Achieving Zero Ms Handover Interruption In New Radio With Higher Throughput Using D2d Communication

The demand for high data rate and data volume has been increased rapidly over the last decade. This is due to the growth of bandwidth-hungry wireless applications and services. Thus, the 5G cellular network is expected to solve this problem while supporting seamless mobility. This brings the demand for low latency handover in cellular networks. According to 3GPP, the target for Handover Interruption Time (HIT) is 0 ms. Thus, in this paper, we propose to exploit Device-to-Device (D2D) communication to achieve 0 ms HIT and thus support seamless mobility. The D2D based handover considers two modes of operation, viz. direct and D2D. During handover, the gNodeB (gNB) computes the best mode of operation (direct or D2D) for the data transfer to the receiver User Equipment (UE). In the case of the D2D mode of operation, the gNB finds an RRC Connected/RRC Inactive UE to act as a relay for transferring the content from the gNB to the receiver UE with higher throughput. A complete handover procedure that explains the above D2D based handover mechanism is proposed. With extensive simulations, we demonstrate that the proposed D2D based handover procedure achieve 0 ms HIT with higher throughput as compared to the direct mode of data transmission. We also demonstrate that with the increase in the user density from 50 to 200 in the given cellular region, the number of D2D based handover increases by 573% as compared to that of the direct mode of operation which increases by 137%. Further, we observe that 42.9% of total handover achieves up to 20% increment in throughput by employing D2D based relay mode as compared to the direct mode.