Pin-Han Ho

University of Waterloo | UWaterloo · Department of Electrical & Computer Engineering

Fast reroute (FRR) is among the fastest survivable routing approaches in packet-switched networks, because the routers are equipped with a resilient routing table in advance such that the packets can be rerouted instantly upon failures solely relying on local information, i.e., without notification messages. However, designing the routing algorithm...

This paper presents a novel framework called Failure-Alarm Correlation Tree based Failure Localization (FACT-FL), designed to localize failed optical layer device boards in an Optical Transport Network (OTN). Specifically, FACT-FL aims to construct a set of FACTs by correlating the failed boards and alarms, where each FACT takes one failed board an...

Unmanned aerial vehicles (UAVs) offer advantages in serving as aerial small cells (ASCs) to support public safety terrestrial cells (PSTCs) while providing pervasive coverage during disasters. To ensure reliable communications for long-term evolution-based public safety (PS-LTE) users, it is crucial to obtain an accurate understanding of network pe...

To fully exploit the potential of reconfigurable intelligent surface (RIS), the controllable channel state information (CSI) should be accurate for its future applications. Unfortunately, in vehicular communications, obtaining exact instantaneous CSI presents substantial challenges. Moreover, even with an instantaneous CSI acquisition, a processing...

The article investigates aerial computing terrestrial-support-free multi-layer multi-access edge computing (AC-TMMEC) systems within the context of massive machine-type communications (mMTC) beyond 5G (B5G). With its four layers, namely space platform (S), high-altitude platform (HAP), low-altitude platform (LAP), and ground mobile access point pla...

Space-air-ground integrated networks (SAGINs) hold immense potential for improved network coverage and dynamic service delivery. Yet, current methods often depend on separate, uncoordinated unmanned aerial vehicles (UAVs), leading to scalability issues and limited energy efficiency – challenges that persist even when applying intelligent machine le...

Multi-hop communication has gained prominence within the realm of the Internet of Underwater Things (IoUT) owing to its exceptional reliability amidst the challenges posed by the underwater acoustic environment. Despite this, the persistence of limitations caused by propagation delay, high collision rate, and limited energy in underwater communicat...

This paper addresses the virtual network (VN) mapping problems for the network profit optimization in space-division-multiplexing optical data center networks (SDM-ODCNs). We first define both link resource availability (LRA) and node resource availability (NRA) for the VN mapping optimization, by which an integer linear program (ILP) model and two...

Cybertwin technology introduces a novel paradigm employing digital twins to model complex physical systems within a cyber environment, thus enhancing communication, collaboration, and decision-making capabilities. By harnessing advanced technologies, such as reconfigurable intelligent surfaces (RISs) and multi-access edge computing (MEC), seamless...

This letter investigates secrecy performance for cognitive transmissions, where a secondary user (SU) shares same spectrum with a primary user (PU) simultaneously ensuring the quality-of-service (QoS) of primary transmissions. Additionally, an eavesdropper (Eve) overhears cognitive transmissions from SU to base station (BS). To against eavesdroppin...

This article presents an in-depth examination of aerial reconfigurable intelligent surface (ARIS) technology, an innovative development in wireless communication networks facilitated by unmanned aerial vehicles (UAVs). ARIS introduces a dynamic approach to augmenting communication links, particularly vital in environments characterized by rapid cha...

In the context of the rapid deployment of IoT, 5G, and cloud computing, numerous emerging applications demand efficient networked computing capacity for task offloading from mobile and IoT users. This paper focuses on the optimization of network resource allocation and reduction of end-to-end (E2E) latency through the strategic decision of whether...

Grant-free access (GFA) has been envisioned to play an active role in massive Machine Type Communication (mMTC) under 5G and Beyond mobile systems, which targets at achieving significant reduction of signaling overhead and access latency in the presence of sporadic traffic and small-size data. The paper focuses on a novel K-repetition GFA (K-GFA) s...

This paper explores the usage of low-voltage Power-Line Communication (PLC) links for Enhanced Common Public Radio Interface (eCPRI)-based front-hauling in 5G IoT indoor mobile coverage environments, using a split Centralized Radio Access Network (C-RAN) architecture. This research aims to analyze how parameters such as wireless IoT device count, b...

This paper presents the design and implementation of a simulator comprising the following components: a rule database, a topology generator, a failure generator, and an alarm generator. The topology generator produces network topologies to simulate various network conditions, while the failure generator generates simulated failures. Subsequently, t...

In this letter, we investigate the wireless communication system assisted by hybrid intelligent reflecting surface (RIS), which is composed of both passive and active elements integrated reflection-type amplifiers. Different from conventional hybrid RIS system, the amplifying power used at active RIS is considered as one part of the total power for...

In the rapidly evolving field of wireless communications, the emergence of 5G and the progression towards 6G technologies highlight the demands for innovative frameworks capable of enhancing network performance under complex environmental factors. According to this trend, this work introduces a novel system model for aerial reconfigurable intellige...

This letter studies an aerial reconfigurable intelligent surface (ARIS)-aided multiple-input multiple-output (MIMO) ground communication system, where downlink transmission from a multi-antenna base station (BS) to a set of terrestrial single-antenna users is investigated. We target at optimizing the sum-rate of all users by jointly considering the...

For future wireless communication networks to be highly efficient with both spectrum and energy, reconfigurable intelligent surface (RIS) has emerged as a practical technology. In this paper, we investigate an RIS-aided cooperative non-orthogonal multiple access (C-NOMA) system serving two power-domain users, where a near user as a decode-and-forwa...

This paper addresses the problems of core and spectrum assignment (CSA) in space-division-multiplexing (SDM) elastic optical networks (EONs) with multi-core fiber (MCF). We first present spectrum sensitivity (SS) of the crosstalk-sensitive core matrix to evaluate inter-core crosstalk (XT) in trench-assisted (TA) MCF. We then propose the XT-sensitiv...

This article presents a novel and efficient failure localization framework in Optical Transport Network (OTN), called Instance Correlation based Failure Localization (IC-FL). Specifically, IC-FL aims to localize faulty network devices in OTN optical layer via correlation among the state changes of network devices and alarms using a trained binary c...

This paper investigates the scenario of the Internet of things (IoT) data collection via multiple unmanned aerial vehicles (UAVs), where a novel collaborative multi-agent trajectory planning and data collection (CMA-TD) algorithm is introduced for online obtaining the trajectories of the multiple UAVs without any prior knowledge of the sensor locat...

With deployment of 5G and emerging 6G networks, the demand of wireless communication for transmission capacity as well as the transmission security in consumer electronics is increasing. Reconfigurable intelligent surface (RIS) has shown a great potential in physical layer security (PLS) due to its enabling technology to engineer the radio signal p...

With the rapid development of Internet of Things (IoT), IoT mobile devices host more computation-intensive and real-time applications, such as face recognition, online gaming, and augmented reality/virtual reality services. This paper mainly addresses the problems of the selective resource offloading in order to achieve resource optimization in clo...

In the insecure transmission environment, compared with the passive eavesdropper (Eve), the active Eve plays a more threatening role in the physical layer security (PLS), since it can wiretap and jam the signals. To simultaneously decrease the wiretap massage for Eve and improve secrecy outage probability (SOP) for the legitimate users, an enhanced...

This paper investigates physical-layer security (PLS) for an energy-harvesting cognitive network with non-orthogonal multiple access (EHCN-NOMA), where a cognitive base station (CBS) communicates with two cognitive users named cognitive near user (CNU) and cognitive far user (CFU) by adopting the NOMA principle under an active or passive eavesdropp...

This letter explores the potential of reconfigurable intelligent surface (RIS) to enhance vehicle-to-vehicle (V2V) communications under predictable mobility conditions. We analyze the impact of multipath fading and Doppler effects induced by high-mobility vehicles on the proposed system. Moreover, we present a Pareto optimal RIS configuration desig...

This study explores the utilization of low-voltage indoor power line communication (PLC) technology within the framework of a split centralized radio access network (C-RAN) architecture, aimed at enhancing 5G indoor mobile coverage for the Internet of Things (IoT). A primary focus of this investigation is the comprehensive evaluation of the system’...

In this paper we consider machine-type communications (MTC) in 5G cellular networks for internet-of-thing (IoT) applications, where a large number of MTC devices simultaneously communicate with a base station (BS) over an uplink channel. To overcome the resource-constrained nature of the MTC nodes, we introduce a novel cooperative non-orthogonal mu...

In order to realize the green computing of the edge-cloud fiber-wireless networks, the cooperation between the edge servers and the cloud servers is particularly important to reduce the network energy consumption. Therefore, this paper proposes an energy-efficient workload allocation (EEWA) scheme to improve the energy efficiency by using the archi...

With the rise of the Industrial Internet of Things (IIoT), more and more industrial devices can be connected via the network. Data collection, processing, analysis, task execution, and other devices that can product network traffic volume are gradually being deployed to IIoT. However, under the limited spectrum resources and low-cost and low-energy...

With low-cost energy consumption, the reconfigurable intelligent surface (RIS) technique is a potential solution to the real-time data processing for intelligent transportation systems (ITSs). In this paper, an intelligent transmissive surface is introduced into the vehicular communications, enabling vehicle-to-infrastructure (V2I) signals to penet...

In this letter, a novel reconfigurable intelligent surface (RIS) aided partial non-orthogonal multiple access (P-NOMA) downlink is investigated, where the passive beamforming on the RIS is designed for serving paired user equipments (UEs), with their signal frequencies partially overlapped. We consider the general case that all UEs have both direct...

In this paper, we investigate an innovative physical layer security (PLS) scheme for an uncertain reconfigurable intelligent surface- (RIS-) assisted communication system under eavesdropping attack. Specifically, in our proposed system, we consider that the uncertain RIS is known to the legitimate user while not to the eavesdropper (Eve). In this m...

In this letter, a novel reconfigurable intelligent surface (RIS)- and relay-assisted cooperative network with non-orthogonal multiple access (NOMA) is proposed, where the line-of-sight (LoS) and non-LoS (NLoS) scenarios are both considered for different locations of users. For the proposed cooperative NOMA systems, we first analyze the capacities o...

Inspired by the promising potentialof reconfigurable intelligent surface (RIS)-based transmission, this paper investigates the RIS-aided vehicle-to-everything (V2X) communication system with the social trust, where multiple vehicle-to-infrastructure (V2I) links share the spectrum with vehicle-to-vehicle (V2V) links. Subject to the reliability const...

Residential power line is considered a cost-effective communication media for building a digital indoor distributed network thanks to its ubiquity in the indoor environment. This paper investigates a front-hauling system under the split centralized radio access network (C-RAN) architecture, aiming to examine the feasibility of implementing common p...

The spectrum efficiency is a greatly important issue when we establish connection requests in elastic optical data center networks (EODCNs). In this article, we address the spectrum efficiency problems of the shared-path protection with spectrum-sharing-maximized approaches for the optical network survivability. Two integer linear program (ILP) mod...

Use of online social networks (OSNs) undoubtedly brings the world closer. OSNs like Twitter provide a space for expressing one’s opinions in a public platform. This great potential is misused by the creation of bot accounts, which spread fake news and manipulate opinions. Hence, distinguishing genuine human accounts from bot accounts has become a p...

In this article, the physical layer security (PLS) is investigated for reconfigurable intelligent surface (RIS)-aided wireless communication systems, where one RIS is deployed to assist the communications between a pair of transmitter (Alice) and receiver (Bob), under a passive eavesdropper (Eve) attack. For the Eve, different from the bounded chan...

Prediction of social IoT (SIoT) data traffic is helpful in characterizing the complicated relationships for such as device-to-device, user-to-user, and user-to-device. One of the most popular traffic prediction methods in noisy environments is the Kalman filter (KF), which is extremely simple and general. Nevertheless, KF requires a dynamic traffic...

This paper investigates energy-efficient secure communication design with the help of multiple phase-adjustable intelligent reflecting surfaces (IRSs). By creating desirable radiation patterns of wireless environment, the IRSs are used to significantly improve the number of bits securely delivered to the destination per energy consumption in Joule,...

Reconfigurable intelligent surface (RIS) offers a potential performance boost for next-generation wireless networks, with significant improvements in spectral and energy efficiencies. In this paper, considering a two-user multiple-input single-output non-orthogonal multiple access (MISO-NOMA) downlink, we propose a RIS-aided cooperative transmissio...

Collaborative Intrusion Detection Systems are considered an effective defense mechanism for large, intricate, and multilayered Industrial Internet of Things against many cyberattacks. However, while a Collaborative Intrusion Detection System successfully detects and prevents various attacks, it is possible that an inside attacker performs a malicio...

Unmanned aerial vehicles (UAV) are widely applied for service provisioning in many domains such as topographic mapping and traffic monitoring. These applications are complicated with huge computational resources and extremely low latency requirements. However, the moderate computational capability and limited energy restrict the local data processi...

Instant and precise localization of indoor mobile users is fundamental for supporting various sophisticated location-aware services. Using Bluetooth low-power beacons for mobile user positioning has been reported as an effective approach, where the beacon deployment positioning (BDP) problem has been defined. The paper introduces a novel approach f...

In this article, we introduce a novel millimeter wave (mmWave) access architecture, called mmWave over cable (mmWoC), for achieving effective indoor coverage under integrated access backhaul. The proposed mmWave access architecture is characterized by using an analog link over local area network cables to relay the frequency-converted signals betwe...

In this paper, we introduce a novel mmWave access architecture, called mmWave over cable (mmWoC), for achieving effective indoor coverage, which is characterized by using an analog modulated relay link to transport the outdoor mmWave signalsto the indoors. To enable an effective mapping of radio signals onthe cable sub-carriers, we introduce non-co...

An orthogonal frequency division multiplexing (OFDM) transmitter for 802.11ah uplink may consume unnecessarily high power due to the malicious effect of a large peak-to-average power ratio (PAPR). This is particularly a problem for client devices (CDs) under the low-power wide-area (LPWA) technology in an Internet of thing (IoT) system, where high...

This paper investigates the feasibility of using residential low voltage (LV) power line communication (PLC) as the last hop of the CPRI-based front-haul(Common Protocol Radio Interface) to the indoor users, where unmodified time division multiplexed (TDM) CPRI hyper-frames are transported in between the outdoor distributed unit (DU) and the indoor...

Deep learning has received increasing attention in the last decade. Its amazing success, is partly attributed to the evolution of normalization and activation techniques. However, less works have devoted to explore both modules together. This work, therefore, aims at pushing for a deeper understanding on the effect of normalization and activation t...

This paper considers a cooperative device-to-device (D2D) system with non-orthogonal multiple access (NOMA). We assume that the base station (BS) can simultaneously communicate with all users to satisfy the full information transmission requirement. In order to characterize the impact of the weak channel and different decoding schemes, two novel de...

This article considers a radio-over-cable (RoC)based analog link on a local area network (LAN) cable [e.g., category (CAT) 5] as the last hop of the fronthaul for indoor mobile service coverage. We first present state-of-the-art mobile systems with RoC-based fronthauls and then discuss a number of critical issues regarding real implementation. Thes...

This article investigates cross-layer design of nonorthogonal layered (NOL) coding schemes over relay-assisted downlink of cellular networks that incorporates with successive refinement (SR) source code for transmission of adaptive multiresolution multimedia content. Two novel-layered relaying strategies, namely NOL compress-forward (NOL-CF) and NO...

Disaster management, search and rescue missions, and health monitoring are examples of critical applications that require object localization with high precision and sometimes in a timely manner. In the absence of the global positioning system (GPS), the radio received signal strength index (RSSI) can be used for localization purposes due to its si...

Flexible duplexing is a promising technique to improve the spectral efficiency of future cellular networks, which has been proposed mainly to provision asymmetric uplink (UL) and downlink (DL) traffic scenarios, through flexible channel allocations; however, this flexibility in the channel allocation process, which is responsible for allocating the...

Recent Progress has shown that exploitation of hidden layer neurons in convolutional neural networks (CNN) incorporating with a carefully designed activation function can yield better classification results in the field of computer vision. The paper firstly introduces a novel deep learning (DL) architecture aiming to mitigate the gradient-vanishing...

In energy detection for cognitive radio spectrum sensing, the noise variance is usually assumed given, by which a threshold is set to guarantee a desired constant false alarm rate (CFAR) or a constant detection rate (CDR). However, in practical situations, the exact information of noise variance is generally unavailable to a certain extent due to t...

The paper proposes a novel adaptive radio-over-fiber (RoF) system for next-generation cloud radio access network (C-RAN), aiming to optimize the operation cost in terms of power consumption while maintaining required data rate. By jointly considering the nonlinear distortion from Mach-Zehnder modulator (MZM) and high power amplifier (HPA) due to hi...

Existing datacenter networks (DCNs) support the legacy Cloud services well, nonetheless, it is inherently short of provisioning the emergying IoT services, such as the vehicle services, where real-time intelligence, cognition and security are required, mainly due to its long distance with the IoT devices that generate the intelligent services. Rega...

In order to overcome the non-line-of-sight nature of the indoor environment so as to achieve a cost-effective solution of 5G indoor service provisioning, distribution of antenna units in indoor chambers is the most straightforward solution. This paper investigates a novel distributed antenna access architecture that allows the antenna units to be d...

Fifth generation wireless networks are expected to provide advanced capabilities and create new markets. Among the emerging markets, Internet of Things (IoT) use cases are standing out with the proliferation of a wide range of sensors that can be configured to continuously monitor and transmit data for intelligent processing and decision making. De...

This paper investigates the joint user scheduling (US) and user association (UA) problem for OFDMA based networks under the centralized radio access network (C-RAN) architecture. We first formulate the joint optimization problem for US and UA, which is intractable in its exact form, therefore, we propose a corresponding upper bound problem, with mu...

We study theoretical performance of Maximum Likelihood (ML) estimation for transmit power of a primary node in a wireless network with cooperative receiver nodes. The condition that the consistence of an ML estimation via cooperative sensing can be guaranteed is firstly defined. Theoretical analysis is conducted on the feasibility of the consistenc...

A key enabler for Cognitive Radio (CR) is spectrum sensing, which is physically implemented by sensor and actuator networks typically using the popular energy detection method. The threshold of the binary hypothesis for energy detection is generally determined by using the principles of constant false alarm rate (CFAR) or constant detection rate (C...

Deploying femtocells has been taken as an effective solution for removing coverage holes and improving wireless service performance in 3G-beyond wireless networks such as WiMAX and Long Term Evolution (LTE). This article investigates a novel framework of dynamic spectrum management for femtocell networks, called cognitive-empowered femtocells (CEF)...

Recent Progress has shown that exploitation of hidden layer neurons in convolution neural networks incorporating with a carefully designed activation function can yield better classification results in the field of computer vision. The paper firstly introduces a novel deep learning architecture aiming to mitigate the gradient-vanishing problem, in...

The paper introduces a novel hybrid network coding scheme in a three-node two-way relaying network (TWRN) in a wireless fading environment. The proposed hybrid scheme is featured by an opportunistic mechanism which employs one of the two network coding schemes, namely physical-layer network coding (PNC) and digital network coding (DNC), according t...