---
title: CTTelephonyNetworkInfoDelegate
framework: coretelephony
role: symbol
role_heading: Protocol
path: coretelephony/cttelephonynetworkinfodelegate
---

# CTTelephonyNetworkInfoDelegate

The methods that the system invokes when data service changes occur.

## Declaration

```swift
protocol CTTelephonyNetworkInfoDelegate : NSObjectProtocol
```

## Topics

### Responding to Data Service Changes

- [dataServiceIdentifierDidChange(_:)](coretelephony/cttelephonynetworkinfodelegate/dataserviceidentifierdidchange(_:).md)

## Relationships

### Inherits From

- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Getting Information About the Cellular Service Provider

- [dataServiceIdentifier](coretelephony/cttelephonynetworkinfo/dataserviceidentifier.md)
- [delegate](coretelephony/cttelephonynetworkinfo/delegate.md)
- [serviceCurrentRadioAccessTechnology](coretelephony/cttelephonynetworkinfo/servicecurrentradioaccesstechnology.md)
- [Radio Access Technology Constants](coretelephony/radio-access-technology-constants.md)