Slide1 l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

Channel Access Algorithms with Active Link Protection for Wireless Communication Networks with Power Control PowerPoint PPT Presentation


  • 66 Views
  • Uploaded on
  • Presentation posted in: General

Channel Access Algorithms with Active Link Protection for Wireless Communication Networks with Power Control. Nicholas Bambos, Shou C. Chen, Gregory J. Pottie. Agenda. Overview Motivation (Problem statement) Foundation work DPC/ALP algorithm Properties of DPC/ALP algorithm

Download Presentation

Channel Access Algorithms with Active Link Protection for Wireless Communication Networks with Power Control

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Slide1 l.jpg

Channel Access Algorithms with Active Link Protection for Wireless Communication Networks with Power Control

Nicholas Bambos, Shou C. Chen, Gregory J. Pottie


Agenda l.jpg

Agenda

  • Overview

  • Motivation (Problem statement)

  • Foundation work

  • DPC/ALP algorithm

  • Properties of DPC/ALP algorithm

  • Extensions to algorithm VDO and FDO

  • Simulation results and extensions

  • Comments


Overview dpc alp l.jpg

Overview: DPC/ALP

  • DPC: An Algorithm for transmit power control

    • Adaptive

    • Distributed

    • On-line

    • Different QoS levels

  • ALP: Admission control algorithm

    • Protect existing users form disruption

    • Method for new users to enter wireless network

    • “Smooth dynamics”


Motivation problem statement l.jpg

Motivation (Problem Statement)

  • Power control with

    • Entry and

    • Egress from the network

  • While maintaining QoS

    • For existing users

Admissible?


Model l.jpg

Model

QoS constraint


Foundation work dpc l.jpg

Foundation Work: DPC

  • Distributed Power Control

    • P(k+1)=FP(k)+u

    • P->P* where

  • But

    • Convergence path may lead to “outage” or QoS problems

  • Alternative form:

Foschini and Miljanic


Dpc alp algorithm l.jpg

DPC/ALP Algorithm

  • Based on DPC (above)

  • Active link protection – Ensures existing users QoS is maintained when new users are added.

  • Distributed admission control

  • Extended – Voluntary drop out Mechanism for “hot spots”


Dpc alp algorithm continued l.jpg

new

DPC/ALP Algorithm – continued

admitted

Geometric power up

Protection margin or buffer zone


Properties of dpc alp l.jpg

Properties of DPC/ALP

  • User is admitted when

    • Once admitted continuously admitted

    • bounded power overshoot

  • New users

    • Increasing SIR’s

    • If admissible then admitted in bounded time

  • But infinite power may be required

Admissibility vs. admissibility


Dpc alp vdo l.jpg

DPC/ALP/VDO

  • Voluntary Drop-Out

    • When too many new users none wins

    • Solution is one or more links backs off

  • Types of VDO

    • Coin flipping after a parameterized number of tries

    • Timer based


Dpc alp vdo fdo l.jpg

DPC/ALP/VDO/FDO

  • Power constraint

  • FDO – forced drop out

    • Active user nears max

    • Signals local users seeking admission to drop out

    • Reduces contention for resources


Simulation results l.jpg

Simulation results

  • VDO

    • Increases number of users significantly

    • Results in backlog of users not yet admitted

      • Threshold effect for great enough arrival rate of new users! Clogging effect

  • VDO and FDO

    • Decrease in time to admission

    • Higher through-put

Hot spots

Congestion control


Extensions l.jpg

Extensions

  • Probing

    • Predict admissibility from two SIR samples

Solve for X Y

Admit after k=


Comments l.jpg

Comments

  • Dynamics of admission control

    • Critical to ad-hoc networks

    • Rapidly changing user group

  • Results are very parameter sensitive


  • Login