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An enhanced-MDP based vertical handoff algorithm for QoS support over heterogeneous wireless networks

- Sharna, Shusmita, Amin, Mohammad, Murshed, Manzur

  • Authors: Sharna, Shusmita , Amin, Mohammad , Murshed, Manzur
  • Date: 2011
  • Type: Text , Conference proceedings
  • Relation: Proceedings of 2011 IEEE International Symposium on Network Computing and Applications (NCA 2011),Cambridge, MA, 25-27th Aug, 2011
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  • Description: Vertical handoff plays an important role in guaranteeing users to be always connected in an overlapped multi-network environment. During the vertical handoff procedure, handoff decision is the most important step that affects the normal working of communication. An incorrect handoff decision or selection of a non-optimal network may result in undesirable effects such as higher costs, poor quality of service (QoS) experience, and even dropped communication. Among the existing vertical handoff decision algorithms, the Markov Decision Process (MDP) based algorithm by Stevens-Navarro et al. is promising due to its ability to achieve the optimal expected reward. However, the reward function used by this algorithm is flawed as it favors reducing expected number of vertical handoffs at the expense of diminished expected values of other QoS parameters. This paper presents an extended MDP based algorithm (EMDP) with novel reward function formulation. Analysis shows that EMDP outperforms the MDP based algorithm in terms of improved expected values of all QoS parameters considered while keeping the vertical handoff number reasonably low.

Performance analysis of m-retry BEB based DCF under unsaturated traffic condition

- Siddique, Md, Kamruzzaman, Joarder

  • Authors: Siddique, Md , Kamruzzaman, Joarder
  • Date: 2010
  • Type: Text , Conference paper
  • Relation: 2010 IEEE Wireless Communications and Networking Conference (WCNC) p. 1-6
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  • Description: The IEEE 802.11 standard offers a cheap and promising solution for small scale wireless networks. Due to the self configuring nature, WLANs do not require large scale infrastructure deployment, and are scalable and easily maintainable which incited its popularity in both literature and industry. In real environment, these networks operate mostly under unsaturated condition. We investigate performance of such a network with m-retry limit BEB based DCF. We consider imperfect channel with provision for power capture. Our method employs a Markov model and represents the most common performance measures in terms of network parameters making the model and mathematical analysis useful in network design and planning. We also explore the effects of packet error, network size, initial contention window, and retry limit on overall performance of WLANs.

Extremum seeking control with sporadic packet transmission for networked control systems

- Premaratne, Upeka, Halgamuge, Saman, Tan, Ying, Mareels, Iven

  • Authors: Premaratne, Upeka , Halgamuge, Saman , Tan, Ying , Mareels, Iven
  • Date: 2020
  • Type: Text , Journal article
  • Relation: IEEE transactions on control of network systems Vol. 7, no. 2 (2020), p. 758-769
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  • Description: Extremum seeking control (ESC) is a data-driven optimization technique that can steer a dynamic plant toward an extremum of an unknown but measurable input to steady-state output. In the context of networked control systems, a new implementation method for ESC inspired by the well-known Luus-Jaakola algorithm is proposed. The main motivation is to minimize the communication burden associated with the search phase of ESC. In the proposed method, the controller only requires a notification of a change registered at the sensor, rather than the full information available at the sensor. This event-based approach leads to sporadic packet transmission. In addition, the proposed method is able to directly account for constraints while seeking the desired extremum. The constraints may be of the inequality or equality type. The algorithm's behavior is illustrated on a networked water pump control system.

A comprehensive spectrum trading scheme based on market competition, reputation and buyer specific requirements

- Hassan, Rakib, Karmakar, Gour, Kamruzzaman, Joarder, Srinivasan, Bala

  • Authors: Hassan, Rakib , Karmakar, Gour , Kamruzzaman, Joarder , Srinivasan, Bala
  • Date: 2015
  • Type: Text , Journal article
  • Relation: Computer Networks Vol. 84, no. (2015), p. 17-31
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  • Description: In the exclusive-use model of spectrum trading, cognitive radio devices or secondary users can buy spectrum resources from licensed users or primary users for a short or long period of time. Considering such spectrum access, a trading model is introduced where a buyer can select a set of candidate sellers based on their reputation and their offers in fulfilling its requirements, namely, offered signal quality, contract duration, coverage and bandwidth. Similarly, a seller can assess a buyer as a potential trading partner considering the buyer's reliability, which the seller can derive from the buyer's reputation and financial profile. In our scheme, seller reputation or buyer reliability can be either obtained from a reputation brokerage service, if one exists, or calculated using our model. Since in a competitive market, the price of a seller depends on that of other sellers, game theory is used to model the competition among multiple sellers. An optimization technique is used by a buyer to select the best seller(s) and optimize purchase to maximize its utility. This may result in buying from multiple sellers of certain amount of bandwidth from each, depending on price and meeting requirements and budget constraints. Stability of the model is analyzed and performance evaluation shows that it benefits sellers and buyers in terms of profit and throughput, respectively. © 2015 Elsevier B.V. All rights reserved.

A Joint framework for QoS and QoE for video transmission over wireless multimedia sensor networks

- Usman, Muhammad, Ning, Yang, Jan, Mian, Xiangjian, He, Min, Xu, Kin-Man, Lam

  • Authors: Usman, Muhammad , Ning, Yang , Jan, Mian , Xiangjian, He , Min, Xu , Kin-Man, Lam
  • Date: 2018
  • Type: Text , Journal article
  • Relation: IEEE transactions on mobile computing Vol. 17, no. 4 (2018), p. 746-759
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  • Description: With the emergence of Wireless Multimedia Sensor Networks (WMSNs), the distribution of multimedia contents have now become a reality. Without proper management, the transmission of multimedia data over WMSNs affects the performance of networks due to excessive packet-drop. The existing studies on Quality of Service (QoS) mostly deal with simple Wireless Sensor Networks (WSNs) and as such do not account for an increasing number of sensor nodes and an increasing volume of data. In this paper, we propose a novel framework to support QoS in WMSNs along with a light-weight Error Concealment (EC) scheme. The EC schemes play a vital role to enhance Quality of Experience (QoE) by maintaining an acceptable quality at the receiving ends. The main objectives of the proposed framework are to maximize the network throughput and to cover-up the effects produced by dropped video packets. To control the data-rate, Scalable High efficiency Video Coding (SHVC) is applied at multimedia sensor nodes with variable Quantization Parameters (QPs). Multi-path routing is exploited to support real-time video transmission. Experimental results show that the proposed framework can efficiently adjust large volumes of video data under certain network distortions and can effectively conceal lost video frames by producing better objective measurements.
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