Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

pretalx.sysmocom.de

Post reply on HN
Print view View original

11–20 of 30 posts

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#11

Post by blantonl »

runlaszlorun wrote: post #7
KaiserPro wrote: post #2

Related but not quite the same: http://www.dxcluster.org/ Dxcluster used to use a lot of radio links to disseminate data. However fixed internet lines have become much cheaper, so there isn't the need to have massive HF antenna to create relay link any more.

> so there isn't the need to have massive HF antenna to create relay link any more. HF is having quite a resurgance among various militaries.

I'm not sure why this was downvoted. The author is correct.

Given that space communications and the militarization of space is becoming more and more prevalent, we are on the cusp of seeing some military actions in space that could render a few defense agencies impotent with regards to C3.

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#12

Post by yau8edq12i »

macnetic wrote: post #6
DeathArrow wrote: post #4

What HF means in this context? A few GHz? Also, for long range I thought the longer the wave length is, the better.

HF is 3 MHz to 30 MHz. Yes it does not make much sense, the term is ancient.

Ancient? The HF band is still very much in use... Modern developments have not changed the fundamental properties of RF propagation. UHF ("a few GHz") can only be propagated in line of sight reliably. HF can literally travel around the world.

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#13

Post by lxgr »

greenish_shores wrote: post #3

"Multimedia"? Over HF where one "cell" (using the WWAN nomenclature) may have several tens kbps of total (uplink and/or downlink) throughput at most? (see Shannon-Hartley theorem, which is distinct from Shannon-Nyquist sampling theorem) But for emails and the rest of proposed use, sure. Also, OsmoDevCon is iirc invite-only, making linking to its schedule on a public forum mostly pointless (visit #osmocom on Libera fo…

If you consider SSB voice one medium, and CW morse code another, HF has been multimedia for more than a century :)

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#14

Post by lxgr »

macnetic wrote: post #6
DeathArrow wrote: post #4

What HF means in this context? A few GHz? Also, for long range I thought the longer the wave length is, the better.

HF is 3 MHz to 30 MHz. Yes it does not make much sense, the term is ancient.

Even today, it still is higher than low and medium frequency :)

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#15

Post by lxgr »

yau8edq12i wrote: post #12
macnetic wrote: post #6

Earlier quoted context omitted.

HF is 3 MHz to 30 MHz. Yes it does not make much sense, the term is ancient.

Ancient? The HF band is still very much in use... Modern developments have not changed the fundamental properties of RF propagation. UHF ("a few GHz") can only be propagated in line of sight reliably. HF can literally travel around the world.

GP called the term ancient, not the band itself, and I find it hard to disagree with that.

Calling something “high”, “fast”, or “new” is rarely a naming decision that’ll stand the test of time, but given that there were already LF and MF below it, it did make sense at the time. Who could have predicted we’d go up all the way into visible light with our RF communications?

The only thing on a lower frequency used daily by most people would be contactless payment cards and maybe NFC at around 13 MHz.

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#16

Post by nrdgrrrl »

lxgr wrote: post #13
greenish_shores wrote: post #3

"Multimedia"? Over HF where one "cell" (using the WWAN nomenclature) may have several tens kbps of total (uplink and/or downlink) throughput at most? (see Shannon-Hartley theorem, which is distinct from Shannon-Nyquist sampling theorem) But for emails and the rest of proposed use, sure. Also, OsmoDevCon is iirc invite-only, making linking to its schedule on a public forum mostly pointless (visit #osmocom on Libera fo…

If you consider SSB voice one medium, and CW morse code another, HF has been multimedia for more than a century :)

There's also SSTV. Surely images, voice and text counts as multi-media?

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#17

Post by yau8edq12i »

lxgr wrote: post #15
yau8edq12i wrote: post #12

Earlier quoted context omitted.

Ancient? The HF band is still very much in use... Modern developments have not changed the fundamental properties of RF propagation. UHF ("a few GHz") can only be propagated in line of sight reliably. HF can literally travel around the world.

GP called the term ancient, not the band itself, and I find it hard to disagree with that. Calling something “high”, “fast”, or “new” is rarely a naming decision that’ll stand the test of time, but given that there were already LF and MF below it, it did make sense at the time. Who could have predicted we’d go up all the way into visible light with our RF communications? The only thing on a lower frequency used daily…

Millimeter wavelength RF was already studied in the 19th century... The RF communication band you're talking about is smack dab in a band already defined in the original 1937 document.

Honestly the naming scheme makes sense to me. The spectrum is divided into 12 bands of equal (log) size, up to a frequency where we don't know whether such waves will ever be reliably generated at room temperature without breaking the laws of physics. Then these bands are consistently named from "extremely low" to "extremely high", with an extra annoying band at the top. Really, it could be worse.

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#18

Post by zamadatix »

yau8edq12i wrote: post #17
lxgr wrote: post #15

Earlier quoted context omitted.

GP called the term ancient, not the band itself, and I find it hard to disagree with that. Calling something “high”, “fast”, or “new” is rarely a naming decision that’ll stand the test of time, but given that there were already LF and MF below it, it did make sense at the time. Who could have predicted we’d go up all the way into visible light with our RF communications? The only thing on a lower frequency used daily…

Millimeter wavelength RF was already studied in the 19th century... The RF communication band you're talking about is smack dab in a band already defined in the original 1937 document. Honestly the naming scheme makes sense to me. The spectrum is divided into 12 bands of equal (log) size, up to a frequency where we don't know whether such waves will ever be reliably generated at room temperature without breaking the…

I agree it could be worse but the idea it's really any good seems more like us being used to it than anything else. It's a stupid naming scheme. For a log scale I would really have been happier with everyone using band numbers or something rather than explaining "super high frequency" is higher than "Ultra high frequency" and, despite the terms, that's probably where most typical radio device use cases are these days.

Re: Digital Telecommunication in HF band - WWWAN - World-Wide Wireless Area Network

#20

Post by lxgr »

zamadatix wrote: post #18
yau8edq12i wrote: post #17

Earlier quoted context omitted.

Millimeter wavelength RF was already studied in the 19th century... The RF communication band you're talking about is smack dab in a band already defined in the original 1937 document. Honestly the naming scheme makes sense to me. The spectrum is divided into 12 bands of equal (log) size, up to a frequency where we don't know whether such waves will ever be reliably generated at room temperature without breaking the…

I agree it could be worse but the idea it's really any good seems more like us being used to it than anything else. It's a stupid naming scheme. For a log scale I would really have been happier with everyone using band numbers or something rather than explaining "super high frequency" is higher than "Ultra high frequency" and, despite the terms, that's probably where most typical radio device use cases are these days…

Fortunately we have not just one but two competing band designators – IEEE (widely in use in e.g. satellite communication; L-band, Ku-band, Ka-band etc. come from that nomenclature) and EU/NATO (which seems somewhat obsolete) :)

In addition to that, hams (in study materials and exams) use wavelengths, which is always "fun" to convert from/to frequencies.

Post reply on HN