datatracker.ietf.org
Sign in
Version 5.3.0, 2014-04-12
Report a bug

Protocol to Access WS database
charter-ietf-paws-02

Snapshots: 02
Charter for "Protocol to Access WS database" (paws) WG
WG State: Active
Charter State:
Responsible AD: none

Send notices to: none
Last updated: 2011-06-14

Other versions: plain text

Charter charter-ietf-paws-02

Background
    
    Radio spectrum is a limited resource.  National and international
    bodies assign different frequencies for specific uses, and in
    most cases license the rights to use these frequencies.  Locally
    unused spectrum is commonly called "white space" and may be made
    available to other services on a basis of non-interference with
    the primary user of the frequencies concerned (if any). This
    technique can help "unlock" existing spectrum, for example to
    enable the wireless communications industry to provide more
    services over frequencies associated with unused television
    channels.  An obvious requirement is that white space uses must
    not interfere with the primary use of the spectrum.  This is
    achieved through spatial and/or temporal separation of the
    primary user and whitespace user with due consideration made to
    the radio characteristics of the two uses.
    
    Problem Statement
    
    The fundamental problem is enabling a radio device to determine, in
    a specific location and at specific time, if any white space is
    available for secondary use.  There are two parties to such an
    interaction:
    
    1. A database containing records about the protected contours (in
    space and time) of primary spectrum users.  Typically, such databases
    will be populated by information provided by the appropriate spectrum
    regulation bodies and by spectrum licensees.
    
    2. A radio device that wishes to query such a database. Typically, the
    nature of the query will depend on the needs of the device.
    
    The contents of white space databases, and the needs of radio devices,
    are being defined elsewhere.  However, these parties need a protocol
    for communication that will enable radio devices to find out what white
    space is available at a given time in a given location.
    
    It is expected that white space databases will be reachable via the
    Internet, and that radio devices too will have some form of Internet
    connectivity, directly or indirectly.  Therefore, it is appropriate
    to define an Internet-based protocol for querying white space databases
    and receiving responses from such databases.
    
    In rough outline, such a protocol would enable a radio device that
    knows its location and the current time to complete the following tasks:
    
    1. Determine the relevant white space database to query.
  
    2. Connect to the database using a well-defined communication method.
  
    3. Provide its geolocation and perhaps other data to the database
       using a well-defined format for querying the database.
  
    4. Receive in return a list of available white space spectrum
       with their characteristics, using a well-defined format for
       returning information.
  
    5. Report to the white space database anticipated spectrum usage
       at a suitable granularity.
  
    Once the device learns of the available white space (e.g., in a TV
    white space implementation, the list of available channels at that
    location), it can then select one of the bands from the list and
    begin to transmit and receive on the selected band.  If the device's
    parameters have changed (e.g., if some amount of time has passed or if
    the device has changed location beyond a specified threshold), it might
    need to query the database again to determine what white space is still
    available.
    
    Objectives
    
    The overall goals of this working group are to:
    
    1. Standardize a mechanism for discovering a white space database.
  
    2. Standardize a method for communicating with a white space
    database.
  
    3. Standardize the data formats to be carried over the defined
    database communication method.
  
    4. Ensure that the discovery mechanism, database access method,
    and query/response formats have appropriate security levels in place.
    
    By "standardize" is not meant that the working group will necessarily
    develop new technologies.  In completing its work, the group will:
    
    - Evaluate existing discovery mechanisms to determine if one of
      them provides the necessary application features and security
      properties (or can be extended to do so) for discovering a
      white space database.  Examples might include DNS.
    
    - Evaluate existing application-layer transport protocols to
      determine if one of them provides the necessary application
      features and security properties (or can be extended to do so)
      for use as a building block for communication between location-
      aware devices and white space databases.  If such a method
      exists, the group will reuse it; if not, the group will develop
      one.  Examples might include HTTP.
    
    - Develop a method for querying a white space database.  Such
      a method will utilize, so far as possible, the features of
      the application-layer transport protocol and not re-implement
      them in the new protocol. It will include mechanisms to verify
      that the requests and responses come from authorized sources,
      and that they have not been modified in transit.  Examples might
      include LDAP.
    
    - Define extensible formats for both location-specific queries and
      location-specific responses for interaction with radio white
      space databases.  The group will consider whether existing data
      formats can be reused.
    
    The protocol must protect both the channel enablement process and the
    privacy of users.  Robust privacy and security mechanisms are needed
    to prevent: device identity spoofing, modification of device requests,
    modification of channel enablement information, impersonation of
    registered database services, and unauthorized disclosure of a device's
    location.  The group will consider whether existing privacy and
    security mechanisms can be reused.
    
    The task of defining the structure and contents of the databases
    themselves is out of scope.  The group will standardize formats for
    communication between devices and databases, but not the information
    models for the databases, since those models are likely to be
    country-specific or application-specific.  In addition, the particular
    data exchanged between a device and a database might depend on the
    ranges of radio spectrum that are to be used, the requirements of the
    database operators and their governing regulations, and other factors.
    Therefore, the database access method and the query/response data
    formats that are exchanged using that method need to be designed for
    extensibility rather than being tied to any specific spectrum, country,
    or phy/mac/air interface.  For example, the working group should define
    extension points for the database access method and the query/response
    formats, so that use cases other than those currently envisioned can be
    addressed in the future if a community of interest wishes to do so.
    However, the access method and query/response formats will incorporate
    relevant aspects of the parameters needed for the currently envisioned
    use cases to ensure proper operation.
    
    In accordance with existing IETF processes, the group will communicate
    and invite participation with other relevant standards bodies and
    groups, and if necessary reuse existing liaison relationships or
    request the establishment of new liaison relationships, including but
    not limited to IEEE 802.11af and IEEE 802.22.  In order to ensure that
    it takes into account a broad range of possible use cases and
    requirements, the group should also reach out to other potential
    "customers" for a white space database access method and consider input
    from regulatory entities that are involved in the specification of the
    rules for secondary use of spectrum in specific radio bands.
    
    Deliverables
    
    1. A description of the relevant use cases and requirements.  This
    document shall be Informational.  Subject to working group consensus,
    draft-probasco-paws-overview-usecases and draft-patil-paws-problem-stmt
    might be used as a starting point.
    
    2. A specification of the mechanism for discovering a white space
    database, the method for accessing a white space database, and the
    query/response formats for interacting with a white space database.
    This document shall be Standards Track.