Phased arrays are everywhere. An incredibly common example are many cellular base station antennas. They are fancy but nothing particularly special these days. Active phased arrays, e.g. steerable with either analog phase / delay shifters or with digital front ends are less common but still much more common than the BAE Systems phased arrays in F35's.
As a practicing EE / RF comms engineer, I will say that it is very obvious when you're working with someone who thinks that their EE coursework wasn't useful for the real world.
I would suggest adding Communication Systems by John Proakis. It is the seminal text for digital comms and should be included, given the plan's foray into SDRs.
It's not pure profit because, a) you can only oversubscribe 20GB/s so much without data caps and speed limits b) a small fraction of the constellation will be over inhabited land and wealthy enough countries at any moment c) I am assuming they lose money the first ~1.5 years to recoup the dish cost and R&D, d) ground link opex e) sats fall out of the sky and need replacing f) subsidized launches via rideshare only work if there is enough demand into inclined LEO, otherwise its $30M per launch at per sat costs go way up g) Customers are not uniformly distributed over earth's landmasses
I don't have any insider info but there is absolutely no chance that the dish is costing them even <2x what they are charging for it. I don't really see how their business model pencils out even assuming massive oversubscription, perfectly geographically distributed customers, and the new laser links. It's just hard to make it work when your satellites fall out of the sky and need replacing. The technology certainly works and is really cool to see as an engineer, don't get me wrong, but even Musk businesses will eventually need to make money. For Tesla, their path to profit was steep, but feasible; here I just don't see it at all.
Going to guess GNURadio based on calling it a Python script executor that outputs xml. If that's true, I'd that it really starts to break down when the desired logic breaks from the "apply sequential steps to a stream of contiguous data" paradigm.
You're confusing energy and power which is leading you to the wrong conclusion. 6KW is 6KW of power. Over 10 minutes it's 1KWh of energy but typically you only care about instantaneous heat dissipation, which is power.
Failing budget? I get that it's super popular right-wing talking point but it just hasn't been true for years. Prior to COVID (which has decimated state budgets Red and Blue) California had a huge surplus and massive rainy-day fund.
This seems like a purposely obtuse hit on California by someone with a political axe to grind. Before the pandemic and global recession which has blown up State and Federal budgets everywhere, California was running a huge budget surplus and saving up billions of dollars in a rainy-day fund.
Deeply red Georgia is also facing a major budget shortfall but you don't see article like this from right-wing commentors lamenting the series of tax cuts passed in recent years.
https://www.latimes.com/science/story/2020-03-22/coronavirus... He seems to be a perfect example of the axiom that deep knowledge in one field doesn't necessarily give you expertise in others. Seems like he should leave Epidemiology to the epidemiologists.
Sure but they are more expensive. You need a rock solid controller with beefy and redundant electronics to make sure you're never going to be connected to the grid when you shouldn't be.
There is a reason everyone uses Ettus Radios (USRP). You will quickly pay back the extra cost though saved engineering time over by not buying cheap hobbyist hardware.
It's not so much that the high performance radios are proprietary as it is that building one of these systems is expensive and requires lots of domain specific knowledge. You could somewhat easily build one of these systems for ~$250k using CoT's hardware, in fact Lund University did a few years ago for some of their MASSIVE MIMO research.
If you don't want to use CoT's hardware for some reason then you can roll your own transceivers. You have a choice of Analog Devices chips or Lime Microsystems. Xilinx has a new platform that would also work but it hasn't been widely released yet. Lime's chip is cheap but it's performance is crap and its drivers are even worse. ADI's chips are easy to use and have fantastic performance but you pay for it. You also need to shell out for the massive FPGA's to handle 64*6.4GB/s of streaming data and then you need a system capable of processing it which will still probably be an FPGA or a DSP.
Well, for one you're not going to get a very wide coverage range or throughput with the ~1 watt of power you're limited to in the ISM bands. Your router will also have to accept interference from 802.11 routers, Bluetooth, etc devices. There is a lot of on going research into dynamic spectrum allocation and cooperative scheduling which this platform is actually supporting but that still requires federation which your use case seems to be against.
It's a myth that Houston doesn't have zoning. They don't have use based zoning but they still have plenty of requirements such as parking minimums and lot sizes that serve as de facto zoning.
You're right, it's not great for actual products. I was talking more about prototyping and debugging. It's super nice to be able to just do a "cat /sys/bus/iio/.../.../out_voltage1" or build a simple tool that does that for you.
Those deadzones are horrible. Also, the calibration routine is absolutely broken.
For example, when userspace requests a certain TX gain, the chip does some calibration black box magic to determine the best way to distribute that gain across the internal amplifies. Nothing special here, the AD9361 does the same thing. The Lime chip will inexplicably fail the calibration but __will continue to operate__. If the PLL didn't lock, the chip sees something dumb like the loopback being down at -45dBFS so it cranks the gain on all of its internal amplifiers to __correct__ the loss. This results in one or more of the internal amplifiers saturating and you end up with horrible intermod. I was seeing -10dBC ACPR on a simple 1MHz QPSK signal. Sure, you can save off good calibrations or do it by hand, but if the simple loopback cal doesn't work and won't tell the user, the chip is irremediably broken.
Even with Lime Microsystems, their chip barely functions compared to the equivalent ADI part. Sure, it's nameplate specs are nice but it the dynamic range is crap and the EVM barely passes the LTE spec.
Even worse is that basically the only product using the chip is Lime themselves so trying to spin your own product would be a nightmare. ADI has a nice eval board and reference design for their chips and you can control it using the lib-iio framework which is built into mainline linux.
In this case, the relationship of "master" and "slave" is intrinsically linked. No one is telling you to stop using "master" in other contexts. It is the master-slave relationship here that is the issue. You are beating down a strawman that wants to remove the term master in all contexts.
I mean if you want to conflate social norms with debates about knowledge and practice, sure great zinger you have there.
Unfortunately, many people do not have the luxury of treating their race, sexuality, gender, religion, etc, as a matter of ideological debate. The perspective of framing the social treatment of immutable identities as encouraging orthodoxy comes from a position of privilege.
> However, I largely kept my mouth shut because I was afraid of the social repercussions.
So, social norms? There are plenty of things we collectively don't say or do because of enforced social norms yet all of a sudden when those social norms start to include the perspectives of traditionally oppressed groups, certain people start acting like Western Society as we know it is collapsing by the hands of the censorship police.
The rules have always been there, but as the filing mentions, ICE said in March that the rule would be suspended for the duration of the emergency. They are now going-back on that statement which given the timing of the announcement is causing chaos.
That is not true. T-Mobile has Release 15 5G deployed in the 600 MHz band right now -- I'm looking at being broadcast over-the-air on my spectrum analyzer here in the south eastern US.