Understanding Spectrum

  1. What is spectrum?

    Spectrum refers to the range of electromagnetic wavelengths. This electromagnetic spectrum creates light and colors, but also powers electronic devices, wireless communication, and broadcast -- AM and FM radio, walkie talkies, cell phones, radar, satellites, etc.

    Spectrum is divided into different frequency bands to avoid interference so your local radio station doesn’t interfere with your mobile phone call to your mom.

  2. Why is spectrum so valuable?

    Spectrum is a scarce resource you use every day, including when you use a mobile phone or Wi-Fi, listen to the radio, or click a remote control. All of these technologies depend on the availability of spectrum. Most useful spectrum has already been allocated for AM and FM radio, broadcast TV, mobile phones, satellite, radar, and military or government purposes. As demand for spectrum increases, the supply becomes scarce.

    The effective management and allocation of spectrum can provide a massive benefit to Internet users, improve wireless communications, and help put better and faster Internet connections in the hands of the public.

  3. Who manages spectrum?

    Each country has their own communications regulator that manages spectrum. In the U.S., the Federal Communications Commission (FCC), an independent regulatory agency, administers spectrum designated for non-federal use, while the National Telecommunications and Information Administration, in the Department of Commerce, administers spectrum designated for federal use.

  4. What are the different types of spectrum?

    Licensed: Most spectrum bands are licensed for exclusive use and allocated to a specific function by a regulatory body (such as the FCC in the U.S.). Licensed bands are allowed to be used only by the company that holds a license, which is given out by the regulatory authority. For example, the radio station 89.7 is exclusively licensed to public radio in the Boston area.

    Unlicensed: These bands of spectrum are used by anyone who has a compliant device that follows basic guidelines set by the regulator. For example, anyone without a license can set up a Wi-Fi router, which uses the 2.4 Ghz and 5 Ghz bands. The Wi-Fi 802.11 standard defines how mobile devices communicate with a Wi-Fi router without causing interference with other devices. Unlicensed use allows multiple people to broadcast on the same spectrum frequency at the same time.

  5. What is the TV white space?

    One important form of unlicensed spectrum is TV white space, unused channels in the broadcast television spectrum band. Many parts of the world have dozens of open TV channels, especially in rural areas, that can travel distances up to 10 miles. The FCC, Ofcom, and other regulators are providing a path to allow Wi-Fi to broadcast over unused TV channels. White space could help bridge the digital divide by providing wireless internet to rural areas and help enable technology innovation.

Spectrum Database Overview

  1. Why is Google working on this?

    Google is doing our part to make more spectrum available for broadband Internet access. One way we are doing this is through dynamic spectrum sharing. Specifically, we’re working to promote dynamic spectrum sharing through a TV white space database.

  2. What is spectrum sharing?

    Spectrum sharing can take a number of forms, but its purpose is to allow spectrum to be used by another party when not in use or needed by the primary user. For example, if a government communications system does not require spectrum at specific times, that spectrum can be freed up for commercial purposes during those times. With dynamic sharing, multiple users, including federal and commercial entities, can share available bands of radio spectrum and help increase the availability of a precious resource.

  3. What is the purpose of a spectrum database?

    Since spectrum is a limited resource, our spectrum database aims to allow dynamic spectrum sharing to maximize the use of spectrum and the benefits of that use. Dynamic spectrum sharing allows registered devices to query a database and determine, for a given location, what frequencies can be used while protecting licensed entities and wireless microphone signals from harmful interference.

  4. How do you know this isn’t going to cause harmful interference?

    Certified databases conform to FCC rules to protect against interference. Specifically, the rules ensure that TV white space spectrum will be made available to users only when its use does not interfere with protected entities.

  5. What is the current status of the database?

    The Google Spectrum Database had been certified by the Federal Communications Commission (FCC) and is available to wireless devices that are approved by the FCC for the TV white space bands. Device manufacturers, researchers and anyone interested can now use our API to identify and use TV white space spectrum that is available.

    We currently serve the United States, and plan to expand to more countries in the future.

  6. How do I find more information on the database?

    If you are interested in contacting us about the database, please fill out this form. Note that we may not be able to respond to every request.

    To learn more about the Spectrum Database API, visit our page in the Google developer site.

Using the Database

  1. What can users do with this database?

    Anyone can use the Browse Spectrum page to see TV white space spectrum that is available in their specific location.

    Developers interested in white space information can also use the Spectrum Database API to obtain TV-band spectrum availability information for any location in the United States. Device manufacturers can also sign up for a commercial agreement to use the Spectrum Database API in their white space devices.

  2. What's the difference between "Fixed" and "Portable" device types?

    A "Fixed" white space device operates from a specified stationary location, and might be suitable for things like commercial Wi-Fi Hot-Spots, rural broadband distribution, or cellular-style installations. These types of devices typically operate at comparatively higher power and with antennas mounted on a tall building or mast. Since the signal from these devices might be stronger and propagate farther than the signals sent by personal devices, the rules for fixed devices are more strict on where and when the devices can operate.

    A "Portable" white space device is one that operates over shorter distances and uses less power. These are typically laptops, Wi-Fi access points, tablets, and smartphones. Since these devices generate a relatively small spectrum "footprint", they are allowed to operate in more places and on more channels than Fixed devices.

    The Browse Spectrum page allows users to search for available spectrum using either of these device sharing rules.

  3. How do I find white space in my area?

    With the Browse Spectrum page, users can see what channels are available for TV white space usage at specific locations by inputting an address or latitude and longitude of a location. Once location has been entered, users can click on the "Search" button and a table will show the results. The top of the table shows how many channels and how much spectrum is available for that location. Each column in the table represents a channel, and columns that are green show specific channels that are available. "Non-green" columns are annotated with information on why those channels are not available.

    If you are a developer, you may also use our Spectrum Database API to obtain more detailed TV white space availability information for any geo-location within the United States.

  4. Who is eligible to register for protection?

    The following list summarizes the types of protected entities that may be registered with our database and the eligible operators:

    • Temporary BAS (Broadcast Auxiliary Service) Links - holders of a Broadcast Auxiliary Service license, Television Broadcast license or a FM Broadcast license.
    • MVPD (Multi-channel Video Program Distributor) Receive Sites - operators of a cable TV head-end.
    • Low Power Auxiliary Stations (Licensed Wireless Microphone) - holders of a Low Power Auxiliary license, or a Television Broadcast license.
    • Low Power Auxiliary Device Venue (Unlicensed Wireless Microphone) - holders of an FCC wireless microphone license.

    For more information, please consult the FCC White Space Database Administration Q & A Page.

Collection of Data

  1. What information do you collect in connection with the database, and how do you use that information?

    Google is certified by the U.S. Federal Communications Commission ("FCC") to operate a database of the unlicensed television spectrum bands or "white spaces" in the United States of America. In order to provide the TV white space (“TVWS”) service to database users, Google may collect certain information as specified herein.

    Information regarding protected entities and fixed base stations

    As required by FCC regulations, Google collects the following information from protected entities and fixed base station operators.

    1. Protected Entity Registration. Protected entities are particular types of uses (e.g., wireless microphones, multichannel video programming distributors’ receive sites) that can register with the database for protection from interference from TVWS devices under the FCC’s rules by providing the following information:
      • Callsign and operating channels
      • ULS file number
      • Operator's contact information
      • Transmitter geolocation
      • Receiver geolocation
      • Protection area
      • Specific schedule of operation
    2. Fixed Base Station Registration. Fixed white space device operators are required to register their locations with the FCC by providing the following information:
      • Geolocation
      • FCC ID and manufacturer serial number
      • Antenna height
      • Owner information
        • Name of individual or organization
        • Contact person
        • Address
        • Email
        • Phone number

    Google's TVWS database must interoperate with other FCC-designated database administrators to provide the TVWS services. As a result, the information set forth above may be shared with other certified TVWS database operators, the FCC, and the general public.

    Information gathered from all TVWS devices

    In addition to information collected from registered entities, the FCC also requires Google to collect the following information from all TVWS devices that request spectrum access via the database:

    • The device’s geolocation
    • Its device type as specified in the FCC’s rules (Fixed, Portable Mode I, or Portable Mode II)
    • Its device identifier, which includes FCC ID and manufacturer serial number

    The FCC’s rules require that this requester data and and the database's response to the request be recorded and kept for 30 days for auditing purposes, but this information is not shared with other database providers or the public.

    The information collected may change from time to time. This statement will be updated to reflect the changes, which will not apply retroactively.

    Google’s use of this data

    In general, the Google Privacy Policy explains how we use information we collect.

    Google may use the recorded information regarding its Google Spectrum Database for internal debugging and for providing information to the FCC, if requested. Google will, upon request, provide to the FCC information about devices that is collected in connection with use of the Google Spectrum Database. Such information will be limited to that which Google is legally required to provide.

    Other than as set forth above, information collected by the database will not be made available to any other parties. Consistent with that rule, we do not share personal information with companies, organizations and individuals outside of Google except in the circumstances (such as with your consent, with domain administrators, for external processing and for legal reasons) as more fully set out in the Google Privacy Policy.

  2. How long is this data kept?

    The per-request data for non-fixed devices will be marked for deletion after 30 days.

    The data for fixed devices, as public information, will be kept indefinitely. The registration data provided by entities for protection of their spectrum, as public information, also will be kept indefinitely.

  3. How is internal access to this data controlled?

    The per-request data, as non-public information, is stored in an encrypted manner. Only Google Spectrum Database team members will have permission to obtain the encryption key needed to decrypt the per-request data.