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Shortwave Trading: The West Chicago Tower Mystery

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Re: Shortwave Trading: The West Chicago Tower Mystery

#101

Post by bobvan13 »

dx034 wrote: post #38
JustSomeNobody wrote: post #24

Earlier quoted context omitted.

I can't imagine they'd need the TCP/IP stack. You might do better with something like: SOH EOH STX ETX CRC EOT Then the receiver would send an ACK or NACK. Repeat as necessary.

Would you even acknowledge? The data is worthless after one round-trip, so you wouldn't send it twice. The receiver just needs to make sure that they read information correctly and can deal with losses.

Right. A shortwave link would be used in addition to a fiber link, not as a replacement for it. Assuming ACKs aren't latency sensitive, they could flow back over the fiber.

Re: Shortwave Trading: The West Chicago Tower Mystery

#102

Post by dx034 »

jandrese wrote: post #89
dx034 wrote: post #38

Earlier quoted context omitted.

Would you even acknowledge? The data is worthless after one round-trip, so you wouldn't send it twice. The receiver just needs to make sure that they read information correctly and can deal with losses.

Wouldn't it be valuable to know if your trade actually occurred?

No, your trading engine is on the other end, the link only sends prices. Let's assume you want to trade on a future in Chicago that's based on London prices (e.g. a world wide equity index). You know Chicago prices and NYC prices and what people in Chicago think London prices are. If you then get from London a price indication that this has changed, you can quickly trade against it to make money. The London link never needs to know what happened, they just send prices that could be interesting. All logic sits at the exchange where trades happen since that's dependent on local prices at time of execution.

Re: Shortwave Trading: The West Chicago Tower Mystery

#103

Post by cameldrv »

andai wrote: post #29
madengr wrote: post #12

They are probably also monitoring HF propagation paths, as there can be ground wave and sky wave, with varying dispersion. The X300 has some latency too. I’ll be they are doing the majority of processing directly on the FPGA to avoid SDR latency. The X310 has a larger FPGA, and would be tell-tale. Bring on the comms with neutrinos or entangled particles.

Up next: Tachyon trading

Maybe not, but almost as exotic: https://www.forbes.com/sites/brucedorminey/2012/04/30/neutri...

While all of the other chumps are trying to bounce their signals around the surface in fibers or various layers of the atmosphere, you just blast straight through the earth with (anti)neutrinos!

We live in a weird, weird world, and there's real money behind this idea. It might even affect the strategic nuclear balance, because submarines are supposed to be silent and invisible. Their nuclear reactors do generate extremely large numbers of antineutrinos though...

Re: Shortwave Trading: The West Chicago Tower Mystery

#104

Post by pbhjpbhj »

dmeeker wrote: post #16
tomalpha wrote: post #11

Earlier quoted context omitted.

That might well be true, but if you've only got a few kbits/second of bandwidth even that might be too much.

Sure, you're certainly not sending a full feed -- presumably you've got some algo sitting in Chicago that's looking for interesting / potentially profitable price / vol changes and sending them via the fast path, while the remainder of the feed is going via higher-bandwidth but slower paths.

You might as well have your decision logic before the communication path, then you can send like buy/sell orders in code using an agreed decryption pad/dictionary. (Akin to Morse's original conception).

Re: Shortwave Trading: The West Chicago Tower Mystery

#105

Post by pbhjpbhj »

wglb wrote: post #56
avip wrote: post #39

Earlier quoted context omitted.

Long-time "sniper in mahwah" follower here. The author is without the slightest doubt an elite tech reporter with in-depth understanding of RF tech. He always provides an overwhelming body of evidence to back his writing.

But why not then listen and figure out what frequencies are being used? That skill would be well within the "elite" category, no?

Eavesdropping laws?

Re: Shortwave Trading: The West Chicago Tower Mystery

#106

Post by pbhjpbhj »

cat199 wrote: post #83
tudorconstantin wrote: post #77

Earlier quoted context omitted.

Could an adversary send buy/sell fake signals and profit? Given the low bandwidth I assume they can't use very sophisticated authentication mechanisms

It would be extremely trivial to transport a time-keyed, completely random one-time-pad out of band (e.g. over a commodity internet link/vpn) so long as there is sufficient difference in bandwidth, and then simply XOR the data with it.. good luck cracking that. and that's just what a few seconds of thinking came up with.

How do you use a one-time pad on a single bit of data?

(Actually I see how that's possible, A XOR B, upticks are 1, etc.)

If the pad is coming via a side-channel then the speed increase is limited by that side-channel, you lose all your gains by waiting for the pad, then lose more by decrypting and verifying.

That aside my first thought was someone could jam the signal by blasting the receiver with noise; I wonder how they mitigate that.

Re: Shortwave Trading: The West Chicago Tower Mystery

#107

Post by CamTin »

pbhjpbhj wrote: post #104
dmeeker wrote: post #16

Earlier quoted context omitted.

Sure, you're certainly not sending a full feed -- presumably you've got some algo sitting in Chicago that's looking for interesting / potentially profitable price / vol changes and sending them via the fast path, while the remainder of the feed is going via higher-bandwidth but slower paths.

You might as well have your decision logic before the communication path, then you can send like buy/sell orders in code using an agreed decryption pad/dictionary. (Akin to Morse's original conception).

I'm not an algo trader, but you need the data from both ends of the link to determine if there is a trade you want to make, right? One side or the other is going to need prices from both ends in order to make a trading decision, and preferably both, since each side can only make decisions that are relevant to their side of the link, because needing a round trip negates all of the speed advantage you incurred by developing a top secret HF trading link.

Edit: I meant the HF here to refer to the "high frequency" wavelengths in use in the link (in Ham parlance, HF and shortwave are roughly synonymous), but just realized it also could be "high frequency" as in the frequency of trades.

Re: Shortwave Trading: The West Chicago Tower Mystery

#108

Post by bobvan13 »

Ftuuky wrote: post #93
yangcanvas wrote: post #76

Earlier quoted context omitted.

Rougue Code by Mark Russinovich was a novel I enjoyed about a HFT heist.

Can I read it without reading the first two books?

Yup, it stands alone well. I give it a strong recommendation for accuracy and storytelling.

Re: Shortwave Trading: The West Chicago Tower Mystery

#109

Post by bobvan13 »

wglb wrote: post #56
avip wrote: post #39

Earlier quoted context omitted.

Long-time "sniper in mahwah" follower here. The author is without the slightest doubt an elite tech reporter with in-depth understanding of RF tech. He always provides an overwhelming body of evidence to back his writing.

But why not then listen and figure out what frequencies are being used? That skill would be well within the "elite" category, no?

The license applications list a range of frequencies where operation is allowed. Indeed, many SWLers have documented such transmissions, e.g. https://www.youtube.com/watch?v=ySzpz8LWrjA The trouble is that when you do listen, you either hear test signals as recorded on YouTube, or you just get pseudorandom noise because it's encrypted.

Re: Shortwave Trading: The West Chicago Tower Mystery

#110

Post by bobvan13 »

jhpankow wrote: post #43
dx034 wrote: post #32

Earlier quoted context omitted.

This is microwave based. Those lines are well known by now and there are known routes within Europe (most notable Frankfurt London) and the US (NYC Chicago). However, microwave only works over short distances (FRA LON has multiple towers to cover the distance). Crossing the atlantic isn't possible. Shortwave could deliver a similar speedup over long distances. I'm a bit sceptical though. Don't the waves have to bounc…

I'd suspect the latency improvement is control over the entire path and not specifically about the propagation speed/delay. Getting your data across a long haul undersea fiber requires aggregating it with everyone else's data at a central point before it gets sent out optically. This adds latency. Even with the propagation variability of the wireless path you might be saving hundreds of nanoseconds.

There is some latency savings because the radio path is far straighter than the fiber path, even considering the ricochetting off the ionosphere and the earth. But the bulk of the latency savings comes from the fact that radio waves move at the full speed of light while photons through fiber only move at about 2/3 of that speed. So yeah, it works out to about a 10 ms savings on shortwave compared to fiber.
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