Patent ID: 9065698
Filing Date: 2015-06-23
Classification: H04L

Abstract:
1. A communications apparatus comprising: a data communicating unit configured to perform data communication; and a frequency channel detecting unit configured to (i) detect a frequency channel from a time interval between two pulses of a signal with signals for corresponding frequency channels overlapped, the frequency channel being detected with reference to a table which previously associates a time interval between two pulses in a wake-up signal with each of the frequency channels, and (ii) cause said data communicating unit to perform the data communication over the detected frequency channel, the detected frequency channel being the frequency channel of the wake-up signal, wherein the detected frequency channel indicated by the interval between the two pulses is selected from among the frequency channels by a second communications apparatus which is different from said communications apparatus that is a first communications apparatus, the wake-up signal is generated of wake-up information including at least address information by pulse interval modulation based on a code assigned to the frequency channel over which the wake-up signal is transmitted, the address information specifying a partner communications apparatus performing data communication with the second communications apparatus, said frequency channel detecting unit is configured to: the first communications apparatus is (i) a part of an apparatus included in a sensor network and obtaining information and (ii) different from the second communications apparatus which transmits the wake-up signal to establish the data communication with the first communications apparatus, said communications apparatus further comprises a frequency converting unit configured to generate, from an input signal received via an antenna and including radio-frequency signals for the corresponding frequency channels, a low-frequency signal including low-frequency signals each transmitted on a corresponding one of the radio-frequency signals, said frequency channel detecting unit is configured to determine, from the generated low-frequency signal, whether or not the wake-up signal is already transmitted over the detected frequency channel among the frequency channels, and said data communicating unit is configured to (i) perform the data communication with the second communications apparatus when said frequency channel detecting unit detects the transmission of the wake-up signal, and (ii) avoid the data communication when said frequency channel detecting unit does not detect the transmission.