---
title: "setTransmissionMode(_:channelUUID:completionHandler:)"
framework: pushtotalk
role: symbol
role_heading: Instance Method
path: "pushtotalk/ptchannelmanager/settransmissionmode(_:channeluuid:completionhandler:)"
---

# setTransmissionMode(_:channelUUID:completionHandler:)

Sets the audio transmission mode for the channel you specify.

## Declaration

```swift
func setTransmissionMode(_ transmissionMode: PTTransmissionMode, channelUUID: UUID, completionHandler: (@Sendable ((any Error)?) -> Void)? = nil)
```

```swift
func setTransmissionMode(_ transmissionMode: PTTransmissionMode, channelUUID: UUID) async throws
```

## Parameters

- `transmissionMode`: The transmission mode.
- `channelUUID`: The channel identifier the participant becomes active in.
- `completionHandler`: The completion handler that contains an optional error.

## Discussion

Discussion important: You can call this method from synchronous code using a completion handler, as shown on this page, or you can call it as an asynchronous method that has the following declaration: func setTransmissionMode(_ transmissionMode: PTTransmissionMode, channelUUID: UUID) async throws For information about concurrency and asynchronous code in Swift, see Calling Objective-C APIs Asynchronously. By default, a channel’s transmission mode is PTTransmissionMode.halfDuplex — indicating that only one participant can send or receive audio at a time. Use PTTransmissionMode.fullDuplex to allow a person to transmit and receive audio simultaneously. Set the transmission mode to PTTransmissionMode.listenOnly to prevent a participant from transmitting any audio.