Performance evaluation of multipath cellular networks in obstacle mobility model for downlink packet video communication
- Authors: Al Yusuf, Abdullah , Murshed, Manzur
- Date: 2008
- Type: Text , Conference paper
- Relation: 2008 IEEE 68th Vehicular Technology Conference p. 1-5
- Full Text: false
- Reviewed:
- Description: Obstacles present in the line of sight transmission path of a wireless signal severely attenuates the received signal power. Extreme fluctuations of the received signal power caused by shadowing can create "blind spots". Blind spots are areas within the cellular coverage area from where no communication is possible to the base station (BS). For single path packet based services link failures results in total loss of communication. The problem of link failure and blind spots can almost be eliminated in the recently proposed multipath cellular architecture (MCA) which provisions up to three different communication links from the mobile node (MN) to three adjacent BSs through overlapped coverage. Voice and/or multimedia packet delivery can thus benefit by establishing communication from the best interface in terms of received signal power. In this paper, we evaluate the performance of the multi-path MCA model in reducing link failure and blind spot communication problems in presence of multiple obstacles and shadow fading. Obstacle mobility model is utilized as the preferred user mobility model. Video transmission performance improves significantly in terms of reduced packet loss and improved reproduced signal quality at the receiver for the multipath MCA model compared to the existing single path cellular network architecture
An algorithm for network and data-aware placement of multi-tier applications in cloud data centers
- Authors: Ferdaus, Md Hasanul , Murshed, Manzur , Calheiros, Rodrigo , Buyya, Rajkumar
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Network and Computer Applications Vol. 98, no. (2017), p. 65-83
- Full Text: false
- Reviewed:
- Description: Today's Cloud applications are dominated by composite applications comprising multiple computing and data components with strong communication correlations among them. Although Cloud providers are deploying large number of computing and storage devices to address the ever increasing demand for computing and storage resources, network resource demands are emerging as one of the key areas of performance bottleneck. This paper addresses network-aware placement of virtual components (computing and data) of multi-tier applications in data centers and formally defines the placement as an optimization problem. The simultaneous placement of Virtual Machines and data blocks aims at reducing the network overhead of the data center network infrastructure. A greedy heuristic is proposed for the on-demand application components placement that localizes network traffic in the data center interconnect. Such optimization helps reducing communication overhead in upper layer network switches that will eventually reduce the overall traffic volume across the data center. This, in turn, will help reducing packet transmission delay, increasing network performance, and minimizing the energy consumption of network components. Experimental results demonstrate performance superiority of the proposed algorithm over other approaches where it outperforms the state-of-the-art network-aware application placement algorithm across all performance metrics by reducing the average network cost up to 67% and network usage at core switches up to 84%, as well as increasing the average number of application deployments up to 18%. © 2017 Elsevier Ltd
Enhanced IEEE 802.11 by integrating multiuser dynamic OFDMA
- Authors: Ferdous, Hasan , Murshed, Manzur
- Date: 2010
- Type: Text , Conference paper
- Relation: Ninth Wireless Telecommunications Symposium p. 1-6
- Full Text: false
- Reviewed:
- Description: In this paper, we discuss the problems associated with the present contention resolution mechanism of IEEE 802.11 DCF and present a new, dynamic and robust approach to improve it. Our new MAC, using OFDMA in the physical layer, can incorporate multiple concurrent transmissions or receptions in a dynamic manner and can adjust the collision probability based on the traffic load when nodes are endowed with a single half-duplex radio only. Simulation results show that our system improves throughput by up to 40 percent, reduces collision in control messages by up to 80 percent and reduces the average delay for data transmission by up to 20 percent.
Advances in multimedia sensor networks for health-care and related applications
- Authors: Hossain, M. Shamim , Pathan, Al-Sakib , Goebel, Stefan , Rahman, Shawon , Murshed, Manzur
- Date: 2015
- Type: Text , Journal article , Editorial
- Relation: International Journal of Distributed Sensor Networks Vol. 2015, no. (2015), p. 1-2
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- Description: Multimedia sensor services and technologies play an important role in seamlessly providing andmanaging health, sports, and other services to anyone, everywhere, and anytime. Media sensors are usually equipped with cameras, microphones, and other devices that produce media content and services. Such services and technologies enable caregivers and related professionals to have immediate access to required information for efficient decision making. Since media sensing technology development is growing, many research opportunities are emerging in a broad spectrum of application domains.
Attack-resistant sensor localization under realistic wireless signal fading
- Authors: Iqbal, Anindya , Murshed, Manzur
- Date: 2010
- Type: Text , Conference paper
- Relation: 2010 IEEE Wireless Communications and Networking Conference p. 1-6
- Full Text: false
- Reviewed:
- Description: In a decentralized sensor network, localization process relies on the integrity of participating sensors. Existence of malicious beacon nodes in the vicinity of non-beacon nodes affects this process. This paper presents a trilateration-based secure localization technique, which is capable of estimating the location of a sensor with high accuracy so long four neighbouring beacon nodes are benign, irrespective of the number of neighbouring liars and without assuming any trust model. In realistic scenarios of wireless environment where transmitted signals attenuate randomly due to fading, the liar-tolerance level of this attack-resistant technique has to be relaxed accordingly. Superiority of this technique against the state-of-the-art has been established with extensive simulation results in terms of location estimation accuracy and liar-filtering probability.
A hybrid wireless sensor network framework for range-free event localization
- Authors: Iqbal, Anindya , Murshed, Manzur
- Date: 2015
- Type: Text , Journal article
- Relation: Ad Hoc Networks Vol. 27, no. (2015), p. 81-98
- Full Text: false
- Reviewed:
- Description: In event localization, wireless sensors try to locate the source of an event from its emitted power. This is more challenging than sensor localization as the power level at the source of an event is neither predictable with precision nor can be controlled. Considering the emerging trend of long sensing range for cost-effective sensor deployment, locating events within a region much smaller than the sensing area of a single sensor has gained research interest. This paper proposes the first range-free event localization framework, which avoids expensive hardware needed by the range-based counterparts. Our approach first develops a sensing range model from the statistical information on the emitted power of a type of events so that user-defined event-detection quality can be provisioned using a minimal network of static sensors. Then an accurate event location boundary estimation technique is developed from the sensing feedbacks, which also facilitates guided expansion of the area of possible event location (APEL) to deal with sensing errors. Finally, user-defined event-localization quality guarantee is provisioned cost-effectively by inviting mobile sensors on-demand to target positions. Analytical solutions are provided whenever appropriate and comprehensive simulations are carried out to evaluate localization performance. The proposed event localization technique outperforms the state-of-the-art range-based counterpart (Xu et al., 2011) in realistic environment with path loss, shadow fading, and sensor positioning errors.
Workload-aware incremental repartitioning of shared-nothing distributed databases for scalable OLTP applications
- Authors: Kamal, Joarder , Murshed, Manzur , Buyya, Rajkumar
- Date: 2016
- Type: Text , Journal article
- Relation: Future Generation Computer Systems Vol. 56, no. March (2016), p. 421-436
- Full Text: false
- Reviewed:
- Description: On-line Transaction Processing (OLTP) applications often rely on shared-nothing distributed databases that can sustain rapid growth in data volume. Distributed transactions (DTs) that involve data tuples from multiple geo-distributed servers can adversely impact the performance of such databases, especially when the transactions are short-lived and these require immediate responses. The. k-way min-cut graph clustering based database repartitioning algorithms can be used to reduce the number of DTs with acceptable level of load balancing. Web applications, where DT profile changes over time due to dynamically varying workload patterns, frequent database repartitioning is needed to keep up with the change. This paper addresses this emerging challenge by introducing incremental repartitioning. In each repartitioning cycle, DT profile is learnt online and. k-way min-cut clustering algorithm is applied on a special sub-graph representing all DTs as well as those non-DTs that have at least one tuple in a DT. The latter ensures that the min-cut algorithm minimally reintroduces new DTs from the non-DTs while maximally transforming existing DTs into non-DTs in the new partitioning. Potential load imbalance risk is mitigated by applying the graph clustering algorithm on the finer logical partitions instead of the servers and relying on random one-to-one cluster-to-partition mapping that naturally balances out loads. Inter-server data-migration due to repartitioning is kept in check with two special mappings favouring the current partition of majority tuples in a cluster-the many-to-one version minimising data migrations alone and the one-to-one version reducing data migration without affecting load balancing. A distributed data lookup process, inspired by the roaming protocol in mobile networks, is introduced to efficiently handle data migration without affecting scalability. The effectiveness of the proposed framework is evaluated on realistic TPC-C workloads comprehensively using graph, hypergraph, and compressed hypergraph representations used in the literature. To compare the performance of any incremental repartitioning framework without any bias of the external min-cut algorithm due to graph size variations, a transaction generation model is developed that can maintain a target number of unique transactions in any arbitrary observation window, irrespective of new transaction arrival rate. The overall impact of DTs at any instance is estimated from the exponential moving average of the recurrence period of unique transactions to avoid transient fluctuations. The effectiveness and adaptability of the proposed incremental repartitioning framework for transactional workloads have been established with extensive simulations on both range partitioned and consistent hash partitioned databases. © 2015 Elsevier B.V.
A novel anonymization technique to trade off location privacy and data integrity in participatory sensing systems
- Authors: Murshed, Manzur , Sabrina, Tishna , Iqbal, Anindya , Alam, K.
- Date: 2010
- Type: Text , Conference paper
- Relation: 2010 Fourth International Conference on Network and System Security p. 345-350
- Full Text: false
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- Description: Abstract—Preserving privacy in participatory sensing systems has recently gained research interest as voluntary contribution in such systems is not worthy if the privacy of the participants is not protected. On the other hand, data integrity is desired imperatively to make the service trustworthy and user-friendly. In this paper, we have proposed an adaptive location anonymization technique, which is capable of retaining an acceptable level of data integrity while keeping its vulnerability to eavesdropping adversaries low. Experimental results establish the proposed concept as a superior approach in balancing, somehow orthogonal, user privacy and data integrity.
Privacy in participatory sensing systems
- Authors: Sabrina, Tishna , Murshed, Manzur
- Date: 2013
- Type: Text , Book chapter , Book
- Relation: Network and Traffic Engineering in Emerging Distributed Computing Applications. Chapter 6. pg 124-143
- Full Text: false
- Reviewed:
- Description: Participatory sensing is a revolutionary new paradigm where ordinary citizens voluntarily sense their environment using readily available sensor devices such as mobile phones and systematically study, and then reflect on and share this information using existing wireless networks. It provides data collection, processing, and dissemination opportunities for socially-responsible applications spanning environmental monitoring, intelligent transportation, and public health, which are often not cost-viable using dedicated sensing infrastructure. The uniqueness of the participatory sensing system lies in its data communication infrastructure which is constituted by the deliberate participation of community people. However, the potential lack of privacy of the participants in such system makes it harder to ensure their voluntary contribution. Thus preserving privacy of the individuals contributing data has introduced a key challenge in this area. On the other hand, data integrity is desired imperatively to make the service trustworthy and user-friendly. Different interesting approaches have been proposed so far to protect privacy that will encourage participation of the owners of data sources in turn.
Performance analysis of vertical handoff algorithms with QoS parameter differentiation
- Authors: Sharna, Shusmita , Murshed, Manzur
- Date: 2010
- Type: Text , Conference paper
- Relation: 12th IEEE International Conference on High Performance Computing and Communications p. 623-628
- Full Text: false
- Reviewed:
- Description: Despite recent interests in developing vertical handoff decision algorithms, an essential component of the architecture of the next generation heterogeneous wireless networks, very few studies have so far reported any meaningful comparative performance analysis. This paper attempts to fill this gap in the literature by presenting a comprehensive study on the performance of three vertical handoff decision algorithms, namely, SAW (Simple Additive Weighting), TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), and MDP (Markov Decision Process). We have used both analytical and simulation tools (ns-2.29) to evaluate and compare expected total QoS offerings in the mean duration of a service under different state transition probability distributions, user perception models on the importance of QoS parameters, and network switching costs. To our surprise, we have observed TOPSIS achieving the best performance despite MDP's using the optimal policy. We suspect that the user satisfiability model used in MDP to estimate link rewards might have contradicted the underlying user perception model used to estimate normalised weight of each QoS parameter, which will be investigated in future.