Abstract: An access point diagnosis unit 201 controls a radio access terminal portion 213 included in the access point 100, to execute a test of connection with the access point 100. A switch within the access point selectively connects the radio access terminal portion 213, with any of an antenna and radio reception parts of the own access point 100. In accordance with a failing part, the failure information which contains the failing part and/or a failure content is transmitted from the radio access terminal portion 213 to the radio access terminal 108 (1) along a first path tracing the radio reception part connected by the switch, etc. of the access point 100, or (2) along a second path tracing the antenna connected by the switch and the other access point 101.

Abstract: An access point diagnosis unit 201 controls a radio access terminal portion 213 included in the access point 100, to execute a test of connection with the access point 100. A switch within the access point selectively connects the radio access terminal portion 213, with any of an antenna and radio reception parts of the own access point 100. In accordance with a failing part, the failure information which contains the failing part and/or a failure content is transmitted from the radio access terminal portion 213 to the radio access terminal 108 (1) along a first path tracing the radio reception part connected by the switch, etc. of the access point 100, or (2) along a second path tracing the antenna connected by the switch and the other access point 101.

Abstract: An information recording and reproducing apparatus wherein a light beam is applied onto an optical disk having pits previously formed in optical manner thereon. A tracking signal is detected from the light beam which has been modulated by the pits, and information is recorded by applying a record beam modulated by an information signal onto an area between one pit and the succeeding pit while tracking is effected by using the tracking signal.

Abstract: A device for optically tracking information recorded on an optical disc wherein a photodetector is disposed on the optical axis of an optical system for guiding diffracted waves to the photodetector. The origin of a fictitious X-Y coordinate system at the photodetector is placed on the above-mentioned optical axis, X- and Y-axes of the coordinate system are made parallel to and perpendicular to an information track having the information pits on the rotating recording medium, and the photodetector is divided into four equal parts. A first summation signal indicating the sum of output signals from the four parts of the photodetector is converted into a binary signal, and a difference signal between second summation signals each indicating the sum of output signals from a pair of photodetector parts facing each other with the origin of the coordinate system therebetween is converted into another binary signal.

Abstract: An optical information tracking apparatus for reproducing information by applying light beam onto a track on a rotating record medium, sensing the diffracted light beam thus generated by means of a photodetector and transforming the diffracted light beam into electrical signals, wherein the origin of said photodetector is aligned with the light axis of the optical system, the X axis is placed in parallel with the direction of said track, the Y axis is placed perpendicular to said track. Electrical signals are taken out respectively from photodetector elements which exist respectively in the first, second, third and fourth quadrants. A difference signal representing the difference between a signal which is the sum of the output signal from the first quadrant and that from the third quadrant and a signal which is the sum of the output signal from the second quadrant and that from the fourth quadrant as well as a sum signal representing the sum of output signals from the first to fourth quadrants are calculated.