  In this paper, we investigate the problem of power control for streaming
variable-bit-rate (VBR) videos in a device-to-device (D2D) wireless network. A
VBR video traffic model that considers video frame sizes and playout buffers at
the mobile users is adopted. A setup with one pair of D2D users (DUs) and one
cellular user (CU) is considered and three modes, namely cellular mode,
dedicated mode and reuse mode, are employed. Mode selection for the data
delivery is determined and the transmit powers of the base station (BS) and
device transmitter are optimized with the goal of maximizing the overall
transmission rate while VBR video data can be delivered to the CU and DU
without causing playout buffer underflows or overflows. A low-complexity
algorithm is proposed. Through simulations with VBR video traces over fading
channels, we demonstrate that video delivery with mode selection and power
control achieves a better performance than just using a single mode throughout
the transmission.
