D2D Discovery Research Articles

A game theoretic approach for spectral and energy efficient D2D communication in 5G-IoT networks

In the context of fifth generation (5G) technology, Device-to-Device (D2D) communication plays a pivotal role, requiring swift and intelligent decision-making in mode selection and device discovery. This study addresses the challenge of rapid mode selection and device discovery within 5G communication networks, focusing specifically on enhancing spectral and energy efficiency for Internet of Things (IoT) applications. A novel self-centered game theory-based algorithm is introduced to optimize spectral efficiency and support intelligent mode selection. Additionally, the utilization of the support vector machine (SVM) expedites mode selection decisions. For D2D discovery, the Frank-Wolfe method is adopted, significantly improving the differentiation between D2D and Cellular users based on signal strength and interference, thereby enhancing spectral efficiency. The proposed approach maximizes spectral efficiency while adhering to strict power and interference constraints, intelligently partitioning bandwidth into two subparts using game theoretic principles to amplify spectral efficiency. Furthermore, the emphasis on energy efficiency is underscored through iterative calculations to achieve maximum energy-efficient spectral allocation. Numerical analyses validate the efficacy of the proposed technique, revealing substantial improvements in accurately predicted labels. As the number of devices increases, precision and recall rates experience noteworthy enhancements, ultimately leading to superior bandwidth utilization. This research presents a significant contribution to the field of 5G communication, particularly concerning energy efficiency, which is paramount for IoT applications. By accelerating D2D connectivity and optimizing energy and spectrum resources, it advances the goals of energy-efficient D2D communication within 5G-IoT networks.

A Novel Approach to D2D Discovery in PSN for Post-Disaster: Throughput Based Discovery Algorithm (TDA)

After a disaster occurs, effective communication between the people and the institutions of disaster or emergency management is vital. Device to device (D2D) discovery and communication provides communication services in such difficult situations without the requirement of network infrastructure and by reducing call traffic in cellular communication networks. Considering the fact that almost everyone uses a smart mobile device (UE-User Equipment), the D2D communication method seems the most suitable solution for a post-disaster situation. In particular, this method plays important role in fifth generation 5G communication networks. The device discovery or UE discovery is fundamental strategy in D2D communication. In this study, a Throughput-based Discovery Algorithm (TDA) is proposed to find D2D peers among devices on Public Security Network (PSN) in a post-disaster situation. A sample scenario was created to test the performance of the proposed TDA, and the TDA was compared to some discovery algorithms, such as Shortest Distance Algorithm (SDA), Maximum SINR with No limit on the distance of discovery Algorithm (MSNA), and Maximum SINR with Limit on the distance of discovery Algorithm (MSLA). In terms of the outage SINR and average pair SINR metrics, the proposed TDA showed better performance than the other discovery (MSNA, SDA, and MSLA) algorithms for D2D discovery in the disaster area.

Energy-Efficient Device Discovery Mechanism for Device-to-Device Communications in 5G Networks

The conventional direct device discovery scheme which uses the random access protocol and encounters contentions or collisions is highly energy and time-consuming. To reduce the energy consumption of user equipments (UEs), this work proposes a two-phase hybrid device discovery mechanism for device-to-device (D2D) communications. In the first phase, the evolved packet core (EPC) or base station (BS) uses the location information of UEs to judge whether two UEs are able to establish a D2D link. In the second phase, UEs use Wi-Fi Direct to discover their target UEs. The BS directly assigns UEs’ states and allocates appropriate Wi-Fi channels to UEs. UEs no longer have to search or listen to all channels, thus reducing the discovery delay. The proposed mechanism saves cellular spectrum resources because it uses unlicensed bands for D2D discovery and communications. The performance of the proposed hybrid D2D discovery mechanism is also theoretically analyzed in this paper. Evaluation results show that the proposed D2D discovery mechanism has better performance in terms of energy consumption, discovery delay and discovery success rate, compared with the conventional direct D2D discovery scheme, especially in the network scenarios with smaller cells such as 5G networks. Additionally, the analytic results coincide with simulation results, demonstrating that our theoretic analysis is accurate.

Interference Cancellation Techniques for Device-to-Device Discovery in Out-of-Coverage Networks

Nowadays, the number of users and connected devices linked to a cellular network is very large. For that reason, new technologies that do not need network support, such as Device-to-Device (D2D) communication, have been developed. D2D communications may occur randomly, uncoordinated and unscheduled, giving rise to interference, which critically impairs the ability of a device to identify its neighbors - a process known as D2D discovery. This work proposes an innovative method to mitigate the interference problem in the D2D discovery process; it is based on a new approach to enhance the detection of multiple concurrent transmitting devices, namely by considering the use of multiple orthogonal pilot sequences jointly with a new receiver block, and on a new procedure that extends the Successive Interference Cancellation (SIC) technique using a single time slot (intra-SIC) to a SIC process that is able to consider several time slots (inter-SIC), which is made possible due to the creation of a new frame concept - the virtual frame. A simulation framework is implemented with the purpose of demonstrating how the proposed method would work and confirm its suitability and effectiveness. It is shown that, for a high number of contending devices and without the use of any type of SIC, about 50% of the discovery sessions are successfully completed; by applying intra-SIC, the discovery success ratio increases to 75%-80%; however, by considering the method proposed herein, 85%-95% of the discovery sessions are successfully completed.

Cyclic Block-Spreading Direct Discovery for D2D Networks

Device-to-device (D2D) communications has become a pivotal piece to complete the puzzle of future generation of wireless communication systems. The enabling technology for the D2D communications lies in its discovery mechanism. Plenty of works have been proposed to enhance the efficiency of direct D2D discovery without network assistance. Generally, the main idea of these works is to avoid unnecessary collisions during the discovery period. However, owing to the limited resources for D2D discovery, the effectiveness of the collision avoidance based schemes is always restricted. Instead, we aim to make the discovery beacon robust against collisions. To achieve this, the cyclic block spreading (CBS) scheme is proposed to spreading the beacon over multiple subframes without widening the bandwidth and the need of redesigning the beacon. That means that solely minor modification of specification is required. The simulation and analytic results show that using the CBS direct discovery scheme, the performance in terms of outage probability, collision rate and time periods for complete discovery can be significantly improved.

Energy-Efficient Device Discovery in D2D Cellular Networks for Public Safety Scenario

Energy-efficient device discovery is vital in public-safety systems. We investigate the problem of maximizing the number of discovered users under the major constraint of overlay interference, which occurs in device-to-device (D2D) communications, from users simultaneously accessing the resources. To solve this problem, we propose a D2D discovery maximization (D2D-DM) iterative algorithm, which provides the capability to switch the discovery mode from half-duplex to in-band full-duplex, when signal-to-interference-noise ratio falls below a predefined threshold. Moreover, the open-loop power control scheme is adopted for power-limited users. Simulation results demonstrate that the proposed D2D-DM scheme significantly enhances the number of discovered users as compared to conventional static resource allocation and the random backoff schemes.

In-Band Device to Device (D2D) Communication and Device Discovery: A Survey

Device to device (D2D) communication is one of the potentials to achieve the established standards for 5G. It represents a direct communication between two devices located in the vicinity of each other. In D2D communication, user's data traffic can be offloaded without passing through the base transceiver system (BTS) and the core network. In order to initiate the D2D communication, device discovery is needed, and it is a major design issue for D2D communication. To achieve a potential discovery, there are some requirements such as energy efficient discovery capability, supporting a large number of devices and proximity discovery in the network assisted underlay D2D communication network. In this paper, device discovery processes and methods are presented and assessed using different approaches. In addition, a device discovery technique is proposed for single cell and a multi cell which capable to provide accurate and fast discovery with energy efficient and optimized routed path. D2D discovery techniques are evaluated, its main challenges are analyzed and potential solutions are also suggested.

Enhancing Device-to-Device direct discovery based on predicted user density patterns

Device-to-Device (D2D) direct discovery service is a key component for Proximity Services (ProSe) and D2D communications. Depending on the type of the studied network (pedestrian, vehicular, residential, industrial), large spatio-temporal fluctuation in mobile users’ density may occur inducing several patterns throughout the day. The current standards only account for fixed configurations of this service, and currently, the research into adaptive algorithms is done using analytical models and synthetic scenarios and configurations, which makes such solutions perform poorly on real systems. We propose an adaptive D2D discovery algorithm that, building upon existing work on user density prediction analytical models of the discovery process, uses historic network traces to update its operational parameters dynamically. We test the proposed algorithm and compare it to the discovery mechanism, defined in the Third Generation Partnership Project (3GPP) standards, in order to analyze the feasibility of these types of solutions. The simulation results show that the proposed algorithm strikes a balance between network utilization and time required for discovery, which is a very promising starting point for further research on this type of solutions.

A Social-Aware Virtual MAC Protocol for Energy-Efficient D2D Communications Underlying Heterogeneous Cellular Networks

In this paper, a social-aware virtual medium access control (SV-MAC) is devised to integrate virtualization and social awareness to D2D communications underlying heterogeneous cellular networks. SV-MAC is a converged network layer. Through SV-MAC, heterogeneous networks can be unified in a single protocol stack, providing a common abstraction for users and mobile network operators (MNOs) to share their network resources. Leveraging users' social information, SV-MAC can realize social-aware D2D discovery, association, and resource allocation for improved D2D communication efficiency. In order to validate the advantages of the proposed SV-MAC protocol, we study the cellular and D2D resource allocation problems under the SV-MAC protocol. The problems are formulated as maximizing the cellular and D2D energy efficiency (EE). The cellular resource allocation problem is first solved considering its priority to D2D users. The resource allocation problem for D2D users is solved after cellular users to control the D2D-to-cellular interference within a tolerable threshold. In the simulation, we introduce real mobile user traces to simulate the user social information. Simulation results show that the proposed SV-MAC resource allocation schemes obtain a beneficial EE improvement comparing with conventional schemes.

SDN-based handover scheme for multi-tier LTE/Femto and D2D networks

Femto Access Points (FAP) and Device-to-Device (D2D) communications have recently been considered as potential candidates for 5G network densification and cell-edge performance. Mobility and handover management is a major issue in heterogeneous networks (HetNet) offering different access technologies. Recently, many Fuzzy and Multi-Attribute Decision Making (MADM) handover decision algorithms have been proposed to ensure Quality of Service (QoS), reduce the number of handovers and handover blocking probability of mobile users. However, network discovery is still an issue as it increases the total handover delay and drains the battery of the user equipment (UE). In addition, the UE may undergo high interference with other co-channel users after the handover is executed, thus limiting the overall network performance. Currently, the emerging Software Defined Networking (SDN) has been proposed in which one centralized controller can assist in the handover discovery, handover decision, and co-channel interference coordination. SDN-based handover algorithms ensure QoS, Quality of Experience (QoE), reduce delay and interference. In this paper, we will integrate the Fuzzy logic into the SDN to assist in FAPs and D2D discovery, and the decision of candidate networks based on the networks’ QoS parameters. Then, the UE will make the final handover decision by selecting the best network based on the predicted QoE using TOPSIS and AHP algorithms. Frequency reuse and appropriate power control are also applied in order to increase network capacity and reduce interference. Performance results show that the proposed SDN-based Fuzzy MADM handover scheme reduces unnecessary handovers, blocking probability and total handover delay. In addition, throughput is increased as the number of users increases.

Neighbourhood‐aware out‐of‐network D2D discovery

Device-to-device communication in 5G networks will require fast and efficient neighbour discovery. This Letter shows that with an initial knowledge of proximity, devices can increase discovery probability. However, in out-of-coverage scenarios, devices do not have information about neighbourhood which decreases the discovery probability. Hence, this Letter proposes an algorithm that enables neighbourhood-awareness in out-of-coverage environments, and increases discovery probability.

Novel Device-to-Device Discovery Scheme Based on Random Backoff in LTE-Advanced Networks

Device-to-device (D2D) discovery is a key enabler of D2D communications for the direct exchange of local area traffic between proximity users (UEs) to improve spectral efficiency. The direct D2D discovery relies on the capabilities of the D2D UEs to autonomously indicate their presence to proximity D2D UEs. Despite its potential of reducing energy and signaling burden, the direct D2D discovery has not drawn adequate attention. In this paper, we propose a direct D2D discovery scheme based on the random backoff procedure, where D2D UEs randomly choose a backoff interval and retransmit a beacon. Compared with existing schemes, the performance of the proposed scheme can be significantly enhanced in terms of the discovery probability and the discovery delay. Several useful guidelines for its design are proposed based on our analysis. Finally, numerical results provide valuable insights on the performance tradeoff inherent to the proposed D2D discovery scheme.

VANET Aided D2D Discovery: Delay Analysis and Performance

Existing solutions for integrating device-to-device (D2D) communication in cellular networks require added functionalities and consume valuable network resources, mainly in the discovery process. This paper effectively reduces the consumption of valuable resources in the LTE—A network through proposing a new D2D discovery scheme that works for vehicular users. The proposed scheme is able to offload a portion of the D2D discovery traffic and processing that involve vehicular drivers and passengers to Vehicular Ad-hoc Networks. The proposed scheme uses the inherent knowledge of the road side units about vehicular users in their coverage areas. In addition, this paper develops an analytical model to analyze the duration of peer discovery in highway scenarios. The results are validated through simulations done using real environments. The analytical and numerical results demonstrate the effectiveness of the proposed scheme, and show that a low discovery latency can be attained.

Interference Alignment Algorithm Based on Feedback Concentration in D2D Communications

This paper proposed an effective interference alignment algorithm based on channel state feedback concentration (FCIA) for device-to-device (D2D) communications. The algorithm iteratively calculates the precoding matrix by using the global channel state information. Furthermore, as D2D discovery is the premise of the D2D communications, an effective interference alignment algorithm based on D2D discovery is also proposed. Simulation results show that, the proposed FCIA algorithm reduces the feedback overhead for transmission coordination compared with the existing full feedback based algorithm. The proposed interference alignment scheme based on D2D discovery feedback is compared with the existing D2D discovery scheme: it is found that although the discovery time slots has increased by about 6.2%, the sum rate achieved by interference alignment is improved by almost 50%.

LTE D2D 디스커버리에서 무작위 자원 선택 방법에 대한 성능 분석

LTE D2D는 근접한 단말끼리의 직접적인 정보 교환을 통해 셀룰러 시스템의 데이터 트래픽 부하를 해결하는 핵심 기술이다. 특히 D2D 디스커버리는 LTE D2D를 위한 첫 단계로서 단말이 각자의 상태 정보를 주변 단말에게 브로드캐스트 하여 자신을 알리는 과정이다. 디스커버리 메시지 전송의 안정성을 평가하기 위해 시뮬레이션 기반의 성능 평가가 수행되었지만, 한정적인 상황에서 이루어진 경우가 많아 본 논문에서는 일반적인 환경에서 이를 평가할 수 있는 수학적 분석을 제안한다. 제안하는 분석은 확률 기하 이론을 바탕으로 수행되며, 자원 충돌과 인밴드 방사에 의한 간섭의 효과를 모두 고려한다. 우리는 디스커버리 메시지의 수신 성공 확률을 송수신 단말 간의 거리의 함수로 유도하고, 시뮬레이션 결과를 통해 제안하는 분석의 정확도를 확인한다. Long Term Evolution device-to-device (LTE D2D) is a key technology to mitigate data traffic load in a cellular system. It facilitates direct data exchange between neighboring users, which is preceded by D2D discovery. Each device advertises its presence to neighboring devices by broadcasting its discovery message. In this paper, we develop a mathematical analysis to assess the probability that discovery messages are successfully transmitted at the D2D discovery stage. We make use of stochastic geometry for modeling spatial statistics of nodes in a two dimensional space. It reflects signal to noise plus interference ratio (SINR) degradation due to resource collision and in-band emission, which leads to the discovery message reception probability being modeled as a function of the distance between the transmitter and the receiver. Numerical results verify that the newly developed analysis accurately estimates discovery message reception probabilities of nodes at the D2D discovery stage.

Performance Analysis of Network-Assisted D2D Discovery in Random Spatial Networks

Device-to-device (D2D) discovery is the inextricable prelude for the direct exchange of local traffic between cellular users in proximity. The D2D discovery process can be based on either autonomous actions taken by D2D-enabled devices, also known as network-assisted D2D discovery or core network functionalities to estimate proximity, also known as network-assisted D2D discovery. A key advantage of network-assisted D2D discovery is its potential to reduce the energy, signaling, and interference required for D2D discovery, by exploiting knowledge of the network layout. We analyze the performance of network-assisted D2D discovery in random spatial networks and derive useful guidelines for its design. We derive approximate expressions for the distance distribution between two D2D peers conditioned on the core network’s knowledge of the cellular network layout, assuming that the base stations are distributed according to the Poisson point process. The expressions are used to assess the interplay between the D2D discovery probability and key system parameters, such as network intensity and transmit power, as well as to identify conditions to maximize the D2D discovery probability. Numerical results validate the accuracy of our findings and provide insights on the performance tradeoffs of network-assisted D2D discovery.

Efficient D2D Discovery Scheme for Channel Measurement of Interference Alignment

Device-to-device (D2D) communications have the potential to improve spectrum efficiency and link capacity by allowing nearby devices to communicate directly with each other on the licensed frequency bands. Hence, co-channel interference (CCI) among D2D users are major issues to be solved when they are utilizing the same frequency bands. Consequently, interference alignment (IA) as an effective interference management approach has been implemented to the D2D communications for the frequency sharing. However, the measurement of channel state information (CSI) between transmitter and receiver of a D2D pair and cross-channel state information (C-CSI) among D2D pairs are the major issues that need to be resolved for the implementation of IA from theory to practical. Therefore, in this paper, we propose an effective D2D discovery scheme to overcome this problem, which can measure the CSI and C-CSI based on the transmission of discovery messages. Simulation results show that, under perfect conditions, even though the proposed D2D discovery scheme increases the needed time slots to establish D2D communications compared with the conventional D2D discovery without considering IA by 6.2%, it increases the throughput up to 50% than the conventional D2D communications without considering IA, i.e., it improves the spectrum efficiency.

Efficient device‐to‐device discovery and access procedure for 5G cellular network

AbstractA large number of new data‐consuming applications are emerging, and many of them involve mobile users. In the next generation of wireless communication systems, device‐to‐device (D2D) communication is introduced as a new paradigm to offload the increasing traffic to the user equipment. Before the traffic transmission, D2D discovery and access procedure is the first important step which needs to be completed. In this paper, our goal is to design a device discovery and access scheme for the fifth generation cellular networks. We first present two types of device discovery and access procedures. Then we provide performance analysis based on the Markov process model. In addition, we present numerical simulation on the Vienna Matlab platform. The simulation results demonstrate the viability of the proposed scheme. Copyright © 2015 John Wiley & Sons, Ltd.

Recent progress of long‐term evolution device‐to‐device in third‐generation partnership project standardisation

Device-to-device (D2D) is considered as a promising technique to increase resource utilisation and to provide new application in future wireless networks. This study reviews the standardisation progress of D2D in third-generation partnership project. Three scenarios, in-coverage, partial-coverage and out-of-coverage, are defined. For these scenarios, channel model is obtained by the amendment of existing channel model. The function of D2D operation is divided into three building blocks: synchronisation, discovery and communication. The synchronisation procedure and synchronisation signal/channel are discussed first. Then the design aspects of D2D discovery and communication are discussed in detail, including channel structure design, resource allocation mechanisms, interference management and so on. Future works towards post Rel-12 releases are also briefly outlined.

Device-to-Device Discovery for Proximity-Based Service in LTE-Advanced System

In this paper, we propose a device-to-device (D2D) discovery scheme as a key enabler for a proximity-based service in the Long-Term Evolution Advanced (LTE-A) system. The proximity-based service includes a variety of services exploiting the location information of user equipment (UE), for example, the mobile social network and the mobile marketing. To realize the proximity-based service in the LTE-A system, it is necessary to design a D2D discovery scheme by which UE can discover another UE in its proximity. We design a D2D discovery scheme based on the random access procedure in the LTE-A system. The proposed random-access-based D2D discovery scheme is advantageous in that 1) the proposed scheme can be readily applied to the current LTE-A system without significant modification; 2) the proposed scheme discovers pairs of UE in a centralized manner, which enables the access or core network to centrally control the formation of D2D communication networks; and 3) the proposed scheme adaptively allocates resource blocks for the D2D discovery to prevent underutilization of radio resources. We analyze the performance of the proposed D2D discovery scheme. A closed-form formula for the performance is derived by means of the stochastic geometry-based approach. We show that the analysis results accurately match the simulation results.