Ethernet Passive Optical Networks

Ethernet Passive Optical Networks

Ethernet Passive Optical Networks PON Definition Point to multipoint optical networks Architecture build up from two elements An Optical Line Terminal (OLT) at Network Provider's premises Multiple Optical Network Units at users' premises Fiber to the home solution (FTTH) Fiber to the business solution (FTTB) Fiber to the curb solution (FTTC) Transmissions occur between OLT and the ONUs No active elements in signals' path Employ passive combiners, couplers and splitters only. Ethernet PON Data is encapsulated in Ethernet frames

IEEE 802.3ah Ethernet in the first mile Ethernet Passive Optical Networks Example of EPON architecture for Access Networks Ethernet Passive Optical Networks Transmissions in an EPON Downlink Broadcasting ONUs select their packets based on MAC address Uplink ONUs compete for using the channel CSMA cannot be used, since collisions cannot be avoided Solution : TDM with polling arbitration scheme (MPCP protocol) Scheduling in EPON Uplink transmissions require scheduling Two parts

Inter-ONU (arbitrated by the OLT) Given by the dynamic bandwidth allocation algorithm Intra-ONU IEEE 802 family : Strict priority scheduling, class based Ethernet Passive Optical Networks Scheduling in EPON Intra-ONU scheduling can be arbitrated either by the OLT or by the ONU Both approaches have drawbacks When arbitrated by the ONU, fairness among users from different ONU cannot be assured. When arbitrated by the OLT, scalability issues arises.

Number of classes must be small Session-by-session scheduling is unachievable Ethernet Passive Optical Networks Our proposal We propose an hierarchical scheduling approach to circumvent both drawbacks A utility function is defined for each session For a given session, the utility function represents the benefit of receiving some amount of bandwidth The utility functions reflect either the demand or the target performance of the sessions A weight is assigned to each session

For the system, the weights represent the benefit of allocating some amount of bandwidth to each session The weights reflect either the priority or the willingness-topay of the sessions Bandwidth is dynamically allocated so that the weighted sum of the utility is maximized over time (utility-based fairness approach) OLT consolidates the demand of all ONU ONU performs the intra-ONU based on the global demand information received from OLT and the utility of the sessions Ethernet Passive Optical Networks Advantages

QoS orientation Individual bounds on performance metrics (latency and delay) can be obtained Fairness Utility-based fairness Fairness is assured even among sessions from different ONUs Scalability Session-by-session scheduling is achieved Limit is mostly given by the capacity of the network Simplicity The arbitration process requires less information and computation Most of the computation is performed at ONU or at the users premises, in a distributed manner MPCP arbitration messages can be made shorter

Recently Viewed Presentations

  • Conduction and Induction - Mr. Hoover's Science Classes

    Conduction and Induction - Mr. Hoover's Science Classes

    Conduction and Induction. SNC1P. Charged Objects. An electroscope is an instrument that can be used to detect static charge. The study of static electric charges is called . electrostatics. The electroscope was first invented in 1748 by a French clergyman...
  • An Introduction to Judaism - Mrs. Cottrill

    An Introduction to Judaism - Mrs. Cottrill

    An Introduction to Judaism The first of the 10 Commandments * They believe that the only way to keep the Covenant is to live by the laws that are set out by God. * * There are two rabbis who...
  • Online Sampling: Collecting Data related to Political Online ...

    Online Sampling: Collecting Data related to Political Online ...

    The possible use of local political online forums to engage young people in local politics. Kerill Dunne Overview Background / definitions Criteria / forum type Methodology Sampling strategy Data entry Concepts Findings Participatory budgeting Hazel Blears (the new communities secretary)...
  • Pitch Angles of Clustered Spiral Galaxies in the

    Pitch Angles of Clustered Spiral Galaxies in the

    We have examined a set of 125 spiral galaxies lying in the Chandra Deep Field South for which we have redshifts & pitch angles from previous work. Upon cross-referencing this set with the larger & comprehensive COMBO-17 survey, we found...
  • Seed3D P&Cs nurturing innovation

    Seed3D P&Cs nurturing innovation

    Seed3D. Schools register for seed3D by Me3D. community member buys a Me2. school earns 10% off A me2 for every one sold. by *For full terms and conditions visit www ...
  • Chapter 5

    Chapter 5

    A data-flow diagram of the scope of an organizational system that shows the system boundaries, external entities that interact with the system and the major information flows between the entities and the system. Level-O Diagram. A data-flow diagram that represents...
  • Drug & Alcohol Family Support Needs Analysis Report

    Drug & Alcohol Family Support Needs Analysis Report

    Needs Analysis - Background. This research: Aims to contribute to a greater understanding of the ways families affected by substance use seek support in the western region. Explores the availability and effectiveness of supports to families from a service perspective...
  • Thinking and Language - Liberty Union High School District

    Thinking and Language - Liberty Union High School District

    Homework: Advertising Poster. Pretend that you are advertising a product. On a small poster (paper size), show a visual advertisement (could be real or you could make it up) that uses words and pictures to demonstrate the methods, strategies, and...