S. de Valk, G. H. P. van der Helm, M. Beld, P. Schaftenaar, C. Kuiper and G. J. J. M. Stams
Violence is a common problem in secure residential units for young people. Group workers often think that young people have to learn to behave by means of punishment. The purpose…
Abstract
Purpose
Violence is a common problem in secure residential units for young people. Group workers often think that young people have to learn to behave by means of punishment. The purpose of this paper is to investigate whether this approach is effective in these settings, and, if so, under what circumstances. Furthermore, it aims to provide alternatives to punishment when dealing with violence.
Design/methodology/approach
Recent evidence on the effectiveness of punishment in secure residential units is reviewed. In addition, methods which are promising in dealing with violence are described.
Findings
The review shows that punishment is often used to regain control by group workers or, alternatively, is a result of professional helplessness in the face of escalating problems. Only when the living group climate is marked by trust and cooperation can punishment be effective.
Originality/value
Punishment in secure residential settings can have severe negative consequences. Nevertheless, group workers are tempted to use it as a response to violence in an attempt to gain control.
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Ching‐Wen Chen and Chun‐Liang Lai
In this paper, the design of multiple channels to achieve the goal of a high‐performance medium access control (MAC) protocol is to be proposed to solve the problem of wasting…
Abstract
Purpose
In this paper, the design of multiple channels to achieve the goal of a high‐performance medium access control (MAC) protocol is to be proposed to solve the problem of wasting bandwidth resources due to waiting for the backoff time.
Design/methodology/approach
In the MAC design of this paper, a control channel and a data channel are used to improve bandwidth utilization. When the control channel waits for the backoff time, the data channel may transfer data. As a result, bandwidth utilization can be improved. In order to have better bandwidth utilization in multiple channels, the authors also propose a bandwidth allocation strategy for control channels and data channels. According to the strategy, the control and data signals can be smoothly transmitted without blocking or waiting, thereby not wasting bandwidth resources. Finally, the authors propose multiple control sub‐channels and data sub‐channels to further reduce the backoff time penalty and make more communication pairs work in a transmission range to increase the throughput.
Findings
The paper solves the following problems bandwidth waste that results from waiting for the backoff time in the single channel model and bandwidth allocation strategy for the control and data sub‐channels in the multiple channel model to achieve throughput enhancement in mobile ad‐hoc networks.
Research limitations/implications
The proposed method needs the support of multiple channels.
Practical implications
From the result, the bandwidth allocation ratio of the proposed method performs better than other various allocation ratios. In addition, the proposed method with the bandwidth allocation strategy and multiple data and control sub‐channels results in a better throughput than IEEE 802.11 DCF by 22.3 per cent.
Originality/value
The proposed method using multiple control and data sub‐channels can improve the throughput and reduce bandwidth waste over IEEE 802.11 DCF.
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Ruey‐Shin Chen, Louis R. Chao, Ching‐Piao Chen and Chih‐Hung Tsai
Video transmission effectiveness in the Ad Hoc network is becoming important recently, if different routing protocols are applied. Some researchers conclude that the reactive…
Abstract
Video transmission effectiveness in the Ad Hoc network is becoming important recently, if different routing protocols are applied. Some researchers conclude that the reactive protocols are better for file transfer protocol (FTP) and constant bit rate (CBR) or hypertext transfer protocol (HTTP) transmission in an Ad Hoc wireless network but the performance report of video transmission is not much. This study adopts Qualnet (Network Simulator) as a simulation tool for environmental designing and performance testing, and employs an experimental design with eight groups. Our experiment shows that: (1) The performance of AODV (reactive) protocol is better than DSDV, ZRP and DSR when the transmission load has only one video stream; (2) Proactive (DSDV) and Hybrid protocols (ZRP) are better for a smaller Ad Hoc network when it transmits a video stream with some applications (VoIP, FTP and CBR). We conclude that packet loss rate is sensitive to the quality of video transmission and it has negative relationship with Peak Signal‐to‐Noise Ratio (PSNR) value. In addition, our experiment also shows that PSNR is a simple Metric for the performance evaluation of video transmission.
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Quan Le‐Trung, Paal E. Engelstad, Vinh Pham, Tor Skeie, Amirhosein Taherkordi and Frank Eliassen
The purpose of this paper is to describe the required functionalities on providing internet connectivity and mobility management for mobile ad hoc networks (MANETs), present…
Abstract
Purpose
The purpose of this paper is to describe the required functionalities on providing internet connectivity and mobility management for mobile ad hoc networks (MANETs), present discovered problems such as inconsistent contexts, and provide the corresponding solutions. It also provides a hybrid metric for the load‐balance of intra/inter‐MANET traffic over multiple internet gateways (IGWs).
Design/methodology/approach
The paper uses both mathematical analyses and simulations to discover the required functionalities and problems on providing internet connectivity and mobility management for MANETs. The proposed hybrid metric for IGW selection is a replacement of the shortest hop‐count (HC) metric, and consider three factors: HC distance, intra‐MANET traffic, and inter‐MANET traffic.
Findings
Simulation results show that ad hoc routing protocols, using the proposed metric, get better performance in terms of packet delivery ratio and transmission delay, at the cost of slightly increased signalling overhead.
Research limitations/implications
In the assessment, simulation results are taken from two mobility scenarios, and the hybrid metric is integrated into only reactive ad hoc routing. Thus, more case studies need to be carried out to demonstrate the outcomes of the proposed metric compared with others.
Practical implications
This paper provides the needed functionalities for broadening the richness of MANET applications to internet users, and vice verse.
Originality/value
This paper contributes to the research on internetworking and mobility management between MANETs and the internet.
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Jehn‐Ruey Jiang, Chau‐Yuan Yang, Ting‐Yao Chiou and Shing‐Tsaan Huang
There are two types of medium access control (MAC) layer power‐saving (PS) protocols for IEEE 802.11‐based mobile ad hoc networks: synchronous and asynchronous ones. This paper…
Abstract
Purpose
There are two types of medium access control (MAC) layer power‐saving (PS) protocols for IEEE 802.11‐based mobile ad hoc networks: synchronous and asynchronous ones. This paper seeks to propose a hybrid PS protocol to take advantages of both types of protocols.
Design/methodology/approach
The protocol utilizes the concept of dual‐channel and dual‐transmission‐range clustering. It divides all the hosts into clusters. Each cluster has a head and all the heads are organized as a virtual backbone to help route data. The protocol also utilizes the cluster head dismissal mechanism to avoid the ever‐increasing of cluster heads and to adapt to topology changing.
Findings
Simulation results demonstrate that the proposed protocol is more power‐efficient and more scalable than related protocols.
Originality/value
The proposed protocol is applicable to MANETs composed of hosts with single IEEE 802‐11 network interface card.
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Rama Rao A., Satyananda Reddy and Valli Kumari V.
Multimedia applications such as digital audio and video have stringent quality of service (QoS) requirement in mobile ad hoc network. To support wide range of QoS, complex routing…
Abstract
Purpose
Multimedia applications such as digital audio and video have stringent quality of service (QoS) requirement in mobile ad hoc network. To support wide range of QoS, complex routing protocols with multiple QoS constraints are necessary. In QoS routing, the basic problem is to find a path that satisfies multiple QoS constraints. Moreover, mobility, congestion and packet loss in dynamic topology of network also leads to QoS performance degradation of protocol.
Design/methodology/approach
In this paper, the authors proposed a multi-path selection scheme for QoS aware routing in mobile ad hoc network based on fractional cuckoo search algorithm (FCS-MQARP). Here, multiple QoS constraints energy, link life time, distance and delay are considered for path selection.
Findings
The experimentation of proposed FCS-MQARP is performed over existing QoS aware routing protocols AOMDV, MMQARP, CS-MQARP using measures such as normalized delay, energy and throughput. The extensive simulation study of the proposed FCS-based multipath selection shows that the proposed QoS aware routing protocol performs better than the existing routing protocol with maximal energy of 99.1501 and minimal delay of 0.0554.
Originality/value
This paper presents a hybrid optimization algorithm called the FCS algorithm for the multi-path selection. Also, a new fitness function is developed by considering the QoS constraints such as energy, link life time, distance and delay.
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A Bluetooth scatternet is a network topology that is formed by inter‐connecting piconets. A piconet is a starshaped ad‐hoc networking unit that can accommodate eight Bluetooth…
Abstract
A Bluetooth scatternet is a network topology that is formed by inter‐connecting piconets. A piconet is a starshaped ad‐hoc networking unit that can accommodate eight Bluetooth devices, a master and up to seven slaves. By designating certain piconet nodes as bridges, or gateways, we can interconnect piconets by forcing the bridge nodes to interleave their participation in multiple piconets. Bridge nodes form an auxiliary relay connection between adjacent piconet masters and are fundamental for establishing scatternets. In this paper we present a new fault‐tolerant approach to scatternet formation that is selfhealing and operates in a multi‐hop environment. Our Bluetooth Distributed Scatternet Formation Protocol (BTDSP) establishes a flat scatternet topology, allows incremental node arrival, and automatically heals scatternet partitions by re‐incorporating disconnected nodes. By maintaining neighbor associations in soft state, existing links can also be re‐established quickly upon disconnection due to intermittent wireless connectivity. By only using slave/slave bridges, the algorithm is resilient to both node failure and wireless interference. It also prevents time‐slot waste due to master/slave bridges being away from their piconets.
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Weining Qi, Hongyi Yu, Jinya Yang and Xia Zhang
Abstract‐CEDAR protocol is a distributed routing protocol oriented to Quality of Service (QoS) support in MANET, and bandwidth is the QoS parameter of interest in this protocol…
Abstract
Abstract‐CEDAR protocol is a distributed routing protocol oriented to Quality of Service (QoS) support in MANET, and bandwidth is the QoS parameter of interest in this protocol. However, without energy efficiency consideration, earlier node failure will occur in overloaded nodes in CEDAR, and in turn may lead to network partitioning and reduced network lifetime. The storage and processing overhead of CEDAR is fairly high because too many kinds of control packets are exchanged between nodes and too much state information needs to be maintained by core nodes. The routing algorithm depends fully on the link state information known by core nodes. But the link state information may be imprecise, which will result in route failures. In this paper, we present an improved energy efficient CEDAR protocol, and propose a new efficient method of bandwidth calculation. Simulation results show that the improved CEDAR is efficient in terms of packet delivery ratio, throughput and mean‐square error of energy.