NodeConf EU 2017: Building a radio data network with Node.js

A fun and nerdy talk introducing the audience to the concept of encoding bits onto a radio wave. We’ll learn how to pack data tightly to achieve high bandwidth and how to recover from data loss without retransmission. The theories will be put to the test using a Software Defined Radio built using nothing but Node.js and a few radio parts.

Transcript

1. @wa7son
2. Who am I? • Thomas Watson • Open Source developer at github.com/watson • Node.js Engineer at Elastic • Member of the Diagnostics Working Group under the Node.js Foundation • Tweets as @wa7son @wa7son
3. Radio Data Network Building a @wa7son With Node.js
4. In Software Reimplementing WiFi @wa7son
5. Software Defined Radio @wa7son
6. @wa7son Expensive: $5,000+
7. @wa7son • DVB-T • DAB • FM Marketed as TV / radio tuner for: Contains a Realtek RTL2832U chip Supports approx. 24 MHz – 1766 MHz Hackable! Cheap: $10 - $20
8. @wa7son Funded by: Affordable: $299
9. Radio 101 @wa7son
10. @wa7son
11. @wa7son
12. @wa7son
13. @wa7son
14. Demo Time Modulation @wa7son
15. “In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.” @wa7son - Wikipedia
16. @wa7son
17. @wa7son
18. @wa7son Girls
19. @wa7son
20. @wa7son
21. Digital Modulation @wa7son
22. @wa7son 0110101110…
23. @wa7son On/Off Keying (OOK)
24. @wa7son Symbols 0: No voltage 1: High voltage Symbol rate = Bit rate 1 bit = 1 symbol
25. The Three Basic Modulation Types @wa7son
26. @wa7son 56K = 56,000 bits/sec 8000 baud = 8,000 symbols/sec 56,000/8,000 = 7 bits/symbol
27. QAM Quadrature Amplitude Modulation One Modulation To Rule Them All @wa7son
28. Remember Trigonometry? @wa7son
29. What is a sine wave? @wa7son
30. What is a sine wave? @wa7son
31. The Unit Circle @wa7son
32. 4 QAM Modulation @wa7son
33. 16 QAM Modulation @wa7son
34. 16 QAM Modulation @wa7son Practical Signal Processing, ISBN: 978-1-107-41182-1
35. Error Correction @wa7son
36. • 1949 - Golay Codes (Voyager 2: Jupiter and Saturn missions in ’79-’81) • 1950 - Hamming Codes (ECC memory) • 1954 - Reed-Muller Codes (Mariner spacecraft in ’69-’77) • 1960 - Reed-Solomon Codes (Voyager 2 in ’77 + CD, DVD, Blueray, Barcodes) • 1993 - Turbo Codes (3G/4G e.g. UMTS+LTE + deep space satellite communication) Error-Correction Codes @wa7son
37. npm install @ronomon/reed-solomon @wa7son
38. Demo @wa7son
39. References github.com / watson / monster-drift github.com / mappum / node-hackrf greatscottgadgets.com / sdr @wa7son @wa7son
40. @wa7son github.com/watson Thank you