GPON Docela dobré https://www.broadband-forum.org/download/MR-246.pdf str. 16 - přenos základy - rozdělení rámců a jejich skládání str. 22 - záhlaví a ovládání downstreamu GPON ITU-T Specifications strana 15 System requirements–G.984.1 Physical (PMD) layer–G.984.2 Protocol (TC) layer–G.984.3 Management (OMCI) layer–G.984.4, supersededby G.988 Downstream and upstream: non-return to zero (NRZ) coding. https://scholar.google.cz/scholar?q=nrz+optical+modulation&hl=en&as_sdt=0&as_vis=1&oi=scholart gigabit PON transmission convergence (GTC) adaptační podvrstva GEM GPON encapsulation mode G.984.3 str. 19 - alokace místa pro upstream a strana je to číslíčko dole na stránce 8.1 Downstream GTC frame structure strana 37 str. 76 a následující - úvahz o časech FEC str. 93 intro - BER - změna FEC str. 93 a dál, nohoře v PDF str. 101 skrambler str 105 mapping ethernet frame to GPON str. 137 TAdz je skrambler http://www.ieee802.org/3/10G_study/public/june99/bottorff_1_0699.pdf na straně 8 The downstream GTC frame is scrambled using a frame-synchronous scrambling polynomial. The polynomial used is x7 + x6 + 1. This pattern is added modulo two to the downstream data. The shift register used to calculate this polynomial is reset to all-ones at the first bit following the PSync field of the PCBd, and is allowed to run until the last bit of the frame. -------------------------------------------- EPON nejdříve Ethernet, ethernet frame, hub, switch , pak porovnat splitter a hub, splittre a switch vysvětlit, proč je EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. naprostá kravina EPON https://www.electronicdesign.com/unused/article/21799542/whats-the-difference-between-epon-and-gpon-optical-fiber-networks EPON The Institute of Electrical and Electronic Engineers (IEEE) developed another newer PON standard. Based on the Ethernet standard 802.3, EPON 802.3ah specifies a similar passive network with a range of up to 20 km. It uses WDM with the same optical frequencies as GPON and TDMA. The raw line data rate is 1.25 Gbits/s in both the downstream and upstream directions. You will sometimes hear the network referred to as Gigabit Ethernet PON or GEPON. EPON is fully compatible with other Ethernet standards, so no conversion or encapsulation is necessary when connecting to Ethernet-based networks on either end. The same Ethernet frame is used with a payload of up to 1518 bytes. EPON does not use the CSMA/CD access method used in other versions of Ethernet. Since Ethernet is the primary networking technology used in local-area networks (LANs) and now in metro-area networks (MANs), no protocol conversion is needed. There is also a 10-Gbit/s Ethernet version designated 802.3av. The actual line rate is 10.3125 Gbits/s. The primary mode is 10 Gbits/s upstream as well as downstream. A variation uses 10 Gbits/s downstream and 1 Gbit/s upstream. The 10-Gbit/s versions use different optical wavelengths on the fiber, 1575 to 1580 nm downstream and 1260 to 1280 nm upstream so the 10-Gbit/s system can be wavelength multiplexed on the same fiber as a standard 1-Gbit/s system. Porovnání EPON a GPON - nic moc https://www.eetimes.com/epon-vs-gpon-a-practical-comparison/# OFA - dobré https://www.youtube.com/watch?v=UYaEINQA7QI&wide ********************** tohle dál se naučte z EPONu česky http://access.feld.cvut.cz/view.php?cisloclanku=2009050003 je to staré, ale dobré a je tam použitelný popis EPONu zhruba v polovině je Protokol MPCP a dále je popis rámce, kde v preambuli jsou ty informace pro optiku ****************************************************** a k tomu potřebujete znát Ethernetový rámec https://ssz-ai-hk-3.readthedocs.io/en/latest/tech/7.html a máš to v tom, co jsi ukazoval 3A - protokol RSTP ale to využijete i v Datových sítích The preamble of an Ethernet packet consists of a 56-bit (seven-byte) pattern of alternating 1 and 0 bits, allowing devices on the network to easily synchronize their receiver clocks, which is followed by the SFD to mark a new incoming frame. docela dobrý Ethernet frame https://www.geeksforgeeks.org/ethernet-frame-format/ Gigabite frame https://www.cse.wustl.edu/~jain/cis788-97/ftp/gigabit_ethernet/index.html OFA má mnoho videí atd. atd. https://www.ofacom.cz/ofa-pedie/vyukova-videa/ výrobce diod atd. https://www.innolume.com/products/products.htm?gclid=CjwKCAiAnIT9BRAmEiwANaoE1ej1MmGn038l8s9_us_mtpgcOwhns6SURlmh5FJ863bRy01HZVxvGRoCdWoQAvD_BwE eye diagram - pro měření http://users.encs.concordia.ca/~assi/courses/encs6811/epon_wiley.pdf str. 19 je ten rámwec strana 15 8.3.3 Multi-Point Control Protocol (MPCP) https://www.piedmontscte.org/resources/jul2012/Introduction-to-EPON-v1.0.pdf strana 14 Ethernet rámec file:///C:/Users/kubalik/Downloads/Introduction%20to%20IEEE%20802.3av%2010Gbits%20Ethernet%20Passive%20Optical%20Networks.pdf https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://lafibre.info/free-les-news/10gbs-limite-a-8gbs/%3Faction%3Ddlattach%3Battach%3D59868&ved=2ahUKEwiHjvfxppaKAxVb0wIHHX0EGaIQFnoECCMQAQ&usg=AOvVaw0KvTtR2WH29UPQorMF5B1B