Now, on to the Qualcomm MDM9615 LTE modem and RTR8600 multi-band/mode RF transceiver packages. We covered the MDM9615 extensively in the iPhone 5 teardown, but here's a quick rundown:

The MDM9615 allows for multi-spectrums, multi-mode LTE support. It is responsible for transmitting simultaneous voice and data transfer on LTE (provided the carrier has the infrastructure to allow simultaneous voice and data transfer.)

The Qualcomm RTR8600 is a multi-band/mode RF transceiver. The RTR8600 is paired alongside the MDM9615 to support various bands, including 5 UMTS bands, and over 5 LTE and 4 EDGE bands.

So what's pictured on this step, you say?

The first image depicts the HG11-N3877 LTE Baseband die.

The second image is of the Samsung 1G-F-MC 128 MB memory die, also found in the MDM9615.

The third image shows the RTR8600 die.