A label swapping technique using synchronous phase modulation without wavelength conversion

We demonstrate a label swapping technique for differential-phase-shifted-keying (DPSK) encoded labels using synchronous phase modulation (SPM). For the first time label erasure and insertion are performed in a single step without a need for wavelength conversion. The receiver sensitivity penalty of label swapping is limited to 1 dB when the timing mismatch between the new label and old label is kept from −18% to 18%.