ADS-B Coverage and Site Performance Update

Today my ADS-B receive site here at the house has moved into position 291 on the FlightAware Leader Board! Just a few days ago it was at around 350.

There’s only so many a/c that can overfly my general coverage area – Scottsdale Arizona is not Amsterdam, London or Paris. Heck, it’s not even the greater NYC area with its multiple major airports and sheer number of flights. In other words, there’s only so much improvement to be had. The site will never even crack the top 100.

In my search for high-ranking sites in the general US west I found the one which I think will be the one to chase. The site is near to the top or atop Abajo Peak (elev 11,365′) in far southeastern Utah. In addition to being a whopping big mountain, Abajo is one of several major laccoliths in the Four Corners / Colorado Plateau region and the tallest thing for 44 miles. There’s even a live webcam atop Abajo.

From atop Abajo, the visible horizon is below 0 degrees in nearly every direction, with the 44-miles-away Mounts Mellenthin and Peale the only pieces of earth that just barely break 0° (0 degrees, or horizontal). Check out Abajo Peak at HeyWhatsThat.

From atop Abajo, a good receiver will capture a fair amount of the commercial traffic crossing over the western US. An aircraft at 40k ft can be over 200 miles from Abajo and still be above the zero-degree horizon. Since the actual horizon at Abajo averages about -0.5 degrees, this adds another 40 miles or so of crows-flight range. And that’s still not including atmospheric refraction and the occasional edge diffraction. Likely that the Abajo Peak site can hear out to 250 mi / 400 km for an a/c at 40k ft.

While a high site is a great thing, the potential number of a/c is limited by population center locations, flight routes, number of flights, number of non-commercial airports, etc. Abajo doesn’t have a major US hub airport next door. Flights headed from Denver to nearly anywhere in the West will pass through, as will flights from ORD to SoCal airports, PHX, and LAS. Flights from DFW headed west to any locations above about Los Angeles will as well, but not the great majority of flights to SoCal, which is a lot of airports. Pretty much any intercontinental from the NE US to the Southwest will intersect that area. There are a bunch of small civil airports in the footprint, as well.

Let’s compare Abajo’s stats to the Scottsdale site’s stats for the past two weeks (I know, that’s not much of a sample set, but that’s all I have).

8-Feb-15 7-Feb-15 6-Feb-15 5-Feb-15 4-Feb-15 3-Feb-15 2-Feb-15 1-Feb-15 31-Jan-15 30-Jan-15 29-Jan-15 28-Jan-15 27-Jan-15 26-Jan-15
Sun Sat Fri Thu Wed Tue Mon Sun Sat Fri Thu Wed Tue Mon
Abajo position reports 189,086 215,723 251,825 259,477 245,641 250,943 242,716 203,284 232,858 269,162 269,226 229,558 224,085 233,383
Scottsdale position reports 206,155 223,556 269,480 268,903 243,494 239,195 223,117 133,820 175,748 158,466 241,074 234,657 203,885 209,868
Difference (%) 8% 4% 7% 4% -1% -5% -9% -52% -32% -70% -12% 2% -10% -11%
Abajo a/c count 1,910 1,939 2,211 2,218 2,021 2,103 2,100 1,762 2,013 2,277 2,240 1,928 1,843 1,964
Scottsdale a/c count 1,491 1,594 1,760 1,747 1,639 1,734 2,063 1,420 1,590 1,624 1,792 1,540 1,475 1,535
Difference (%) -28% -22% -26% -27% -23% -21% -2% -24% -27% -40% -25% -25% -25% -28%

What the above two weeks of data appears to show is that Scottsdale gets somewhere on the order of the same amount of position reports per day, but that Abajo sees a whole lot more a/c per day.

The Scottsdale best-case 30k ft+ range is to the ESE at just over 240 miles. (It may be just as good to the S, but there’s very few a/c flying down there due to the US/MX border.) However, I’d say the average 30k ft+ range is more like 150-160 mi due to the local hills and more distant mountains. In any case, that’s pretty amazing given that the antenna is 15′ off the ground and in a valley. A little of the performance is likely due to the desert climate and general lack of dense vegetation on exposed ridgelines.

I’ll keep working on improving the setup here at Scottsdale and see how the statistics line up with Abajo’s.

City-Wide (sort of) Wi-Fi Service

I spent much of last year in the boroughs of NYC, and a bit up the Hudson and Bronx river valleys, as well as some time along the rails in CT up to New Haven. What I started to notice was a great number of Wi-Fi access points called “CableWiFi” or similar. I also discovered that, in the right areas with enough signal strength, I could associate to these and get a login screen which asked me if I was a cable service subscriber for any of a number of cable ISPs. One of these was Cox, and as we’re a Cox subscriber here in Arizona, I eventually figured out which username/password to enter into the authentication page and BOOM I was on the Internet. Speeds were often (if not always) better than what I could get on the hotel Wi-Fi.

A number of large cable ISPs have gotten together and are rolling out in volume Wi-Fi access points in major metro areas. In the NYC greater-metro-tri-state area, there are apparently well over 250k APs now available. You can recognize them certainly by seeing SSIDs that are “CableWiFi” or similar, but also the physical devices hanging along the distribution cable on phone poles. As far as I can tell, it’s only in areas where there is above-ground ISP coaxial cable hanging on phone poles.

I grabbed a few shots of one hanging on the line near the house. Sorry about the poor resolution, all I have is my iPhone to snap pictures with. The boxes are Cisco APs, hardened outdoor devices in cast metal cases, with three antenna bumps on the base of the case. Here’s a few pictures.

General View, Cable Provider Wi-Fi AP (circled) hanging from Cable Messenger
Close-up View of the 3 Antennas on the Base of the Enclosure (note the F connector on the side coax)
Another View
Another View
Detail of Cable AP Wiring

This last photo gives some insight into how the Cisco AP is connected into the cable. Here, at least two coupler/splitters (left boxes) are visible, with the AP to the right. There are also 3 distribution coaxes visible, one coming from beneath the ground (the one exiting conduit on pole). There has to be power supplied as well for the AP to work, I don’t know the details but there’s likely a constant source of DC or AC impressed on the coax. The smaller grey coupler (most left) has a connection directly to the Cisco AP, and supplies both the backhaul connection and power via the thin coaxial jumper cable. If I had a camera with a real optical zoom lens, I could read the labels and perhaps decipher a bit more about the setup.

The service is pretty good. I have a Win 7 PC in the truck which has one of the Amped Wireless UA230A dual-band Wi-Fi transceivers installed, and the YAWCam application pulling images every 15 seconds from the Mobius ActionCam attached to the windshield. When the PC detects the Cox/CableWiFi connection, it associates and then can push an image or more to my main website page.

I’m slowly collecting position information data for CoxWiFi / CableWiFi APs in the greater PHX area, and will publish some maps soon. Until then, it’s possible to get that kind of information from Cox’s website.

 

Two Weeks of ADS-B Coverage

It’s been over two weeks since I installed my ADS-B setup, and it’s been a real performer and seems to be very reliable. As I’ve pointed out, I’ve continued to tweak the setup, first with a better antenna, then by raising the antenna a bit, then with a cheap satellite preamp.

An important thing I still don’t know is the absolute amount of air traffic on any one day. ADS-B transmitters are only on a limited number of civil a/c, so it doesn’t see all the non-equipped a/c that might be flying on that particular day. I’ve never looked in any detail at commercial traffic repeatability, so I can’t say for sure if flight XYZ123 between airport A and airport B flies  every day of the week. I don’t know if Monday is a busier flight day locally than is Tuesday. And with so many non-commercial airports within hearing range (KSDL, KDVT, KGEU, KFFZ, KCHD, KPAN, etc.) the number of small a/c equipped with ADS-B could change dramatically on any given day. KDVT has an especially large number of ADS-B-equipped a/c and they’re constantly flying loops around KDVT, so they provide a good number of position reports.

With all that said, when I saw the precipitous drop (34%) in location reports on the rainy day here on the 30th, I was concerned that my setup might have some issues that needed resolution. After doing a few checks, it appeared that things were nominal, so the next thing was to compare my station’s statistics with those of other stations near me. There aren’t any stations within 7 miles, but that was good enough to start as the rain was a southern-AZ-wide event, a good soaking, steady winter rain, which was over a very large area.

I took the best performing stations and a couple of typical stations for comparison. I also marked when I changed something in my setup to see if what I did actually mattered or if everyone else reflected some change that day which might indicate that my equipment changes had no particular effect.

Jon Adams ADS-B station vs other local ADS-B stations

The above graph (done in Excel) compares the JonAdams ADS-B receive site against two other solid performers (SN and DR) and two others down in the typical performance range (LY and PE). Raising the antenna (just noticed I drew it one day later than it should be) improved the performance from about 130k reports to about 150k reports. Adding the preamp was the real improvement, improving sensitivity and increasing the number of reports between 25 and 35%. I also noticed that my ultimate range improved as well. At least the preamp change to my station’s setup doesn’t correspond with significant changes in the other stations, so I’d say that the preamp was a big deal.

Another important thing, and why I started this article, was my concern over the rain having a specific deleterious effect on my station. But, it appears that the other high performers suffered very similar degradation. In my case, the drop was 34%. Comparing that to station SN, the drop there was also 34%. For station DR, the drop was 63%. For the other two typical stations, there was no particularly significant change in performance.

So, for now I will conclude that my ADS-B station has no unique problems not faced by other high performing stations. I remain interested in the cause of the drop, but have never had so much data at this particular frequency range that it’s going to take a little more Googling to figure out why and to what extent the rain should have an impact.

ADS-B Coverage Range Improvements

 

1090 MHz ADS-B Coverage from N7UV QTH

The above is a screenshot of the aggregated coverage over an approximate 120 hour period from last Saturday to now. The rings are spaced 50 km apart. As you can see, there are even a few a/c locations over 400 km away, which is incredible given that the house is in a bowl surrounded by hills or mountains in nearly all directions. For that one particular coverage radial SE into Sonora, that happens to be a very narrow clear shot (not including trees) from the house toward the horizon.

Initially, my setup included a simple discone antenna already sitting up on the roof, but in a day I had built the “QST Special” ADS-B antenna and my number of location messages went up from about 35k per day to over 130k per day.

After a few days of that, I raised the QST antenna by 4′ to get it above the parapet wall that surrounds the roof and the number of position reports went up by about 10-15% to about 150k. Next, I found in the garage a cheap (cheap being $5) cable satellite preamp and put that in line with the antenna. The position reports skyrocketed from about 150k to well over 200k per day. In fact, yesterday’s summary shows 240k+ position reports, and about 300 per second at peak times of the day. Here’s a chart which shows the changes in performance as a function of time and setup.

ADS-B Stats from 15 Jan to 2100 hours 30 Jan

As can be seen, the performance continues to improve as the setup is further tweaked. Today (30 Jan) looks to be a bad day for reception. It has been raining lightly (about 0.03″/hr) since before midnight. I expect that at the current rate the station will receive only about 160k position reports today, which will be about 2/3 of yesterday’s performance.

My assumption right now is that the connected rain drops on the antenna radome are causing significant loss of signal at the antenna radome (the ABS pipe it’s covered with). It’s also possible that the added attenuation of the signals as they travel through the rain clouds and falling rain is a factor. Not sure which is more significant. At 1090 MHz, light rain shouldn’t be a really significant issue, but perhaps the PiAware software decoder is running right on the edge of performance so even a dB or so of added loss could have an impact.

While the rain is great, I look forward to a few weeks of dry skies so that I can get a solid number on the performance as a function of day of week.

 

OMG – ADS-B & RaspPI

Enough about non-wireless stuff for the time being. Today, after a few weeks of inaction, I set up my Raspberry Pi B+, the FlightAware PiAware ADS-B code image, and deployed my first ADS-B receive site! It was easier than cake. It was stupid simple. In fact, the most challenging thing was discovering I didn’t have a microSD card and so I had to drive over to Fry’s and grab one.

What’s ADS-B? Why, it’s “Automatic Dependent Surveillance – Broadcast”. many (and more every month) aircraft, private and commercial, have GPS and a 1080 MHz transmitter on board to send a position message every second. For air traffic controllers, this means much improved position/speed/heading/altitude resolution. For the rest of us, it’s like having our own window at the air traffic control center and watching blips on the radar moving at 400 – 500 mph.

More soon as I get things going.

Venus and Mercury

After a number of days of clouds and rain here, I walked out of the grocery store and was impressed to see two bright planets low in the western sky. One was obviously Venus, the other was a little orangey and initially I thought it might be Mars. However, a quick check on the Internet shows it to be Mercury!

Both planets stand out beautifully in the twilight sky, and with Mercury preceding its brighter sibling toward the western horizon. I pointed the N7UVCAM2 Roving Reporter toward the pair, and captured a few images. I will post them here as soon as I figure out what’s going on with WordPress.

What Good Is a Wireless IP Camera?

I recently installed a new weather station here at the homestead. With a weather station, it’s always nice to be able to have a picture of the sky to see what the sky looks like, to augment and bring to life the sparse yet functional gauges and dials.

The world of digital image capturing devices is a miasma of terminology, mis-terminology, ignorance and sometimes (at least so it seems) a bit of disingenousity. Go to eBay, type in “IP network camera outdoor”, and there’s at least a zillion, give or take, cameras available from no end of sources, mostly in Asia.

Not being really up on the latest and greatest for IP network cameras, all I really knew going in was what I wanted. The camera needed to be 1) able to withstand living outdoors, in the direct sun and rain; 2) at least 1080p vertical resolution; 3) as sensitive as practical, so I could see an image at night, and hopefully see a few stars; 4) cheap (hard to define); 5) have an included webserver so that with a browser it’d be possible to see the image, and be able to ftp an image on a scheduled (not event) basis to the WUnderground site where my Personal Weather Station data is displayed; and 6) straightforward to configure and tweak. I know, it’s a lot to ask, especially with 4).

One thing that is missing in the above list, and some might wonder why, is the choice of wired vs wireless for the connectivity. After all, it’s the “WirelessJon” website! For this particular installation, it really wasn’t much of a decision to make. A camera takes a significant amount of power to operate (several watts at least). A wireless camera takes at least as much power to operate as an equivalent wired camera. Since a wireless camera would need a source of power, likely the house mains, a cable would still have to be run to supply the power to the camera. If I’m going to the trouble to run wire, I might as well kill two birds with one stone and use that wire to supply connectivity as well. Also, my desired camera might be streaming video on occasion, and that could end up being a significant load on my home wireless network. Finally, ensuring that the wireless coverage from the inside of the house would be good enough for robust connectivity to gadgets on the roof would mean that there’d be a constant unknown as to whether or not a problem in viewing the camera’s image was caused by RF propagation or by some hardware issue. So, like I said, the decision to go wired was pretty straightforward. I have another reason which made it simpler to go this way, which I’ll discuss in a future post on rooftop routers.

As can be imagined, many of the requirements listed above are mutually incompatible. And by “cheap”, I was aiming for somethiing under $100 delivered. Nonetheless, I started my search through Google and eBay as well, working to figure out some of the more esoteric terms (RTSP, DNC, AE, etc.) and attempting to validate things like FTP server and web browser functionality and configurability. A simple thing that I wanted was a scheduled capture on a regular, timed basis – something that doesn’t seem to be offered in most cameras listed on eBay – most offered appear to target the surveillance video market, and the cameras trigger video based upon events like movement in the field of view, or whatever. There were some challenges to figure out what many of the cameras actually did.

Another minor tricky thing was camera sensitivity to light; remember in my wish list I wanted a camera that could even see stars (not just the Sun). I’ve always had in my mind something that I call the PoleCam, which is a camera trained at the north celestial pole and capable of watching the current pole star, Polaris, in its daily orbit around the north pole, Yep, it’s true, Polaris isn’t really at the celestial pole. It’s close (about 3/4 of a degree away, close enough for government work), but it’s not stationary. The ideal camera would allow me to see the movement of Polaris as well. But, I digress: the main purpose of this camera is weather observation.

Cameras come with two different types of image sensor, CCD or CMOS, and a variety of lenses with different angular fields of view (FOV). Some cameras have varifocal lenses, where the “zoom” factor of the image can be changed to accommodate. For me, CCD is the only way to go for improving low-light sensitivity; compare a CCD imager with its equivalent CMOS imager and you’re sure to find that the CCD imager provides a higher quality image with better low-light performance. As far as lenses, it seemed that there were generally 4 mm, 8, mm and 12 mm used on the cameras for sale. Since I’d never bought one of these cameras before, I didn’t know how difficult it’d be to change the lens, so I decided to go with an 8 mm lens which should have about a 40 degree horizontal FOV.

A tricky thing I discovered (I know, I was born yesterday) was that some of the eBay ads had confusing, conflicting, or flat incorrect information about the product offered. Doing searches which included “CCD” didn’t always return only cameras with CCD imagers – in fact, some sites would use the term “CCD” in several places when selling a CMOS camera. Also, attempting to figure out if a camera had a webserver built-in, and whether that webserver could respond successfully to queries that came in on Chrome, or Firefox, or whatever, not just IE, is quite challenging.

Suffice to say, I did find a camera which appeared, at least in theory, to meet many (but not all) of my desirements. The camera I discovered appeared to have the following features: 1) outdoor operation, with an included sunshade; 2) 1920 x 1080 resolution; 3) CCD imager for good low-light sensitivity (hard to tell until it’s in your hands, though); 4) $70 delivered; and 5) built-in webserver, FTP server, etc. The things it didn’t appear to have included: 1) power over Ethernet (PoE), so I’d have to do that externally; 2) no idea of what the software was or how to configure the camera for my desired operating method; no idea if the camera was any good at all given the low price, and many other unknowns which wouldn’t be answered until I had one in my hands.

So, I placed the order on eBay and awaited delivery of my amazing new $70 super webcam. More soon on what I found out when I opened the box!

 

Wired vs Wireless Weather Station

Welcome back to the WirelessJon blog – I’d taken a long respite from blogging, but it’s time to dive back in.

Six weeks ago I decided that it was high time that the WirelessJon household had a professional-grade weather station. I’d been toying with $90 LaCrosse Technology all-in-one wx stations from Costco for many years, and each year or two or three I’d have to replace the hardware because something had stopped working. As well, the LaCrosse stuff didn’t have a nice way to fire the data to WeatherUnderground (or any other online service), so I had to run WUHU on a PC that was also running the LaCrosse Heavy Weather software. It was a kludge at best!

One of my long-time friends and fellow ham Dave KD7DR is a local expert on weather stations. He’s been using both Peet Bros. and Davis Instruments stations for a long time now. He suggested to me that the Davis had better hardware quality – he uses a wired Davis Vantage Pro2 atop Pinal Mountain, an ~8,000′ peak about 60 miles east of Phoenix, and it’s survived well over the years. I also had some personal experience with a Peet, as I’d installed one at a 5,000′ site above the Tehachapi Loop in southern California back in 2008, and except for losing the anemometer cups to a heavy ice storm, it’s been a pretty solid unit as well.

After some discussion and consideration, I chose the Davis Vantage Pro2 as the baseline. The next decision was whether it would be the wired or wireless version. The external sensor location is on the roof of the house, and I already had a 2″ cable conduit running out to the general location. However, that conduit is stuffed with other cables, including RF coaxial cable, and I didn’t know whether I wanted to pull yet another cable through the already-tight conduit and didn’t know how the slight leakage from the RF coaxial cables might impact the weather sensor readings. Time for more investigation.

I went through the Davis literature and discovered that they’d had the foresight to put “low-pass” filtering on the sensor lines, so what coupling there might be should be alleviated by the filtering. As well, my RF coaxial cable is either LMR400 or LMR240, double-shielded, very low leakage, and none of my transmitters are more than about 50 watts, so it’s likely that the amount of power deposited onto the wx sensor cable leads would be pretty low. It would also be common mode, so that might help reduce any concerns as well.

The last factor for wireless was the choice of RF frequency that the Davis unit uses. It employs some sort of proprietary frequency-hopping transmitter in the license-exempt 902-928 MHz band. Given that I’m a ham and may want to operate in that band (actually, I do have some equipment but it’s currently receive-only in the house), I decided that I didn’t want to pollute that band any more than it was already.

Importantly, I had to look at the type of cable that connects the Davis weather sensors to the console and what connectors are used. Again, a few checks using Google and I found that the cable supplied by Davis is just 4-wire “phone” cable, much like the old silver-colored soft, flexible wire which connected old-time wired POTS phones to the wall outlet. Except that the Davis wire had a UV-resistant jacket. Kind of necessary for an outdoor install, especially here in Arizona. The connectors were the clear plastic 6P4C “RJ15” type, readily available in my garage, as was the crimp tool. Finally, the way the cable was constructed was straight-through, so there was no need to worry about some custom wiring configuration.

The next consideration was how much weather did I want to sense? Since I tinker with solar power a bit, both on the house and on the truck, I’ve always wanted to know the total solar insolation at the house, and ultimately be able to calculate the peak, average and cumulative power/energy delivered to the ground. And while I was spending all this money, I decided to get the UV sensor as well. Never know. I chose not to get the active aspirated temperature sensor, but I believe I could add that on later if I choose.

One final consideration in the wired vs wireless debate is how to get power to the sensors. Weather sensors are just like any other device – they need some juice to allow them to make measurements and report back the information. The wireless Davis unit employs an add-on small solar panel and built-in battery to collect and store electrical power to run the sensors and the wireless transmitter. According to everything I’d read, it works well and the batteries have a good lifetime. But, here in Phoenix, things exposed to the sun get very warm, and batteries up on the roof are going to be in a fairly harsh summer environment. Also, the failure of the most recent LaCrosse unit appeared to be a failure of the built-in solar cell to charge the little NiMH batteries in the anemometer. Using a cable would allow me to avoid completely any concern over having to change batteries in the future.

Now that the wired vs wireless decision was made, it was time to look at the ability for the Davis to push data to the internet. They have a number of interface dongles which plug into the display unit. One is a serial port connection, which requires a PC to run software to manipulate and push the data to the web, and the other was a thing called the WeatherLink IP, a slightly different dongle which plugged into the same socket on the Davis display head but instead of serial had a nifty RJ45 socket and talked IP. It seemed that this allowed me to divorce the entire process from a PC. The one primary drawback was that the literature indicated that the weather data could only be pushed once every 15 minutes. At this point, that seemed ok (i’d come to be unhappy with this later).

That was that. I called up Andrew Revering at Convective Development and placed the order for the Davis Vantage Pro 2 Plus wired station and the WeatherLink IP dongle. Less than a week later a big box showed up on the doorstep, and the day after Thanksgiving I installed the entire thing.

Later on I’ll talk about some of the good, could-be-improved, and mediocre things I’ve found with the Davis, both mechanically and operationally.

IEEE 802.15.4p Rail Communications and Control – Getting Ready for the Mainline!

IEEE 802.15.4p task group has just completed letter ballot and has been approved to move forward to Sponsor Ballot. The participants within the IEEE group have been terrific – engaged, collaborative, and flexible.
The group includes 90 participants from around 70 private companies, academic institutions and US and foreign government transportation entities. Every milestone denoted on the schedule established back in fall 2011 has been met or exceeded.
We met the requirement that 75% of the current 802.15 Working Group voters must participate in the vote. “Yes” votes comprised over 96% of the returned ballots. Comments may be submitted by any voter, but must be submitted by any “no” voter. The comments received during this letter ballot were a good mix of technical and editorial and should be able to be resolved over the next several weeks.
What all this means is that there’s a high probability of getting the standard released by the end of the year or in January 2014. It appears that there are several companies out there which may be releasing a compliant product shortly after the spec release.
To our participants, keep up the steady progress and collaboration. To the rail operators, be prepared for train wireless data communications that are based on open international standards.

IEEE 802.15 Positive Train Control Study Group

Many of you may be familiar with the IEEE 802 organization, if in no other way by its standards that have become the mainstay of wireless communications, like IEEE 802.11 (Wi-Fi), 802.16 (WiMAX), 802.15.4 (used by ZigBee, WirelessHART, ISA 100, 6LoWPAN, and others).

Standards development is a challenging matter, since it only comes by bringing together competitors and opposing entities into the same room and working together to create standardized approaches to a variety of problems.

The group that I helped to create, IEEE 802.15 Positive Train Control (PTC) Study Group, is focused on the vital wireless link between the train or locomotive and the infrastructure along the track ahead. While the current concentration is mostly to ensure that a train does not “exceed its limits authority” or exceed its speed restrictions, the future could see the need for a train to talk to bridges, overpasses, or other infrastructure that could impact the safety of a fast-moving train.

Now that we are in Study Group phase, this means that it’s time for us to concentrate on writing our Project Authorization Request (PAR) and our Five Criteria (5C) documents. To make that effort possible, the group will have a Call for Applications, which will allow interested parties to begin to submit technical proposals for how a future wireless standard will be applied in the real world. Fortunately, PTC is a fairly well defined application, but even there, there are nuances that may prove very important to the final standard. As well, this standard must be something that can grow and remain flexible for future applications which we may not even have considered yet.

While what we’re working on is a new standard, in IEEE parlance, the work could result in an amendment to an existing standard (like 802.15.4) or a new number (802.15.10?). That’s why the call for applications is so important – it helps establish the scope of the task.

Some important considerations might include the use of licensed bands, support for narrow-band, possibly non-contiguous radio channels, fairly low data rates, very high speed mobility, and a lot of non-line-of-sight (NLOS) propagation paths. As a train moves along, it may pass from one geographic region to another, and the operating channels may be required to change as the train moves. And it always needs to be kept in mind that this may ultimately be for vital (life and safety) communications, so reliability, robustness and security are important matters as well.

I’ve been working on systems in many ways similar to this for most of my professional career, from deep-space missions (where oops! could mean the end of a multi-billion US$ mission), to very high volume consumer and industrial silicon chip-level wireless systems, and for the past 10 years working to drive standardization of approaches used in the industry to reduce cost, increase the potential for interoperability, and generally to improve reliability and robustness.

If this is your cup of tea, I strongly encourage you to participate in our Study Group. You can get plenty of details here.

Commentary and insight on many topics, sometimes even about wireless

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