Difference between revisions of "LAA-WiFi-Coexistence"

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== Overview ==
 
== Overview ==
  
ns-3 is well-known for providing high fidelity, packet-level models of [https://www.nsnam.org/docs//models/html/wifi.html Wi-Fi] and [https://www.nsnam.org/docs//models/html/lte.html LTE], but simulation studies to date have not tried to combine the technologies on the same channel.  In industry, 3GPP is defining standards for [http://www.3gpp.org/news-events/3gpp-news/1603-lte_in_unlicensed using LTE in unlicensed spectrum].  The term License-Assisted Access (LAA) is frequently used to refer to these extensions, and refers to the fact that the use of unlicensed spectrum is complementary to the use of licensed spectrum for LTE, with the unlicensed spectrum providing complementary or secondary carriers that can be aggregated with carriers on licensed frequencies.
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This page describes a project originally sponsored by [http://www.wi-fi.org/ Wi-Fi Alliance] to improve ns-3 models to facilitate studies about the coexistence, on the same channel, of Wi-Fi and unlicensed variants of LTE (see [http://www.3gpp.org/news-events/3gpp-news/1603-lte_in_unlicensed this brief description]), with a special emphasis on aligning to methodologies defined by the 3GPP RAN1 and IEEE 802.11ax standards development organizations.  The term License-Assisted Access (LAA) is frequently used to refer to these extensions, and refers to the fact that the use of unlicensed spectrum is complementary to the use of licensed spectrum for LTE, with the unlicensed spectrum providing complementary or secondary carriers that can be aggregated with carriers on licensed frequencies.  The project has been conducted by [http://www.cttc.es/ CTTC] and the [https://depts.washington.edu/funlab/members/ University of Washington] from 2015-16.  The project seeks additional industrial sponsors to continue development; please contact [mailto:tomhend@u.washington.edu Tom Henderson] if interested in funding additional development or obtaining training or support.
 
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This page describes a project sponsored by the [http://www.wi-fi.org/ Wi-Fi Alliance] to improve ns-3 models to facilitate studies about the coexistence of Wi-Fi and unlicensed variants of LTE on the same channel.  The project is being conducted by [http://www.cttc.es/ CTTC] and the [https://depts.washington.edu/funlab/members/ University of Washington].
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== Design ==
 
== Design ==
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=== Phase 2 ===
 
=== Phase 2 ===
  
Current work is focused on developing models related to the current standardization process for [http://www.3gpp.org/news-events/3gpp-news/1628-rel13 Release 13].  In particular, a "Listen-Before-Talk" (LBT) mode is being developed for LTE, and scenarios are being constructed to evaluate technical topics such as the sensitivity on performance on the Energy Detection threshold used for the LBT CCA mechanism.
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Phase 2 was focused on developing models related to the standardization process for [http://www.3gpp.org/news-events/3gpp-news/1628-rel13 Release 13] which concluded in December 2015.  In particular, a "Listen-Before-Talk" (LBT) mode was developed for LTE, and scenarios were constructed to evaluate technical topics such as the sensitivity on performance on the Energy Detection threshold used for the LBT CCA mechanism.
 +
 
 +
Phase 2 resulted in a Wi-Fi Alliance contribution to 3GPP RAN1 in November 2015 (see below).
 +
 
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=== Phase 3 ===
 +
 
 +
Phase 3 further developed the models to include a voice application model, efficiency updates to the interaction between the LAA scheduler and channel access manager, and the ITU InH indoor channel model, among other enhancements.
 +
 
 +
Phase 3 resulted in a Wi-Fi Alliance liaison response to 3GPP RAN1 in August 2016 (see below).
  
 
== Software ==
 
== Software ==
  
 
The software is available in a repository at ns-3's main code server, http://code.nsnam.org:
 
The software is available in a repository at ns-3's main code server, http://code.nsnam.org:
* The phase 1 code is available with Mercurial, can be [http://code.nsnam.org/laa/ns-3-laa/ browsed on the web], or by download in a [http://code.nsnam.org/laa/ns-3-laa/archive/tip.zip zip] or [http://code.nsnam.org/laa/ns-3-laa/archive/tip.tar.bz2 tar.bz2] format.
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* The phase 1 code is available with Mercurial, can be [http://code.nsnam.org/laa/ns-3-laa/ browsed on the web], or by download in a [http://code.nsnam.org/laa/ns-3-laa/archive/tip.zip zip] or [http://code.nsnam.org/laa/ns-3-laa/archive/tip.tar.bz2 tar.bz2] format.
* The phase 2 code (under current development as of this January 2016 writing) is available with Mercurial, can be [http://code.nsnam.org/laa/ns-3-lbt/ browsed on the web], or by download in a [http://code.nsnam.org/laa/ns-3-lbt/archive/tip.zip zip] or [http://code.nsnam.org/laa/ns-3-lbt/archive/tip.tar.bz2 tar.bz2] format.
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* The phase 2 code is available with Mercurial, can be [http://code.nsnam.org/laa/ns-3-lbt/file/fbb156e4ed76 browsed on the web], or by download in a [http://code.nsnam.org/laa/ns-3-lbt/archive/fbb156e4ed76.zip zip] or [http://code.nsnam.org/laa/ns-3-lbt/archive/fbb156e4ed76.tar.bz2 tar.bz2] format.
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* The phase 3 code is available with Mercurial, can be [http://code.nsnam.org/laa/ns-3-lbt/file/9529febb7ebc browsed on the web], or by download in a [http://code.nsnam.org/laa/ns-3-lbt/archive/9529febb7ebc.zip zip] or [http://code.nsnam.org/laa/ns-3-lbt/archive/9529febb7ebc.tar.bz2 tar.bz2] format.
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* The current tip of the repository is available with Mercurial, can be [http://code.nsnam.org/laa/ns-3-lbt/ browsed on the web], or by download in a [http://code.nsnam.org/laa/ns-3-lbt/archive/tip.zip zip] or [http://code.nsnam.org/lbt/ns-3-laa/archive/tip.tar.bz2 tar.bz2] format.
  
The software will eventually be migrated to ns-3 releases, but as of the latest ns-3.24 release, none of the above extensions are available in the main release.
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The software will eventually be migrated to ns-3 releases, but as of the latest ns-3 release, the LAA extensions are not available in the main release.
  
 
The extensions reside in four main directories:
 
The extensions reside in four main directories:
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== Reports ==
 
== Reports ==
  
A contribution to the November 3GPP RAN1 meeting ([http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_83/Docs/R1-156621.zip R1-156621]) has been generated. Steps to reproduce the experiments in the contribution are documented in the file 'src/laa-wifi-coexistence/experiments/README.txt' in the phase 2 repository.
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* A contribution to the November 2015 3GPP RAN1 meeting ([http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_83/Docs/R1-156621.zip R1-156621]) has been produced.   The implementation has evolved since the November 3GPP RAN1 meeting and more current results are documented in the links below, and in the liaison response R1-167881 below.
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* A publication preprint, based on code from the June 2016 timeframe, is available [http://arxiv.org/abs/1604.06826 here].
 +
* A liaison response to the August 2016 3GPP RAN1 meeting ([http://www.3gpp.org/ftp/tsg_ran/WG1_RL1/TSGR1_86/Docs/R1-167881.zip R1-167881]) has been produced.
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* A recent presentation about the models and scenario support (May 2016) is available [http://www.nsnam.org/~tomh/ns-3-lbt-presentations/LAA-Wi-Fi-Coexistence-May2016.pdf here].
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== Getting started ==
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All figures and data in the 3GPP RAN1 meeting contribution can be generated by following the steps in the above ns-3-lbt Phase 2 archive by consulting the README.txt in the software directory under 'src/laa-wifi-coexistence/experiments/README.txt'.
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Specifically, the following versions of the ns-3-lbt repository are aligned with results shown in the following documents:
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* '''R1-156621''' (November 2015):  Corresponds to revision 18 of http://code.nsnam.org/laa/ns-3-lbt
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* '''arxiv paper''' (July 2016):  Corresponds to revision 41 of http://code.nsnam.org/laa/ns-3-lbt
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* '''R1-167881''' (August 2016):  Corresponds to revision 66 of http://code.nsnam.org/laa/ns-3-lbt (if you are using OS X, try revision 69 instead to fix some build issues).
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Additional documentation (updated as of February 2016, and consistent with Phase 2) is available at the following URLs:
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* HTML:  https://www.nsnam.org/~tomh/ns-3-lbt-documents/html/lbt-wifi-coexistence.html 
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* PDF:  https://www.nsnam.org/~tomh/ns-3-lbt-documents/lbt-wifi-coexistence.pdf
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== Citations ==
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If you wish to cite this work in your publication, please cite our arXiv paper "Simulating LTE and Wi-Fi Coexistence in Unlicensed Spectrum with ns-3" at http://arxiv.org/abs/1604.06826.
  
 
== Contacts ==
 
== Contacts ==
  
Contact Tom Henderson (tomh@tomh.org) for more information.
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Contact Tom Henderson (tomhend@u.washington.edu) for more information.

Latest revision as of 01:36, 7 March 2017

Main Page - Current Development - Developer FAQ - Tools - Related Projects - Project Ideas - Summer Projects

Installation - Troubleshooting - User FAQ - HOWTOs - Samples - Models - Education - Contributed Code - Papers

Overview

This page describes a project originally sponsored by Wi-Fi Alliance to improve ns-3 models to facilitate studies about the coexistence, on the same channel, of Wi-Fi and unlicensed variants of LTE (see this brief description), with a special emphasis on aligning to methodologies defined by the 3GPP RAN1 and IEEE 802.11ax standards development organizations. The term License-Assisted Access (LAA) is frequently used to refer to these extensions, and refers to the fact that the use of unlicensed spectrum is complementary to the use of licensed spectrum for LTE, with the unlicensed spectrum providing complementary or secondary carriers that can be aggregated with carriers on licensed frequencies. The project has been conducted by CTTC and the University of Washington from 2015-16. The project seeks additional industrial sponsors to continue development; please contact Tom Henderson if interested in funding additional development or obtaining training or support.

Design

Phase 1

This phase has produced a new Wi-Fi Spectrum-based physical layer, enabling Wi-Fi devices and LTE devices to coexist on the same ns-3 channel. Beyond this enabling capability, several enhancements to the ns-3 models have been made:

  • Enhancements to Wi-Fi clear-channel access (CCA) and frame synchronization models
  • A Wi-Fi roaming model for AP selection based on received signal strength
  • LTE interference model enhancements
  • New indoor and outdoor propagation models
  • Wi-Fi MIMO and interference models for fading model D
  • Duty-cycled LTE transmission model
  • Scenarios corresponding to the indoor and outdoor scenarios defined in 3GPP TR36.889
  • A framework for executing simulation campaigns and quickly plotting the results

Phase 2

Phase 2 was focused on developing models related to the standardization process for Release 13 which concluded in December 2015. In particular, a "Listen-Before-Talk" (LBT) mode was developed for LTE, and scenarios were constructed to evaluate technical topics such as the sensitivity on performance on the Energy Detection threshold used for the LBT CCA mechanism.

Phase 2 resulted in a Wi-Fi Alliance contribution to 3GPP RAN1 in November 2015 (see below).

Phase 3

Phase 3 further developed the models to include a voice application model, efficiency updates to the interaction between the LAA scheduler and channel access manager, and the ITU InH indoor channel model, among other enhancements.

Phase 3 resulted in a Wi-Fi Alliance liaison response to 3GPP RAN1 in August 2016 (see below).

Software

The software is available in a repository at ns-3's main code server, http://code.nsnam.org:

The software will eventually be migrated to ns-3 releases, but as of the latest ns-3 release, the LAA extensions are not available in the main release.

The extensions reside in four main directories:

  • Scripts, tests, and documentation to construct simulations involving these new models are in 'src/laa-wifi-coexistence'
  • Extensions to LTE to enable unlicensed variants are in 'src/lte'
  • Extensions to the Wi-Fi module to enable the SpectrumWifiPhy and new error models are in 'src/wifi'
  • Propagation model extensions are in 'src/propagation'

Reports

  • A contribution to the November 2015 3GPP RAN1 meeting (R1-156621) has been produced. The implementation has evolved since the November 3GPP RAN1 meeting and more current results are documented in the links below, and in the liaison response R1-167881 below.
  • A publication preprint, based on code from the June 2016 timeframe, is available here.
  • A liaison response to the August 2016 3GPP RAN1 meeting (R1-167881) has been produced.
  • A recent presentation about the models and scenario support (May 2016) is available here.

Getting started

All figures and data in the 3GPP RAN1 meeting contribution can be generated by following the steps in the above ns-3-lbt Phase 2 archive by consulting the README.txt in the software directory under 'src/laa-wifi-coexistence/experiments/README.txt'.

Specifically, the following versions of the ns-3-lbt repository are aligned with results shown in the following documents:

Additional documentation (updated as of February 2016, and consistent with Phase 2) is available at the following URLs:

Citations

If you wish to cite this work in your publication, please cite our arXiv paper "Simulating LTE and Wi-Fi Coexistence in Unlicensed Spectrum with ns-3" at http://arxiv.org/abs/1604.06826.

Contacts

Contact Tom Henderson (tomhend@u.washington.edu) for more information.