Showing posts with label bandplan. Show all posts
Showing posts with label bandplan. Show all posts

Wednesday, July 10, 2013

The HT of the Future?


Bob, K0NR wrote back in 2012 about the theory of dualband (2M/70cm) handheld transceiver that is built on top of the Android operating system.



He wrote:
"While this hardware configuration is exciting, the real power comes from having a software developers kit (SDK) with a stable Application Programming Interface (API). This would unleash the creativity of all those software-oriented hams out there and a plethora of apps would emerge"
I agree.

Since then, smartphones like the Runbo X5 are available, these have a built in UHF two way radio.

More recently Bruce Perens K6BP has been giving talks about his vision of the "HT of the Future."
Some of his points are:

Narrower bandwidth, not more than 3 KHz
Higher end units run Android, and host applications which communicate over digital radio.

-The prototype we are working on is based on Chris Testa's Whitebox design, and an Android touchscreen computer as the user interface and application host.
 
-It can run Android applications in conjunction with it's packet, digital voice, or FM two-way radio.

- It has WiFi, Bluetooth, GPS, USB, Ethernet.

The problem is Apps use data to transfer information to work.  If we are talking 1200 or even 9600 baud, then the app space is doomed by this limitation.  There really isn't any talk about apps as those will be a third party thing. However I feel you should identify what some potential ones would be, so that the hardware can be designed to accommodate. I don't see that, so it's more or less; here it is, if you can make it do what you want, cool.  Else not cool. In short I think the data rate will significantly impact what you can do with it.
 

Whitebox is SDR design optimized for a handheld.  It uses a Flash based gate-array for low power consumption.  The problem is it's a narrow band I/Q modulator design.  This version probably isn't good for spread spectrum. However HackRF, an open source SDR platform by Michael Ossmann would be.

I have written many times that ham radio needs to embrace spread spectrum.  I have also pointed out that is somewhat incompatible with our gentlemen's developed bandplans.


So I'd like to compile a list of things (think big) you'd like to see your future HT do. Here are some of my initial thoughts:

Mesh style, were if your HT can't reach the repeater/ other person it will find a relay (your mobile etc - think same band crossband)

GPS for APRS as well as auto downloading/programming local repeater frequencies on the fly. Street level map display for APRS (android interface)

Voicemail - if your not answering a directed call it will go to a hunt group, and lastly voicemail till next time you PTT (SIP integration)

Ability to use the HT as a remote base for your frequency agile home station.

RTL like ability- able to monitor public safety trunked systems out of of the ham band, while simultaneously monitoring the ham channel.

Please put your thinking hat on. 


Wednesday, February 27, 2013

Narrowbanding?

I posted a link to the Advanced Repeater Systems Webpage, titled No Ham Narrowband FM on twitter. Subtitled: "If you're not upgrading to digital, don't downgrade to Narrowband FM!"

For the most part I agree with it.  Mostly I liked the technical analysis of the issue.

I received a tweet back, asking if I was for or against narrowbanding on Ham bands.  He seemed to think I would be for it, being more of a tech guy.

I responded I think we need to go wider.

Several years back, I explained why I feel this on my VOIP/DV page.



Hams are not bound by these narrowband rules, refarming nor will there ever likely even ever be a rebanding.  We have oodles of spectrum available to us, most of it un-used.
What is actually disappointing about D-Star is that  it's only a 4800 baud total data stream equivalent signal.  2400 bps is reserved for actual digital voice, 1200 bps is reserved for FEC (forward error correction)  on the digital voice.  (This is for callsign and short message data.)  1200 baud is reserved for serial data low speed digital data .  (This is for APRS, and text messages/text query's.)  The sad part is 1200 baud data is what we were doing in the 1980's. 
So if 4800 baud can fit into a 6kHz bandwidth, we could have had a 12800 (12.8k) baud total data stream equivalent signal fit into our existing 16 kHz bandwidth plans.  This could have left us with 9.2k left for data.  Or at the very least more could have been given for the digital voice codec, so that we could use other license free-codecs that sound more natural.

Less far back, I blogged about the problems with frequency coordination.

What bothers me is that most of the VHF-UHF bands are inundated with mostly inactive repeaters.

The problem is frequency coordinators have broken the bands into channels most fairly narrow in width, with conventional input and outputs. I think this image/model discourages potential other use, that may not fit the convention.
And my last blog was about a potential rules re-write to encourage some new developments in the hobby.

Ham radio has always used hand-me-down gear from the commercial world.  And I would be absolutely irate if some coordination body told me as an existing repeater owner that I had to narrow band.

I think a some guidelines would be;

-If you are putting a new analog repeater on the air, if it's narrow band capable, it should be.   To start a 5-year phase-in plan for 6.25kHz channel centers and mandatory 2.5 kHz narrowband FM deviation on analog. 

-The number of wide band and narrow band analog channels needs to be rationed.  I'd like to see some effort to slowly over time (via attrition)  clear out and reserve some wider channels on the VHF and UHF bands for new techniques.

-I think when it comes to coordination requests, newer modes should be given priority.  If there are 10 analog repeaters in a given area, and someone proposes to put up a P25 system, but there are no channels available... back to rationing space for older modes.



Of all the VHF/UHF digital radio modes I have played with.  I like TETRA the most, as it's the most versatile.   The biggest problem is price.

It supports 4 TDMA channels in a 25 kHz bandwidth channel.  Mototrbo/DMR does 2 TDMA channels in a 12.5 kHz bandwidth channel.

The main reason I like it is because it doesn't sound digital.  It sound like a telephone grade voice path.  This is because the radios also function like mobile phones.  There is Asterisk SIP tie in support.

And for IP packet data services, DMR offers a throughput of 2.0 kb/s per timeslot, whereas TETRA offers 3.5 kb/s per timeslot.  So if you code an application for DMR that uses both slots, the max is 4 kb/s.  With TETRA 4 timeslots can be combined into a single data channel to achieve higher rates.

And if you are not in range of the repeater system, DMO mode allows you to repeat though a sequence of one or more TETRA terminals as relays to reach your destination.  (Think same-band crossband using alternate time slots)


So in summary, narrow banding just so we can have more of the same (under used analog repeaters) is just plumb stupid in my opinion.

Here are some relation observations that I made early in 2011:

During an interview, the Beaver Valley ARA revealed that ARRL President, Kay Craigie, N3KN got licensed in 1983 because she was jealous of all the fun her husband was having with ham radio. She was a computer hobbyist at the time and became a ham just when computers were starting to be integrated with amateur radio.

So it would seem natural to assume her stance on the future of digital communications is strong.

Brennan Price, N4QX is the new Technical Relations Manager filling the vacancy created by the retirement of Paul Rinaldo, W4RI.

It was Paul, W4RI's recommendation (back in 2001), to the Board that  the HSMM Working Group be founded and he has written many-many articles over the years on packet radio and other digital aspects.

I don't know much about Brennan, N4QX, other that his stated goal is  to "defend Amateur Radio spectrum. So it would seem that encouraging new uses and techniques would be logical.

I fell strongly about the ARRL Technology Task Force. I hope he can  fill the shoes as well as Paul did.

So far I haven't really seen anything happen at the league level that affirms my above assumptions of these two.  I kind of expected these jokers to file comments to the FCC along the lines of what Bruce Perens did in terms of getting some rules relaxed to help move things forward.

Thursday, June 28, 2012

Frequency Coordination

This the only place in Part 97 that discusses the duties and authority of a frequency coordinator.

§ 97.3 Definitions.
(a) The definitions of terms used in part 97 are:
(22) Frequency coordinator. An entity, recognized in a local or regional area by amateur operators whose stations are eligible to be auxiliary or repeater stations, that recommends transmit/receive channels and associated operating and technical parameters for such stations in order to avoid or minimize potential interference.
Please note that it doesn't say it requires any recommendation of the FCC, the ARRL, or existing frequency coordinators, etc. So it doesn't say that there can't be more than one frequency coordinator in a local or regional area.

Here is something interesting I ran across in some recent ARRL Executive Meeting Minutes:

4.1. Mr. Imlay reviewed material he had circulated to the committee prior to the meeting with regard to a repeater coordinator dispute in Wyoming. He explained that while the longstanding policy of both the ARRL and the National Frequency Coordinators’ Council (NFCC) is that there should be only one recognized frequency coordinator for a band in a given geographic area, FCC rules and policies do not rule out the possibility of there being more than one. In Wyoming there are two coordination entities, each of which can claim recognition by amateur operators in the state. While the ARRL is not directly involved in frequency coordination, there is a Memorandum of Understanding between the ARRL and the NFCC and ARRL policy is to accept only information supplied by NFCC-certified coordinators for publication in the Repeater Directory. NFCC has experienced a period of inactivity, which has caused the current accuracy of its list of certified coordinators to be called into question. However, new NFCC officers have just been elected.

What bothers me is that most of the VHF-UHF bands are inundated with mostly inactive repeaters.

Where in Part 97 does it say that a frequency coordinator should be in charge of parceling out exclusive (both geographic and frequency) usage of 144 - 148 MHz (etc)?

It doesn't make any sense at all to be attempting to more finely regulate that all of the potential "repeater channels" on 2m, 70cm, for all of an area, are not actively in use.

Frequency coordination made sense 20 years ago when there was intense demand for repeaters and there weren't easy ways to do coordination without a slow, manual, group effort.

Back then the Frequency Coordinators newsletter was a good source to share/disseminate technical information regarding building a repeater.  Since then websites like repeater builder have taken over that aspect.

The technical justification for coordination has also greatly diminished.  The days of custom ground crystals and waiting weeks for their arrival went away when PLL gear took over the market.  Changing frequency isn't as big of a deal anymore.

It is interesting to note that repeater coordination has only been around since 1985? (per docket 85-22). It was prompted a number of repeaters causing interference to one another.

Now there's little, and falling usage of voice repeaters, and coordination can easily be accomplished with a wiki page listing who is responsible for a particular system that's operating on a particular frequency at a particular location.

Modern sites like Repeater Book allows you to update your own listing.  And that is the bottom line to most repeater owners.  Being listing with minimal fuss.

I and others had the unfortunate experience of the coordination body complaining that some aspect of the repeater isn't up to their standards. Perhaps it was a short distance move, or some other minimal system change. The communication had no merit as there was no other official station complaint. They just want to be the repeater police, and justify their existence.

I think that for the most part, a frequency coordination body has little service to ham radio these days. It seems most just likes making paper work for themselves.

I think their continued existence actually, actively Harms Amateur Radio by propagating a mistaken impression that repeaters on the air should be "rationed".  Yet in reality, their job is to accommodate.

When the repeaters are idle the majority of the time, the chance of interference is low, which begs the question why bother with it at all?

Since a receive tone is a requirement of coordination, you really seldom notice if you are prone to interference which may be affecting your fringe areas.

It should be easy for an individual, club, or group to put up more equipment to make better use of Amateur Radio spectrum. Instead, the coordination policies and procedures make it difficult to do so, and people walk away discouraged and disgusted from even trying to put up interesting systems on the air.

The problem is frequency coordinators have broken the bands into channels most fairly narrow in width, with conventional input and outputs. I think this image/model discourages potential other use, that may not fit the convention.

Take a look at CDMA Spread Spectrum, in the implementation of Cellular Telephony. We had tons of buzz about this in 80's-90's but it never went anywhere in ham radio. How could it? It's totally incompatible with the way we slice up the bands.

And even with conventional channels plans, there is room for determent. Shouldn't we try to accommodate a multitude of different experiences?

Lets say there are 5 available pairs in a given area. Three are already filled by conventional analog repeaters. There are two requests for pairs for D-Star. One request for a P25 (APCO 25) mixed-mode repeater, and one for DMR. How does or should these be doled out? Does the policy say the first requested, is the first filled? Does this help the hobby move forward, and provide opportunities to area hams for multiple mode exposures/experiences?

I think anyone who wants to put a system on the air - packet, D-Star, WiFi, P25, whatever, should simply monitor the band in question, find the quietest spot in the "repeater section" of the band in the geographic area you plan to construct the system, and put it on the air. Likely you won't interfere with anything. On the off chance that you interfere with a system that's actually used for more than ID'ing itself, then relocate. You'll find a place in short order.

In the past there have been FCC reports on interference situations.  They looked at the total history of both sides and at technical levels. The FCC takes all of this on a case-by-case basis. They do not automatically side with a coordination body. They take the total situation into account.

http://www.thenfcc.org/ billcross1.pdf
ftp://ftp.tapr.org/fccreg/fccreg.9911

What you can take away from this is that the FCC regards repeater coordination as a volunteer thing taken on by the amateur community. They don't appoint  them, and regard repeater coordination as a self-enforcement or self-regulation issue. That talk by Bill Cross is a reaffirmation of policies they developed nearly 10 years ago. It also states that the FCC does not officially recognize any coordinating body.

When the repeaters are idle the majority of the time, the chance of interference is low, which begs the question why bother with it at all? Most of who participate really only primarily concern themselves with being listed. A way to advertise their systems.

Frequency coordination needs sweeping changes and to move forward. One of the purposes of a frequency coordinator is to recommend standard operating procedures.

The ARRL recently revised their outdated microwave bandplans. Now it's time for regional coordination bodies to adopt these, and put some thought into their coordination policies not only for microwave, but VHF and UHF as well.

(It's no wonder the NFCC has been dangling by a thread for years.)

It's worth pointing out that GMRS does not have coordination, and they have even less “channels” to work with.
It has been suggested: To start a 5-year phase-in plan for 6.25kHz channel centers and mandatory 2.5 kHz narrowband FM deviation on analog.

I also think we should have more shared non protected repeater pairs available on each band. While I am not a fan of more repeaters, I am also not a fan of unnecessary rules and other deturants that might prevent someone from experimenting. If someone wants the experience of trying to build their own repeater, and / or how a particular location plays, let them. Even if no one really uses it. Amateur radio is a playground for learning.

Thought should be given to creating digital repeater segments within each band. Just like we have sub-bands for ATV and packet, perhaps we should be doing this with digital repeaters? Hitting the scan button on an analog rig, and having it screech, and beep on a digital repeater right next to an analog one is less than desirable. Due to "crowding," this would have to be a process of clearing / reserving segments via a process of attrition over time.

I'd like to suggest repeater coordination newsletters should be a clearing house for sharing technical info from time-to-time. Again, ham radio should be about learning.

If you are still believing "tradition must continue,"  read on.

Local frequency coordination bodies guard their frequency database carefully.  They attach a copyright to the data (at least the format of it - legally speaking).  They sell the list to the ARRL for the ARRL's directory for a substantial annual fee. Both are copyrighted, so anyone else publishing repeater data either has to get their own (a daunting task), or illegally use copyrighted data (though some argue the validity of the copyright for the actual data). However, the irony is many coordination bodies put their data on the web for personal use.

You pay or donate to a frequency coordinator, and provide them with your data, that they copyright and sell.  I am sorry, but ham radio has always been a collaboration of people working together and sharing information freely, so this irks me as bad as the AMBE patented algorithms.

It's time to relax the rules, while the band activity is low, and allow a gestation period.

Monday, October 19, 2009

ARRL Approves Study Committee to Research & Develop Plan for Narrowband

From: http://www.arrl.org/announce/board-0907/

Minutes of the 2009 Second Meeting
ARRL Board of Directors

Teleconference July 17-18, 2009


29. On motion of Mr. Sarratt, seconded by Mr. Frenaye, the following resolution was ADOPTED:

WHEREAS, there is current substantial amateur radio movement, activity, and innovation in the digital narrowband area; and

WHEREAS, the FCC has mandated that by 2013 commercial radio move to narrowband channels and Amateur Radio manufacturers normally follow commercial practices; and

WHEREAS, the VHF/UHF Amateur Radio band plan currently uses 15 and 20 kHz FM channels; and

WHEREAS, with the increasing use of narrowband across the country amateurs are placing and using narrowband equipment outside the repeater subband because there is no real place to fit the narrowband pairs; and

WHEREAS, for ARRL to remain a respected leader in technology, we must be actively involved in innovative solutions to problems by bringing about a productive discussion on a technical paradigm shift; now

THEREFORE, the President shall appoint a study committee for the purpose of research and to consider developing a plan to move the US amateur community to narrowband channel spacing.



I would be in favor of this IF it meant there was some thought behind it. It would be nice to clear a few ~50 KHz wide channels on 2 meters for higher speed data applications. This of course should go hand in hand with some other modernized regulations.

Promoting narrow band just so we can accommodate more repeaters (more of the same) is a poor reason. Perhaps if there was less effort to squeeze in more repeaters, this would promote exploration of other bands.

Saturday, June 6, 2009

Are you narrow or wide?

Recently our local repeater coordinator began asking your emission designator on the application form. A break-down of emission designators can be found in section 2.201 of the telecommunications part of the code of federal regulations.

20K0F3E - FM Voice 20kHz bandwidth - Wide 
16K0F3E - FM Voice 16kHz bandwidth - Narrow
11K2F3E - FM Voice 11.2kHz bandwidth
8K10F1E - P25, phase 1, 12.5kHz Bandwidth
5K76G1E - P25, phase 2, 6.25kHz Bandwidth
6K00F7W - D-Star, 6kHz bandwidth

The confusion I often see lies whether a system is narrow or wide. 20 KHz bandwidth or 16 KHz. To determine this we must look at Carson's bandwidth rule.

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

As you can see in the analog world, your bandwidth will be determined by transmitter deviation. If you have 5 KHz deviation (now a days considered wide band I guess) you will occupy 20kHz of bandwidth. If your deviation is in the 2-3 KHz area you will occupy 16kHz bandwidth now referred to as narrow FM.

Now a days wide / narrow transmitter deviation is usually a software selectable option. The quote/unquote standard for ham radio has been 5KHz max deviation/20kHz bandwidth.

If you can't determine by software/programming configuration you'll likely need access to a deviation meter or service monitor to determine your deviation.

+/-2.5kHz maximum deviation is also a standard for 800 MHz and above and has been since the mid 90's. This is why you typically see 12.5kHz channel spacing up there. Actually I have never seen any Wide analog FM above 800 MHz except on remote broadcast studio-transmitter links. 

So if nothing else use the mid 1990's as a date of determination. If we are talking VHF/UHF commercial equipment manufactured 1997 or more recently you can probably assume it's "narrow FM"/Max 3 KHz deviation - yielding 16kHz bandwidth. Another clue is if it was in commercial service using a 12.5 kHz step/channel spacing scheme, it is likely narrow FM.

Here is the history: 
A process of "refarming" the informal name of a notice and comment rule-making proceeding (PR Docket No. 92-235) opened in 1992 to develop an overall strategy for using the spectrum in the private land mobile radio (PLMR) allocations more efficiently to meet future communications requirements. The FCC created mandates for the two-way radio equipment manufacturers. In 1997, all new two-way radio models had to be capable of operation on the "new 12.5 kHz narrowband" channels. This is often called "dual-mode" equipment since the radio can accommodate both narrow- and wide-band channels. The idea was to begin to move gently toward narrowband channel operation over time. At that time, the FCC did not create any mandates to remove older wideband radio units from service or require you to use a new narrowband channel.
The Part 90 LMR narrowbanding mandate was released 12-23-2004 by the FCC for all Part 90 business, educational, industrial, public safety, and local and state government two way radio system licensees currently operating legacy "wideband" (25 KHz) voice or data/SCADA radio systems in the 150-174 MHz (VHF) and 421-512 MHz (UHF) bands. The executive summary of the FCC order  establishes January 1, 2013 deadline for migration to 12.5 KHz technology.


(Note many ham HT's are capable of WFM / Wide FM receive, intended for reception of FM radio/ Analog TV audio. Don't confuse this with the two way standard... Broadcast Wide FM is 150 KHz of bandwith.)

True narrowbanding a receiver is what is hard.  I am talking narrowing the receiver IF bandwidth.

Just be aware that converting a 1950's era repeater to D-Star or P-25 that might have a 60 Khz I.F. would be vulnerable to adjacent channel interference. A good overview of the theory can be found in a reprinted article from Ham Radio Magazine 1985, by WD5IBS.

Wednesday, December 17, 2008

Use it or lose it




The ARRL seems to only represent less than 0.2% (3.75 MHz of the total 24.165 GHz) of the total amateur spectrum.

About 40 years ago 2 meters and 70 cm were basically uncharted areas. Now they are populated. Undoubtedly the future of ham radio is in our huge - virtually unused microwave allocations. They have the necessary bandspace to support wideband modes.

The concept of a re-banding or significantly altering existing bandplans where established systems and modes are in place, would go over like a lead balloon. There would be so much unrest at just the mere suggestion that the ARRL membership would be in jeopardy, which is their pocket book.   

I've blogged before that the average ham is now in their 60's.  

And with age comes a love for tradition and to re-live the past, and cling to legacy modes for dear life. Retired, well-off folks are where the money is for the ARRL as well. So the league will cater to that 0.2 %, as that's where the bulk of their memberships and revenue are.

It would be great if the ARRL would pay more attention to operating practices on 50 MHz and above. Just about every month there is an article on CW in QST.. I don't think it's possible for that magazine to go a whole 6 months or a year without mentioning it. Instead I wish they would at least quarterly have an article from the technology task force. QST, the main magazine of the ARRL should put more emphasis on future technologies in my opinion.

*I stole the title from a piece that David, WA6NMF wrote in the TAPR PSR DCC 2007 issue, titled "Use It or Lose It, SHF Edition." He points out that companies are putting a lot of pressure on the FCC to allow unlicensed operations over a wider frequency range. There is much more amateur spectrum to lose if we don’t use it more actively. I highly recommend reading his piece.

HSMM can put our microwave frequency allocations to good use. These allocations (23cm-300GHz) make up 99% of hams total available frequency allocations. Yet, it's estimated that only 1% of hams are involved with any microwave operations.