Mesh Telephony
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http://www.youtube.com/watch?v=Z3p2BYFXBkU&list=UUD7iJhnqGVKyjoXavxJrFRA&index=9&feature=plcp
http://www.youtube.com/watch?v=K819ggBvkU0&feature=related
- Complementary to Towers and Satellites
- 2.4Ghz
- 868 MhZ
- FCC and
- licensing is national
- ISM 915 MhZ - available in enough countries
- WiFi was illegal in many countries before large user base
- $1/4M for a single tower in africa - defending tower and diesel generator
- Key: vast majority of calls are in local areas
- Store and forward - Serval rhizome
- Single house for WiFi
- For 10 house range - 1% of people need to be on
- 10kb codec 2 1400 bps for clear voice - CODEC2, 175bytes per second with no interframe compression
- 915MHz 100kbit = +19db versus 2.4GHz wifi @1mbit
- ~9db is from band propagation differences
- +10db from 10x lower bit rate = 10x more energy per bit
- 6.02db = 2x range. 19 ~= 2x2x2 = 8x range
- "a few hundred metres" in urban/indoors
- "one to a few km" in clear line of site/outdoors
Cost
- $100-300 cost (small vs. tablet)
- $100k - custom phone from a phone pro
Design
- CPU - 600 MHz
- Touch screen
Applications
- GSM, 3G
- CDMA
- Mesh phone - medical diagnostic. Remote hospital.
- Open MRS
- pulse-oxy - $1-10 - pulse rate and oxygenation
- bloodpressure cuff < $100 - blood pressure - difference between difference between systolic and diastolic via doppler ultrasound, can get difference, but not absolute
- imaging ultrasound = ? <$500 - natal care, etc.
- on the open market now, cheap imaging ultrasound is $4k
- $10 - $50k for hospital-style units
- phone + pulseoxy + imaging ultrasound = ~$500 at low end, <$1k at high-end
Political
- Prior to Industrial Revolution, corporations could not produce better than a cottage - but could do it more times (without economy of scale)
- Now, in a back yard, one can do what a multi-billion dollar industry can do
- For a brief time in global history, where advantage of economy of scale clearly outweighed the disadvantages
- We give up a bit of sovereignty for a reduced cost of goods
- Peak of modernist movement/attitude 1960 - value of centralization/economy of scale vs individual effort
Phones
- Huawei IDEOS X1
- Samsung Galaxy Tab
- Can root - android and