Reception device and method of detecting supervisory control signal

A method of detecting a supervisory control signal, the method comprising:

• receiving a wavelength-multiplexed optical signal so as to generate an electrical signal of the wavelength-multiplexed signal, by a receiver;
• filtering with a digital signal processor including a plurality of electrical filters including a first electrical filter, a second electrical filter and a third electrical filter, the filtering including
• first filtering with the first electrical filter a first portion of the electrical signal corresponding to
• a specific wavelength of the wavelength-multiplexed optical signal,
• second filtering with a second electrical filter a second and only a portion of the electrical signal that corresponds to only a portion of a first of adjacent wavelength of the wavelength-multiplexed optical signal that is adjacent to the specific wavelength from the wavelength-multiplexed optical signal,
• third filtering with a third electrical filter a third portion of the electrical signal corresponding to a third portion of the electrical signal that corresponds to only a portion of a second adjacent wavelength of the wavelength-multiplexed optical signal that is opposite the first adjacent wavelength and adjacent to the specific wavelength,
• a bandwidth of the first electrical filter is greater than a bandwidth of the second electrical filter and a bandwidth of the third electrical filter;
• analyzing outputs of the first electrical filter, the second electrical filter and the third electrical filter to obtain identification numbers of a superchannel including the specific wavelength, the first adjacent wavelength, and the second adjacent wavelength,
• comparing the obtained identification numbers;
• and
• recognizing a position within the superchannel of the specific wavelength based on the comparison of the identification numbers.