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Small cell support
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Devices launched with Android 11 or higher can provide
support for closed subscriber groups (CSGs) through methods in the
cell identification APIs
that get information about a cell's CSG information. This is useful for mobile
network operators (MNOs) that manage small cells through closed subscriber
groups. Information about CSGs is represented in the
ClosedSubscriberGroupInfo
class.
Implementation
To support CGGs on devices running Android 11 or
higher, implement the following functions in
radio/1.5/types.hal.
ClosedSubscriberGroupInfo: Included optionally with every
CellIdentity instance. This structure is used to provide details about
the closed subscriber group to which a cell belongs, if any. This is
commonly used to identity small cells such as personal LTE devices. It
can also be used in deployments such as CBRS LTE.CellIdentityLte: Supports a list of additional PLMN-IDs.CellIdentityWcdma: Supports a list of additional PLMN-IDs.CellIdentityTdscdma: Supports a list of additional PLMN-IDs.RegStateResult: Includes an updated CellIdentity structure and a
field to indicate the RPLMN.
Validation
To test your implementation, run the following CTS test:
CellInfoTest.
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Last updated 2025-06-18 UTC.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-06-18 UTC."],[],[],null,["# Small cell support\n\nDevices launched with Android 11 or higher can provide\nsupport for closed subscriber groups (CSGs) through methods in the\n[cell identification APIs](https://developer.android.com/reference/android/telephony/CellIdentity)\nthat get information about a cell's CSG information. This is useful for mobile\nnetwork operators (MNOs) that manage small cells through closed subscriber\ngroups. Information about CSGs is represented in the\n[`ClosedSubscriberGroupInfo`](https://developer.android.com/reference/android/telephony/ClosedSubscriberGroupInfo)\nclass.\n\nImplementation\n--------------\n\nTo support CGGs on devices running Android 11 or\nhigher, implement the following functions in\n[`radio/1.5/types.hal`](https://android.googlesource.com/platform/hardware/interfaces/+/refs/heads/android16-release/radio/1.5/types.hal).\n\n- `ClosedSubscriberGroupInfo`: Included optionally with every `CellIdentity` instance. This structure is used to provide details about the closed subscriber group to which a cell belongs, if any. This is commonly used to identity *small cells* such as personal LTE devices. It can also be used in deployments such as CBRS LTE.\n- `CellIdentityLte`: Supports a list of additional PLMN-IDs.\n- `CellIdentityWcdma`: Supports a list of additional PLMN-IDs.\n- `CellIdentityTdscdma`: Supports a list of additional PLMN-IDs.\n- `RegStateResult`: Includes an updated `CellIdentity` structure and a field to indicate the RPLMN.\n\nValidation\n----------\n\nTo test your implementation, run the following CTS test:\n[`CellInfoTest`](https://android.googlesource.com/platform/cts/+/3c3d33a/tests/tests/telephony/src/android/telephony/cts/CellInfoTest.java)."]]
