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 a wireless 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 (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 and Fort 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:

• US 6,782,057 Very High Speed Digital RF Clipper/Modulator, filed Dec. 2002
• US 6,839,571 RF Shielding Design for Wireless High-Speed Internet Access System, filed May 2001
• US 6,901,246 Suppressed Cycle Based Carrier Modulation Using Amplitude Modulation, filed Jul. 2001
• US 6,968,014 Missing Cycle Based Carrier Modulation, filed Feb. 2000
• US 7,003,047 Tri-State Integer Cycle Modulation, filed Jun. 2004
• US 7,023,932 Modulation Compression Method for the Radio Frequency Transmission of High Speed Data, filed Jan. 2004

See also

• Shannon-Hartley theorem
• WiMax
• VMSK

External links

• Portal for xMax
• xg Technology
• TechWorld.com – xMax sparks low power wireless revolution
• MRT Magazine Features xMax - Too good to be true?
• New Technology Could Kill WiMax?
• Joseph A. Bobier's Vision Statement about his brain child xMax
• wireless voodoo? Skeptical article in The Register
• Phil Karn's analysis of xG/xMax public demo and of xMax related patent for *TriState Integer Cycle Modulation. Phil (works for Qualcomm) is not impressed.
• marconig.wordpress.com Skeptical comments on xMax