Cell phone companies have been scrambling to reduce the amount of dangerous radiation produced from phones and headsets, but a Texas-based company says many telecom companies left something out: credit for a ground-breaking patent now in wide use.

The Dallas litigation firm of Reyes Bartolomei Browne has filed patent-infringement litigation on behalf of Tyler, Texas-based DownUnder Wireless, LLC, against 21 companies. Defendants in the lawsuit including Samsung, as well as service providers including AT&T, Sprint Nextel, T-Mobile and Verizon. Retailers named in the litigation include Amazon.com, Best Buy, Target, Wal-Mart and others.

According to the lawsuits, DownUnder invented a design that calls for cell phone antennas to be placed in the base of the phone rather than the traditional placement in the earpiece near the user's head. DownUnder's design, which was awarded U.S. Patent No. 6,741,215, also angles the antenna away from the user. Both features work together to reduce the amount of potentially harmful radiation that could be transmitted into an individual's brain.

Researchers have already linked cell phones to a biological effect on the brain. Before the end of the year, the World Health Organization (WHO) is expected to publish the results of a decade-long investigation into links between cell phone radiation and brain cancer. Published reports say the WHO study will show a "significantly increased risk" of some brain tumors related to long-term usage of mobile phones.

Writes Wired magazine: The effect of cellphone radiation on users has become an important issue for scientists, environmental organizations and cellphone industry groups. In the United States, the Federal Communications Commission sets the acceptable radiation standards for cellphones. As part of the device certification process, all handset makers have to offer a certificate from an independent lab that show how the device rates.

Children have much thinner skull bones and their brains have a lot more fluid, so their brain tissues would likely absorb twice more radiation compared to an adult’s brain. But cellphone radiation standards set by the government remains the same for both groups.