[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["很难理解","hardToUnderstand","thumb-down"],["信息或示例代码不正确","incorrectInformationOrSampleCode","thumb-down"],["没有我需要的信息/示例","missingTheInformationSamplesINeed","thumb-down"],["翻译问题","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["最后更新时间 (UTC):2025-08-18。"],[],[],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)."]]