Upgradable WDM system
US8750722B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 2010 |
| Grant date | Jun 10, 2014 |
| Priority date | — |
| Expiry date | Jun 5, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/0257
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Consistent with the present disclosure, a wavelength division multiplexed (WDM) optical communication system including on-off-keying (OOK) transmitters, for example, may be upgraded to include advanced modulation format transmitters, such as quadrature phase shift keying (QPSK) transmitters. Rather than replace all the OOK transmitters with QPSK transmitters at once, each OOK transmitter is replaced with a lower rate modulation format transmitter, such as a binary phase shift keying (BPSK) transmitter, as capacity needs increase. The BPSK transmitters supply (BPSK) optical signals that are more tolerant of noise caused by cross phase modulation (XPM) induced by OOK signals. Accordingly, such BPSK optical signals have fewer associated data detection errors in the receiver. Moreover, BPSK modulated optical signals induce little XPM-related noise in co-propagating QPSK modulated optical signals. Thus, once the OOK transmitters have been replaced with the BPSK transmitters, the BPSK transmitters may be replaced with QPSK transmitters or controlled to output QPSK modulated optical signals, as capacity need further increase, and such QPSK modulated optical signals may be transmitted with…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.