Yang Cao

Huazhong University of Science and Technology | hust · Department of Electronics and Information Engineering

Multimedia Internet-of-Things (IoT) systems have been widely used in surveillance, automatic behavior analysis and event recognition, which integrate image processing, computer vision and networking capabilities. In conventional multimedia IoT systems, videos captured by surveillance cameras are required to be delivered to remote IoT servers for vi...

Mobile edge caching is a promising technique to reduce network traffic and improve the quality of experience of mobile users. However, mobile edge caching is a challenging decision making problem with unknown future content popularity and complex network characteristics. In this article, we advocate the use of DRL to solve mobile edge caching probl...

In scalable video coding (SVC) multicast, videos are encoded into several layers that represent multiple quality levels. Mobile users with different wireless channel conditions can obtain different numbers of layers and have different quality of experience (QoE). To enhance the QoE of the users that suffer from the worse channel quality, it is bene...

Recently, many applications (e.g., wearable cognitive assistance) with the devices of Internet of Things (IoT) (e.g., Apple Watch, Google Glass) have been fast developed. However, the current Internet may not be suitable for the future IoT applications due to the limited capabilities of the data caching and content processing services with the exis...

To meet the explosive demand on delivering high-definition video steams over cellular networks, we design a So cial-aware video multiCast (SoCast) system leveraging device-to-device (D2D) communications. One salient feature of SoCast is to stimulate effective cooperation among mobile users (clients), by making use of two types of important social t...

In this paper, we explore distributed edge computation offloading (DECO) that offloads computation to distributed edge devices connected wirelessly, which perform the offloaded computation in parallel. By integrating edge computing with parallel computing, DECO can substantially reduce the total computation delay. In particular, we study the fundam...

Cache pollution attack is a security problem of cache in Content-Centric Network (CCN). Cache pollution attacks include False Locality Attack (FLA) and Location Disruption Attack (LDA). This paper mainly considers FLA attacks, and cache pollution attacks mentioned in this paper are also referred to FLA attacks. Cache pollution attack mainly refers...

Maximizing quality of experience (QoE) for interactive video streaming has been a long-standing challenge, as its delay-sensitive nature makes it more vulnerable to bandwidth fluctuations. While reinforcement learning (RL) has demonstrated great potential, existing works are either limited by fixed models or require enormous data/time for online ad...

Introducing multi-UAV network with flexible deployment into mobile edge computing(MEC) can effectively improve the quality of service of Internet-of-Things services, reduce the coverage cost and resource waste rate of edge nodes, and also bring some challenges. This paper first introduces the current situation and pain points of mobile edge computi...

Distributed edge computation offloading makes use of distributed wireless edge devices to perform offloaded computation in parallel, which can substantially reduce the computation time. In this paper, we explore distributed edge computation offloading where the computation workloads of edge devices are correlated with their communication workloads....

In this paper, we propose a user selection algorithm suitable for digital and hybrid maximum ratio transmission (MRT) precoding to alleviate inter-user interference. For digital MRT, the minimum inter-user interference problem is reduced to the notorious NP-hard called max k -cut. We first relax the max k -cut problem into a semi-definite...

This paper investigates the content placement problem to maximize the cache hit ratio in device-to-device (D2D) communications overlaying cellular networks. We consider offloading contents by users themselves, D2D communications and multicast, and we analyze the relationship between these offloading methods and the cache hit ratio. Based on this re...

An important issue in an edge computing (EC) network is to increase the utilities of the end users concurrently accessing the computation resources. In this paper, we consider the task offloading in EC-enabled networks where the end users efficiently utilize the dispersed computation and communication resources in a multi-path multi-hop manner. We...

This letter investigates a delay optimization problem in device-to-device (D2D) networks where users have pre-downloaded subfiles following a coded caching rule. Due to acquiring rest subfiles, users may suffer both receiving and transmitting delays. To achieve the delay minimization, we first propose a delay-aware mode-selection strategy to adapti...

Nowadays unmanned aerial vehicles (UAVs) are being widely applied to a wealth of civil and military applications. Robust and high-throughput wireless communication is the crux of these UAV applications. Yet, air-to-ground links suffer from time-varying channels induced by the agile mobility and dynamic environments. Rate adaptation algorithms are g...

Nowadays unmanned aerial vehicles (UAVs) are being widely applied to a wealth of civil and military applications. Robust and high-throughput wireless communication is the crux of these UAV applications. Yet, air-to-ground links suffer from time-varying channels induced by the agile mobility and dynamic environments. Rate adaptation algorithms are g...

Recent advances in unmanned aerial vehicle (UAV) technology have revolutionized a broad class of civil and military applications. But the design of wireless technologies that enable real-time streaming of high-definition video between UAVs and ground devices presents a conundrum. Most existing adaptive bitrate (ABR) algorithms are not optimized for...

Recent advances in unmanned aerial vehicle (UAV) technology have revolutionized a broad class of civil and military applications. However, the designs of wireless technologies that enable real-time streaming of high-definition video between UAVs and ground clients present a conundrum. Most existing adaptive bitrate (ABR) algorithms are not optimize...

In heterogeneous networks (HetNets), user association approaches should be able to achieve load balancing among base stations (BSs). This paper investigates how to jointly optimize user association and resource allocation in Backhaul constrained HetNets for capacity enhancements. We consider two major limitations in HetNets: the backhaul bottleneck...

In this paper, a non-orthogonal multiple access (NOMA) enhanced scalable video coding (SVC) multicast scheme for cellular networks is proposed. This scheme combines the successive video-layer decoding in SVC with the successive interference cancellation (SIC) in NOMA, which enables a further reduction of the bottleneck effect imposed by celledge us...

Connected devices in Internet-of-Things (IoT) continuously generate enormous amount of data, which is transient and would be requested by IoT application users such as autonomous vehicles. Transmitting IoT data through wireless networks would lead to congestions and long delays, which can be tackled by caching IoT data at the network edge. However,...

Streaming of multimedia contents over the Internet is experiencing an unprecedented growth, which puts tremendous pressure on terrestrial networks. It is challenging to support multimedia content distribution in short end-toend delay with limited network resources (e.g., bandwidth). In this context, we study the benefit of adopting the spaceground...

This article proposes an architecture for D2D-enabled cellular networks, which allows multiple user equipments to proactively cache and then share multi-bitrate videos. Further, a proactive caching strategy is put forth to optimize the system utility that strikes a balance between quality-of-experience and cost, while considering the coordination o...

With the growing popularization of Electric Vehicles (EVs), charging management has become an increasingly important research problem in smart cities. Different from plug-in charging technology, we alternatively enable the battery switch technology to provide fast EV charging (reduce the service waiting time from tens of minutes to a few minutes),...

In this article, we first survey the current situation of video processing on the edge for multimedia Internet-of-Things (M-IoT) systems in three typical scenarios, i.e., smart cities, satellite networks, and Internet-of-Vehicles. By summarizing a general model of the edge video processing, the importance of developing an edge computing platform is...

In this paper, the imbalance edge cloud based computing offloading for multiple mobile users (MUs) with multiple tasks per MU is studied. In which, several edge cloud servers (ECSs) are shared and accessed by multiple wireless access points (APs) with the backhaul links, and each MU has multiple computing intensive and latency critical tasks should...

In a device-to-device (D2D) communications underlaying cellular network, any user is a potential eavesdropper for the transmissions of others that occupy the same spectrum. Physical-layer security mechanism is typically employed to guarantee secure communications, at the cost of reducing the system’s throughput. As hand-held devices are carried by...

As one of the key drivers of smart grid, EVs are environment-friendly to alleviate CO2 pollution. Big data analytics could enable the move from Internet of EVs, to optimized EV charging in smart transportation. In this article, we propose a MECbased system, in line with a big data-driven planning strategy, for CS charging. The GC as cloud server fu...

Unlike traditional ICEVs, the introduction of EVs is a significant step toward green environment. Public CSs are essential for providing charging services for on-the-move EVs (e.g., EVs moving on the road during their journeys). Key technologies herein involve intelligent selection of CSs to coordinate EV drivers' charging plans, and provisioning o...

Machine-to-machine (M2M) systems enable machines or devices to collect data, exchange information, and act on the environment without direct human intervention. A device in an M2M system not only collects data for its own usage but also shares the data with other devices automatically to achieve certain goals. Therefore, emerging M2M systems for ci...

The increasing demand of mobile applications creates challenges for mobile devices on energy consumption and data usage. As a solution, device-to-device communication can serve as a powerful paradigm in future cellular networks to enable local cooperation of mobile devices. By leveraging social awareness, users can share surplus communication and c...

The transmission of simultaneous and latencysensitive data puts forth a significant challenge for the smart grid communications. In this paper, we investigate the application of device-to-device (D2D) communications for the energy management in the electric distribution network. Specifically, we develop a D2D-assisted relaying framework to exploit...

The ever-increasing demands for local area services underlaying cellular networks benefit from direct device-to-device (D2D) communications, where an efficient scheme for resource allocation is needed to increase the system capacity as the result of interference caused by spectrum sharing. Current works mainly focus on maximizing the overall transm...

As a potential and promising technique for future wireless broadband communications, the OAM technique has attracted a significant attention due to its high capacity. In this article, a radio system based on OAM, called an RV system, is proposed. Specifically, a vortex modulation method and an azimuthal angle integral method are developed for the t...

The continuing advances in the storage and transmission abilities of user equipment have made it possible to share videos through device-to-device communications, which may be an efficient way to enhance the capacity of cellular network to provide wireless video services. In adaptive D2D video streaming, user experience is greatly influenced by the...

Relay-assisted D2D communication extends the communication range of the D2D pairs and helps users to form D2D pairs effectively. However, due to the introduction of the multi-hop relaying, the D2D communication has to occupy extra transmission time, which may decrease the efficiency of the communication system. In this paper, we propose a scheme to...

To meet the increasing demand of wireless broadband applications in 4G/beyond 4G cellular networks, D2D communication can serve as a candidate paradigm to improve spectrum efficiency. By reusing the spectrum of cellular users, two D2D users can form a direct data link without routing base stations and core networks; thus, the spectral efficiency ca...

To increase the number of accommodated users in the cellular heterogeneous network (HetNet), we propose an energy efficient load balancing strategy for device-to-device (D2D) based relay communications. In a HetNet, user could sent data to an adjacent uncongested femtocell through the D2D-based relay communications rather than wait for the response...

提出了一种基于设备间数据直传（D2D）中继的异构网络负载均衡策略，通 过设备之间的直接数据传输，将满载大基站的数据分流到其覆盖范围内的空闲小基 站中。具体提出了频谱资源和发射功率的联合资源分配算法，深入研究了在异构网 络中利用D2D 通信进行数据中继的传输速率最大化问题。仿真结果显示，提出的 方法在保证原有用户的通信性能的前提下，增加了系统的可接入用户数和总体吞吐 率，从而提升了自组织异构网络的整体性能。

In Internet data center operations, the operators are faced with high energy cost and carbon emission. Moreover, for socially responsible Internet data center operators, they are expected to minimize energy cost and carbon emission simultaneously. Since smart microgrids have many advantages in supporting the operations of Internet data centers (e.g...

With the adoption of smart grid, some cyber-related vulnerabilities may also be introduced. When cyber attacks are launched, the power grid may become unstable and ultimately power outages may occur. In this situation, backup generators would be scheduled to support the operation of Internet data centers. Since the generation cost of backup generat...

In practice, some workloads are delay-tolerant, which can be adopted to reduce energy cost of Internet data centers by utilizing the temporal diversity of electricity prices, i.e., executing the workloads when prices are low and delay the workloads when prices are high. To avoid the penalty for violating the service level agreements, heterogeneous...

In this paper, we investigate the problem of minimizing energy cost for distributed Internet data centers (IDCs) in smart microgrids while taking system dynamics into consideration. Specifically, IDC operators expect to minimize the long-term energy cost with the uncertainties in electricity price, workload, renewable energy generation, and power o...

This chapter introduces the background knowledge on smart grid and Internet data centers. Specifically, the definitions, characteristics, components of smart grid, and the architecture of Internet data centers are elaborated. Since the operations of Internet data centers lead to large power consumption, high energy cost, and carbon emission, Intern...

The increasing capabilities of mobile devices (MDs) enable users to run desktop-level applications and tasks anywhere. However, the local execution of resource-demanding mobile tasks, such as real-time rendering in 3D gaming, may result in poor performance and short battery lifetime on MDs. One solution to the resource scarcity problem on MDs is to...

Load shaping is one of important and challenging issues in power grid. In this paper, we propose a novel load shaping strategy based on energy storage and dynamic pricing in smart grid. In the proposed strategy, a consumer is encouraged to draw a certain amount of energy (i.e., quota) from the grid. When the actual energy demand is deviated from th...

publications/rights/index.html for more information. Abstract—In this paper, we investigate the problem of minimizing the long-term energy cost for an Internet data center (IDC) in deregulated electricity markets. Specifically, IDC operators intend to minimize energy cost by scheduling workload and battery jointly, which can fully exploit the tempo...

In this paper, we investigate the problem of minimizing carbon-aware energy cost for distributed Internet data centers (IDCs) in smart microgrids. Specifically, a socially responsible IDC operator intends to jointly minimize the long-term energy cost and carbon emission in IDC operations. Since the future system parameters (e.g., electricity price,...

In this paper, we study the problem of achieving the optimal tradeoff between operation risk and expected energy cost for Internet data center (IDC) operators in deregulated electricity markets according to the risk preferences of IDC operators. To achieve the target above, we propose a risk-constrained stochastic programming decision framework. Th...

In this paper, we propose SoCast - a cooperative video multicast framework to stimulate effective cooperation among mobile users (clients), by leveraging two types of important social ties, i.e., social trust and social reciprocity. By using SoCast, clients can form groups to restore incomplete video frames by obtaining missing packets from other c...

Resource allocation is an important issue in wireless communication networks. In recent decades, cognitive radio-based networks have garnered increased attention and have been well studied to overcome the problem of spectrum scarcity in future wireless communications systems. Many new challenges in resource allocation appear in cognitive radio-base...

In this article, we investigate the strategies of access and handoff in the opportunistic spectrum access (OSA) based cognitive cellular networks (CCNs). Then, a three dimension (3D) continuous- time Markov chain (CTMC) is constructed to derive the grade of service (GoS) performance metrics in the OSA-based CCNs. Through the 3D CTMC, both the non-h...

This paper studies the cognitive broadcast channel in which the primary user communicates to the primary receiver, while the secondary user has noncausal knowledge of the primary radio's codeword and expects to communicate to two secondary receivers. Comparing with the existing cognitive radio channel which considers only one secondary receiver, co...

In this paper, we propose a risk-constrained stochastic programming decision framework for Internet data center (IDC) operators under smart grid environment, which can achieve the tradeoff between operation risk and expected energy cost according to the risk preferences of IDC operators. In the proposed decision framework, self-generation is adopte...

In Internet Data Center (IDC) operations, some uncertainties are needed to be managed. Otherwise, IDC operators will be faced with a high operation risk. In existing work, electricity forward contract is adopted to minimize the IDC operation risk in smart grid environment under the assumption that workload and spot electricity price are independent...

We study joint expansion planning of conventional generation capacity, wind generation capacity and tie line capacity in a multi-area smart grid system. Specifically, we formulate the expansion planning problem as a two-stage stochastic programming problem: 1) in the first stage, resource expansion plans are made to minimize the expected overall co...

针对现有方案在系统服务等级约束下可能会降低认知无线网络可达业务负荷的问题，提出了一种新的频 谱共享机制以提高系统服务等级约束下具有异构业务的认知无线网络可达业务负荷。该机制的主要思想是根据实 时业务和非实时业务的不同延时特性，分别引入剥夺优先权和缓冲队列，进而同时减小异构次用户呼叫的强制中 断概率和阻塞概率。仿真结果表明，所提机制能有效提高系统服务等级约束下认知无线网络的可达业务负荷。

In this paper, we propose a novel transmission probability scheduling (TPS) scheme for the opportunistic spectrum access based cognitive radio system (OSA-based CRS), in which the secondary user (SU) optimally schedules its transmission probabilities in the idle period of the primary user (PU), to maximize the throughput of the SU over a single cha...

In this paper, we propose a novel framework of cognitive radio assisted cooperation (CRAC) for downlink transmissions in orthogonal frequency-division multiple access (OFDMA) - based cellular networks. In the proposed CRAC framework, relay stations are deployed in each cell and have spectrum sensing capability. In turn, they can access unoccupied w...

In this paper, we consider the Gaussian cognitive broadcast channel in which the primary user communicate to the primary receivers and the cognitive user has noncausal knowledge of the primary radio's codeword and wishes to communicate to two receivers. We characterize the largest rate region at which the cognitive user could reliably communicate u...

In this paper, we propose a novel proportional fair scheduling algorithm for MAC-layer sensing in the cognitive radio networks (CRNs). According to the secondary user (SU) channel state information and primary user (PU) traffic patterns, the SUs are adaptively scheduled to carry out sensing and transmission in different channels. Moreover, we joint...

In this paper, a novel spectrum sharing scheme is proposed to improve the achievable traffic load of secondary users (SUs) under grade of service (GoS) constraints in cognitive wireless networks with heterogeneous traffic. The key idea of the proposed scheme is to introduce preemptive priority and buffering mechanism for real-time traffic and non-r...

Recently, cyber foraging has been proposed to reduce the application response time and to save energy for the mobile hosts by offloading the resource-demanding tasks to the surrogates via wireless networks. However, communication overheads are further aggravated in the cyber foraging network (CFN), where multi-hosts share the same spectrum to offlo...

In this paper, we propose a novel transmission probability scheduling scheme for opportunistic spectrum access in cognitive radio networks. With the proposed scheme, the secondary user's throughput over a single channel is maximized while collision probability perceived by the primary user is constrained under a required threshold since the seconda...

Opportunistic spectrum access (OSA) which allows a secondary user to access channels when primary users are not transmitting has been considered a promising way to increase the spectrum efficiency. To coexist with the primary user in the same frequency band, the secondary user has to adopt strict interference control rules to avoid interference tow...