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This document provides information about how to use and set channel masks for your
Citizens Broadband Radio Service Device (CBSD).
When you request a channel mask, channel restrictions take effect immediately
for spectrum inquiry requests and new grants. Any existing grants that overlap
with newly restricted channels are terminated at the time specified in the
Pending changes section of the Coex tab for that CBSD.
Depending on your CBSD vendor, you might need to request grants
for the available channels manually.
By default, Spectrum Access System (SAS) shows all channels as available to all
CBSDs. Only users can set a channel mask. SAS
doesn't automatically assign channel masks for any CBSDs.
After you set a channel mask for a CBSD, SAS
rejects all new grant requests from that CBSD for the channels that
you have restricted.
Use channel masks for the following:
To make sure that your CBSD uses the highest quality channel.
Occasionally, a CBSD automatically requests a grant for
channels that you don't want to use. In this case, use channel masks to hide channels so that the
CBSD doesn't request grants for them.
You can only use channel masks for a CBSD that has channel
quality scores. Channel quality scores appear up to four hours after a
CBSD configuration reaches the Ready for CPI status.
Learn how to choose a channel.
Channel masks must be set on one CBSD at a time. Currently,
channel masks can't be set in bulk for an entire deployment or a subset of one.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-25 UTC."],[],[],null,["# Use channel masks\n\nThis document provides information about how to use and set channel masks for your\nCitizens Broadband Radio Service Device (CBSD).\n\nWhen you request a channel mask, channel restrictions take effect immediately\nfor spectrum inquiry requests and new grants. Any existing grants that overlap\nwith newly restricted channels are terminated at the time specified in the\n**Pending changes** section of the **Coex** tab for that CBSD.\nDepending on your CBSD vendor, you might need to request grants\nfor the available channels manually.\n\nBy default, Spectrum Access System (SAS) shows all channels as available to all\nCBSDs. Only users can set a channel mask. SAS\ndoesn't automatically assign channel masks for any CBSDs.\n\nAfter you set a channel mask for a CBSD, SAS\nrejects all new grant requests from that CBSD for the channels that\nyou have restricted.\n\nUse channel masks for the following:\n\n- To make sure that your CBSD uses the highest quality channel.\n- When you select new channels for a single CBSD with [channel guidance](/spectrum-access-system/docs/cbsd/channels) or for multiple CBSDs with a [channel plan](#channel-network).\n- Occasionally, a CBSD automatically requests a grant for channels that you don't want to use. In this case, use channel masks to hide channels so that the CBSD doesn't request grants for them.\n\nRequirements to use a channel mask\n----------------------------------\n\n- To use channel masks, register through the [early access sign-up](https://docs.google.com/forms/d/e/1FAIpQLSfrjhKpdzOosLnsHI-kKY6wUVrKf_LpAHT0Zle-5nK2ZOwqpQ/viewform) form.\n- You can only use channel masks for a CBSD that has channel quality scores. Channel quality scores appear up to four hours after a CBSD configuration reaches the **Ready for CPI** status. [Learn how to choose a channel](/spectrum-access-system/docs/cbsd/channels).\n- Channel masks must be set on one CBSD at a time. Currently, channel masks can't be set in bulk for an entire deployment or a subset of one.\n\nSet a channel mask\n------------------\n\n| **Important:** Channel masks don't terminate active grants until [Coordinated\n| Periodic Activities among SASes (CPAS)](/spectrum-access-system/docs/key-terms#cpas).\n\nTo set a channel mask, follow these steps:\n\n1. Go to the [SAS Portal](https://wirelessconnectivity.google.com/sas/).\n2. Click **View deployments**.\n3. Select the deployment, and then click **Open**.\n4. Select the CBSD. On the right, the CBSD page opens.\n5. On the **Coex** tab, for **Channel mask** , click *expand_more* **Expand**.\n6. Click *lock_open* **Lock node**.\n7. Click **Select channels**, and then select all the channels that you want the\n CBSD to use.\n\n | **Tip:** You can sort channels by frequency or by channel quality.\n8. Click **Schedule request** . The **Channel mask** section updates with your scheduled channel mask.\n\n | **Tip:** When you re-enable previously restricted channels, those channels become available to the CBSD immediately.\n\nWhat's next\n-----------\n\n- [Choose the best channels for a CBSD](/spectrum-access-system/docs/cbsd/channels).\n- [Choose the best channels for your network](/spectrum-access-system/docs/cbsd/network-channel).\n- Learn about [Spectrum Access System](/spectrum-access-system/docs/overview).\n- Learn about [key SAS terms](/spectrum-access-system/docs/key-terms).\n- [Troubleshoot SAS issues](/spectrum-access-system/docs/troubleshooting)."]]