 |
 |
 |
|
|
|
|
|
|
||||||||||||||||||
|
|
|||||||||||||||||||
|
|
|||||||||||||||||||
|
|||||
|
|
Report to the ARRL Board of Directors Annual Meeting
January 2003
On October 10, 2002, Paul Rinaldo, W4RI, passed the job of managing the ARIA program to Greg Lapin, N9GL. Mr. Rinaldo will remain active as a member of the ARIA Steering Committee with Joel Harrison, W5ZN, and Jim Maxwell, W6CF.
Dr. Lapin's first orders of business were twofold: 1) Investigate automating many of the functions in the ARIA test plan, and 2) to better advertise to the general population of radio amateurs what ARIA is and its need for volunteers. Both sets of tasks were motivated by the difficulty that the ARIA project has had in recruiting and retaining volunteers to make measurements.
1. Previous Status of ARIA
An ARIA test plan has been written and details the tasks that must be performed by ARIA volunteers.
The ARRL Laboratory has developed a calibration noise source for ARIA receivers. A calibrating setup consists of a noise source board developed by the ARRL lab, a 2.4 GHz log periodic antenna, and a 2.45±0.05 GHz band pass filter.
2. Automating ARIA
Automation of ARIA data collecting and reporting serves two purposes. It decreases the amount of work that must be performed by ARIA volunteers to monitor frequencies, and it provides an increased level of confidence that the reported data conform to the standard procedures and are free from human error.
Dr. Lapin enlisted the help of Ed Hare, W1RFI, ARRL Laboratory Supervisor. Mr. Hare has been working on electromagnetic compatibility issues as part of his duties in the laboratory and in his position as staff liaison to the ARRL Electromagnetic Compatibility Committee. Many of the goals of identifying and locating interference sources for the work of the EMCC are similar to those required for ARIA.
Mr. Hare worked on developing a simple computer program to control tuning a receiver and reading back signal strength, either as an S-meter reading or by digitizing the audio via the computer's sound card and calculating the signal strength.
In a related task, Mr. Hare is collecting sound bites to demonstrate what different noise sources sound like. These example sounds will be digitized and made available as .WAV files over the ARIA web page. At some point it will be important to demonstrate that signals monitored by ARIA are Part 15 device noise and not actual signals from Amateur Radio or other licensed sources, or even noise from ISM sources, which has precedence on the 2.4 GHz band.
3. Advertising ARIA
Dr. Lapin and Mr. Hare have started developing a plan for an ARIA web page that will be accessed from the ARRL web site. This page will serve to update ARIA volunteers, and prospective volunteers, on the current state of the project, will be a source of ARIA documentation, and will make training and informational material available.
Dr. Lapin presented an introduction to ARIA at the North Shore Radio Club in Highland Park, Illinois on October 8, 2002. The 45-minute talk was accompanied by a PowerPoint presentation and a live demonstration of 2.4 GHz Part 15 noise using an IEEE 802.11b card in a laptop PC and an Icom R3 receiver. The PowerPoint presentation will be made available on the ARIA web page for use at other club meetings. Following this presentation, 10 club members signed up to help with ARIA monitoring. If similar volunteerism results from talks at other ham clubs across the country, ARIA should have as many volunteers as it can use.
4. FCC Technological Advisory Council
The potential status of ARIA was elevated at the December 4, 2002 meeting of the FCC TAC. At this meeting, Paul Kolodzy, Ph.D., the chair of the FCC Spectrum Policy Task Force, presented the current status and goals of his committee. A large part of his presentation dealt with the need to monitor the spectrum to determine the characteristics of the signals and noise found there. He announced that one of the frequency assignment techniques being considered by the task force would consider frequency use not only in the spectral domain but also in the time and spatial domains. He emphasized the need for good information about what is heard on the spectrum at different time and at different locations.
Even though ARIA was designed to monitor only Amateur Radio frequency bands, the techniques for measuring and reporting noise that are developed and the experience in trying to implement them on a wide scale will be invaluable to the FCC in moving forward with their objectives. This is an opportunity for Amateur Radio to lead the way technically and to be recognized for it.
I recommend viewing Dr. Kolodzy's presentation on the FCC website (Real Viewer required) at
http://www.fcc.gov/realaudio/mt120402.ram and fast-forwarding to a time of 1:36:12.
An overview of ARIA was presented at an FCC TAC meeting in Fall 2001, with an update in June 2002. I mentioned ARIA at this meeting and, even though there was little new to report, the TAC members continued to express interest and understood that this was a long-term project.
We were introduced to Mari Maeda, PhD, from the National Science Foundation, who is heading up a program to monitor signals on the radio spectrum.
5. Future Goals
The ARIA analysis software has been customized for use with the Icom PCR-1000. Initial testing and monitoring will be performed by volunteers who already have this radio. As experience is gained the software will be enhanced and eventually modified to work with other radios. The more radios that are supported, the more likely ARIA is to get volunteers.
ARIA needs a database format that is compatible with the requirements of the FCC Spectrum Policy Task Force. If the ARIA database is designed this way and put to use, it is likely that the FCC will adopt it so that monitoring information can be shared.
Reporting of data should be performed automatically over Internet. I envision the final structure of this to be similar to the recent SETI project, where data were automatically transferred between the central server and the many volunteers automatically as needed.
A mathematical proof is needed to develop equivalence between scanning frequencies with different bandwidths. ARIA is designed to scan with an IF bandwidth that is roughly equal to a narrowband FM signal. This reflects the motivation of the project, which is to identify a noise level that would interfere with Amateur Radio communications. The FCC, on the other hand, appears to be more interested in how an increasing noise level affects interaction between multiple spread spectrum signals, and monitors with an IF bandwidth of 1 MHz. Add to this the statistical uncertainty of a finite scanning rate detecting a frequency hopping spread spectrum signal. The mathematics must be developed to be able to express the noise level for one purpose when frequencies are scanned for the other purpose.
ARIA needs to continue to communicate with the appropriate people at the FCC and the NSF to make sure that whatever we do meets their needs. There may also be funds available from NSF for development of this project.
Respectfully Submitted,
Gregory D. Lapin, Ph.D., P.E., N9GL
ARIA Manager
