sense! Better use of the existing spectrum was the only thing that billions should have been spent on, and I suspect this will never be published as a response because it is unpopular. Sometimes the truth isn't.   

John Patrizi 

 


 

In response to “SouthernLINC: No iDEN Shutdown Date” from April 30

Editor:

If I were SouthernLINC, I’m not sure I’d bet the farm on a push-to-talk (PTT) solution for Long Term Evolution (LTE) that’s proven for mission-critical operations by 2018. I’d look at a proven mission-critical PTT technology for voice that’s integrated with LTE for data. A solution like this has already been demonstrated.

The PTT technology SouthernLINC ought to consider, given its legacy iDEN system and its type of customer, is TETRA. This is a logical path for any iDEN operator as TETRA can almost be dropped in place, and TETRA is the best mission-critical technology today for transit and utility customers. Project 25 (P25)/LTE could also be a solution should the customer base be public-safety first responders.

Alcatel-Lucent with Cassidian has already demonstrated an TETRA/LTE integration in several markets around the world, and this combination makes sense. (link to http://www.radioresourcemag.com/onlyonline.cfm?OnlyOnlineID=426)

I, for one, am not holding my breath for a mission-critical PTT-over-LTE capability anytime soon.

Andrew Schwartz
Director, Radio Communications
New Jersey Transit

 


 

Click here for the April 2014 Inbox.
Click here for the February 2014 Inbox.
Click here for the January 2014 Inbox.

 



 
 
Post a comment
Name: *
Email: *
Title: *
Comment: *
 

Comments

No Comments Submitted Yet

Be the first by using the form above to submit a comment!


Magazines in Print







Events
May 2018

2 - 3
Comms Connect Auckland
Auckland, New Zealand
www.comms-connect.co.nz/

15 - 17
Critical Communications World (CC World)
Berlin
www.critical-communications-world.com/

More Events >

Site Navigation

Close