PAM4: New standard for high bandwidths

Addressing the new challenges of the DCI market

High technological transparency with PAM4 (Pulse Amplitude Modulation)

The rising demand for higher bit rate fiber connections has been around for more than a decade, setting a bar at currently 100/200G per wavelength to become a wide-adopted standard. As the technology evolves and becomes more mature, newer concepts and improvements appear on the market. The massive increase of optical pluggable interface deployments in the Data Center field drives the need for alternative cost-effective solutions for interconnection.

The increasing disaggregation of network functions and the shift from managed optical to open line systems (OLS) brings also new plug-able concepts to the market such as non-coherent DWDM using PAM4 modulation. However the main driver of this innvovation here is a cost of one connection and a need for technology transparency across different vendors.

The variety of currently available 100G DWDM transceivers comprise coherent ACO (Analog Coherent Optics) and DCO (Digital Coherent Optics). The latter features an integrated DSP with advanced SD-FEC, HD-FEC technology. These transceivers have significant reach advantages and suit the long haul transmisson purpose best. However Data Centers are usually deployed near each other, so that the physical connections are way shorter, approx. 15-25 km and hence these connections may demand another technical and economical approach in terms of their realisation. In the meanwhile DCI interconnection has been established as an independent, rapidly growing market niche over the last decade.

PAM4: The Technology

100G PAM4 relies on an analogue modulation rather than comprehensive Digital Signal Processing as in case with coherent transmission. Therefore it has lower manufacturing costs. The transceivers are intended to be used directly embedded with the end device like switches or a router instead of separate optical transport systems. However, in order to achieve sufficient transmission reach, separate optical equipment is required, which leverages the limited signal capabilities of the optical transceiver module. This additional equipment usually comprises DWDM MUX, Chromatic Dispersion Compensation, and an optical amplifier.

PAM4: The Solutions

Pan Dacom Direkt takes advantage of existing standardized industry components which have already proven their reliability over the years across different WDM application scenarios. Compatible with the SPEED-Booster to increase the transmission up to 120 km or even further by use of complementary SPEED-PREAMP at the end of the link of each site.

Successfully tested in different scenarios PAM4 is an effective way to reduce costs, and the consumption of space and power. Pan Dacom Direkt helps you to realize your PAM4 projects. Contact us today and learn more about our services and PAM4-compatible products.

Contact Person
Jörn Randt
Business Development Manager
+49 6103 834 83 180