Reuse and compatibility with P802.3ba sub layers– 40GBASE-LR4 vs. 40GBASE-xR Key to Architecture Diagram 1. Identical Specification and Implementation with P802.3ba 40GBASE-LR4 (clauses 80-82, clause 83 for PMA(4:4)). 2. Specification Reuse from P802.3ba. While a 40GBASE-R PMA(4:1) is not required to support any P802.3ba PMD, clause 83 fully specifies how the PMA(4:1) will behave 3. New PMD specification required for 40GBASE-xR OTN Support 40GBASE-LR4 vs 40GBASE-xR The information content (ITU-T term = “characteristic information”) of an 802.3ba signal is comprised of the PCS lanes. The way that those PCS lanes are mapped or sequenced onto physical lanes (as long as
If you spend much time in the company of network technicians you will eventually hear them say something like “That’s Layer 2 only” or “That’s our new Layer 4 switch”. The technicians are referring to the OSI (Open System Interconnection) Reference Model. This model defines seven Layers that describe how applications running upon network-aware devices may communicate with each other. The model is generic and applies to all network types, not just TCP/IP, and all media types, not just Ethernet. It is for this reason that any network technician will glibly throw around the term“Layer 4” and expect to be
The demand for increased bandwidth is constant, and to avoid investing huge amounts in new systems, most operators, if not all of them, are looking to re-use their existing fiber infrastructure. This, however, poses a problem because the standard train of “1” and “0”, called on-off keying (OOK), simply can’t be pushed any further on most of the installed bases. To resolve this issue, system vendors have introduced higher bits per symbol modulation formats. One of the most popular ones is called DP-QPSK: dual polarization quadrature phase shift keying. Unfortunately, direct detection used with OOK doesn’t work with such
This article examines the options for the modulation formats for serial optical transmission of 100 Gb/s and beyond.
The first part covers classical binary electronic time division multiplexed 100 Gbit/s NRZ systems, operating a highest speed, and mature product solutions of system vendors running at lower symbol rates which are using quaternary phase shift keying and polarization division multiplexing, coherent technologies and digital signal processing in the receiver.
The second part covers the next generation of transmission systems carrying data at channel bitrates higher than 100 Gbit/s, e.g. 400 Gbit/s up to 1 Tbit/s or even beyond, which may apply higher constellation M-QAM modulation of a single carrier or multiple electrical carriers and optical superchannels which also form one WDM channel.
Here we list some of the international and national standards that govern optical cable characteristics and measurement methods. This may not be a complete list, but it covers most of the standard bodies. :: International Standards There are two main groups that cover international standards: IEC and ITU. 1. IEC – International Electrotechnical Commission IEC is a global organization and it makes international standards that covers all electrical, electronic, and related technologies. These international standards serve as a basis for national standardization. IEC is composed of many technical committees. Each committee prepares technical documents on specific subjects. For example,
