In coverage d2d communications between two user

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In-Coverage D2D communications between two user devices are fully controlled by the network infrastructure of operators, such as BS or core networks. In this scenario, all user devices are located in the coverage of cellular networks. The operator manages the shared cellular licensed spectrum between the D2D links and normal cellular connections. Typical use cases of this scenario not limited to local traffic offloading from the core networks and operator controlled local
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Fig. 5. D2D communication application scenario data services, such as local content sharing, gaming, and Machine-to-Machine (M2M) communications. Relay-Coverage In this scenario, D2D communications can improve network service quality at the edge of network coverage by extending the coverage of cellular networks. User devices that are out of Base Station (BS) coverage can use other covered devices as a data communication relay and by means of them communicate with the core network (BS). Like the previous scenario, the operator fully controls the connection establishment, resource allocation for both User-to-BS connections and D2D (User-to-User) connections and D2D link used the shared cellular licensed spectrum. Out-of-Coverage This D2D communication scenario looks similar to MANETs. “Out -of- Coverage” scenario serves as the important component for emergency communication services, (e.g., national security, disaster relief, and public safety communications)[14][15]. In an urgent situation where the cellular infrastructure has been severely damaged, caused by a flood, storm, fire etc., D2D user devices, without the assistance of any operators, can establish connections and start D2D communications with each other in proximity. D2D communications are expected to be an underlying network of LTE-Advanced (LTE-A). In order to introduce the D2D communications into existing LTE Networks and make them compatible with LTE-A, the 3rd Generation Partnership Project (3GPP) proposed ProSe (i.e., D2D communications) system architecture under the framework of LTE Networks[16]. Vehicle-to-Vehicle (V2V) applications for safety and infotainment are based on IEEE 802.11p [17]. Internet-of-Things (IoT) is defined as the interconnection via the internet of computing devices embedded in everyday objects, enabling them to send and receive data. M2M communication is a form of data communication that involves one or more entities that do not necessarily require human interaction or intervention in the process of communication[18]. M2M communication is also named as Machine Type Communication (MTC) in 3GPP. This type of communication could be carried over mobile networks (e.g., LTE or LTE-A) and regarded as an underlaying technology on IoT. D2D communications can apply for M2M communications in the IoT, which means that under the supervision and control of core networks, like Base Station or M2M server, enable intelligent machines to interchange data, communicate directly with each other, and consequently improve network performance, lower power consumption, and
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  • Fall '19
  • Radio resource management, Cellular network, Cell site

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