Problems with WiFi? Try renewing DHCP lease

In newly revised Knowledge Base article #305715, Apple provides a two-step process that can resolve issues in many instances when the iPhone is connected via WiFi:

1. "Tap Settings > Wi-Fi Networks, then pick the network.
2. "In the DHCP panel, select the Renew Lease button."

The article details solutions to a number of other WiFi issues as well, including persistent reversion to EDGE.