| 1. |
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| 2. |
- Abbasi, Shirin, et al.
(författare)
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Internet of Vehicles : Architecture, services, and applications
- 2021
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Ingår i: International Journal of Communication Systems. - : John Wiley and Sons Ltd. - 1074-5351 .- 1099-1131. ; 34:10
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Tidskriftsartikel (refereegranskat)abstract
- The connection between objects and information exchange has been possible in recent years, with the advent of the Internet of Things (IoT) in different industries. We can meet different requirements in each industry utilizing this feature. Intelligent transportation uses the Internet of Vehicles (IoV) as a solution for communication among vehicles. It improves traffic management applications and services to guarantee safety on roads. We categorize services, applications, and architectures and propose a taxonomy for IoV. Then, we study open issues and challenges for future works. We highlighted applications and services due to drivers' requirements and nonfunctional requirements, considering the qualitative characteristic. This paper summarizes the current state of the IoV in architectures, services, and applications. It can be a start view to provide the solutions for challenges in traffic management in cities. The present study is beneficial for smart city developments and management. According to this paper's result, the services and applications evaluate performance with 34% frequency, safety and data accuracy, and security with a 13% frequency in selected papers. These measurements are essential due to the IoV characteristics such as real-time operation, accident avoidance in applications, and complicated user data management.
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| 3. |
- Chaudhary, Rajat, et al.
(författare)
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A comprehensive survey on software-defined networking for smart communities
- 2022
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Ingår i: International Journal of Communication Systems. - : John Wiley & Sons. - 1074-5351 .- 1099-1131.
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Tidskriftsartikel (refereegranskat)abstract
- The need to provide services closer to the end-user proximity leads to the exchange of a large volume of data generated from the smart devices deployed at different geo-distributed sites. The massive amount of data generated from the smart devices need to be transmitted, analyzed, and processed. This requires seamless data exchanges among geo-separated nodes, which results in a considerable burden on the underlying network infrastructure and can degrade the performance of any implemented solution. Therefore, a dynamic, agile, and programmable network management paradigm is required. To handle the challenges mentioned above, software-defined networking (SDN) gained much attention from academia, researchers, and industrial sectors. Shifting the computational load from forwarding devices to a logically centralized controller is a dream of every network operator who wants to have complete control and global visibility of the network. Also, the concept of network functions virtualization (NFV) in SDN controller is required to increase resource utilization efficiency. Thus, in this paper, a comprehensive survey on SDN for various smart applications is presented. This survey covers the infrastructural details of SDN hardware and OpenFlow switches, controllers, simulation tools, programming languages, open issues, and challenges in SDN implementation with advanced technologies such as 5G and microservices. In addition, the challenges on the control plane and data plane are highlighted in detail, such as fault tolerance, routing, scheduling of flows, and energy consumption on OpenFlow switches. Finally, various open issues and challenges future scope of SDN are discussed and analyzed in the proposal.
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| 4. |
- Fodor, Gabor, 1964-
(författare)
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Mode selection schemes for unicasting device-to-device communications supported by network coding
- 2018
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Ingår i: International Journal of Communication Systems. - : Wiley. - 1074-5351 .- 1099-1131. ; 31:11
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Tidskriftsartikel (refereegranskat)abstract
- Device-to-device (D2D) communication in a cellular spectrum increases the spectral and energy efficiency of local communication sessions, while also taking advantage of accessing licensed spectrum and higher transmit power levels than when using unlicensed bands. To realize the potential benefits of D2D communications, appropriate mode selection algorithms that select between the cellular and D2D communication modes must be designed. On the other hand, physical-layer network coding (NWC) at a cellular base stationwhich can be used without D2D capabilitycan also improve the spectral efficiency of a cellular network that carries local traffic. In this paper, we ask whether cellular networks should support D2D communications, physical-layer NWC, or both. To this end, we study the performance of mode selection algorithms that can be used in cellular networks that use physical-layer NWC and support D2D communications. We find that the joint application of D2D communication and NWC scheme yields additional gains compared with a network that implements only one of these schemes, provided that the network implements proper mode selection and resource allocation algorithms. We propose 2 mode selection schemes that aim to achieve high signal-to-interference-plus-noise ratio and spectral efficiency, respectively, and take into account the NWC and D2D capabilities of the network.
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| 5. |
- G, Fodor, et al.
(författare)
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Modelling and Analysis of Routing and Resource Allocation Techniques in Multi-service Networks
- 1999
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Ingår i: International Journal of Communication Systems. - : WILEY. - 1074-5351 .- 1099-1131. ; 12:2, s. 103-123
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Tidskriftsartikel (refereegranskat)abstract
- In this paper a novel call level model based on the extension of the classical Erlang multi-rate model for broadband integrated services networks is proposed. We use the model to study routing strategies in multi-service networks where service classes with/without QoS guarantees coexist. Examples for such networks include ATM and IF-based integrated networks. In ATM, the CBR and VER service classes provide QoS guarantees, while the ABR and UBR service classes are of the best effort type. In IF, traditional TCP/IP traffic is of the best effort type, while new protocols like the RSVP or the differentiated services with central resource handling attempt to support QoS parameters. The coexistence of guaranteed and best effort traffic gives rise to new challenging problems since for a given elastic (best effort) connection the bottleneck link determines the available bandwidth and thereby puts constraints on the bandwidth at the other links along the connection's path. Since the available bandwidth fluctuates in rime following the load on the links, routing and link allocation in this environment together with blocking probability calculations and fairness issues need to be studied. By means of our proposed model we are able to conduct a survey of various routing and link allocation techniques as well as to develop a modified shortest path routing algorithm which, according to the numerical examples, performs well in this environment. Copyright (C) 1999 John Wiley & Sons, Ltd.
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| 6. |
- G, Fodor, et al.
(författare)
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On multi-cell admission control in CDMA networks
- 2008
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Ingår i: International Journal of Communication Systems. - : John Wiley & Sons. - 1074-5351 .- 1099-1131. ; 21:1, s. 25-50
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Tidskriftsartikel (refereegranskat)abstract
- We consider a multi-cell (MC) code division multiple access (CDMA) system that supports multiple service classes, including peak rate allocated and elastic ones. Peak rate allocated sessions—when admitted into the system—transmit at a constant bit rate, while elastic sessions can be slowed down at the expense of increasing their residency time. Admitted sessions cause an instantaneous bit rate-dependent interference in neighbour cells. In this rather general setting, we propose a method to calculate the class-wise blocking probabilities as the functions of the estimated so-called inter-cell coupling factors. In the paper this coupling factor is the ratio between the uplink path gains to different Node-B:s (that can be easily obtained in a CDMA system from pilot measurement reports), but our model could include other coupling measures as well. We find that when these coupling factors are underestimated, the system may get into false states (FSs) or false rate states(FRSs) that lead to violating the noise rise threshold. As traffic becomes increasingly elastic, the probability of FSs decreases, but the probability of FRSs increases. Based on numerical results, we make the point that as the traffic becomes more elastic, avoiding the underestimation of these coupling factors as well as exercising MC admission control plays an increasingly important role in guaranteeing proper service quality.
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| 7. |
- G, Fodor, et al.
(författare)
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On providing blocking probability and throughput guarantees in a multi-service environment
- 2002
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Ingår i: International Journal of Communication Systems. - : WILEY. - 1074-5351 .- 1099-1131. ; 15:4, s. 257-285
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Tidskriftsartikel (refereegranskat)abstract
- As the Internet evolves from a packet network supporting a single best effort service class towards an integrated infrastructure supporting several service classes-some with QoS guarantees-there is a growing interest in the introduction of admission control and in devising bandwidth sharing strategies, which meet the diverse needs of QoS-assured and elastic services. In this paper we show that the extension of the classical multi-rate loss model is possible in a way that makes it useful in the performance analysis of a future admission control based Internet that supports traffic with peak rate guarantee as well as elastic traffic. After introducing the model, it is applied for the analysis of a single link, where it sheds light on the trade-off between blocking probability and throughput. For the investigation of this trade-off, we introduce the throughput-threshold constraint, which bounds the probability that the throughput of a traffic flow drops below a predefined threshold. Finally, we use the model to determine the optimal parameter set of the popular partial overlap link allocation policy: we propose a computationally efficient algorithm that provides blocking probability- and throughput guarantees. We conclude that the model and the numerical results provide important insights in traffic engineering in the Internet. Copyright (C) 2002 John Wiley Sons, Ltd.
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| 8. |
- G, Fodor, et al.
(författare)
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Performance analysis of a reuse partitioning technique for multi-channel cellular systems supporting elastic services
- 2009
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Ingår i: International Journal of Communication Systems. - : John Wiley & Sons. - 1074-5351 .- 1099-1131. ; 22:3, s. 307-342
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Tidskriftsartikel (refereegranskat)abstract
- For multi-cell systems employing intra-cell orthogonal communication channels, inter-cell interference mitigation techniques are expected to be one of the key radio resource management functions. In this paper we propose and analyze a simple reuse partitioning technique (with random and coordinated resource block allocation in neighbor cells) that is able to reduce inter-cell interference. We propose a model that is able to take into account that sessions dynamically enter and leave the system. Rigid sessions require a class-specific fixed number of resource blocks, while elastic sessions can enter the system if a minimum number of resources are allocated to them. In this rather general setting (and using the example of a system employing frequency division for multiple access) we analyze the system performance in terms of the expected number of channel collisions, the session-blocking probabilities, the signal-to-interference-and-noise ratio (SINR) and packet error rate performance. We present numerical results on the various trade-offs between these measures (including the trade-off between the reuse factor and the SINR performance) that provide insight into the behavior of multi-channel cellular systems and help dimensionalize the parameters of a reuse partitioned system.
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| 9. |
- G, Fodor
(författare)
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Performance analysis of resource sharing policies in CDMA networks
- 2007
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Ingår i: International Journal of Communication Systems. - : John Wiley & Sons. - 1074-5351 .- 1099-1131. ; 20:2, s. 207-233
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Tidskriftsartikel (refereegranskat)abstract
- We consider an interference-limited code division multiple access (CDMA) network, in which some of the service classes are explicit rate controlled. Such rate-controlled service classes include adaptive ones whose holding time does not depend on the sending rate, while the holding time of elastic services becomes longer when their sending rate is slowed down. We develop a Markov model that allows us to study the impact of employing service differentiation (prioritization) during admission control and rate control on the classwise blocking probabilities and throughputs. The admission control takes into account the interference from adjacent cells as a log-normally distributed random variable and employs service class and state-dependent (soft) blocking in addition to hard blocking. The state-dependent rate control algorithm takes into account the minimum and maximum requested rates of admitted sessions in a fairness policy-dependent manner. Our conclusion is that work conserving bandwidth sharing policies may have a major impact on the moments of the time spent in the system by elastic services, but only a minor one on the classwise blocking probabilities. When the admission control algorithm takes into account the neighbour cell caused interference, the blocking probability of all classes increases somewhat, but the throughput of the accepted sessions increases. Blocking prioritization in the soft blocking model affects the classwise total blocking probabilities but has little impact on the throughput of adaptive and elastic traffic.
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| 10. |
- Huang, Xin, et al.
(författare)
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Security protocols in body sensor networks using visible light communications
- 2016
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Ingår i: International Journal of Communication Systems. - : Wiley. - 1099-1131 .- 1074-5351. ; 29:16, s. 2349-2363
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Tidskriftsartikel (refereegranskat)abstract
- The fifth generation (5G) wireless system aims to support body sensor networks (BSNs) by increasing the interconnectivity of electronic devices. BSNs in the 5G era will enable many interesting applications, for example, medical services. In these applications, sensor networks collect sensitive information of individual human beings. Thus, security becomes significantly important in BSNs. However, many key distribution protocols are based on pre-deployed secrets. There are some problems: It is difficult to update pre-deployed secrets after they are compromised, or users want to re-deploy a device node. In this paper, we propose several security protocols including two key establishment protocols for BSNs by using visible light communications (VLCs). These protocols have a number of advantages. First, they can be widely applied in current BSNs without extra conditions because VLCs can be supported in most BSNs. Second, these protocols do not need pre-shared secrets; thus, it is not necessary for users to change pre-shared secrets if they are compromised. Experiments and analysis further show that (1) VLCs based on on–off keying are preferred; (2) computation and communication burden of these protocols are acceptable; and (3) these protocols bring little burden on users.
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