Subject: [paws] Use cases and requirements I-D: sections 1 to 3 (Introduction, Conventions and Terminology, Prior Work)

From: <[email-masked]>
Date: Wed, 25 Jan 2012 20:49:09 +0000

Hello All,

As editors of the problem statement, use cases & requirements draft we are
attempting to prepare a completed draft which could be ready for working
group last call before IETF83. In the coming days we will post the
sections of the draft to the mailing list. Our request is that you review
these sections and reply to the email with any comments.

Below is the text for sections 1 to 3. This text has not changed from
version-01 as uploaded October 31, 2011. Our goal is that any discussion
on this text will conclude by February 1. To be clear, approval of the
document will go through the normal process of last calls etc.. We are
simply asking for your assistance in preparing a complete & accurate
document that could progress the work. So please review the text and send
your comments either directly to the editor or to the mailing list.

Kind Regards,
Raj & Scott

1.  Introduction

1.1.  Introduction to TV white space

   Wireless spectrum is a commodity that is regulated by governments.
   The spectrum is used for various purposes, which include
   entertainment (e.g. radio and television), communication (telephony
   and Internet access), military (radars etc.) and, navigation
   (satellite communication, GPS).  Portions of the radio spectrum that
   are allocated to a licensed, primary user but are unused or
   unoccupied at specific locations and times are defined as "white
   space".  The concept of allowing secondary transmissions (licensed or
   unlicensed) in white space is a technique to "unlock" existing
   spectrum for new use.  An obvious requirement is that these secondary
   transmissions do not interfere with the primary use of the spectrum.
   One interesting observation is that often, in a given physical
   location, the primary user(s) may not be using the entire band
   allocated to them.  The available spectrum for a secondary use would
   then depend on the location of the secondary user.  The fundamental
   issue is how to determine for a specific location and specific time,
   if any of the primary spectrum is available for secondary use.
   Academia and Industry have studied multiple cognitive radio
   mechanisms for use in such a scenario.  One simple mechanism is to
   use a geospatial database that records the primary users occupation,
   and require the secondary users to check the database prior to
   selecting what part of the spectrum they use.  Such databases could
   be available on the Internet for query by secondary users.

   Spectrum useable for data communications, especially wireless
   Internet communications, is scarce.  One area which has received much
   attention globally is the TV white space: portions of the TV band
   that are not used by broadcasters in a given area.  In 2008 the
   United States regulator (the FCC) took initial steps when they
   published their first ruling on the use of TV white space, and then
   followed it up with a final ruling in 2010 [FCC Ruling].  Finland
   passed an Act in 2009 enabling testing of cognitive radio systems in
   the TV white space.  The ECC has completed Report 159 [ECC Report
   159] containing requirements for operation of cognitive radio systems
   in the TV white space.  Ofcom published in 2004 their Spectrum
   Framework Review [Spectrum Framework Review] and their Digital
   Dividend Review [DDR] in 2005, and have followed up with a proposal
   to access TV white space.  More countries are expected to provide
   access to their TV spectrum in similar ways.  Any entity holding
   spectrum that is not densely used may be asked to give it up in one
   way or another for more intensive use.  Providing a mechanism by
   which secondary users share the spectrum with the primary user is
   attractive in many bands in many countries.

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   Television transmission until now has primarily been analog.  The
   switch to digital transmission has begun.  As a result the spectrum
   allocated for television transmission can now be more effectively
   used.  Unused channels and bands between channels can be used as long
   as they do not interfere with the primary service for which that
   channel is allocated.  While urban areas tend to have dense usage of
   spectrum and a number of TV channels, the same is not true in rural
   and semi-urban areas.  There can be a number of unused TV channels in
   such areas that can be used for other services.  The figure below
   shows TV white space within the lower UHF band:

        Avg  |
        usage|                             |-------------- White Space
             |                    |    |   |   |  |
          0.6|                   ||    ||  V   V  ||
             |                   ||   |||    |    ||
          0.4|                   ||   ||||   |    ||
             |                   ||   ||||   |    ||<----TV transmission
          0.2|                   ||   ||||   |    ||
             |----------------------------------------
             400     500       600      700       800
                      Frequency in MHz ->

                Figure 1: High level view of TV White Space

   The fundamental issue is how to determine for a specific location and
   specific time if any of the spectrum is available for secondary use.
   There are two dimensions of use that may be interesting: space (the
   area in which a secondary user would not interfere with a primary
   user, and time: when the secondary use would not interfere with the
   primary use.  In this discussion, we consider the time element to be
   relatively long term (hours in a day) rather than short term
   (fractions of a second).  Location in this discussion is geolocation:
   where the transmitters (and sometimes receivers) are located relative
   to one another.  In operation, the database records the existing
   user's transmitter (and some times receiver) locations along with
   basic transmission characteristics such as antenna height, and
   sometimes power.  Using rules established by the regulator, the
   database calculates an exclusion zone for each authorized primary
   user, and attaches a time schedule to that use.  The secondary user
   queries the database with its location.  The database intersects the
   exclusion zones with the queried location, and returns the portion of
   the spectrum not in any exclusion zone.  Such methods of geospatial
   database query to avoid interference have been shown to achieve
   favorable results, and are thus the basis for rulings by the FCC and

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   reports from ECC and Ofcom.  In any country, the rules for which
   primary entities are entitled to protection, how the exclusion zones
   are calculated, and what the limits of use by secondary entities are
   may vary.  However, the fundamental notion of recording primary
   users, calculating exclusion zones, querying by location and
   returning available spectrum (and the schedule for that spectrum) are
   common

   This document includes the problem statement, use cases and
   requirements associated with the use of white space spectrum by
   secondary users via a database query protocol.

1.2.  Scope

1.2.1.  In Scope

   This document applies only to communications required for basic
   service in TV white space.  The protocol will enable a white space
   radio device to complete the following tasks:

   1.  Determine the relevant white space database to query.

   2.  Connect to the database using a well-defined access method.

   3.  Register with the database using a well-defined protocol.

   4.  Provide its geolocation and perhaps other data to the database
       using a well-defined format for querying the database.

   5.  Receive in return a list of currently available white space using
       a well-defined format for returning information.

   As a result, some of the scenarios described in the following section
   are out of scope for this specification (although they might be
   addressed by future specifications).

1.2.2.  Out of Scope

   The following topics are out of scope for this specification:

   TBD

2.  Conventions and Terminology

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2.1.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.2.  Terminology

   Database

      In the context of white space and cognitive radio technologies,
      the database is an entity which contains current information about
      available spectrum at any given location and other types of
      information.

   Device ID

      A unique number for each master device and slave device that
      identifies the manufacturer, model number and serial number.

   Location Based Service

      An application or device which provides data, information or
      service to a user based on their location.

   Master Device

      A device which queries the WS Database to find out the available
      operating channels.

   Protected Entity

      A primary user of white space spectrum which is afforded
      protection against interference by secondary users (white space
      devices) for its use in a given area and time.

   Protected Contour

      The exclusion area for a Protected Entity, held in the database
      and expressed as a polygon with geospatial points as the vertices.

   Slave Device

      A device which uses the spectrum made available by a master
      device.

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   TV White Space

      TV white space refers specifically to radio spectrum which has
      been allocated for TV broadcast, but is not occupied by a TV
      broadcast, or other licensed user (such as a wireless microphone),
      at a specific location and time.

   White Space

      Radio spectrum which has been allocated for some primary use, but
      is not fully occupied by that primary use at a specific location
      and time.

   White Space Device (WSD)

      A device which is a secondary user of some part of white space
      spectrum.  A white space device can be an access point, base
      station, a portable device or similar.  In this context, a white
      space device is required to query a database with its location to
      obtain information about available spectrum.

3.  Prior Work

3.1.  The concept of Cognitive Radio

   A cognitive radio uses knowledge of the local radio environment to
   dynamically adapt its own configuration and function properly in a
   changing radio environment.  Knowledge of the local radio environment
   can come from various technology mechanisms including sensing
   (attempting to ascertain primary users by listening for them within
   the spectrum), location determination and internet connectivity to a
   database to learn the details of the local radio environment.  TV
   White Space is one implementation of cognitive radio.  Because a
   cognitive radio adapts itself to the available spectrum in a manner
   that prevents the creation of harmful interference, the spectrum can
   be shared among different radio users.

3.2.  Background information on white space in US

   Television transmission in the United States has moved to the use of
   digital signals as of June 12, 2009.  Since June 13, 2009, all full-
   power U.S. television stations have broadcast over-the-air signals in
   digital only.  An important benefit of the switch to all-digital
   broadcasting is that it freed up parts of the valuable broadcast
   spectrum.  More information about the switch to digital transmission
   is at : [DTV].

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   With the switch to digital transmission for TV, the guard bands that
   existed to protect the signals between stations can now be used for
   other purposes.  The FCC has made this spectrum available for
   unlicensed use and this is generally referred to as white space.
   Please see the details of the FCC ruling and regulations in [FCC
   Ruling].  The spectrum can be used to provide wireless broadband as
   an example.  The term "Super-Wifi" is also used to describe this
   spectrum and potential for providing wifi type of service.

3.3.  Air Interfaces

   Efforts are ongoing to specify air-interfaces for use in white space
   spectrum.  IEEEs 802.11af task group is currently working on one such
   specification.  IEEE 802.22 is another example.  Other air interfaces
   could be specified in the future such as LTE.

---

From: <[email-masked]>
Date: Mon, 30 Jan 2012 16:55:31 +0000

Scott

[Ofcom Implementing] appears in the references section but not the main text. I propose to reference it from the end of one sentence in the second paragraph, and slightly amend the wording. The changed text would be:

Ofcom published in 2004 their Spectrum Framework Review [Spectrum Framework Review] and their Digital Dividend Review [DDR] in 2005, with proposals from 2009 onwards to access TV white space, culminating in the 2009 Ofcom Statement Implementing Geolocation [Ofcom Implementing].

Regards

Andy

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of [email-masked]
Sent: 25 January 2012 20:49
To: [email-masked]
Subject: [paws] Use cases and requirements I-D: sections 1 to 3 (Introduction, Conventions and Terminology, Prior Work)

Hello All,

As editors of the problem statement, use cases & requirements draft we are attempting to prepare a completed draft which could be ready for working group last call before IETF83. In the coming days we will post the sections of the draft to the mailing list. Our request is that you review these sections and reply to the email with any comments.

Below is the text for sections 1 to 3. This text has not changed from
version-01 as uploaded October 31, 2011. Our goal is that any discussion on this text will conclude by February 1. To be clear, approval of the document will go through the normal process of last calls etc.. We are simply asking for your assistance in preparing a complete & accurate document that could progress the work. So please review the text and send your comments either directly to the editor or to the mailing list.

Kind Regards,
Raj & Scott

1.  Introduction

        Avg  |

1.2.  Scope

1.2.1.  In Scope

1.2.2.  Out of Scope

   TBD

2.2.  Terminology

   Database

   Device ID

   Location Based Service

   Master Device

   Protected Entity

   Protected Contour

   Slave Device

   TV White Space

   White Space

   White Space Device (WSD)

3.  Prior Work

3.3.  Air Interfaces

_______________________________________________
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https://www.ietf.org/mailman/listinfo/paws

---

From: <[email-masked]>
Date: Mon, 30 Jan 2012 17:56:32 +0000

Scott

Sorry, there is an error in my own correction... it should read "2011 Ofcom Statement" not 2009.

Regards

Andy

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of [email-masked]
Sent: 30 January 2012 16:56
To: [email-masked]; [email-masked]
Subject: Re: [paws] Use cases and requirements I-D: sections 1 to 3 (Introduction, Conventions and Terminology, Prior Work)

Scott

Regards

Andy

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of [email-masked]
Sent: 25 January 2012 20:49
To: [email-masked]
Subject: [paws] Use cases and requirements I-D: sections 1 to 3 (Introduction, Conventions and Terminology, Prior Work)

Hello All,

Kind Regards,
Raj & Scott

1.  Introduction

        Avg  |

1.2.  Scope

1.2.1.  In Scope

1.2.2.  Out of Scope

   TBD

2.2.  Terminology

   Database

   Device ID

   Location Based Service

   Master Device

   Protected Entity

   Protected Contour

   Slave Device

   TV White Space

   White Space

   White Space Device (WSD)

3.  Prior Work

3.3.  Air Interfaces