|
![]() |
|||||||||||||||||||
![]() |
|
|||||||||||||||||||
|
|||||
|
American Radio Relay League
Technology Task Force
Report to the Board
From
The High Speed Multimedia Working Group -- 2003
EXECUTIVE SUMMARY: This was an extremely productive year for the High Speed Multimedia (HSMM) Working Group. The amateur radio application of high speed digital radio networks evolved as never before, and more amateurs than ever started viewing digital radio as the future of their service. In the past year alone over two dozen presentations were made and more than a dozen articles were published. There are now better than four web pages dedicated exclusively to HSMM research and development.
EXTENSIVE PRESENTATIONS: On behalf of the League and the TTF the HSMM Working Group made the following presentations regarding our research into high-speed amateur radio digital networking:
Ken Cuddeback, KT7K-
Neil Sablatzky, K8IT-
Jeff King, WB8WKA --
RESEARCH AND DEVELOPMENT PROJECTS
Microsoft Windows Media 9 Applications within HSMM, a sub-report.
John
Champa, K8OCL, our Chairman, inquired about possible HSMM applications of the
Windows Media Player technology. Since then I have investigated the Application
Programming Interfaces (or APIs) and associated SDKs for the Windows Media
Player. I have created a very basic proof-of-concept that demonstrated to me
how to use the media player component from C# (a .NET programming language).
Before I proceed further, I have gathered up a couple of high-level
requirements as John suggested in his reply to my posting. They are as follows:
- A small image window in one corner of the GUI application that
provides a digital-still image of a picture of the amateur radio
operator. In this way you could see an image of the operators face
(although still) while he is showing you something else. Or, you could view a
digital still image of the site where the broadcast is occurring.
- The majority of the GUI application area would be devoted to the
display of a live streaming video from a web cam feed. This feed display would
have an associated text banner display area above or below it (location,
description, etc.).
- A small portion of the GUI application area would include an IRC-style
text messaging area for real-time text-based communications.
- (New) a separate tab with a map that shows you where the live web feed
is occurring.
Additional requirements or comments are welcome.
Thanks,
Respectfully submitted to the HSMM WG,
Kevin Wittmer, KB8VME
The
HSMM-HF Project, a sub report
In the last seven months extensive investigations of the newer digital
modes have been conducted and several are still under evaluation. One of
the most interesting is Q15X25 as it has similar characteristics to a
proposed high speed network. Tuning and general operating practices for
this mode is still hard to find, and several members of the WG are
planning to do some on the air testing in the coming weeks. This
evaluation will assist us in selecting the best form of modulation for
our network.
On the air testing of several modulation possibilities between amateur experimenters
has been restricted due to current FCC regulations. However, some bench testing
with point to point coax connected the rigs, have been achieved. This setup
employed a function generator feeding voltage controlled pin diode coaxial
attenuators in an effort to simulate QSB on HF bands. Of course this test
illustrated the need for a good RF link; however approximately 30dB of signal fade
resulted in no degradation of the data link. The basic modulation consisted of
OFDM, with a bandwidth of approximately 25KHz wide, and data rates exceeding
70Kbps. Efforts to conduct similar testing for different modes (such as PSK31) still
need to be conducted.
Respectfully submitted,
Neil Sablatzky, k8IT
Bi-Directional Amplifier (BDA) Design, a sub report
NOTE: HSMM modes such 802.11b require the use if special fast switching amplifiers know as BDAs.
I have designed a 40 dBm bi-directional amplifier to include schematics, parts list-
vendors and samples. At the request of an HSMM member, I am reworking the RSSI instead for Eb/No and verifying this against the specs. I hope to soon be able to obtain the MESFET (10W) as soon as it is available for shipping (sample).
I am starting to do the layout of the PCB and investigate thermal requirements.
I'd like to know if it would be possible to have Ed Hare, W1RFI, at the ARRL Lab test and verify this unit once I am able to populate the board and once everyone has had the opportunity to evaluate the design?
Respectfully, submitted,
John Ingram, KA3LIE
Other HSMM WG Member Projects
Jeff King, WB8WKA: Low power 76Kbps XE1202 based 900 MHz ISM transceiver; Thermal testing on Dlink DWL-810 and DWL-810+ 802.11b client; Built and Modified BiQuad antenna; Built Warbler 80meter data transceiver, placed on air late Dec 2003.
FINDINGS, CONCERNS, AND RECOMMENDATIONS TO THE BOARD
1. The HSMM Working Group strongly recommends to the Board that any band planning efforts, especially above 902 MHz, include a qualified HSMM WG representative.
2. The ARRL needs to alter QST policy to allow publishing of equipment reviews relating to HSMM operation. This will assist in the growth of this mode.
3. The ARRL needs to propose experimental digital sub bands where new digital modes can be evaluated over the air. While it has been suggested that 10M and especially 6M might be useful for these types of tests, propagation characteristics such as HF QSB is difficult to test over such short paths. It is proposed that the ARRL consider the Novice band segments to allow data transmissions with relaxed symbol rate and bandwidth conditions.
4. That we can work within the existing rules to (largely) accomplish our goals is not a universal feeling of the HSMM WG members. There is a difference of opinion as to what we should be doing here, so needed regulation changes are frequently discussed.
5. We are trying to sell refrigerators to Eskimos! It is felt that too many hams are not that interested in HSMM. They don't have the vision. This vision is held by the Part 15 community networking folks. These are the folks we need to reach out to and make ham radio attractive to them. We have taken steps to do this, but we must not loose sight of this.
6. ANY computer logging network should be recognized as an embryonic basis of a broader ham computer network. The fact that hams have already started using wireless in their logging networks is very encouraging. We recommend that any FD organization using a single Part 97 computer logging network be freed from the physical limitations on their site (1000 feet diameter rule).
7. There is not enough emphasis being placed on mobile routing technology. There's a lot of IETF work being done in this area we believe believe the Internet-free ham networks will have some unique requirements that are not being considered by the IETF.
ACKNOLEDGEMENTS
Our WG report would not be complete without thanking the many loyal and dedicated members of the ARRL Headquarters staff for their strong support for our all our efforts throughout the year: Dave Sumner, K1ZZ; Mary Hobar, K1MMH; Steve Ford, WB8IMY; Rick Linquist, N1RL; Bob Inderbitzen, NQ1R; and Paul Rinaldo, W4RI. We owe special thanks to our Staff Liaison, Ed Hare, W1RFI, who has assisted and guided use in more ways than we can count.
A special thanks also to our TFF Leader, Howard Huntington, K9KM.
Finally, the WG expresses its strong appreciation to the FAB Corp for its support and encouragement of our R&D efforts, and the special recognition it provides for the HSMM effort.