arXiv subjects

Ali Mohammad Afshin Hemmatyar

Publications and source records attributed to Ali Mohammad Afshin Hemmatyar.

6 recordsLinked to original sources

arXiv2024

LIMO: Load-balanced Offloading with MAPE and Particle Swarm Optimization in Mobile Fog Networks

Fog computing is essentially the expansion of cloud computing towards the network edge, reducing user access time to computing resources and services. Various advantages attribute to fog computing, including reduced latency, and improved user experience. However, user mobility may limit the benefits of fog computing. The displacement of users from one location to another, may increase their distance from a fog server, leading into latency amplification. This would also increase the probability of over utilization of fog servers which are located in popular destinations of mobile edge devices. This creates an unbalanced network of fog devices failing to provide lower makespan and fewer cloud accesses. One solution to maintain latency within an acceptable range is the migration of fog tasks and preserve the distance between the edge devices and the available resources. Although some studies have focused on fog task migration, none of them have considered load balancing in fog nodes. Accordingly, this paper introduces LIMO; an allocation and migration strategy for establishing load balancing in fog networks based on the control loop MAPE (Monitor-Analyze-Plan-Execute) and the Particle Swarm Optimization (PSO) algorithm. The periodical migration of tasks for load balancing aims to enhance the system's efficiency. The performance of LIMO has been modeled and evaluated using the Mobfogsim toolkit. The results show that this technique outperforms the state-of-the-art in terms of network resource utilization with 10% improvement. Furthermore, LIMO reduces the task migration to cloud by more than 15%, while it reduces the request response time by 18%.

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arXiv2022

A Generalized Framework for Joint Dynamic Optimal RF Interface Setting and Next-Hop Selection in IoT networks with Similar Requests

Many applications which run on the Internet-of-Things machines require similar bandwidths. These machines are equipped with multiple Radio Frequency (RF) interfaces for machine-to-machine or machine-to-Base Station(BS) communications. Joint dynamic optimal RF interface setting and next-hop selection in data transmission can maximize the network data rate. For this purpose, we propose a generalized framework for simultaneous selection of these components according to the required bandwidth of machines. This framework is suitable for networks with multiple BSs and sources with similar bandwidth requests. Simulation results show that using the proposed framework, the average data rate of network sources increases up to 117%.

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arXiv2021

A New Dynamic Optimal M2M RF interface setting in Relay Selection Algorithm (DORSA) for IoT Applications

Machine-to-Machine (M2M) communication is an important type of communication in the Internet-of-Things (IoT). How to send data in these high-density communications using relay selection can help improve the performance of this type of communication in various applications. In addition, the possibility of simultaneous use of different Radio Frequency (RF) interfaces helps to use the spectrum more efficiently. In this work, we try to further use machine communication RF equipment and improve the average data rate of networks in some applications such as the IoT, which have their own bandwidth requirements. Therefore, we provide an optimization algorithm for relay selection as well as the simultaneous and dynamic multiple M2M RF interface setting that is called Dynamic Optimal Relay Selection and RF interfaces Setting Algorithm (DORSA). The simulation results show that the average data rate of DORSA with three interfaces (DORSA_W-B-Z) can be improved up to 10% compared to the existing methods such as optimal direct transmission and relay selection algorithms with static RF interface setting.

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arXiv2020

Novel Relay Selection Algorithms for Machine-to-Machine Communications with Static RF Interface Usage

Machine-to-Machine (M2M) communications have been introduced to improve the communication capacity in dense wireless networks. One of the most important concerns for network designers is maintaining the high performance of the network when the quality of connections between sources and their destinations is poor. Thus the careful selection of relays between data sources and their destinations is a very important issue. The possibility of simultaneous use of different Radio Frequency (RF) interfaces for transmitting data, which communication devices are equipped with them, can increase the capacity of data transmission over the network. In this paper, two novel M2M relay selection algorithms are proposed, named as Optimal Relay Selection Algorithm (ORSA) and Matching based Relay Selection Algorithm (MRSA). ORSA is a centralized algorithm for the optimal selection of relays by transforming the main problem to a k-cardinality assignment problem that can be solved using the Hungarian algorithm. MRSA is a distributed algorithm that leverages concepts from matching theory to provide a stable solution for the relay selection problem. In both proposed algorithms static RF interfaces usage is applied to enable simultaneous use of different interfaces for data transmission. The simulations show that ORSA is optimally solving the relay selection problem. MRSA has an optimal stable result, that when there is no restriction on the number of channels, is only about 1% lower than ORSA. Besides, MRSA provides better results than direct transmission Without any Relay Selection Algorithm (WRSA) and Random Relay Selection Algorithm (RRSA), about 15% and 98%, respectively.

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arXiv2018

A Low Overhead Cooperative-based Authentication Protocol for VANETs

Vehicular ad-hoc networks (VANETs) have been proposed to automate transportation industry in order to increase its accuracy, efficiency, throughput, and specially safety. Security plays an Undeniable important role on implementing VANETs in real life. Authentication is one of the basic elements of VANETs security. Proposed authentications protocols suffer from high overhead and cost. This paper presents a computation division based authentication which divide signature approvals between neighbor vehicles consequently decrease vehicles computation load. Simulation shows presented protocol propose an almost constant latency and closely zero message loss ratio related to traffic load, and improved efficiency compared with GSIS protocol.

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arXiv2018

Study of Uniform Jitter Mechanism for Metric-based Wireless Routing

Many wireless protocols wait a small and random amount of time which is called jitter before sending a packet to avoid high contention and packet collision. Jitter has been already proposed for many routing protocols including AODV and LOADng. However, since they do not consider any link quality parameters or metrics (such as ETX) in routing, they fail to be efficient in metric-based routing protocols. A metric-based jitter mechanism is proposed in this paper and a closed form expression is derived that enables us to obtain the probability of delay inversion for all jitter mechanisms available. Simulation results are also presented to show the performance of different jitter mechanisms.

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