An optical communication system comprising: a network element, the network element comprising: a passthru section (355, 356, 351, 352) for passing through a number of wavelength channels from an input optical fiber to an output optical fiber; an add/drop module for adding one or more wavelength channels for transmission to the output optical fiber and for dropping one or more wavelength channels from the input optical fiber; the network element characterized in further comprising: a configurable idle tone source for providing optical power at a set of idle tone wavelengths distributed across a spectral band used in the optical communication system, wherein the configurable idle tone source is communicatively coupled to the output optical fiber and the spectral band is divided into wavebands and each waveband is defined by the idle tones; and a controller for controlling the configurable idle tone source such that optical power is present in the output optical fiber at each one of the set of idle tone wavelengths; and the optical communication system further comprising: a network controller for selecting a wavelength channel from a pool of available wavelength channels to carry network traffic based on a weight assigned to each of the wavebands, wherein said weight is determined based on a spectral hole width generated by the set of idle tone wavelengths and the network controller is configured to perform load balancing of traffic channels among all the wavebands based on the weights; wherein each waveband starts with a corresponding idle tone wavelength and includes non-idle wavelengths between the corresponding idle tone wavelength and the next idle tone wavelength in the spectral band. a passthru section (355, 356, 351, 352) for passing through a number of wavelength channels from an input optical fiber to an output optical fiber; an add/drop module for adding one or more wavelength channels for transmission to the output optical fiber and for dropping one or more wavelength channels from the input optical fiber; the network element characterized in further comprising: a configurable idle tone source for providing optical power at a set of idle tone wavelengths distributed across a spectral band used in the optical communication system, wherein the configurable idle tone source is communicatively coupled to the output optical fiber and the spectral band is divided into wavebands and each waveband is defined by the idle tones; and a controller for controlling the configurable idle tone source such that optical power is present in the output optical fiber at each one of the set of idle tone wavelengths; and the optical communication system further comprising: a network controller for selecting a wavelength channel from a pool of available wavelength channels to carry network traffic based on a weight assigned to each of the wavebands, wherein said weight is determined based on a spectral hole width generated by the set of idle tone wavelengths and the network controller is configured to perform load balancing of traffic channels among all the wavebands based on the weights; wherein each waveband starts with a corresponding idle tone wavelength and includes non-idle wavelengths between the corresponding idle tone wavelength and the next idle tone wavelength in the spectral band. a configurable idle tone source for providing optical power at a set of idle tone wavelengths distributed across a spectral band used in the optical communication system, wherein the configurable idle tone source is communicatively coupled to the output optical fiber and the spectral band is divided into wavebands and each waveband is defined by the idle tones; and a controller for controlling the configurable idle tone source such that optical power is present in the output optical fiber at each one of the set of idle tone wavelengths; and the optical communication system further comprising: a network controller for selecting a wavelength channel from a pool of available wavelength channels to carry network traffic based on a weight assigned to each of the wavebands, wherein said weight is determined based on a spectral hole width generated by the set of idle tone wavelengths and the network controller is configured to perform load balancing of traffic channels among all the wavebands based on the weights; wherein each waveband starts with a corresponding idle tone wavelength and includes non-idle wavelengths between the corresponding idle tone wavelength and the next idle tone wavelength in the spectral band.