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.
TAPR's Statement on Spread Spectrum Technology Development
TAPR was founded in 1982 as a membership supported non-profit amateur radio research and development organization with specific interests in the areas of packet and digital communications. In the tradition of TAPR, the Board of Directors at their Fall 1995 meeting voted that the organization would begin to actively pursue the research and development of amateur radio spread spectrum digital communications. At the Spring 1996 board of directors meeting, the following statement of purpose was passed:
"TAPR believes that the technical facts support our conviction that conventional and spread spectrum systems can coexist without detriment to conventional systems on all frequencies from MF to EHF. To this end, TAPR will begin to research spread spectrum systems that will develop technology for future deployment."
As stated above, the TAPR board feels strongly about TAPR's focus on spread spectrum technology and especially how it relates to the potential coexistence on frequencies that will have increased number of users occupying them. The amateur radio bands, like other spectrum will become more heavily utilized in the future. It is in the interest of amateur radio to develop systems that are interference-resistant while not interfering with other primary or secondary users on those frequencies.
TAPR understands the concerns many have with the new technology, and believes that efforts in both education and research is necessary in order to allay the fears about interference and to demonstrate the benefits of the technology.
TAPR believes that todays' communications technology is moving toward all digital transmitters and receivers. These advances in technology, combined with the swift evolution of cell based transmission and switching protocols, are opening up a new set of possibilities for unique new services utilizing intelligent networks. These will contain smart transmitters, receivers, and switches. Today's Internet is perhaps the best example of a self-regulating structure that embodies these new technological approaches to communications in the networking domain. However, to date, many of these innovations have not moved into the wireless networking arena. TAPR will work on moving these innovations into the amateur radio community.
TAPR feels that the VHF/UHF/SHF radio networks of the future will involve a mixture of links and switches of different ownership, which terminate at the end-user via relatively short-distance links. What will then be required is a built-in, distributed, self-governing set of protocols to cause the network's behavior to make more efficient use of a limited, common shared resource, the radio spectrum. Creating such a self-regulating structure for the optimal sharing of spectrum will require much effort.
One of the major problems which stands in the way of these new approaches today is the current FCC regulatory environment and the manner in which spectrum is managed and allocated under its rules.
Historically, the current regulatory approach to radio has been based upon the technology that was in use at the time that the Communications Act of 1934 was framed, basically what we would call today, 'dumb' transmitters speaking to 'dumb' receivers. The technology of that time required reserved bandwidths to be set aside for each licensed service so that spectrum would be available when needed. Given this regulatory approach, many new applications cannot be accommodated since there is no available unallocated spectrum to 'park' new services. However, given the new set of tools available to the entrepreneur with the advent of digital technology, what once were 'dumb' transmitters and receivers can now be smart devices which are capable of exercising greater judgment in the effective use and sharing of spectrum. The more flexible the tools that we incorporate in these devices, the greater the number of uses that can be accommodated in a fixed, shared spectrum.
Therefore, TAPR will focus its spread spectrum effort in the following areas:
* TAPR will work to promote rules and technologies to make the most efficient use of the spectrum through power control, forward error correction, and other means to minimize interference among spread spectrum users and existing communications systems. * TAPR will work on issues and efforts with other national organizations to change the regulatory environment and rules in order to promote the experimentation, development, and later deployment of spread spectrum technology. * TAPR will work to develop information on the topic to help educate members and the amateur community as a whole about spread spectrum technology, and to disseminate this information via printed publications, the World Wide Web, presentations at conferences and meetings, and other means. * TAPR will work to foster experimentation, development, and design of spread spectrum systems, and to facilitate the exchange of information between the researchers and other interested parties. * TAPR will work to develop a national intra-network to foster the deployment of future high-speed spread spectrum systems into regional and local communities, including the development of suitable protocols and guidelines for deployment of these systems. * TAPR will work with commercial companies who manufacture spread spectrum devices which operate in spectrum shared by the amateur radio service (ARS), in order to make them more aware of the nature of ARS operations on those bands with the goal to work towards the deployment of devices which will minimize interference between all spectrum sharing partners. * TAPR will work with commercial companies who manufacture spread spectrum devices in order to identify equipments that can be either used or modified for use for Part 97 operation.
Adopted by the TAPR Board on September 20th, 1996 at SeaTac, Washington Board Meeting.
Spread Spectrum Statement Committee: Greg Jones, WD5IVD Dewayne Hendricks, WA8DZP Barry McLarnon, VE3JF Steve Bible, N7HPR
In 1994 Merticom, established them selves as owner of Ricochet Networks was one of the pioneering wireless Internet service providers in the United States. They provided 128 kbps broadband services to the general public using unlicensed 1 watt 900 MHz FHSS radios mounted to light poles in several major cities by 2001, just before the filed for chapter 11 bankruptcy. At the time, many hams in these large cities complained that the Ricochet Networks made the 900 MHz band virtually unusable due to the high noise floors caused by the wide deployment.
The TAPR FHSS Radio project was displayed at the 1997 ARRL and TAPR Digital Communications Conference, October 10-12, 1997 and officially started that year.
The development of this 1 watt, 128 Kbps 900 MHz FHSS radio, suggested this is the future for amateur packet radio.
October 1999 TAPR signed an agreement with the Dandin Group to take the TAPR design from its current state into production which TAPR has access to production for sale back into the amateur radio community. This is an agreement we have been working on for several months. The bringing together of TAPR's and Dandin's capabilities will help the speed of the project tremendously.
Dewayne Hendricks (WA8DZP) , was the CEO of Dandin Group. Dewayne stated that Dandin was trying to do something like what Metricom was doing, but we were trying to do it in a different way than they were doing it, a different business model.
"The first release of the TDR-900 is designed to operate at 900 MHz with future radio modules to cover other parts of the spectrum."
From October 1999: http://www.tapr.org/tapr/html/taprfhss.html
TAPR has signed an agreement with the Dandin Group to take the TAPR design from its current state into production which TAPR has access to production for sale back into the amateur radio community.
From Dec 2001: http://www.dandin.com/tdr900.html
The TDR-900 is being developed for both commercial and amateur radio deployment. Dandin will be handling the commercial interests in the radio, with TAPR handling the amateur radio service.
The system has been designed so that the digital and RF board are separate units. Additional bands for the radio are in development.
More information on technology availability and licensing will be available once the technology transfer between TAPR and Dandin is complete.
In the fall of 2002 TAPR announced it would discontinue it's stalled 900 MHz FHSS radio efforts. The project did not reach completion as they were faced with continuing parts obsolescence problems that resulted in continual redesign, and second, we were unable to obtain the RF design expertise needed to finalize the RF board.
The TAPR Spread Spectrum Radio
Tucson Amateur Packet Radio (TAPR) has announced that a team led by Bob Stricklin, N5BRG, Bill Reed, WD0ETZ, and Tom McDermott, N5EG, is developing the TAPR Frequency Hopping Spread Spectrum radio. At last report, the prototype radio was transmitting, although not yet hopping. The group spent about $15,000 on the project last year-on things like pc board prototypes, development software, parts, and other odds and ends that a project of this magnitude requires and anticipate spending another $15,000 to $30,000 on it in 1999. Thus far, though, TAPR has received a little less than $2,000 toward its overall goal.
TAPR will be sending out a fund raising letter in the next few months to help fund all or part of the costs of this development project. Members are being asked to donate to this worthy cause, and I'm asking the readership of CQ VHF to also consider supporting this valuable project. Please take a serious moment to consider this request and help bring this unique project closer to completion. If you have contact with a local or regional packet organization, contact them about supporting this project as well.
Donations above $25 will receive a handsome certificate acknowledging their contribution to the TAPR FHSS Project, while those donating $250 or more will receive a plaque to let everyone know of their efforts on behalf of this project. All donations are needed and welcome, no matter how large or small. Even if you simply become a member of TAPR-well worth the $20--you can be sure it's appreciated and helpful. Thank you for your consideration. Contact TAPR at 8987-309 E Tanque Verde Rd #337, Tucson AZ 85749-9399; (Phone: (940) 383-0000; Fax: (940) 566-2544. Internet: . Visa and Mastercard are accepted.
-Per N2IRZ, CQ-VHF Magazine, March 1999
The funny thing is you really don't read much about spread spectrum & ham radio anymore. It appears that the main guys who were beating the ham radio drum initially on this apparently made a buck off it in the commercial market.
Which is a dirty shame. I was a follower of the project having been involved in conventional packet radio and seeing the need for speed. Of course the idea of modifying Part 15 spread spectrum radios was never really promoted by TAPR because that was a direct conflict of what was trying to be marketed.
This TAPR / Dandin FHSS radio project wasn't fully successful for them as the project never made it to completion. The reminds me of how ham radio was a test bed, or example for how AMBE / D-Star works. This has given Icom and Kenwood a chance to perfect it and unveil it for APCO25, Phase II.
Lesson learned; commercial influences like this can sometimes screw-up a potential good thing for this hobby, and other times (like with D-Star) being the Guinea pig can help breed some new developments into the hobby and work out for the commercial entity.
Spread spectrum is a radio technique that continuously alters its transmission pattern either by constantly changing carrier frequencies or by constantly changing the data pattern.
If you asking why, then let me point out that in order to support a high speed or multi-media transmissions you will need a bit of bandwidth. The 2 meter band is only 4 MHz wide, and already well populated. Spread spectrum can share the same frequency band (overlay) with other uses.
Spread Spectrum was invented in 1940. Austrian-born Hedy Lamarr, considered one of the sexiest actresses of her time, was also a co-inventor of frequency hopping.
There are two basic types; Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).
DSSS is the basis for CDMA cellphones and 802.11 wireless transmission. FHSS is used for bluetooth devices.
It wasn't till 1981 that the FCC authorized spread spectrum on amateur frequencies. In late 1999 the FCC relaxed Amateur Spread Spectrum rules. (Prior only certain spreading codes where allowed)
Presently Part 97.311 of the rules effectively limits amateur spread spectrum to 1 watt. Please support the passage of RM-11325, to have that 1 watt limit lifted. Spread spectrum this day in age, should not be treated as an inferior mode.
It may seem like a moot point to some. For you see 802.11b is direct sequence spread spectrum (DSSS), but it has largely be replaced by 802.11g and 802.11a, both of which use Orthogonal frequency-division multiplexing (OFDM) modulation instead of DSSS. OFDM is technically not spread spectrum and thusly is not encumbered by the 1 watt rule.
Frequency hopping spread spectrum (FHSS) is in my mind the best fit for the present ham band plans. In FHSS the carriers are narrow and "hop" around only staying on a given frequency for less than a second. It's also hops around interference.
DSSS on the other hand is spread over a wide fixed spread of frequencies, usually occupying several megahertz. 900 MHz and above the bands are pretty un occupied so fitting DSSS in isn't really and issue. But as you should see FHSS stands the best chance of working in amateur radio on band 70 centimeters and below, on bands where there is already occupancy.
Data networking aside, there are now some new FHSS voice radios out there for 900 MHz. They are both obviously digital voice and capable of text messaging.
Motorola DTR650 Apparently Motorola has repackaged their off network iDen 900 MHz ISM FHSS walkie talkie feature into a simplex radio. Range is actually 1/2 way decent on them from what I've seen, couple miles line of sight. It has a removable antenna. The price is around $300
TriSquare eXRS Radios 906 to 923.75 MHz, 50 hopping channels, 1 watt power, -124 dBm receive sensitivity, 397 ms. dwell time, 11.5 KHz occupied bandwidth. Integrated antenna, but can be modified with an SMA connector. Nothing to compare with the Motorola DTR radios. Nowhere near the price either. These can be picked up at higher end sporting good stores usually for under $100 a pair.
Brian NB9E writes about the Trisquare radios:
While doing some mountain top maintenance on some of our ham repeaters here in northeastern NV (Elko area) I made contact with my wife (kc1ndy) around 30 miles from Swails Mt in Carlin to Pleasant Valley(near Lamoille). One radio was modified with an SMA connector and an SMA-3 Comet rubber duck which is rated for 2m,440 and 915!!! Impressive range to say the least for 1 watt!!! As far as legalities go the unit operates in the ham band limits and can be re-certified under Part 97 rules. The unit boasts over 1 billion channels actually hopping sequences. It really only hops 50 channels between 906 and 923 about 396 Ms each if I remember correctly. A better choice though might be the Moto DTR-650 which has a removable antenna!!! I've yet to get my hands on a pair of these yet, but they're on my list!!!
The TriSquare units use use analog FM instead of digital modulation for the voice, while the Motorola DTR's use digital modulation. There have been reports that an Optoelectronics R-10 can lock right onto the TriSquare FHSS signal and hearthe audio with no problems whatsoever.
