Mohan Gurusamy's research while affiliated with National University of Singapore and other places

Publications (158)

Preprint
Achieving network resilience in terms of attack tolerance and service availability is critically important for Internet of Vehicles (IoV) networks where vehicles require assistance in sensitive and safety-critical applications like driving. It is particularly challenging in time-varying conditions of IoV traffic. In this paper, we study an attack-r...
Article
In this paper, we present MARK, a data synthesis method to synthesize patterns for evolving normal network behaviors as well as unknown network attacks for detection of an anomaly in the network. We propose a novel semi-supervised learning approach that takes data (containing normal behaviors and known attacks) and apply clustering to determine the...
Preprint
The integration of ML in 5G-based Internet of Vehicles (IoV) networks has enabled intelligent transportation and smart traffic management. Nonetheless, the security against adversarial attacks is also increasingly becoming a challenging task. Specifically, Deep Reinforcement Learning (DRL) is one of the widely used ML designs in IoV applications. T...
Preprint
p>Networks regularly face various threats and attacks that manifest in their communication traffic. Recent works proposed unsupervised approaches, e.g., using a variational autoencoder, that are not only effective in detecting anomalies in network traffic, but also practical as they do not require ground truth or labeled data. However, the problem...
Preprint
p>Networks regularly face various threats and attacks that manifest in their communication traffic. Recent works proposed unsupervised approaches, e.g., using a variational autoencoder, that are not only effective in detecting anomalies in network traffic, but also practical as they do not require ground truth or labeled data. However, the problem...
Article
Machine Learning (ML) has emerged as an attractive and viable technique to provide effective solutions for a wide range of application domains. An important application domain is vehicular networks wherein ML-based approaches are found to be very useful to address various problems. The use of wireless communication between vehicular nodes and/or in...
Article
The growth of 5G and edge computing has enabled the emergence of Internet of Vehicles. It supports different types of services with different resource and service requirements. However, limited resources at the edge, high mobility of vehicles, increasing demand, and dynamicity in service request-types have made service placement a challenging task....
Preprint
Machine learning (ML) has made incredible impacts and transformations in a wide range of vehicular applications. As the use of ML in Internet of Vehicles (IoV) continues to advance, adversarial threats and their impact have become an important subject of research worth exploring. In this paper, we focus on Sybil-based adversarial threats against a...
Article
Vehicular networks, like any other wireless networks, are prone to jamming due to the inherent nature of the wireless environment. In this paper, we consider an attacker who jams the network whenever he observes that a packet is being transmitted i.e. some communication happening in the network. Such a strategy leads to an increase in the packet dr...
Preprint
The growth of 5G and edge computing has enabled the emergence of Internet of Vehicles. It supports different types of services with different resource and service requirements. However, limited resources at the edge, high mobility of vehicles, increasing demand, and dynamicity in service request-types have made service placement a challenging task....
Preprint
The emergence of technologies such as 5G and mobile edge computing has enabled provisioning of different types of services with different resource and service requirements to the vehicles in a vehicular network.The growing complexity of traffic mobility patterns and dynamics in the requests for different types of services has made service placement...
Preprint
Machine Learning (ML) has emerged as an attractive and viable technique to provide effective solutions for a wide range of application domains. An important application domain is vehicular networks wherein ML-based approaches are found to be very useful to address various problems. The use of wireless communication between vehicular nodes and/or in...
Article
Software defined networking (SDN) is gaining the confidence of network operators, who are increasingly motivated to introduce it in their networks. However, since SDN is based on centralized control plane (decoupled from the data plane), it is incompatible with distributed control plane of legacy networks. As adopting SDN by complete overhaul of ex...
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Full-text available
The fast-growing Internet of Things (IoT) market has opened up a large threat landscape, given the wide deployment of IoT devices in both consumer and commercial spaces. Attacks on IoT devices generally consist of multiple stages and are dispersed spatially and temporally. These characteristics make it challenging to detect and identify the attack-...
Preprint
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Classification of IoT devices into different types is of paramount importance, from multiple perspectives, including security and privacy aspects. Recent works have explored machine learning techniques for fingerprinting (or classifying) IoT devices, with promising results. However, existing works have assumed that the features used for building th...
Article
The separation of control and data plane in Software Defined Networking (SDN) introduces new security threats. A compromised controller can leverage its position to perform attacks by installing malicious rules in switches while avoiding detection. Current approaches propose broadcast of flow-setup requests to multiple controllers simultaneously an...
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In software-defined networks, a compromised controller that is Byzantine in nature would issue inconsistent messages selectively to its communicating nodes. Defending against such threats is very challenging since the infected messages look legitimate. To defend against f simultaneous controller failures using the conventional Byzantine fault toler...
Article
In a multi-controller SDN, the network state is replicated or distributed between the controllers requiring repeated synchronization. This synchronization cost depends on controller locations, as well as needs to be low and resilient to network failures. Leveraging a Steiner tree-based inter-controller latency model, a multi-objective integer linea...
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Cloud data centers nowadays play an important role in providing computing and network resources for online applications and services. Such applications obtain cloud resources by submitting resource requests in the form of virtual networks that are embedded in the cloud infrastructures, referred to as virtual network embedding (VNE). Developing an e...
Article
In a distributed Software Defined Networking (SDN) architecture, the Quality of Service (QoS) experienced by a traffic flow through an SDN switch is primarily dependant on the SDN controller to which that switch is mapped. We propose a new controller-quality metric known as the Quality of Controller (QoC) which is defined based on the controller’s...
Article
In recent years, Software Defined Networking (SDN) has emerged as a pivotal element not only in data-centers and wide-area networks, but also in next generation networking architectures such as Vehicular ad hoc network and 5G. SDN is characterized by decoupled data and control planes, and logically centralized control plane. The centralized control...
Conference Paper
A 5G network slice is comprised of several service chains (SCs)-a chain of virtualized network functions (VNFs) each performing a function (e.g., firewall) to serve diverse traffic requirements. These VNFs are hosted on servers/physical-machines in one or more data-centers. In this context, a fault/attack on a 5G network could be as fine-grained as...
Conference Paper
Full-text available
Fast failure recovery is a critically-important problem in networks. To address this problem in software-defined networks (SDN), backup paths can be chosen in a proactive and adaptive manner in accordance with the traffic dynamics. Existing proactive approaches make use of only the network topology knowledge or a combined knowledge of the topology...
Article
Full-text available
With the proliferation of network devices and rapid development in information technology, networks such as Inter- net of Things are increasing in size and becoming more complex with heterogeneous wired and wireless links. In such networks, link faults may result in a link disconnection without immediate replacement or a link reconnection, e.g., a...
Article
We address the problem of embedding service chains consisting of a sequence of virtual network functions (VNF) for 5G slices, considering diversified slice requirements. We develop a fine-grained approach that considers resource requirements and limited traffic processing capacity of VNFs, which can be shared (or not) among slices depending on VNF...
Article
This is the era of smart devices or things which are fueling the growth of Internet of Things (IoT). It is impacting every sphere around us, making our life dependent on this technological feat. It is of high concern that these smart things are being targeted by cyber criminals taking advantage of heterogeneity, minuscule security features, and v...
Article
Full-text available
We address the problem of embedding service chains consisting of a sequence of virtual network functions (VNF) for 5G slices, considering diversified slice requirements. We develop a fine-grained approach that considers resource requirements and limited traffic processing capacity of VNFs, which can be shared (or not) among slices depending on VNF...
Article
Full-text available
Identifying IoT devices connected to a network has multiple security benefits, such as deployment of behavior-based anomaly detectors, automated vulnerability patching of specific device types, dynamic attack mitigation, etc. In this work, we look into the problem of IoT device identification at network level, in particular from an ISP’s perspectiv...
Preprint
Full-text available
Recent developments in intelligent transport systems (ITS) based on smart mobility significantly improves safety and security over roads and highways. ITS networks are comprised of the Internet-connected vehicles (mobile nodes), roadside units (RSU), cellular base stations and conventional core network routers to create a complete data transmission...
Preprint
Full-text available
With the proliferation of network devices and rapid development in information technology, networks such as Internet of Things are increasing in size and becoming more complex with heterogeneous wired and wireless links. In such networks, link faults may result in a link disconnection without immediate replacement or a link reconnection, e.g., a wi...
Conference Paper
Full-text available
In software-defined networks, distributed controller architectures provide improved scalability and reliability by using multiple controllers, each managing a partition of the network. However, due to the dynamics of network control traffic, static switch-controller mapping causes load imbalance while dynamic mapping causes frequent switch migratio...
Article
Full-text available
Big data is becoming a major focus for both industry and academia, requiring drastic changes in all aspects of computer systems in order to store, process and transfer big data. In networks, a fundamental problem is how to efficiently transfer big data since the performance is affected by several factors such as path, bandwidth and scheduled start...
Conference Paper
Full-text available
Communication networks such as wireless sensor networks, Internet of Things and vehicular ad-hoc networks are becoming more complex and increasing in size. This leads to high overhead (network and computation) and difficulty in determining the accurate network topology, which is an important information for traffic engineering and network managemen...
Article
The scale of connected devices in the modern communication network and its heterogeneous nature have made securing the network more challenging. However, with the advent of Software Defined Networking (SDN), the algorithmic complexity is handled at a centralized control plane and the network elements perform only data forwarding based on control pl...
Article
We proposed a novel adaptive carrier phase estimator based on the phase information of the received signal only. Through eliminating the perturbation due to the amplitude of the AWGN, the proposed method outperforms the conventional adaptive filter in terms of both the carrier phase estimation and the filter gain tracking. Additionally, a dynamic t...
Preprint
Full-text available
This is the era of smart devices or things which are fueling the growth of Internet of Things (IoT). It is impacting every sphere around us, making our life dependent on this technological feat. It is of high concern that these smart things are being targeted by cyber criminals taking advantage of heterogeneity, minuscule security features and vuln...
Article
We derive a tight, single-term, purely exponential, lower bound on the Gaussian $Q$ -function, along with a method to optimize its tightness and a fast iterative method for its inversion. To illustrate its application, we show that it enables the accurate, analytical estimation of the signal-to-noise ratio penalty and the laser linewidth tolerance...
Conference Paper
Full-text available
Security in Software Defined Networks (SDNs) has been a major concern for its deployment. Byzantine threats in SDNs are more sophisticated to defend since control messages issued by a compromised controller look legitimate. Applying traditional Byzantine Fault Tolerance approach to SDNs requires each switch to be mapped to 3f + 1 controllers to def...
Conference Paper
Full-text available
Distributed controller architectures in software defined networks raise the issue of switch-controller mapping and control traffic engineering. In a mapping approach where a switch distributes flow setup requests (traffic) to multiple controllers, a solution that finds the optimal switch-controller mapping and traffic distribution among the control...
Article
Full-text available
We propose an effective switch-controller mapping scheme for distributed controller architectures in Software Defined Networks. Our scheme maps a switch to multiple controllers and distributes flow setup requests among them to minimize flow setup time, satisfying the resilience constraint which requires that a specified fraction of setup requests a...
Article
A novel indoor positioning system (IPS) with high positioning precision, based on visible light communication (VLC), is proposed and demonstrated with the dimensions of 100 cm×118.5 cm×128.7 cm. The average positioning distance error is 1.72 cm using the original 2-D positioning algorithm. However, at the corners of the test-bed, the positioning er...
Conference Paper
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Large amount of data is being generated at an alarming rate by various systems and devices such as computing systems, cameras, mobile devices, etc. The insights and findings obtained from data commonly referred to as "big data" , are revolutionizing several aspects of our everyday life. Owing to the huge volume of this data, its processing and anal...
Article
A novel soft-decision-aided maximum likelihood (SDA-ML) carrier phase estimation method and its simplified version, the decision-aided and soft-decision-aided maximum likelihood (DA-SDA-ML) methods are tested in a nonlinear phase noise-dominant channel. The numerical performance results show that both the SDA-ML and DA-SDA-ML methods outperform the...
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Full-text available
Optical switching based on wavelength division multiplexing (WDM) has become a promising network technology to scale the performance of data centers. It provides high bisection bandwidth with low power consumption and low complexity of network wiring. However, it raises new challenges for the flow scheduling problem due to the dynamic arrival of tr...
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The effect of pointing errors on the average bit error probability (ABEP) of an inter-satellite laser communication link is studied. A closed-form expression in terms of the Marcum Qfunction is given for calculating the instantaneous channel gain. This expression provides great potential in further performance analysis and system optimization. In a...
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Full-text available
In Software Defined Networks (SDNs), while a proactive fault tolerance based on the local rerouting approach enables fast failure recovery, it requires to install forwarding rules for the backup paths in the switch Ternary Content Addressable Memory (TCAM) in advance. Since the TCAM size is limited and forwarding rules are long, using large number...
Article
In this paper, an optimal LED arrangement for indoor visible light communications (VLC) is proposed and numerically investigated. By using the concept of inverse design, the LED distribution can be formulated as a convex optimization problem and resolved accordingly. We show that sufficient brightness and uniform signal to noise ratio (SNR) can be...
Conference Paper
We propose an efficient blind carrier frequency offset estimation algorithm for CO-OFDM systems, which utilizes only one OFDM symbol without exhaustive search computations.
Conference Paper
Full-text available
Cloud data centers have become an attractive candidate for network-based large scale applications that require cloud resources in the form of a virtual network. Embedding virtual networks in data centers to allocate resources to their applications is therefore crucial since it affects resource efficiency and thus the final revenue of cloud provider...
Conference Paper
Full-text available
Wavelength division multiplexed optical networks have become an attractive candidate to meet the ever-growing traffic demands in cloud data centers due to the features of large capacity and dynamic reconfiguration capability. While the bandwidth does not affect the makespan of compute-intensive and content-delivery-network applications, it has an i...