Optical Networking Best Practices Handbook

8.4. SUMMARY AND CONCLUSIONS

At this point in the book, it is assumed that the reader is comfortable with the basic concepts of a public telecommunications network, with its separate functions of transmission and switching, and is aware of the context for the growth of broadband traffic. No specific prior knowledge is assumed about hardware or software technologies.

Figure 8.39. An Ethernet PON provides downstream and upstream transmission. A passive optical splitter divides downstream signals among up to 32 fibers. All subscriber terminals receive all packets, but they discard packets addressed to other terminals, as in LANs. Each terminal has an allocated time to transmit upstream signals; so packets from different terminals do not overlap. In single-fiber systems, upstream transmission is at 1300 nm, and downstream at 1490 nm.

The first section of this chapter provides an introduction to the SONET standard. Standards in the telecommunications field are constantly evolving. Information on SONET is based on the latest information available from the Bellcore and ITU-T standards organizations [1].

Section 8.2 discusses synchronous transmission standards in world public telecommunications networks. It covers their origins, features, applications, and advantages, as well as their impact on network design and synchronous signal structure [2].

Furthermore, this chapter concentrates ...