Mode Switching for Device-to-Device Communication in LTE-A Network

Abstract

Device-to-device (D2D) communication enables nearby user equipments (UEs) to communicate directly without passing it through a base station (BS). When UE wish to communicate over direct link it is required to know the channel condition of its D2D link and its cellular link to select a link providing the best quality of service, so-called mode selection. UEs participating D2D communication need to conduct measurement over its UE-UE link and its eNB-UE link as well, and BS makes decision on mode switching based on the measurement report of UE. In this paper, we study the measurement procedures and reporting algorithms required for D2D communication. Frequent measurement report can cause the ping-pong mode switching whereas infrequent measurement report results in the delay of mode switching, thereby, leading to losing opportunity to offload traffic from the network. Wasteful frequent ping-pong mode switching is observed in some cases. We show that our proposal prevents frequent ping-pong mode switching without significant degradation in offloading performance achievable from D2D communication.

A Comprehensive Survey on Mobility-Aware D2D Communications: Principles, Practice and Challenges

“…It randomly and uniformly chooses another direction to move after reaching the edge of the coverage area and also after stopping with a pause-time. The same concept is implemented in D2D communication underlaying cellular networks [65]- [67]. However, this mobility model may not be applicable in certain D2D communication applications, such as using relay in out of coverage scenario.…”

“…Since the variation in the CSI of D2D links is caused by users' movement, therefore D2D links must be constantly monitored for the continuation of communication. It is important due to the fact, that the network should make mode switching between D2D link and cellular link to provide significant QoS and QoE to the users [65], [101]. It is also intriguing believe that the delivery delay is inversely proportional to the average user velocity i.e., by decreasing the user velocity, the delivery delay increases and vice versa.…”

Resource Allocation for Device-to-Device Communications Underlaying Cellular Networks

“…So a reasonable wireless resource allocation method should be applied to mitigate interference so as to guarantee the quality of data transmission [5]. This paper mainly studies the wireless resource allocation method for D2D communications in cellular networks [6].…”