The expression "submillimeter waves." has been used for decades by radio astronomers.
What is strange in that news is that FCC starts the reallocation from
95 GHz, while international frequency allocation tables already extend to at least 275 GHz. Most of these are for passive radio astronomy and earth sensing, containing some interesting spectral lines,
Yeah, but *heaps* of it for the spectrum you're aspiring to work in.
-- No deal? No problem! :-D
And it doesn't stop there. I wonder what a set of calibration standards, interconnects, adaptors, attenuators and whatnot costs for a BW like that. :-/ Steve's going to need very deep pockets - or a friendly investor.
-- No deal? No problem! :-D
Followup on Micron abandoning Keysight Memory.
So they made the decision to go with micron memory early on and it was too late to switch, bad luck. Or are they actually using HBM(2), which offers far more speed and more memory per packacke. HMC just wasn't competitive and is discontinued.
Hybrid Memory Cube (HMC) --> HBM (High-Bandwidth Memory)
Micron is discontinuing the HMC product
Hybrid Memory Cube was co-developed by Samsung Electronics and Micron Technology in 2011,[1] and announced by Micron in September
2011.[2]. It promised a 15 times speed improvement over DDR3.[3] The Hybrid Memory Cube Consortium (HMCC) is backed by several major technology companies including Samsung, Micron Technology, Open-Silicon, ARM, HP (since withdrawn), Microsoft (since withdrawn), Altera (acquired by Intel in late 2015), and Xilinx.[4][5] Micron, while continuing to support HMCC, is discontinuing the HMC product [6] in 2018 when it failed to achieve market adoption.HMC combines through-silicon vias (TSV) and microbumps to connect multiple (currently 4 to 8) dies of memory cell arrays on top of each other.[7] The memory controller is integrated as a separate die.[2]
High Bandwidth Memory (HBM) is a high-performance RAM interface for
3D-stacked SDRAM from Samsung, AMD and SK Hynix. It is used in conjunction with high-performance graphics accelerators and network devices.[1] The first HBM memory chip was produced by SK Hynix in 2013,[2] and the first devices to use HBM were the AMD Fiji GPUs in 2015.[3][4]High Bandwidth Memory has been adopted by JEDEC as an industry standard in October 2013.[5] The second generation, HBM2, was accepted by JEDEC in January 2016.[6]
HBM achieves higher bandwidth while using less power in a substantially smaller form factor than DDR4 or GDDR5.[7] This is achieved by stacking up to eight DRAM dies (thus being a Three-dimensional integrated circuit), including an optional base die with a memory controller, which are interconnected by through-silicon vias (TSVs) and microbumps. The HBM technology is similar in principle but incompatible with the Hybrid Memory Cube interface developed by Micron Technology.[8]
HBM memory bus is very wide in comparison to other DRAM memories such as DDR4 or GDDR5. An HBM stack of four DRAM dies (4?Hi) has two
128?bit channels per die for a total of 8 channels and a width of 1024 bits in total. A graphics card/GPU with four 4?Hi HBM stacks would therefore have a memory bus with a width of 4096 bits. In comparison, the bus width of GDDR memories is 32 bits, with 16 channels for a graphics card with a 512?bit memory interface.[9] HBM supports up to 4 GB per package.
Thanks. I'm not into astronomy and didn't know that. However, if radio astronomy has progressed to such such frequencies, perhaps it might be useful to inform them of micrometers and nanometers?
"FCC ONLINE TABLE OF FREQUENCY ALLOCATIONS" See Pg 68 for the highest frequencies allocated by the FCC. Looks like it's 275GHz. The last entry is "275 - 3000 GHz not allocated" with "amateur radio" as the primary(?) user.
What will probably happen is a replay of the Ligado (LightSquared) allocation problem with GPS interference. Ligado won a chunk of spectrum adjacent to the GPS band and wants to use it for cellular phone and data service. Since they contributed to the campaign of Democrat president, and we now have a Republican in office, they may need to wait until the next Democrat administration approves their science fiction solution to the interference problem.
Something similar happened when the FCC allocated the 24 GHz band for
5G without bothering to look at their own allocation table to see if it was already in use. It seems that it's an important frequency for radiometers used for satellite weather forecasting. Summary: NOAA lost.I expect similar frequency conflicts to be a continuing problem as the FCC merrily monitizes spectrum to support government spending. Frequency bands will be reallocated and auctioned followed by protests by incumbent users. It won't be pretty.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Next there will be an auction for visible spectrum.
-- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
If the FCC thought that companies might pay for those frequencies, they would certainly try to sell it. That could have happened with dark fiber and WDM (wave division multiplex). Proponents of FTTH (fiber to the home) and MAN (metro area networks) proposed an optical network where the various carrier monopolies would provide the necessary switching and routing. I may have saved the wallchart full of proposed topologies which I picked up somewhere. As I vaguely recall, someone suggested that it would be nice if the wavelengths (colors) used by various entities were standardized. I don't know if they were serious or joking, but they recommended that the FCC administer the allocations. Knowing the FCC, I suspect that they would jump at the opportunity to auction off something they don't really understand.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
The military needs GPS for their aircraft and smart bombs. Ligado is not going anywhere.
There is a strong water vapor absorbtion line at 22 GHz, which is useful for determine the amount of vapor in the atmosphere for a specific geographical area.
Why is NOAA talking about 250 MHz frequency difference, when the difference is about 2 GHz ? Perhaps the satellite receiver bandwidth is several GHz wide ?
Insidegnss.com, January 22, 2020
the Nov 18 letter sent to the FCC by Secretary of Defense Mark Esper, whose
many unknowns and the risks are far too great to federal operations to
the potential for widespread disruption and degradation of GPS services
significant negative impact on military operations, both in peacetime and
Esper pointed out that, by law, he could not agree to any restriction on the GPS System proposed by the head of a department or agency of the United
Authorization Act for Fiscal Year 1998 and became law in 1997. Any statute is important but because the FCC is overseen by Congress, and not the
against mandates set by lawmakers when they are, effectively, your bosses.
Because the FCC is political, not mathematical.
"FCC's Pai: Study on 24 GHz Weather Data Issue is Fundamentally Flawed" He said that is because the 5G technology that will be employed in the band is a "rifle shot" not a "shotgun blast."
Really? 5G will be narrowband? So much for gigabit bandwidth via 5G.
He also said the study assumed base stations and devices would be using spectrum simultaneously, which was impossible,
Really? I guess he's never heard of full duplex communications.
and said that the spectrum for 5G and the spectrum for passive weather sensors was separated by 250 MHz.
Well, let's see if that works:
5G will use 24.25 GHz - 24.45 GHz and 24.75 - 25.25 GHz The water vapor radiometer operate at 23.8 and 31.65 GHz. 24.25 - 23.8 = 450 MHz minus half of whatever bandwidth the radiometer requires. This article suggests a 400 MHz bandwidth. I gotta dig some more to find out what is actually used: "The impact of passband characteristics on imaging microwaveradiometer brightness temperatures over the ocean" Therefore, the frequency separation would be: 24,250,000 - 23,800,00 - 400/2 = 250 MHz So, yes... they are separated by 250 MHz, which in my never humble opinion should be sufficient to keep interference to a minimum. There really should be about a 50 MHz guard band between services but what's few MHz when discussing political issues?So, Chairperson Pai got one out of three claims correct. Impressive.
NOAA Water Vapor Imagery Try the vertical scroll bar on the right of the image, spin the mouse wheel, or download the MP4 animation.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
That's the general rule IIUC. In lithography and microscopy, for example, "submicron" means 0.1-1 um, below which you're allowed to use "nanometre" as an adjective.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
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