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Farag, Hossam
Publications (10 of 13) Show all publications
Farag, H., Gidlund, M. & Österberg, P. (2019). DeP-D: A Decentralized Primal-Dual Optimization Algorithm for Industrial Wireless Sensor Networks. In: 2019 15th IEEE International Workshop on Factory Communication Systems (WFCS): . Paper presented at 15th IEEE International Workshop on Factory Communication Systems (WFCS), Sundsvall, 27-29 May, 2019. IEEE, Article ID 8757934.
Open this publication in new window or tab >>DeP-D: A Decentralized Primal-Dual Optimization Algorithm for Industrial Wireless Sensor Networks
2019 (English)In: 2019 15th IEEE International Workshop on Factory Communication Systems (WFCS), IEEE, 2019, article id 8757934Conference paper, Published paper (Refereed)
Abstract [en]

Industrial Wireless Sensor Networks (IWSNs) are emerged as flexible and cost-efficient alternatives to the traditional wired networks in various monitoring and control applications within the industrial domain. Low delay is a key feature of delay-sensitive applications as the data is typically valid for a short interval of time. If data arrives too late it is of limited use which may lead to performance drops or even system outages which can create significant economical losses. In this paper, we propose a decentralized optimization algorithm to minimize the End-to-End (E2E) delay of multi-hop IWSNs. Firstly, we formulate the optimization problem by considering the objective function as the network delay where the constraint is the stability criteria based on the total arrival rate and the total service rate. The objective function is proved to be strictly convex for the entire network, then a Decentralized Primal-Dual (DeP-D) algorithm is proposed based on the sub-gradient method to solve the formulated optimization problem. The performance of the proposed DeP-D is evaluated through simulations and compared with WirelessHART network and the results show that the proposed DeP-D can achieve at least 40% reduction in the average E2E delay.

Place, publisher, year, edition, pages
IEEE, 2019
Keywords
IWSN, Optimization, Sheduling, Protocol, Delay
National Category
Communication Systems
Identifiers
urn:nbn:se:miun:diva-36761 (URN)10.1109/WFCS.2019.8757934 (DOI)000490866300004 ()2-s2.0-85070111073 (Scopus ID)978-1-7281-1268-8 (ISBN)
Conference
15th IEEE International Workshop on Factory Communication Systems (WFCS), Sundsvall, 27-29 May, 2019
Projects
SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle)TIMELINESS
Funder
European Regional Development Fund (ERDF)Knowledge Foundation
Available from: 2019-07-29 Created: 2019-07-29 Last updated: 2019-11-13Bibliographically approved
Farag, H. (2019). Enabling Time- and Mission-Critical Applications in Industrial Wireless Sensor Networks. (Licentiate dissertation). Sundsvall, Sweden: Mid Sweden University
Open this publication in new window or tab >>Enabling Time- and Mission-Critical Applications in Industrial Wireless Sensor Networks
2019 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Nowadays, Wireless Sensor Networks (WSNs) have gained importance as aflexible, easier deployment/maintenance and cost-effective alternative to wired networks,e.g., Fieldbus and Wired-HART, in a wide-range of applications. Initially,WSNs were mostly designed for military and environmental monitoringapplications where energy efficiency is the main design goal. The nodes in the network were expected to have a long lifetime with minimum maintenance while providing best-effort data delivery which is acceptable in such scenarios. With recent advances in the industrial domain, WSNs have been subsequently extended to support industrial automation applications such as process automation and control scenarios. However, these emerging applications are characterized by stringent requirements regarding reliability and real-time communications that impose challenges in the design of Industrial Wireless Sensor Networks (IWSNs) to effectively support time- and mission-critical applications.

Typically, time- and mission-critical applications support different traffic categories ranging from relaxed requirements, such as monitoring traffic to firm requirements, such as critical safety and emergency traffic. The critical traffic is mostly acyclic in nature and occasionally occurs at unpredictable time instants. Once it is generated, it must be delivered within strict deadlines. Exceeding the delay bound could lead to system instability, economic loss, or even endanger human life in the working area. The situation becomes even more challenging when an emergency event triggers multiple sensor nodes to transmit critical traffic to the controller simultaneously. The unpredictability of the arrival of such a type of traffic introduces difficulties with regard to making a suitable scheduling that guarantees data delivery within deadline bounds. Existing industrial standards and related research work have thus far not presented a satisfactory solution to the issue. Therefore, providing deterministic and timely delivery for critical traffic and its prioritization over regular traffic is a vital research topic.

Motivated by the aforementioned challenges, this work aims to enable real-timecommunication for time- and mission-critical applications in IWSNs. In this context, improved Medium Access Control (MAC) protocols are proposed to enablea priority-based channel access that provides a timely delivery for acyclic critical traffic. The proposed framework starts with a stochastic modelling of the network delay performance under a priority-oriented transmission scheme, followed by two MAC approaches. The first approach proposes a random Clear Channel Assessment (CCA) mechanism to improve the transmission efficiency of acyclic control traffic that is generated occasionally as a result of observations of an established tendency, such as closed-loop supervisory traffic. A Discrete-Time Markov Chain (DTMC) model is provided to evaluate the performance of the proposed protocol analytically in terms of the expected delay and throughput. Numerical results show that the proposed random CCA mechanism improves the shared slots approach in WirelessHART in terms of delay and throughput along with better transmission reliability.

The second approach introduces a slot-stealing MAC protocol based on a dynamic deadline-aware scheduling to provide deterministic channel access in emergency and event-based situations, where multiple sensor nodes are triggered simultaneously to transmit time-critical data to the controller. The proposed protocol is evaluated mathematically to provide the worst-case delay bound for the time-critical traffic and the numerical results show that the proposed approach outperforms TDMA-based WSNs in terms of delay and channel utilization.

Place, publisher, year, edition, pages
Sundsvall, Sweden: Mid Sweden University, 2019. p. 42
Series
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 151
National Category
Communication Systems
Identifiers
urn:nbn:se:miun:diva-35572 (URN)978-91-88527-84-4 (ISBN)
Presentation
2019-01-30, M102, Sundsvall, 14:30 (English)
Opponent
Supervisors
Projects
SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle)
Available from: 2019-02-07 Created: 2019-02-04 Last updated: 2019-06-13Bibliographically approved
Farag, H., Sisinni, E., Gidlund, M. & Österberg, P. (2019). Priority-Aware Wireless Fieldbus Protocol for Mixed-Criticality Industrial Wireless Sensor Networks. IEEE Sensors Journal, 19(7), 2767-2780
Open this publication in new window or tab >>Priority-Aware Wireless Fieldbus Protocol for Mixed-Criticality Industrial Wireless Sensor Networks
2019 (English)In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 19, no 7, p. 2767-2780Article in journal (Refereed) Published
Abstract [en]

Industrial wireless sensor networks are becoming popular for critical monitoring and control applications in industrial automation systems. For such type of applications, providing reliable real-time performance regarding data delivery is considered as a fundamental challenge. The problem becomes more prominent with mixed-criticality systems, where different data flow with different levels of criticality (importance) coexist and characterized by different requirements regarding delay and reliability. In this paper, we propose a wireless fieldbus protocol to enable real-time communication and service differentiation for cluster-based mixed-criticality networks. A process monitoring scenario of plastic extrusion is used to define the protocol requirements and elaborate the working principle of the proposed work. In our proposed protocol, each data flow is scheduled for channel access based on its criticality level using a distributed prioritized medium access mechanism that ensures a guaranteed channel access for the most critical traffic over other traffic types. The performance of the proposed protocol is analyzed analytically using a discrete-time Markov chain model to evaluate the performance in terms of delay and throughput. Moreover, the extensive simulations are conducted to prove the analytical claims and different performance assessments are provided, which also demonstrate the effectiveness of the proposed approach compared with the related existing work.

Keywords
Industrial wireless sensor networks, mixed-criticality systems, real-time, wireless fieldbus
National Category
Communication Systems
Identifiers
urn:nbn:se:miun:diva-35807 (URN)10.1109/JSEN.2018.2888729 (DOI)000460683600042 ()2-s2.0-85058876428 (Scopus ID)
Projects
SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle)
Note

Available from: 2019-03-19 Created: 2019-03-19 Last updated: 2019-10-16Bibliographically approved
Farag, H., Österberg, P. & Gidlund, M. (2019). RMA-RP: A Reliable Mobility-Aware Routing Protocol for Industrial IoT Networks. In: : . Paper presented at In Proc. IEEE Global Conference on Internet of Things (GCIoT'19), Dubai, Dec. 2019. IEEE
Open this publication in new window or tab >>RMA-RP: A Reliable Mobility-Aware Routing Protocol for Industrial IoT Networks
2019 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Many emerging Industrial Internet of Things (IIoT) applications involve the use of mobile devices, such as sensors and robots in industrial automation scenarios. Movement of mobile sensor nodes causes intermittent connectivity which in turn deteriorates the network performance in terms of packet loss and delay. The Routing Protocol for Low Power and Lossy Networks (RPL) is introduced as the standard routing protocol for IIoT networks. Although RPL constitutes a reliable and energy-efficient solution for static networks, there is no mechanism defined in the RPL standard of how to support routing in mobile IIoT networks. This paper introduces RMA-RP, a reliable mobility-aware routing protocol to support mobile IIoT networks. RMA-RP utilizes a dynamic motion detection mechanism based on the link quality to cope with topology changes by updating next-hop nodes. Moreover, an adaptive timer is introduced to manage the transmission rate of control messages in order to decrease the network overhead and in turn the energy consumption. We evaluate the performance of RMA-RP through extensive simulations in comparison to existing works and the results demonstrate that RMA-RP has at least 17% higher packet delivery ratio and achieves a reduction of 34% and 51% in terms of delay and network overhead, respectively.

Place, publisher, year, edition, pages
IEEE, 2019
Keywords
Industrial IoT, industrial wireless sensor networks, RPL, mobility.
National Category
Computer Engineering Communication Systems
Identifiers
urn:nbn:se:miun:diva-38202 (URN)
Conference
In Proc. IEEE Global Conference on Internet of Things (GCIoT'19), Dubai, Dec. 2019
Projects
Next Generation Industrial IoT (NIIT)
Funder
Knowledge Foundation
Available from: 2020-01-10 Created: 2020-01-10 Last updated: 2020-01-10
Farag, H., Gidlund, M. & Österberg, P. (2018). A Delay-Bounded MAC Protocol for Mission- and Time-Critical Applications in Industrial Wireless Sensor Networks. IEEE Sensors Journal, 18(6), 2607-2616
Open this publication in new window or tab >>A Delay-Bounded MAC Protocol for Mission- and Time-Critical Applications in Industrial Wireless Sensor Networks
2018 (English)In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 18, no 6, p. 2607-2616Article in journal (Refereed) Published
Abstract [en]

Industrial Wireless Sensor Networks (IWSNs) designedfor mission- and time-critical applications require timelyand deterministic data delivery within stringent deadline bounds.Exceeding delay limits for such applications can lead to system malfunction or ultimately dangerous situations that can threaten human safety. In this paper, we propose SS-MAC, an efficient slot stealing MAC protocol to guarantee predictable and timely channel access for time-critical data in IWSNs. In the proposed SS-MAC, aperiodic time-critical traffic opportunistically steals time slots assigned to periodic non-critical traffic. Additionally, a dynamic deadline-based scheduling is introduced to provide guaranteed channel access in emergency and event-based situations where multiple sensor nodes are triggered simultaneously to transmit time-critical data to the controller. The proposed protocol is evaluated mathematically to provide the worst-case delay bound for the time-critical traffic. Performance comparisons are carried out between the proposed SS-MAC and WirelessHARTstandard and they show that, for the time-critical traffic, theproposed SS-MAC can achieve, at least, a reduction of almost 30% in the worst-case delay with a significant channel utilization efficiency.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-32771 (URN)10.1109/JSEN.2018.2793946 (DOI)000425981100048 ()2-s2.0-85041646182 (Scopus ID)
Projects
SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle)
Available from: 2018-01-30 Created: 2018-01-30 Last updated: 2019-09-09Bibliographically approved
Farag, H., Mahmood, A., Gidlund, M. & Österberg, P. (2018). PR-CCA MAC: A Prioritized Random CCA MAC Protocol for Mission-Critical IoT Applications. In: 2018 IEEE International Conference on Communications (ICC): . Paper presented at IEEE International Conference on Communications (ICC'18), Kansas, USA, 20-24 May 2018.. IEEE, Article ID 8423018.
Open this publication in new window or tab >>PR-CCA MAC: A Prioritized Random CCA MAC Protocol for Mission-Critical IoT Applications
2018 (English)In: 2018 IEEE International Conference on Communications (ICC), IEEE, 2018, article id 8423018Conference paper, Published paper (Refereed)
Abstract [en]

A fundamental challenge in Mission-Critical Internetof Things (MC-IoT) is to provide reliable and timely deliveryof the unpredictable critical traffic. In this paper, we propose an efficient prioritized Medium Access Control (MAC) protocol for Wireless Sensor Networks (WSNs) in MC-IoT control applications. The proposed protocol utilizes a random Clear Channel Assessment (CCA)-based channel access mechanism to handlethe simultaneous transmissions of critical data and to reduce thecollision probability between the contending nodes, which in turn decreases the transmission latency. We develop a Discrete-Time Markov Chain (DTMC) model to evaluate the performance of the proposed protocol analytically in terms of the expected delay and throughput. The obtained results show that the proposed protocolcan enhance the performance of the WirelessHART standard by 80% and 190% in terms of latency and throughput, respectively along with better transmission reliability.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
IWSN, IoT, Determinism, MAC, Low latency
National Category
Communication Systems Computer Engineering
Identifiers
urn:nbn:se:miun:diva-33671 (URN)10.1109/ICC.2018.8423018 (DOI)2-s2.0-85051413092 (Scopus ID)978-1-5386-3180-5 (ISBN)978-1-5386-3181-2 (ISBN)
Conference
IEEE International Conference on Communications (ICC'18), Kansas, USA, 20-24 May 2018.
Projects
SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle)TIMELINESSASIS
Funder
European Regional Development Fund (ERDF)Knowledge Foundation
Available from: 2018-05-28 Created: 2018-05-28 Last updated: 2019-09-09Bibliographically approved
Guntupalli, L., Farag, H., Mahmood, A. & Gidlund, M. (2018). Priority-Oriented Packet Transmissions in Internet of Things: Modeling and Delay Analysis. In: 2018 IEEE International Conference on Communications (ICC): . Paper presented at IEEE International Conference on Communications (ICC'18), Kansas, USA, May 2018. IEEE, Article ID 8422699.
Open this publication in new window or tab >>Priority-Oriented Packet Transmissions in Internet of Things: Modeling and Delay Analysis
2018 (English)In: 2018 IEEE International Conference on Communications (ICC), IEEE, 2018, article id 8422699Conference paper, Published paper (Refereed)
Abstract [en]

Priority-oriented packet transmission (PPT) has been a promising solution for transmitting time-critical packets in timely manner during emergency scenarios in Internet ofThings (IoT). In this paper, we develop two associated discrete time Markov chain (DTMC) models to analyze performance of the PPT in an IoT network. Using the proposed DTMC models, we investigate the effect of traffic prioritization interms of average packet delay for a synchronous medium access control (MAC) protocol. Furthermore, the results obtained from analytical models are validated via discrete-event simulations. Numerical results prove the accuracy of the models and reveal the behavior of priority based packet transmissions.

Place, publisher, year, edition, pages
IEEE, 2018
Keywords
IoT, WSN, WuR, delay, analysis, DTMC
National Category
Communication Systems Computer Engineering
Identifiers
urn:nbn:se:miun:diva-33670 (URN)10.1109/ICC.2018.8422699 (DOI)2-s2.0-85051436438 (Scopus ID)978-1-5386-3180-5 (ISBN)978-1-5386-3181-2 (ISBN)
Conference
IEEE International Conference on Communications (ICC'18), Kansas, USA, May 2018
Projects
SMART (Smarta system och tjänster för ett effektivt och innovativt samhälle)TIMELINESS
Funder
European Regional Development Fund (ERDF)Knowledge Foundation
Available from: 2018-05-28 Created: 2018-05-28 Last updated: 2019-09-09Bibliographically approved
Farag, H. & Mohamed, E. M. (2017). Soft Decision Cooperative Spectrum Sensing with Noise Uncertainty Reduction. Pervasive and Mobile Computing, 35, 146-164
Open this publication in new window or tab >>Soft Decision Cooperative Spectrum Sensing with Noise Uncertainty Reduction
2017 (English)In: Pervasive and Mobile Computing, ISSN 1574-1192, E-ISSN 1873-1589, Vol. 35, p. 146-164Article in journal (Refereed) Published
Abstract [en]

Cognitive radio (CR) is a potential strategy for opportunistic access of idle resources to solve the conflicts between spectrum scarcity and underutilization. Spectrum sensing (SS) constitutes the most critical part in CR systems since the CR needs to detect the presence of primary signals reliably and quickly. Energy detection (ED) based SS is considered as the most preferable SS technique due to its simplicity and applicability. However, it is influenced by the effect of noise uncertainty which highly degrades its sensing performance. Cooperative spectrum sensing (CSS) is also introduced to mitigate some sensing problems such as multipath fading, shadowing, and hidden node problems. In this paper, we propose an enhanced fusion center (FC) rule for soft decision CSS using ED, which highly alleviates the noise uncertainty effect and enhances the sensing performance of cognitive radio networks (CRNs). In the proposed fusion rule, to increase the probability of detection and decrease the probability of false alarm, two dynamic thresholds are utilized by the FC. These thresholds are toggled based on predicting the current activity of the primary user (PU), and their values are dynamically changed based on estimating the noise uncertainty factor of the collected energy measurements from the CRs. To effectively predict (estimate) the current PU activity (the noise uncertainty factor), simple successive averaging processes over the collected energy measurements (the estimated noise variances) are performed by the FC, respectively. Theoretical analysis is performed on the proposed fusion rule for soft decision CSS to evaluate its enhanced false alarm and detection probabilities using different data combining schemes. Performance evaluations are also investigated to confirm the theoretical claims and to prove the effectiveness of the proposed scheme over the conventional ED based soft decision CSS.

National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-31470 (URN)10.1016/j.pmcj.2016.04.001 (DOI)
Available from: 2017-08-23 Created: 2017-08-23 Last updated: 2017-10-17Bibliographically approved
Farag, H. & Mohamed, E. M. (2016). Dynamic Threshold Hard Decision Cooperative Spectrum Sensing Using Two-Stage Censoring. In: 23rd International Conference on Telecommunications, ICT 2016: . Paper presented at IEEE International Conference on Telecommunications (ICT 2016) (pp. 38-42). IEEE
Open this publication in new window or tab >>Dynamic Threshold Hard Decision Cooperative Spectrum Sensing Using Two-Stage Censoring
2016 (English)In: 23rd International Conference on Telecommunications, ICT 2016, IEEE, 2016, p. 38-42Conference paper, Published paper (Refereed)
Abstract [en]

In hard decision cooperative spectrum sensing (CSS), each secondary user (SU) or simply cognitive radio user (CR) senses the primary user (PU) activity via a Sensing channel (S-channel) and forwards its own binary decision to a fusion center (FC) via a Reporting channel (R-channel) to make a final decision regarding PU existence. In practical scenarios, both S-channels and R-channels are contaminated with noise, fading and shadowing effects. Thus, the FC may receive faulty decisions from the CRs, which in turn degrades the overall sensing performance of the cognitive radio networks (CRNs). In this paper, an efficient hard decision CSS with two-stage censoring is proposed for boosting the sensing performance of CRNs against noise uncertainty inherent in the S-channels and erroneous inherent in the R-channels. In the first stage, CRs with low quality R-channels are censored by the FC, hence only CRs with high quality R-channels are selected for the next stage of censoring. In the second stage, the low confident CRs with high noise uncertainty factors of their S-channels are censored by the FC, i.e., the FC selects the candidate CRs with the highest quality R-channels and the lowest noisy S-channels. For boosting the sensing decisions made by the CRs, a double dynamic threshold (DDT) is utilized by each CR based on an estimated value of the noise uncertainty factor of its S-channel. The new detection and false alarm probabilities are evaluated mathematically for the proposed scheme. Moreover, numerical analysis is used to confirm the high potency of the proposed scheme over some existing hard decision CSS schemes.

Place, publisher, year, edition, pages
IEEE, 2016
National Category
Communication Systems
Identifiers
urn:nbn:se:miun:diva-31472 (URN)10.1109/ICT.2016.7500350 (DOI)978-1-5090-1990-8 (ISBN)
Conference
IEEE International Conference on Telecommunications (ICT 2016)
Available from: 2017-08-23 Created: 2017-08-23 Last updated: 2017-10-17Bibliographically approved
Farag, H. & Mohamed, E. M. (2015). Hard Decision Cooperative Spectrum Sensing Based on Estimating the Noise Uncertainty Factor. In: Proceedings - 2015 10th International Conference on Computer Engineering and Systems, ICCES 2015: . Paper presented at International Conference on Computer Engineering & Systems (ICCES 2015) (pp. 217-222). IEEE
Open this publication in new window or tab >>Hard Decision Cooperative Spectrum Sensing Based on Estimating the Noise Uncertainty Factor
2015 (English)In: Proceedings - 2015 10th International Conference on Computer Engineering and Systems, ICCES 2015, IEEE, 2015, p. 217-222Conference paper, Published paper (Refereed)
Abstract [en]

Spectrum Sensing (SS) comprises the most important component in Cognitive Radio (CR) systems. Cooperative Spectrum Sensing (CSS) is proposed as an effective approach to improve detection performance in fading environments. This paper introduces an efficient energy detection based hard decision CSS algorithm to alleviate the noise uncertainty effect. In the proposed algorithm, the decision threshold is dynamically switched between two levels based on a prior prediction of the Primary User (PU) activity. The two threshold levels are evaluated using an estimated value of the noise uncertainty factor to maximize the probability of detection and minimize the probability of false alarm. The proposed algorithm is studied theoretically to deduce the enhanced detection and false alarm probabilities. Moreover, simulation analysis is used to confirm the theoretical claims and prove the high potency of the proposed scheme compared to the conventional CSS using different fusion rules.

Place, publisher, year, edition, pages
IEEE, 2015
National Category
Communication Systems
Identifiers
urn:nbn:se:miun:diva-31474 (URN)10.1109/ICCES.2015.7393049 (DOI)
Conference
International Conference on Computer Engineering & Systems (ICCES 2015)
Available from: 2017-08-23 Created: 2017-08-23 Last updated: 2017-10-17Bibliographically approved
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