Sprint is apparently now briefing its employees on the upcoming launch of the iPhone 4 on its network, reports TUAW. A source at the carrier told them that the briefings had begun and that the launch of the iPhone 4 would take place in October.

The sales team was informed that the iPhone 4 would have access to all of Sprints current data plans but that it will include an additional $10 data premium that is not specific to iPhone. The employee also said that Sprint would be carrying a ‘4G iPad’ but it was unclear whether the briefing was referring to a Sprint 4G hotspot paired up with an iPad, which it already offers, or a new iPad model that was tweaked to interact with Sprint’s network.

The premium data charge has previously been limited to Sprint’s LTE plans only, so it’s a tad frustrating to see it being applied to the decidedly 3G iPhone 4.

According to the report, the iPhone 5 wouldn’t make an appearance on Sprint until 2012, perhaps by early spring. This makes some sense as Apple is likely to give iPhone 5 priority to its current partners AT&T and Verizon.

This report seems to bolster up the previous rumors of the iPhone 4 and 5 coming to Sprint from late last month, as well as a leaked internal Sprint memo that points to the iPhone’s arrival on October 15th.