With the iPhone Configuration Utility you can set your iPad or iPhone carrier's APN manually in case it's not working properly, which can sometimes happen for developers running beta versions of iOS. It's a workaround to be sure, but if you need your device on-network for testing and can't wait for newer betas, sometimes a work around is just what you need.
Follow on after the break for step-by-step instructions.
Google your carrier's APN settings. Take note of them.
Scroll all the way to the bottom and, under Advanced, fill in your carrier's APN info.
Again, this isn't as good as having it work automagically, but it's better than not having it work at all. If you've been having problems, hopefully this helps.