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GPON NetworkSupervised by :Dr-Ali NajiEng-Yaser AlwanPrepared by:

Sara Alkohlany 167\2009Marwa Jalal 289\2009

1ObjectivesAn overview in PONWhat is PON ?How PON works ?What is it type?What is GPON?GPON ArchitectureGPON FeaturesGPON Standardscurrent applications and prospective.

2An overview in PON

What is PON? PON is a kind of passive optical network featuring one-to-multiple-point architecture.

3 How PON works ?A PON uses a P2MP topologyFrom the OLT a single strand of fiber goes out to a passive optical splitter/merger where its signal is split onto fibers terminating at up to 64 different ONUs or ONTs. Splitters can either be single stage (1 X 64) or cascaded (1 X 4 feeding into four 1X 16)The transmit and receive directions operate on different wavelengths. Upstream uses 1310nm Downstream uses 1490nm RF video overlay uses 1550 nmTo transmit downstream the OLT broadcasts all the traffic to every ONT on the PON through the action of the splitters. Each ONT only reads the content of those packets that are addressed to it. Encryption is used to prevent eavesdropping on downstream traffic.In the upstream direction the OLT controls the transmissions from all the ONTs using an arbitration protocol. Popular methods include a TDM timeslot arrangement, or a prescheduled packet allocation or bandwidth-allocation scheme.

4 What is it type?many types of PONs have been defined APONATM PON BPONBroadband PON GPONGigabit PON EPONEthernet PON GEPONGigabit Ethernet PON CPONCDMA PON WPONWDM PONin this course we will focus on GPON

5What GPON?GPON (Gigabit Passive Optical Network) is currently considered the most economic technology for FTTH (Fiber to the Home), since it supports up to 64 passive splits, optimizing the cost of the optical transceivers at the OLT, coupled with the capability to deliver 2.5 Gbps downstream and 1.25 Gbps upstream bandwidth for new services.

6The GPON access network architecture:

GPON Architecture

7Cont:Optical Network Unit (ONU)The ONT connects desktops into the GPON network and primarily provides the optical to electrical signal conversion.ONT also provides AES encryption via ONT key.Optical Line Termination (OLT)The OLT aggregates all optical signal from vendor dependent ONTs into a single multiplexed beam of light which is then converted to an electric signal, formatted to Ethernet packet type standards and presented to a core Ethernet switch for layer 2 or 3 forwarding.splittersThe splitting device simply divides the optical power into N separate paths to the subscribers. The number of splitting paths can vary from 2 to 64.

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GPON Principle----Downstream Data Broadcast mode9GPON Principle----Upstream Data

TDMA mode10GPON FeaturesOperating WavelengthThe operating wavelength range is about 1500 nm for the downstream and 1350 nm for the upstream. In addition a wavelength range 15501560 nm can be used for down-stream RF video distribution. Transmission containers (T-CONT) Transmission containers (T-CONT) are usedfor the management of upstream bandwidth allocation in the GPON.

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Open Bandwidth AllocationBoth, static bandwidth allocation (SBA) as well as dynamic bandwidth allocation (DBA) can be implemented in GPON networks

DBA process.12Cont:Immence Downstream EfficiencyGPON can provide the downstream efficiency up to 92% since non encoded non return to zero (NRZ) is applied.The 8% efficiency is mitigates by use of overhead.Gauranted QoS at UpstreamGPON is a right candidate as it is enhanced with PON layer mechanism that goes beyond layer 2 Ethernet and layer 3 IP class of service (CoS) to ensure the delivery of high quality voice, video and TDM data over TDMA based shared media.

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Cont:GPON QoS/CoS capability that enriched with fragmented payloads.14Cont:SecurityIn GPON, downstream data are broadcasted to all ONUs and every ONU has allocated time when data belongs to it, as like TDM. For this reason some malicious user can reprogram their own ONU and can capture all the down stream data belong to all ONUs connected to that OLT.In upstream, GPON uses point to point connection so that all traffic is secured from eavesdropping. Therefore, each of confidential upstream information (such as security key) can be sent in clear text.The encryption algorithm to be used is the advanced encryption standard (AES) which makes encryption extremely difficult to compromise.

15GPON Standards

16Key Triple-play Service SolutionsVoice Solution.Internet Access Solution.VLAN Stacking Multi-ISP Wholesale Internet Access Solution. L2TP Multi-ISP Wholesale Internet Access Solution.GPON IP Based Video Service Solution

Applications of GPON

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