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TOBB ET Ü B İL 55 2 Internet Architecture. FTTx. Acronmy. The FTTx acronym is widely understood as Fibre-to-the-X, where X can denote a n umber of destinations. These include Home (FTTH), Premise (FTTP), Curb (FTTC), Building (FTTB), Home (FTTH), User (FTTU) and Node (FTTN).
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Acronmy • The FTTx acronym is widely understood as Fibre-to-the-X, where X can denote a number of destinations. • These include Home (FTTH), Premise (FTTP), Curb (FTTC),Building (FTTB), Home (FTTH), User (FTTU) and Node (FTTN). • Clearly, however, thereare overlaps in meaning. FTTP is similar to FTTB, and FTTC resembles FTTN. • How fiberoptics are made animation
Worldwide BB Subs. (Millions Forecast Continuous growth of subscribers 20 (MPEG2) Broadband services Continuous BW requirements growth Mbps Mbps P2P/PON Broadband Access technologies FTTH Continuous capacity growth in the “last mile” VDSL2 FTTC ADSL2+ ADSL 2000 2005 2010
Fibre-to-the-Home (FTTH) • Afibre-optic communications path that extends from the operator’s switchingequipment to at least the boundary of the home living space or business officespace. • The definition excludes those architectures where the optical fibre terminatesbefore reaching either the home living space or business office space and where theaccess path continues over a physical medium other than optical fibre.
Fibre-to-the-Building (FTTB) • A fibre-optic communications path that extends from the operator’s switchingequipment to at least the boundary of the private property enclosing the home(s)or business(es). • In this architecture, the optical fibre will terminate before reachingthe home living space or business office space. The access path will then continueover another access medium – such as copper or wireless – to the subscriber.
Fibre-to-the-Node (FTTN) • A fibre-optic communications path that extends from the operator’s switchingequipment to a point further away from the subscriber than that defined in FTTH or FTTB. • This can include the Curb or Cabinet (FTTC) or some other ‘intermediate’ pointbetween the central office and the subscriber. The access path between theintermediate point and the subscriber is not optical fibre but another transmissionmedium, such as copper or wireless.
PONs & AONs • For operators rolling out FTTH and FTTB, they have a number of networkarchitecture options to consider. These options can be divided into two broadcategories: • PONs (passive optical networks), which require no active electrical componentsbetween the end-user and the central office; • AONs (active optical networks), where active electrical components areinstalled between the end-user and the central office. It is called Active Ethernet sometimes.
Types of PON APON: ATM based PON specification Designed by Full Service Access Network (FSAN) group BPON: Broadband PON standard ITU-T G.983.1 through G.983.10 ;Up to 622 Mbps downstream and 155 Mbps upstream EPON (a.k.a. GE-PON): Ethernet based PON designed by IEEE 802.3ah. Up to 1 Gbps downstream and 1 Gbps upstream.
Types of PONs GPON: Gigabit PON standard ITU-T G.984.1 through G.984.4 Up to 2.5 Gbps downstream, 1.25 Gbps upstream Newest standard, with highest bandwidth GPON Evolution GPON capacity today is 2,5/1,25Mbps. Operators may promote the service as ”up to1000Mbps”. Next generation will have 4 times the capacity and is expected to lanch 2012 The third generation will likey be WDM-PON -a single wavelength to each subscriber. Price erosion is expected to be higher compared to Active Ethernet due to newer technology and rapid ramp up in production volumes
PON Architecture • The PON architecture comprises an optical line terminal (OLT), based in the centraloffice, and the optical networking terminal (ONT) – sometimes referred to as anoptical network unit (ONU) – based on the customer premise. • To connect the OLT and the ONT with data, a fibre-optic cable is used to carry awavelength downstream. • By using a passive splitter (which splits the light wave)the downstream data originating from the OLT can be distributed.
PON Architecture • A series ofpassive splitters may have to be located within the PON architecture to reach therequired number of customers. This is a point-to-multipoint architecturesometimes described as a tree.
AON • It is called Active Ethernet. An active optical network (AON) comprises an active Ethernet switch that acts asthe intermediate point between the central office and the end-user. • By contrast, AON supporters say that one of the key advantages they have over aPON architecture is that it is much easier to remotely manage the network toguarantee bandwidth throughput toindividual customers. That’s because an AONis ‘intelligent’ and the PON is ‘dumb’.
AONs versus PONs AON advantages • User dedicated BW, Higher symmetrical bandwidth capability. • Greater bandwidth scalability. The ability to swap Ethernet line cards in thecentral office to increase bandwidth capability makes AONs far moreflexible than PONs. By virtue of an active Ethernet switch, AONs have moresophisticated remote management tools than PONs to deliver pre-agreedbandwidth rates to specific customers as and when they are required
AONs versus PONs • To run and manage a PON, more expensive IP Layer 3 CPEs are required forthe customer to access the services he or she has subscribed to; these CPEsalso need to have Layer 3 security functionality.By contrast, an AONoperator can move Layer 3 management into the distribution layer (Layer 2)and take advantage of cheaper Layer 2 CPEs. This also makes networkmanagement easier as the AON operator doesn’t have to monitor every CPE.
AON disadvantages • Needs to have energy at building. • Higher opex costs to maintain a multitude of remote active Ethernet switches.Potential difficulty of finding suitable locations for the Ethernet switches(which need to be fed with power). This is particularly true for alternative operators with no existing active elements in their access network. • Higher capex costs associated with point-to-point architectures
