Obviousness

Based on the provided information, a comprehensive obviousness analysis under 35 U.S.C. § 103 for US Patent 10,134,398 cannot be fully performed.

The "Prior Art" section explicitly identifies Rosenberger as the most relevant prior art. However, the U.S. Court of Appeals for the Federal Circuit (CAFC) has already ruled that Rosenberger "cannot anticipate the claims because 'it fails to disclose the limitations directed to exchanging messages while in a low power mode.'" This means that Rosenberger, by itself, does not render the claims of US10134398 obvious, particularly with respect to the "low power mode" limitation.

To establish obviousness under 35 U.S.C. § 103, one would typically need to identify:

1. A primary prior art reference that discloses most, if not all, of the limitations of the claimed invention.
2. One or more secondary prior art references that disclose the remaining limitations.
3. A clear motivation for a person having ordinary skill in the art (PHOSITA) to combine these references to arrive at the claimed invention, with a reasonable expectation of success.

The provided "Prior Art" section only details Rosenberger and explicitly states its deficiency regarding the "low power mode" limitation. It does not provide information about any other prior art references that could potentially fill this gap or disclose the "exchanging messages while in a low power mode" limitation. Without details on other relevant prior art references, including their content and any teachings that a PHOSITA would find combinable with Rosenberger, it is not possible to construct an obviousness argument or explain the motivation to combine them.