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# CTTelephonyNetworkInfo.RadioAccessTechnologyDidChangeMessage

A message that posts when the radio access technology changes for one of the services.

```
struct RadioAccessTechnologyDidChangeMessage
```

## Overview

Use the [`serviceIdentifier`](/documentation/CoreTelephony/CTTelephonyNetworkInfo/RadioAccessTechnologyDidChangeMessage/serviceIdentifier) property  as the key in [`serviceCurrentRadioAccessTechnology`](/documentation/CoreTelephony/CTTelephonyNetworkInfo/serviceCurrentRadioAccessTechnology) to get the value of the new radio access technology for the service.

## Topics

### Instance Properties

[`var serviceIdentifier: String`](/documentation/CoreTelephony/CTTelephonyNetworkInfo/RadioAccessTechnologyDidChangeMessage/serviceIdentifier)

The service identifier for which the radio access technology changed.

## Relationships

### Conforms To

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Sendable`](/documentation/Swift/Sendable)

[`AsyncMessage`](/documentation/Foundation/NotificationCenter/AsyncMessage)

---

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