- XMax
xMax developed by
xG Technology, Inc. is a proposed radio frequency (RF ) modulation and encoding technology that will use individual or "integer" sinusoidal waves to convey information. While supposedly applicable to wired mediums such as copper and coaxial lines, the technology will apparently be introduced first as awireless communications technology, whereby its developers claim that it is capable of extending the range and reducing the transmit power compared to conventional approaches, including cellular technologies and fixed wireless approaches such as WiMAX.The company announced in July 2006 that with regional partners they are building a US-wide mobile phone service using xMax handsets with
VoIP starting in the second quarter of 2007 ( [http://mrtmag.com/news/xg_mobile_voip_071906/ xG Technology announces mobile VoIP program] ).Some current performance claims
* Antenna: One omnidirectional transmitter located on TV broadcast tower at a height of 850 feet.
* Range: 20 miles, covering the cities of
Miami andFort Lauderdale , including inside buildings.* Data rate: At least 10 Mbit/s throughout the coverage area.
* Spectrum used: A 6 kHz carrier on dedicated spectrum and 10 MHz of information-bearing spread spectrum in the unlicensed 900 MHz band.
* Interference: None, despite the presence of a TV transmitter on the same tower.
* Power: A maximum of 50 W for the carrier and less than 0.15 W for the information-bearing channels.
Patents
The published patents assigned to XG so far are:
* [http://www.freepatentsonline.com/patents/us/678/6782057.pdf US 6,782,057] "Very High Speed Digital RF Clipper/Modulator", filed Dec. 2002
* [http://www.freepatentsonline.com/patents/us/683/6839571.pdf US 6,839,571] "RF Shielding Design for Wireless High-Speed Internet Access System", filed May 2001
* [http://www.freepatentsonline.com/patents/us/690/6901246.pdf US 6,901,246] "Suppressed Cycle Based Carrier Modulation Using Amplitude Modulation", filed Jul. 2001
* [http://www.freepatentsonline.com/patents/us/696/6968014.pdf US 6,968,014] "Missing Cycle Based Carrier Modulation", filed Feb. 2000
* [http://www.freepatentsonline.com/patents/us/700/7003047.pdf US 7,003,047] "Tri-State Integer Cycle Modulation", filed Jun. 2004
* [http://www.freepatentsonline.com/patents/us/702/7023932.pdf US 7,023,932] "Modulation Compression Method for the Radio Frequency Transmission of High Speed Data", filed Jan. 2004See also
*
Shannon-Hartley theorem
*WiMax
*VMSK External links
* [http://www.xmax.com/ Portal for xMax]
* [http://www.xgtechnology.com xg Technology]
* [http://www.techworld.com/mobility/news/index.cfm?NewsID=4722&inkc=0 TechWorld.com] – xMax sparks low power wireless revolution
* [http://mrtmag.com/mag/radio_good_true/ MRT Magazine Features xMax - Too good to be true?]
* [http://hardware.slashdot.org/article.pl?sid=05/11/04/1343221&tid=193 New Technology Could Kill WiMax?]
* [http://xgtechnology.s2webtrix.com/Vision%20-%20xMax.pdf Joseph A. Bobier's Vision Statement about his brain child xMax]
* [http://www.theregister.co.uk/2005/11/09/xmax/ wireless voodoo?] Skeptical article in The Register
* [http://www.ka9q.net/xmax.html Phil Karn's] analysis of xG/xMax public demo and of xMax related patent for * [http://www.ka9q.net/tristate.html TriState Integer Cycle Modulation] . Phil (works for Qualcomm) is not impressed.
* [http://marconig.wordpress.com/ marconig.wordpress.com] Skeptical comments on xMax
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