Transmission mode selection and communication establishment in the hybrid device-to-device and cellular networks

The decision-making of the transmission mode and communication establishment are two key issues in the initial procedure for the hybrid system of the cellular and device-to-device (D2D) network. In this paper, according to cellular users and D2D terminals use the same resources or not, we firstly propose two criteria to select the transmission mode. When these two kinds of users reuse resources, the minimum interference to the cellular system is considered to suggest the criterion. However, the system throughput based criterion is derived when they use different resources. To this end, an effective mechanism to establish D2D communication and avoid interference is presented. Simulations show that our criteria are effective and can obtain a better system performance compared with the pure cellular mode and D2D mode.