[[["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):2025-09-01。"],[],[],null,["# Manage PAL Protection Areas\n\nA [PAL Protection Area (PPA)](/spectrum-access-system/docs/key-terms#ppa) is\na geographic area protected from [General Authorized Access (GAA)](/spectrum-access-system/docs/key-terms#gaa)\ninterference when a [Priority Access License (PAL)](/spectrum-access-system/docs/key-terms#pal)\noperator uses a PAL channel. In this document, you learn how to manage and set up a\nPPA for your CBSDs.\n\nPPAs in Spectrum Access System (SAS) are generated automatically for each\nPAL-qualified Citizens Broadband Radio Service Device (CBSD) that requests a grant on an operator's\nPAL channels. The size and shape of a PPA are determined by the following:\n\n- The location of the CBSD.\n- The CBSD's Effective Isotropic Radiated Power (EIRP) capability as specified by the registration request, up to the FCC-certified limit.\n- The CBSD's antenna height, gain, azimuth, and beamwidth.\n- A standard [WInnForum](/spectrum-access-system/docs/key-terms#winforum)-defined propagation model used by all SASs.\n\nTo minimize interference to the PPA, CBSDs located outside but\nnear the PPA might have to reduce power on the PAL channel. Any new\nCBSDs deployed by another operator within the PPA cannot request\ngrants for the PAL channel. [Learn how to find a PPA in the SAS Portal](/spectrum-access-system/docs/use-pals#showpal).\n\nSAS might create one or multiple PPAs within a county for the\nsame PAL channel based on the service areas of one or more PAL-protected\nCBSDs. PPAs are dynamic because they can grow, merge, split, and\nshrink based on the size of the service areas. The SAS merges\nPPAs that overlap into a single PPA when those PPAs are on the same channel and\nin the same county. PPAs are updated daily during\n[Coordinated Periodic Activities among SASs (CPAS)](/spectrum-access-system/docs/key-terms#cpas).\n\nSet up a PPA for your CBSD\n--------------------------\n\nYou can set up a PPA for your CBSD before, during, and after\nCPAS.\n\n**Before CPAS**\n\n- Request a grant on your PAL channels two hours before CPAS. This is to ensure that SAS creates a PPA during CPAS. Protection from CBSDs that have GAA grants begins afterwards.\n- If your PAL channel [doesn't have a high quality score](/spectrum-access-system/docs/cbsd/channels#channel-quality), and your equipment supports multiple grants, use a different grant to transmit until your PAL grant successfully finishes CPAS. This minimizes the risk and impact of interference before PAL protection begins.\n\n**During CPAS**\n\nWe recommend that your CBSD keeps heartbeating on your PAL\ngrant. New PPAs take time to get protected. Other operators'\nCBSDs within the PPA might use the PAL channel until CPAS has\ncompleted, so your PAL channel might experience interference.\n\n**After CPAS**\n\n- The PPA protection begins after CPAS is completed. SAS\n terminates all grants on the PAL channel for other operators'\n CBSDs located within the PPA.\n\n- The CBSD sends heartbeats to receive authorization to transmit.\n Your CBSD is protected from interference from other\n CBSDs on the PAL channel.\n\n- If you experience interference on your PAL channel after the PPA is created,\n contact [SAS Support](/spectrum-access-system/docs/getting-support).\n\nMaintain a PPA for a PAL-protected CBSD\n---------------------------------------\n\nTo maintain a PPA for a PAL-protected CBSD, follow these steps:\n\n1. Continue heartbeating on the PAL grant. If the CBSD does not\n receive a heartbeat on a PAL grant for seven days, the CBSD's\n PPA is removed.\n\n | **Note:** If you use multiple PAL grants and miss heartbeats on one PAL grant, only the PPA associated with that grant is removed. If the CBSD continues to heartbeat on the remaining PAL grants, then the PPAs for the remaining grants are still enforced.\n2. If a PPA is removed from a PAL-protected CBSD,\n [re-establish a PPA](#re-establish-ppa).\n\n| **Tip:** If you relinquish a PAL grant and request a new one within the same day, it does not affect the PPA.\n\nRe-establish a dropped PPA\n--------------------------\n\nTo re-establish a PPA, do not re-register the CBSD. We strongly\ndiscourage re-registration because all of the CBSD's other\ngrants are relinquished and might not be available immediately after\nre-registration.\n\nTo re-establish a dropped PPA, do the following:\n\n1. [Request a new PAL grant](/spectrum-access-system/docs/use-pals) for the same channel.\n2. Wait for the next CPAS cycle.\n3. After the next CPAS cycle, the PPA is established.\n\nWhat's next\n-----------\n\n- Learn how to [use PALs in the SAS Portal](/spectrum-access-system/docs/use-pals).\n- Learn about [SAS sync (or IAP)](/spectrum-access-system/docs/sas-sync).\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)."]]