Mesh Telephony

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