Presentation on theme: "Recent Developments in PON Systems Standards in ITU-T"— Presentation transcript:
1 Recent Developments in PON Systems Standards in ITU-T Dave FaulknerQ2/15 Rapporteur
2 Contents The Role of the ITU in Standardization ITU-PON Access System Fixed Access TimelinesFiber Access SystemsB-PONG-PONRecent Updates to B-PON and G-PON standardsOutlookConclusions
3 The Role of the ITU in Standardization The International Telecommunication Union (www.itu.int),headquartered in Geneva, Switzerland,within United Nations Systemgovernments and the private sector members coordinate global telecom networks and services.ITU-T Recommendations, such as G.982 (PON), G.983.x (Broadband-PON) and G.984.x (Gigabit-PON) are agreed by consensus and provide a framework for the implementation.Question 2 on “Optical systems for fiber access networks” is the focus of activity for PON systems in the ITUFrom an operator's perspective, cost reduction is the key motivator for standardsInteroperability and second sourcing are also important for a de-risking the investment.From a vendor's perspective it is the assurance that products will satisfy the needs of a world-wide market.
5 Fixed Access Timelines 18 M ADSL2plus20 M VDSL2 Cab100 M VDSL2 DP1 GBE10 GBEG-PONWDM/PON10 G-PON8M ADSLInvestment/loss Region.Early introductionOf competitivetechnologyfor premiumservicesProfitable Region“Cash Cow”Technology ‘uncompetitive’Migration to new technologyor loss of market share56k modemVDSL Plateau?ADSL Plateau?BitRate10G1G100M10M1M100k10k1kHong Kong Broadband Network already offers 1Gbit/s access to residential users and BT offers an SHDS system now.There are substantial deployments of 100 Mbit/s access systems in some countries (e.g. Sweden, The Netherlands)Les Humphrey (BT/DSL ITU rep) comment “Historical speed increase are based upon reuse of existing lines and minimal investment in infrastructure. VDSL and fiber will require large investments in infrastructure which is likely to slow up the rate of increase”.Price declines with speed increases mean that the turnover is likely to remain static. Some value-add can be expected if a new ‘killer’ service emerges.Source: “Next generation Broadband in Europe: The Need for Speed” Heavy Reading Report, Vol. 3 No 5 March 2005See Notes
6 Fiber Access Systems- BT Perspective Fiber to the premises (P2P, from CO)Existing deployment for businesses over 3km and 2 Mbit/sIncremental deployment has high cost and long ‘lead’ timesChurn leads to stranded assetsDuct network insufficient for ubiquitous coverageWhile copper stays in placeFiber to the cabinet/VDSL2In BT trialsReuse of copper offers lower CapEx than FTTPOpEx costs under investigation in trialsCapacity is reach dependentSubtended MSANs or Fiber could solve thisCO fed fibers are most likely to be usedFiber to the premises (PON)G-PON (e.g. 2.4/1.2 Gbit/s), favoured for limited use in 21CNLower CapEx and OpEx than (P2P) if deployed over whole areasPON/OLT can act as a traffic concentrator (QoS, possible)
7 Active Optical Networks (P2P from COs/Cabs) - an alternative to PON AONs deployed in parts of Europe by CLECs, approx 500k subscribersP2P can give more capacity than shared access systemsBetter future-proofingUpgradesOnly affect one customerRequire no changes to external plantShared access systems seem to date quicklyE.g. Cable systems are difficult to upgrade, outside plant needs changingShared access not needed with SDV (no broadcasting needed now)Service and Network Management is a concern for operators/standardsExcept SDH when used for direct connection to customersG.985 adds limited network management functionality to Ethernet over fiber
8 B-PON Broadband passive optical network Transport capability based upon 53 byte ATM cells with mini-cells in transmission convergence (TC) layerDownstream ‘grants’ control the sending of upstream cellsRates up to 620 Mbit/s symmetricaland 1240/622 asymmetrical have been standardisedTransport capabilitynative ATMTDM (T1/E1) by circuit emulationEthernet by emulationBusiness or home32 way split (some systems 64 way)multi-casting possibleStandardised in G983.x series in ITU
10 Broadband PON Frame Format Downstream Frame = 56 cells of 53 bytesPLOAMCell 1ATMCell 1ATMCell 27PLOAMCell 2ATMCell 27ATMCell 54Physical layer operations and maintenance (PLOAM) cellsgive grants to upstream ONUs.Maximum rate of 1/100ms. Each contains 27 grantsUpstream Frame = 53 cells per frame (aligned by ranging)The encryption algorithm recommended is the Advanced Encryption Standard (AES). It is a block cipher that operates on 16 byte (128 bit) blocks of data. It accepts 128, 192, and 256 byte keys. This algorithm is described in documents published by the National Institute of Standards and Technology (NIST) in the USA.Normal ranging procedure.The maximum round-trip delay of about 200 µs (equal to 20 km optical fiber) is equal to 69 cells (56 byte-cells), so the equalization delay at the ONU should cover the delay variation from 0 to 32 000 bits (at Mbit/s).Before initiating the ranging process, the OLT sends an Upstream overhead message to indicate to new ONUs which overhead they have to use. Then the OLT initiates the ranging process. The upstream data grants are queued. After the ranging grant leaves the OLT, an upstream window is opened to receive a ranging PLOAM cell. The additional ranging grants or PLOAM grants, allow the ONU optical power set-up and/or the OLT threshold control or amplitude finding etc.ATMCell 1ATMCell 2ATMCell 3ATMCell 533 overhead bytes for guard time, preamble and delimiter
11 ONU Management and Control Interface A management channel between OLT and ONUPart of the baseband signalCarried in the PLOAM cellsPhysical layer operations and maintenanceAccessible by the Network Operator via the element manager on the OLTAllows the PON and services to be configured and managedAuthentication, configuration and fault mangnetService management POTS, Video on demand, WLAN,VLAN, Ethernetetc
12 Dynamic Bandwidth Allocation A powerful conditional access mechanismallows queues at the customer-ends of the PON to be served according to the priority assigned to the traffic flowranging from TDM circuit emulation through to best effort (using spare capacity).also offers 'concentration on the fly',statistical gain for packet-based serviceslikely to become increasingly important as users of IP begin to expect QoS-based services on congested networksAllows bursts close to the maximum PON rateGood for high speed packet transmission
13 B-PON Interoperability Events WhereWhenHostFunctionalityMakuhari, JapanMarch 9-11, 2004NTT/FSAN meetingTC layer with EthernetGeneva, SwitzerlandJune 2-4, 2004ITU ‘All Star Workshop’TC Layer with EthernetSan Ramon, CA, USASept 27, 2004SBC/FSAN meetingVoice and fax services via GR-303Chicago, USAJune 7-9, 2005TIA/ITU, SUPERCOMMVoice service via GR-303H-D IPTV and optical RF Video
14 G.983.3 Enhancement Band Downstream bands for B-PON 1490 (basic band) , 1550 (enhancement band)New laser was required for nm bandEnhanced services in nm bande.g. for broadcast servicesnm upstream band retainedBlocking filters and/or triplexer needed for ONT’sTo receive additional service wavelength(s)e.g.Receive-1.5AcceptRejectnm=nanometers-20-30 dBm
18 Physical Layer Specifications for G-PON 2.4/1.2Gbit/s emerging as most popular rates
19 Key Differences Between Gigabit- PONs ItemFSAN / ITU-T G-PONIEEE GE-PONMACLayerServiceFull services (Ether, TDM, POTS)Ethernet dataFrameGEM frameEthernet framePHYDistance10 / 20 km (Logical: 60 km)10 / 20 kmBranches64 (Logical: 128)16 or overBit rateUp : 155M, 622M, 1.25Gbit/sDown : 1.25G, 2.5Gbit/s1.25Gbit/s (Up and Down)BandwidthSame as above (NRZ coding)1Gbit/s (8B10B coding)Opt. Loss15 / 20 / 25dB15 / 20dBWave-lengthDown : nmUp : nm(Available to video signals overlay)SameUpstream burst timingGuard : 25.6nsPreamble : 35.2ns (Typical)Delimiter : 16.0ns (Typical)Laser turn on / off :512ns (Max)AGC setting and CDR lock : 400ns (Max)
20 Recent Updates to B-PON standards Nov 2004G Revised. ‘Broadband Optical Access Systems Based On Passive Optical Networks (PON)’Includes two previous Amendments, A Corrigendum, and Implementers’ guideG Amendment 2, ‘B-PON ONT Management and Control Interface (OMCI) support for Video Return Path’,Facilitates the use of set-top boxes originally designed for cable networksMay 2005G Revised ‘B-PON ONT Management and Control Interface (OMCI)’.All documents on OMCI have been merged into this revision, G and G through to G plus the Amendments 1 and 2 and Implementers’ guide.New functionality includes mechanized loop testing for telephony and ‘last gasp’ reportingG Amendment 2, “A broadband optical access system with increased service capability by wavelength allocation”Industry best practice optical budgets for the 622/155 B-PON system28dB Optical Distribution Networks for B-PON27dB with Analog video serviceG Amendment 1 on Protocol Implementation Conformance Statements (PICS) for the OLT and ONT.To show that the devices conform with G at the transmission convergence layer
21 Recent Updates to G-PON standards May 2005G Amendment 1 to G-PON Transmission Convergence Layer.Peak Information Rate and Sustained Information Rate parameters are now included and are analogous to ATM for alternative cell lengths such as Ethernet packets.Multicast services may now be supported over GEM (e.g. IPTV).(GEM is the generic encapsulation mode use at in the transmission convergence layer)G Amendment 1 “Gigabit-capable Passive Optical Networks (G-PON): ONT Management and Control Interface specification”.Proposes management features on G-PON in support of Ethernet and IPTV service such as the IEEE802.1p priority mapper, GEM traffic descriptor, and support of multicast connection.
22 Outlook Capacity doubling every year! 1000-fold increase in 10 years.depends upon investment in new infrastructure,Varies between country, region and locationDependent on the economics and national strategy.Can the life of G-PON be extended?Bursting to 1Gbit/s could buy 3 years (to 2016)UpgradesWith the addition of new wavelengths and/or new fiberFaster TDM-10Gbit/sWDM/PON
23 ConclusionsThe B-PON and G-PON series of standards are largely completeB-PON has reached maturity with up to eight vendors with interoperable OLT and/or ONU.The FSAN/Interoperability Task Group promotes standards conformance and interoperability among vendors.Recommendations in the G.984.x series detail G-PON, the latest generation of PON technology.Increasing capacity to Gigabit levels satisfies customer demands for capacity in the range 100 Mbit/s (dedicated) and 1 Gbit/s (shared)G-PON maintains the same optical distribution network, wavelength plan as B-PONoffers more efficient IP and Ethernet handlingNext step is G-PON interoperabilityThe enhancement band is used by some operators to transport analog cable TVIn the future, as TV moves from RF-analogue to digital-in-band the enhancement band is expected to be used for two-way interactive digital services.