The technology works by identifying the unoccupied white spaces to transmit and receive wireless signals.

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The concerns stem from the emissions of radio frequency (RF) radiation by both the handsets and the base stations that transmit and receive the signals.

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Use of these white spaces will allow devices to transmit and receive wireless signals for applications such as broadband access for rural communities, Wi-Fi-like services or new 'machine-to-machine' networks.

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MicroChips' titanium-encased device is about the size of a pager and has a novel flat antenna on one side that can transmit and receive radio signals from several feet outside the body.

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Each of the 20 transceivers or "nodes" can transmit and receive to the other 19, meaning there can be up to 380 measurements (20 times 19) of radio signal strength within a short period of time (the transceivers transmit one after the other).

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This causes the cells in the eye that receive and transmit light information to die over time.

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But those bootleg versions have a more limited frequency range and can only receive signals, not transmit them.

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