Subject: [paws] Use cases and requirements I-D: Section 5 Problem Statement

From: <[email-masked]>
Date: Wed, 25 Jan 2012 21:02:31 +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 section 5. 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

5.  Problem Statement

   The use of white space spectrum is enabled via the capability of a
   device to query a database and obtain information about the
   availability of spectrum for use at a given location.  The databases
   are reachable via the Internet and the devices querying these
   databases are expected to have some form of Internet connectivity,
   directly or indirectly.  The databases may be country specific since
   the available spectrum and regulations may vary, but the fundamental
   operation of the protocol should be country independent.

   An example high-level architecture of the devices and white space
   databases is shown in the figure below:

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           -----------
           |WS Device|                              ------------
           |Lat: X   |\           .---.    /--------|Database X|
           |Long: Y  | \         (     )  /         ------------
           -----------  \-------/       \/               o
                              ( Internet )               o
           -----------  /------(        )\               o
           |WS Device| /         (_____)  \         ------------
           |Lat: X   |/                    \--------|Database Y|
           |Long: Y  |                              ------------
           -----------

    Figure 11: High level view of the White space database architecture

   In the figure above, note that there could be multiple databases
   serving white space devices.  The databases are country specific
   since the regulations and available spectrum may vary.  In some
   countries, for example, the U.S., the regulator has determined that
   multiple, competing databases may provide service to White Space
   Devices.

   A messaging interface between the white space devices and the
   database is required for operating a network using the white space
   spectrum.  The following sections discuss various aspects of such an
   interface and the need for a standard.  Other aspects of a solution
   including provisioning the database, and calculating protected
   contours are considered out of scope of the initial effort, as there
   are significant differences between countries and spectrum bands.

5.1.  Global applicability

   The use of TV white space spectrum is currently approved by the FCC
   in the United States.  However regulatory bodies in other countries
   are also considering similar use of available spectrum.  The
   principles of cognitive radio usage for such spectrum is generally
   the same.  Some of the regulatory details may vary on a country
   specific basis.  However the need for devices that intend to use the
   spectrum to communicate with a database remains a common feature.
   The database provides a known, specifiable Protection Contour for the
   primary user, not dependent on the characteristics of the White Space
   Device or it's ability to sense the primary use.  It also provides a
   way to specify a schedule of use, because some primary users (for
   example, wireless microphones) only operate in limited time slots.

   Devices need to be able to query a database, directly or indirectly
   over the public Internet and/or private IP networks prior to
   operating in available spectrum.  Information about available

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   spectrum, schedule, power, etc. are provided by the database as a
   response to the query from a device.  The messaging interface needs
   to be:

   1.  Radio/air interface agnostic - The radio/air interface technology
       used by the white space device in available spectrum can be
       802.11af, 802.16, 802.22, LTE etc.  However the messaging
       interface between the white space device and the database should
       be agnostic to the air interface while being cognizant of the
       characteristics of various air-interface technologies and the
       need to include relevant attributes in the query to the database.

   2.  Spectrum agnostic - the spectrum used by primary and secondary
       users varies by country.  Some spectrum has an explicit notion of
       a "channel" a defined swath of spectrum within a band that has
       some assigned identifier.  Other spectrum bands may be subject to
       white space sharing, but only have actual frequency low/high
       parameters to define protected entity use.  The protocol should
       be able to be used in any spectrum band where white space sharing
       is permitted.

   3.  Globally applicable - A common messaging interface between white
       space devices and databases will enable the use of such spectrum
       for various purposes on a global basis.  Devices can operate in
       any country where such spectrum is available and a common
       interface ensures uniformity in implementations and deployment.
       Since the White Space device must know it's geospatial location
       to do a query, it is possible to determine which database, and
       which rules, are applicable, even though they are country
       specific.

   4.  Address regulatory requirements - Each country will likely have
       regulations that are unique to that country.  The messaging
       interface needs to be flexible to accommodate the specific needs
       of a regulatory body in the country where the white space device
       is operating and connecting to the relevant database.

5.2.  Database discovery

   Another aspect of the problem space is the need to discover the
   database.  A white space device needs to find the relevant database
   to query based on its current location or for another location.
   Since the spectrum and databases are country specific, the device
   will need to discover the relevant database.  The device needs to
   obtain the IP address of the specific database to which it can send
   queries in addition to registering itself for operation and using the
   available spectrum.

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5.3.  Protocol

   A protocol that enables a white space device to query a database to
   obtain information about available channels is needed.  A device may
   be required to register with the database with some credentials prior
   to being allowed to query.  The requirements for such a protocol are
   specified in this document.

5.4.  Data model definition

   The contents of the queries and response need to be specified.  A
   data model is required which enables the white space device to query
   the database while including all the relevant information such as
   geolocation, radio technology, power characteristics, etc. which may
   be country and spectrum and regulatory dependent.  All databases are
   able to interpret the data model and respond to the queries using the
   same data model that is understood by all devices.

   Use of XML for specifying a data model is an attractive option.  The
   intent is to evaluate the best option that meets the need for use
   between white space devices and databases.