A Novel Multiple Access Scheme for Ethernet Passive Optical Network

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A Novel Multiple Access Scheme for Ethernet
Passive Optical Network

• Professor Ho-Ting Wu
• SpeakerRui-Yi Jian

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Outline

• Introduction
• Operation Steps
• Conclusion

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Outline

• Introduction
• Operation Steps
• Conclusion

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Introduction

• Propose a novel multiple access scheme to
  efficiently share the upstream channel in an EPON

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Propose

• The multiple access scheme contains three parts
  that operate autonomously but are closely related
  to each other
• Parameter-based CAC Mechanism
• EDA
• BGP Scheme

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Terminology

• OLT
• Optical Line Terminal
• ONU
• Optical Network Unit
• SLA
• Service Level Agreement
• RTT
• Round-Trip Time
• BG
• Bandwidth Guaranteed

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Generally three class of traffic

• Expedited Forwarding (EF)
• Voice or Video
• Assured Forwarding (AF)
• Best Effort (BE)
• Email

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Outline

• Introduction
• Operation Steps
• Conclusion

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Operation Steps

• Parameter-based CAC Mechanism
• EDA
• BGP Scheme

Bandwidth Guaranteed Polling
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Parameter-based CAC Mechanism

• Call Admission Control
• Admits customers in consideration of SLA, through
  which ONUs can be divided into two disjoint
  groups served by the OLT differently
• BG ONUs
• Non-BG ONUs

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CAC - Parameter

• ltC, Dgt
• C specifies the minimum peak bandwidth an ONU
  requests
• D indicates the maximum waiting delay an ONU can
  tolerate
• E(Di)
• the worst case average delay E(Di) for each ONU
  that the OLT pre-calculate

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CAC Mechanism -Initialization
Ci , the OLT re-calculate
Check the utilization of network
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EDA

• Evenly Distributed Algorithm
• Determines the polling sequence of ONUs for the
  scheduling scheme

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EDA Step1

• Process the BG ONUs from the one with maximum
  entries to the one with minimum entries

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EDA Step2 (1/3)

• After determining the first entry Ei1 and other
  entries Eij (j2,3,Ni) for BG ONUi with Ni
  entries, fill the Table with this ONUs ID i

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EDA Step2 (2/3)

• Let entry i to be the first entry of ONU i
• Ei1 i
• If the entry i is occupied by other ONU
• Ei1 i n ,
• n 1,2,3,

ONU2
ONU6
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EDA Step2 (3/3)

• Other entries Eij (j2,3,Ni) , and N is the
  total entry number of the Entry Table
• Eijmod(Eil
• int(j-1)N/Ni , N )
• Eijmod((Eil
• int(j-1)N/Ni) n, N )

ONU3 j 3 Ni 4 N 8
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EDA Step3

• All entries that are not occupied by BG ONUs will
  be blank in the Entry Table, then assigned to
  non-BG ONUs dynamically

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EDA Step4

• The List for non-BG ONUs is sequenced in
  ascending order based on non-BG ONUs IDs
• The total number of the elements in the List is
  not fixed

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EDA Benefit

• It will benefit to the BG ONUs with high traffic
  since the packets in the buffer can be allowed to
  transmit after the same intervals
• Thus there will be no burst, caused by the
  scheduling, introduced to the data transmission

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BGP Scheme

• Bandwidth Guarantee Polling
• The proposed scheme is able to guarantee
  bandwidth for high-demand users , and provide a
  best-effort service to low-demand users

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BGP - Steps

• The Entry Table List will determine the
  scheduling order of ONUs
• The OLT sending a control message
• locate which ONU occupies this entry
• grants a transmission window to the ONU
• Duration of the transmission window
• The ONU starts to transmit data frames
• reports its buffer occupancy status

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BGP - Benefit

• Entries in the Table that are not occupied by BG
  ONUs or the superfluous transmission window in
  one entry that is occupied yet unconsumed by an
  ONU can be assigned to non-BG ONUs dynamically

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BGP - Problem

• How to defined a threshold to determine whether
  to use the superfluous transmission window or
  give it up

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Outline

• Introduction
• Operation Steps
• Conclusion

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Conclusion

• This scheme can guarantee bandwidth for
  high-demand customers while providing best-effort
  service to low-demand customers based on the SLA

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