As per this link:
There is no direct way to specify request timeout value in Volley, but there is a workaround, you need to set a RetryPolicy on the request object. The DefaultRetryPolicy class takes an argument called initialTimeout, this can be used to specify a request timeout, make sure the maximum retry count is 1 so that volley does not retry the request after the timeout has been exceeded.
Setting Request Timeout:
request.setRetryPolicy(new DefaultRetryPolicy(20 * 1000, 1, 1.0f));
If you want to retry failed requests (due to timeout) you can specify that too using the code above, just increase the retry count. Note the last argument, it allows you to specify a backoff multiplier which can be used to implement “exponential backoff” that some RESTful services recommend.
The link has a lot of useful tips and tricks for using Volley. Hope this helps!