Papers by Siavash Khorsandi
Cyber threats have been extraordinary increased in recent years. Cyber attackers, including gover... more Cyber threats have been extraordinary increased in recent years. Cyber attackers, including government agencies or hackers, have made significant advances in the use of various tools for attacking target systems in some countries particularly on Islamic republic of Iran. The complexity of cyber threats and the devastating effects of them on critical systems highlights necessity of cyber threats Foresight. This research can prepare the country for countering cyber threats based on existing and potential attack Vectors. First of all, 18 major cyber threats drivers base on attack Vectors through reviewing resources and interviewing with seven experts were identified. We use cross-impact analysis Future studies method to indicate main drivers of future cyber threats such as social engineering, Denial of service, ransomwares, spoofing and fraud and non-state actors. Mic Mac software will be used for this step. Finally, future scenarios for cyber threats were identified by using scenario-based approach. Scenario Wizard software will be used. The results of the research include two strong scenarios and 18 possible scenarios, based on the strongest scenario, ransomware, spoofing, fraud, social engineering and Denial of service are the most likely cyber threats by non-state actors through in a limited level.
BGP/MPLS IP VPN and VPLS services are considered to be widely used in IP/MPLS networks for connec... more BGP/MPLS IP VPN and VPLS services are considered to be widely used in IP/MPLS networks for connecting customers' remote sites. However, service providers struggle with many challenges to provide these services. Management complexity, equipment costs, and last but not least, scalability issues emerging as the customers increase in number, are just some of these problems. Software-defined networking (SDN) is an emerging paradigm that can solve aforementioned issues using a logically centralized controller for network devices. In this paper, we propose a SDN-based solution called SDxVPN which considerably lowers the complexity of VPN service definition and management. Our method eliminates complex and costly device interactions that used to be done through several control plane protocols and enables customers to determine their service specifications, define restriction policies and even interconnect with other customers automatically without operator's intervention. We describ...
Virtualized SDN-Based End-to-End Reference Architecture for Fog Networking
2018 32nd International Conference on Advanced Information Networking and Applications Workshops (WAINA), 2018
Cloud Computing provides a distributed Internet based platform for data and application hosting s... more Cloud Computing provides a distributed Internet based platform for data and application hosting such as Internet of Things (IoT), cloud applications and social applications. Despite increased use of cloud computing, there are serious issues due to inherent problems such as lukewarm reliability, lowgranularity location-awareness, and global view of the network and also dependency on the communication infrastructure for mobility support. Fog computing is a network based computing paradigm that allows essential parts of the computing processes to be moved to a point near the user, and hence emulating a locally provided service improving users quality of experience (QoE) in many dimensions such as response time and availability. The duty of fog networks is to connect each component of the fog architecture seamlessly. However, managing such a complex network, maintaining connectivity and providing on-demand services, particularly in large-scale applications of the Internet of Things (IoT), is so convoluted. Therefore, a new architecture is needed to deal with predicting and maintaining the connectivity graph of network, design distributed SDN system that meet the harsh requirement of fog computing, implement and manage VNFCs through the network, and orchestrate these components together. Hence, an integrated end-to-end SDN/NFV reference architecture by means of orchestration of integrated Cloud, Fog, and network resources has been proposed.
Joint power control and channel assignment in uplink IoT Networks: A non-cooperative game and auction based approach
Computer Communications, 2018
Abstract Internet of Things (IoT) is a network of disparate objects enabled to exchange data with... more Abstract Internet of Things (IoT) is a network of disparate objects enabled to exchange data with each other to implement smart applications. In near future, the possibility of a truly global IoT is expected to be covered by connecting billions of devices through emerging wireless systems such as the fifth generation of cellular networks (5G). Employing enhanced multiple access technologies and providing effective resource allocation schemes to maximize the number of supported devices is a highly important factor to make future networks practical. Most of the current researches consider Orthogonal Multiple Access (OMA) techniques and try to improve Quality of Service (QoS) metrics like the data rate. In this work, we investigate the problem of allocating resources in an uplink MC CDMA wireless IoT network, including channel assignment and power control, to satisfy the signal-to-interference ratio (SIR) requirement of all devices in a scalable manner. The problem is primarily formulated as a Mixed Integer Linear Programming (MILP) problem with the goal of maximizing the number of supported devices while the sum of transmit powers is minimized. We prove that the problem is NP-Hard in general, and use the Lagrangian relaxation and decomposition methods to provide a subgradient-based approach and find at least a near-optimal solution; yet in a homogeneous case where a same feasible SIR requirement and a same path gain are assumed for all devices, a closed-form solution is obtained. Towards an efficient solution for the general case, a centralized heuristic algorithm and an evolutionary distributed algorithm are developed. The distributed scheme consists of a Vickrey auction based channel assignment phase and a non-cooperative target SIR tracking power control phase to allocate resources in an iterative and decentralized manner. In the distributed scheme, the base station is not needed to know path gains. Numerical results show that the difference between the optimal solution and our proposed algorithms are negligible, so they can be efficiently employed in real-world scenarios.
IEEE Access, 2020
Fog computing is an emerging technology to address computing and networking bottlenecks in large ... more Fog computing is an emerging technology to address computing and networking bottlenecks in large scale deployment of IoT applications. It is a promising complementary computing paradigm to cloud computing where computational, networking, storage and acceleration elements are deployed at the edge and network layers in a multi-tier, distributed and possibly cooperative manner. These elements may be virtualized computing functions placed at edge devices or network elements on demand, realizing the "computing everywhere" concept. To put the current research in perspective, this paper provides an inclusive taxonomy for architectural, algorithmic and technologic aspects of fog computing. The computing paradigms and their architectural distinctions, including cloud, edge, mobile edge and fog computing are subsequently reviewed. Practical deployment of fog computing includes a number of different aspects such as system design, application design, software implementation, security, computing resource management and networking. A comprehensive survey of all these aspects from the architectural point of view is covered. Current reference architectures and major application-specific architectures describing their salient features and distinctions in the context of fog computing are explored. Base architectures for application, software, security, computing resource management and networking are presented and are evaluated using a proposed maturity model. Cloud Computing, Edge Computing, Fog Computing, Internet of Things (IoT), Advanced Internet Architecture I. INTRODUCTION A S virtualization technologies mature and are perva- sively adopted, multi-tenancy is becoming possible not only in high-end computing servers but also in network elements and even end-user equipment. Thus, there is a trend towards creating network and user functions as virtual functions that are outsourced for execution in utility-based computing stores. This trend is driven by the emergence of universal composability that transforms monolithic applications into composable micro-services. The tasks and the associated micro-services vary widely in their requirements, including computing resources, elasticity, interactivity, and latency. These developments have given new life to the concept of ubiquitous computing and the notion of "computing everywhere". In this new environment, each and every computing resource may be selected as the best match for some virtual functions or tasks because of location, resources IoT Object's Domain Internet MEC Provider Core Core Cloud Multi-Tier Fog Edge Cloud Small-Cell Femto-Cell Multi-Tier Cloud IoT Gataway
On the Performance Improvement of IoT Networks Using Relay-Based Communications
2016 International Conference on Information Technology (ICIT), 2016
Internet of Things (IoT) is a network of disparate objects enabled to exchange data with other ob... more Internet of Things (IoT) is a network of disparate objects enabled to exchange data with other objects to implement smart applications. In near future, billions of devices are expected to be connected to IoT through wireless connections. Due to the limited capacity of the wireless medium, the effective resource allocation is a highly important factor to improve the network performance, especially in the presence of a large number of devices. In this work, we investigate the problem of allocating resources in an OFDMA-based wireless IoT network, including channel assignment and power control, to satisfy the SINR requirements of all the devices in a scalable manner. The Primary Resource Allocation Problem (PRAP) is formulated as a Mixed-Integer Linear Programming (MILP) problem which is efficiently solvable by mathematical methods. We next develop a new relay-based communication model that results in a significantly improved network performance. The resource allocation in this model i...
Journal of Iranian Association of Electrical and Electronics Engineers, 2016
Proceedings. Seventh International Conference on High Performance Computing and Grid in Asia Pacific Region, 2004.
In this paper we present two new analytical models for a cluster-based parallel system based on O... more In this paper we present two new analytical models for a cluster-based parallel system based on Open Queuing Network Model (QNM). The parallel system under consideration uses hypercube topology for its interconnection network. The proposed models are general enough to model various types of parallel applications. A Multi-Chain QNM is developed that can consider task migration between the nodes. An equivalent Single Chain model is also developed to enhance computation efficiency. Each of them can model real systems with different policies to execute parallel tasks. Numerical study of the proposed models is carried out that confirm their validity.
Many companies use identity information for different goals. There are a lot of market places for... more Many companies use identity information for different goals. There are a lot of market places for identity information. These markets have some practical issues such as privacy, mutual trust and fairing exchange. The management of identity information is one of the most important applications for blockchain, for which researchers have proposed a large number of models. In the present paper, an attempt has been made to solve the problems that mentioned earlier to exchange identity information on the blockchain. By using the game theory we propose a fair model of selling authorized identity information in an environment that include untrusted parties. Moreover we employ ZK-SNARK to protect users’ privacy. Also we use proxy re-encryption to record these information in IPFS.
With the rapid growth of wireless access networks, various providers offer their services using d... more With the rapid growth of wireless access networks, various providers offer their services using different technologies such as Wi-Fi, Wimax, 3G, 4G and so on. These networks compete for the scarce wireless spectrum. The spectrum is considered to be a scarce resource moderated by the spectrum allocation regulatory (“regulatory” for short) which is the governance body aiming to maximize the social welfare through moderation of the spectrum allocation table (SAT). In this paper, we present a three stage dynamic game model directed by the regulatory to maximize the clients' welfare. The regulatory controls the proposed prices announced by networks and it determines the tax in proportion to the price and load of each network. The model simulates the behavior of end users, network providers and the regulatory agent through which spectrum allocation strategy is deducted, the rules and parameters are defined, and the system equilibrium in terms of resource allocation and pricing is anal...
Security and Privacy Smart Contract Architecture for Energy Trading based on Blockchains
2021 29th Iranian Conference on Electrical Engineering (ICEE)
Nowaday, centralized smart grid systems encounter many challenges to peer-to-peer (P2P) energy tr... more Nowaday, centralized smart grid systems encounter many challenges to peer-to-peer (P2P) energy trading, such as communications overhead, security, and privacy issues. Blockchain-based energy trading has been proposed as a possible solution to the above problems. This paper proposes a secure and automated blockchain-based framework that allows energy producers and consumers to conduct energy trade without intermediate entity interaction. Smart contracts have been established to automate the energy trade based on an agreement energy-relevant both from the supply and demand sides without third parties. In a smart contract, if all transactions are successful, the energy trade will take place. We used the Solidity programming language and Metamask wallet to create the smart contract. Then, smart contract implementation results in the Ropsten blockchain network are tested and compared with related works. According to the analysis, the proposed framework has enhanced security and privacy.
IEEE Internet of Things Journal
Price and the quality of service are two key factors taken into account by wireless network users... more Price and the quality of service are two key factors taken into account by wireless network users when they choose their network provider. The recent advances in wireless technology and massive infrastructure deployments has led to better coverage, and currently at each given wirelessly covered area there are a few network providers and each have different pricing strategies. These providers can potentially set unfair expensive prices for their services. In this paper, we propose a novel crowdsourcing-based approach for fair wireless service pricing in Internet of Things (IoT). In our considered oligopoly, the regulatory sets a dynamic maximum allowed price of service to prevent antitrust behaviour and unfair service pricing. We propose a three-tire pricing model where the regulator, wireless network providers and clients are the players of our game. Our method takes client preferences into account in pricing and discovers the fair service pricing just above the marginal costs of each network provider. Our results show that our model is not prone to collusion and will converges only if one network announces the fair price.
A new Walrasian mechanism design for optimal pricing and resource allocation in heterogeneous wireless access networks
Wireless Networks
In this paper, we address joint spectrum allocation and pricing problem in heterogeneous wireless... more In this paper, we address joint spectrum allocation and pricing problem in heterogeneous wireless access networks. In contrast to traditional static spectrum allocation approach, we model the spectrum as a market commodity, dynamically arbitrated by a regulatory agent with the aim of maximizing the social welfare. This is of particular importance with the dominance of wireless technologies in access networks and the sharp increase in the number of overlapping wireless technologies and networks. We designed a novel Walrasian mechanism called economic resource allocation and pricing based on a three-stage game model capable of considering multiple networks and clients with individual attributes and preferences. In the first stage, competition among networks for spectrum allocation is handled where the regulatory evaluates the social welfare and takes corrective action. In the bottom two stages, the complex interactions between clients and networks result in bitrate allocations and service pricings. The equilibrium condition is analyzed using the Walrasian market model which is argued to be the Nash equilibrium of the proposed game. The system behavior is analyzed through extensive simulations. The results confirm the effectiveness of the proposed mechanisms in moving the system towards maximal social welfare.
A semi‐oblivious approach for robust segment routing in software‐defined wide area networks
Transactions on Emerging Telecommunications Technologies
Performance analysis of the internet-protocol multimedia-subsystem's control layer using a detailed queueing Petri-net model
International Journal of Communication Systems
Game theoretic spectrum allocation for competing wireless access technologies to maximize the social welfare
Wireless Networks
Due to its scarce nature, the limited frequency spectrum must be effectively allocated to competi... more Due to its scarce nature, the limited frequency spectrum must be effectively allocated to competing wireless access technologies. A promising approach is to consider frequency spectrum as a commodity and model the spectrum allocation as a market dynamics problem. Using this approach, we have addressed the competition for frequency spectrum by e.g. 3G and 4G technologies where network operators, users and the regulatory agent are the market players. We have modeled the system dynamics as a novel three-stage game creating a unified framework for spectrum allocation, network best response and user welfare. By finding the Nash equilibrium of the game, the influence of regulatory decisions and impact of network/user strategies is analyzed. Through the interaction of networks and users and influence exerted by the regulatory, the resulting spectrum allocations are proved to be Pareto efficient with maximal social welfare. The devised model and following results provides a much needed and important framework for the regulatory and network operators for adjusting spectrum allocation table towards maximizing the social welfare for all the players.
2017 9th International Conference on Information and Knowledge Technology (IKT)
In this paper, we present a mechanism for bandwidth allocation and pricing in heterogeneous wirel... more In this paper, we present a mechanism for bandwidth allocation and pricing in heterogeneous wireless networks. A proposed three stage game involves three types of agents 1) Network providers 2) Regulatory agent and 3) The Clients play the game. The goal of our mechanism design is increasing the social welfare means that while the network providers are satisfied from preparing and releasing the bandwidth, the clients deliver their bandwidth with a suitable price. When the Purchasing power in a society increases, we can interfere that the client welfare is increased but the very-low price for the products is not profitable for the producers thus to increase the social welfare we should attend to the welfare of network providers as well as the clients. The proposed mechanism guarantees the maximum payoff for the network providers and offers the clients to weighting and ranking the available networks and then prepares the best request bundle to receive the service. The violation from the proposed mechanism is not profitable for network providers and clients and as it is proved in the paper the allocation result is Pareto efficient.
A decentralized channel assignment and power control approach using noncooperative game and Vickrey auction in relay-aided MC-CDMA IoT networks
Transactions on Emerging Telecommunications Technologies
A load balancing system for autonomous connection management in heterogeneous wireless networks
Computer Communications, 2016
In modern heterogeneous wireless networks (HWN), multi-mode devices perform autonomous connection... more In modern heterogeneous wireless networks (HWN), multi-mode devices perform autonomous connection management (ACM) to select the best connections. This selection process causes the challenge of providing global objectives such as load balancing, which have a significant impact on utilization of network resources. In this paper, the proposed connection management system considers the load balancing in HWNs through the trade-off between the individual connection quality and global network objectives. First, a centralized entity calculates the load state of the HWNs by predicting stochastic connection interests of the mobile hosts, then the calculated state is used by ACM system of mobile hosts to improve the network global objectives as well as their own connection quality. The system performance is studied through simulation and modeling in various scenarios. The overall system throughput, load distribution in the network, fairness in access to resources and user satisfaction are evaluated. The results show the effectiveness of the proposed system.
NOMS 2016 - 2016 IEEE/IFIP Network Operations and Management Symposium, 2016
BGP/MPLS IP VPN and VPLS services are considered to be widely used in IP/MPLS networks for connec... more BGP/MPLS IP VPN and VPLS services are considered to be widely used in IP/MPLS networks for connecting customers' remote sites. However, service providers struggle with many challenges to provide these services. Management complexity, equipment costs, and last but not least, scalability issues emerging as the customers increase in number, are just some of these problems. Software-defined networking (SDN) is an emerging paradigm that can solve aforementioned issues using a logically centralized controller for network devices. In this paper, we propose a SDN-based solution called SDxVPN which considerably lowers the complexity of VPN service definition and management. Our method eliminates complex and costly device interactions that used to be done through several control plane protocols and enables customers to determine their service specifications, define restriction policies and even interconnect with other customers automatically without operator's intervention. We describe our prototype implementation of SDxVPN and its scalability evaluations under several representative scenarios. The results indicate the effectiveness of the proposed solution for deployment to provide large scale VPN services.
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Papers by Siavash Khorsandi