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Summary: A well‐optimized and well‐performed communication network protocol is necessary to build successful underwater acoustic sensor networks (UWASNs). But for wired and wireless communication, medium access control (MAC) has a great effect on network performance and optimization. But unlike land‐based MAC protocols, underwater MAC protocols come with various challenges and issues like high propagation delay, limited bandwidth for communication signals, large attenuation in network signals, and the high noise level in signals. It is very challenging to build a well‐optimized underwater MAC protocol. Also, in UWASN, sensor nodes are generally divided into sub‐network parts to reduce the propagation delay of data signals. But this creates the problem of non‐uniform traffic load in sensor nodes. So, considering these issues, dynamic hold time MAC (DHT‐MAC) protocol is proposed here. In this protocol, depending on the distance from the central node, sensor nodes are divided into two sub‐network zones (parent node and child node). Depending on the traffic load and propagation delay, the child nodes can change their respective parent nodes dynamically. Advantage of the proposed method is that, if any of the parent nodes stops working, the child node will connect to the nearest parent node. When collecting the data signals, it has been observed that child nodes have a light traffic load compared to parent nodes. So dynamic cooperative transmission MAC (DCT‐MAC) protocol which is a contention‐based MAC protocol has been used in child nodes and as parent nodes have high traffic load, reservation‐based MAC protocol has been used. [ABSTRACT FROM AUTHOR]

Summary: Opportunistic networks (OppNets) are networks that can be used in situations of sparse network connectivity. Strategies for implementing secure transmission of messages in OppNets offer complex and distinctive problems that are wholly different from traditional networks using TCP/IP protocols for data transmission. In this paper, a security protocol named FuzzyPT is proposed which combats black hole attacks in OppNets. The defense mechanism is based on the information extracted from messages in the buffer, potential threat (PT) messages, and fuzzy logic. Fuzziness aids the system in being adaptive by modeling the character of nodes as either benign or malicious. It provides the network with the ability to judge the character of nodes based on relationships between different parameters instead of basing this decision on fixed conditions. FuzzyPT is observed to reduce erroneous decision‐making and decrease the number of false positives and false negatives in the system. An evolutionary game theoretic model is applied, which analyzes the decision‐making ability of relays in choosing varied strategies while forwarding messages. The evolutionary stable state is computed for the protocol, which verifies the proposition that a majority of the relays will cooperate by forwarding messages. The efficiency of the protocol is judged on various grounds such as delivery probability, network overhead ratio, packets dropped, and transmission latency. It is observed that the proposed game theoretic protocol outperforms an existing acknowledge and evolutionary game theory–based security protocol in terms of all the aforementioned performance characteristics. [ABSTRACT FROM AUTHOR]

There has been an escalation in deployment and research of wireless mesh networks by both the business community and academia in the last few years. Their attractive characteristics include low deployment cost, a low-cost option to extend network coverage and ease of maintenance due to their self-healing properties. Multiple routes exist between the sender and receiver nodes because of the mesh layout that ensures network connectivity even when node or link failures occur. Recent advances among others include routing metrics, optimum routing, security, scheduling, cross-layer designs and physical layer techniques. However, there are still challenges in wireless mesh networks as discussed in this paper that need to be addressed. Cross-layer design allows information from adjacent and non-adjacent layers to be used at a particular layer for performance improvement. This paper presents a survey of cross-layer protocol design approaches applied to the IEEE 802.11 standards for wireless multi-hop mesh networks that have been proposed over the last few years for improved performance. We summarize the current research efforts in cross-layer protocol design using the IEEE 802.11 standard in identifying unsolved issues that are a promising avenue to further research. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY The medium access control protocol determines system throughput in wireless mobile ad hoc networks following the ieee 802.11 standard. Under this standard, asynchronous data transmissions have a defined distributed coordination function that allows stations to contend for channel usage in a distributed manner via the carrier sensing multiple access with collision avoidance protocol. In distributed coordination function, a slotted binary exponential backoff (BEB) algorithm resolves collisions of packets transmitted simultaneously by different stations. The BEB algorithm prevents packet collisions during simultaneous access by randomizing moments at stations attempting to access the wireless channels. However, this randomization does not eliminate packet collisions entirely, leading to reduced system throughput and increased packet delay and drop. In addition, the BEB algorithm results in unfair channel access among stations. In this paper, we propose an enhanced binary exponential backoff algorithm to improve channel access fairness by adjusting the manner of increasing or decreasing the contention window based on the number of the successfully sent frames. We propose several configurations and use the NS2 simulator to analyze network performance. The enhanced binary exponential backoff algorithm improves channel access fairness, significantly increases network throughput capacity, and reduces packet delay and drop. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY When one considers the broad range of wirelessly connected mobile devices used today, it is clear that integrating such network-enabled devices into secure roaming over wireless networks is of essential importance. Over the years, many authentication protocols have been suggested to address this issue. Among these protocols, the recently proposed privacy-preserving universal authentication protocol, Priauth, exceeds the security and efficiency of other authentication techniques. This paper studies the existing roaming authentication protocols and shows that they are not strong enough to provide secure roaming services in three aspects. Further, using Priauth as an example, we propose efficient remedies that fix the weaknesses. The experimental results show that the proposed approaches are feasible in practice. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY Password-authenticated group key exchange protocols enable communication parties to establish a common secret key (a session key) by only using short secret passwords. Such protocols have been receiving significant attention. This paper shows some security weaknesses in some recently proposed password-authenticated group key exchange protocols. Furthermore, a secure and efficient password-authenticated group key exchange protocol in mobile ad hoc networks is proposed. It only requires constant round to generate a group session key under the dynamic scenario. In other words, the overhead of key generation is independent of the size of a total group. Further, the security properties of our protocol are formally validated by a model checking tool called AVISPA. Security and performance analyses show that, compared with other related group key exchange schemes, the proposed protocol is also efficient for real-world applications in enhancing the security over wireless communications. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY A new video transport protocol for multicast agents in wireless mesh networks (WMNs) is proposed in this paper. The proposed protocol enables a significant reduction in the transmission overhead, while providing reliable communication for its use in multicast applications. This proposed reliable protocol provides a practical approach for an overlay peer-to-peer multicast facility supported within the application layer. This obviates the need to give upgraded routers capable of handling multicast broadcasting or modify the existing protocol stack. The protocol tolerates partial losses in multimedia transmissions, while supporting control of the delay sensitivity of such transmissions in WMNs. The key issue in this protocol is the ability to detect packet loss, anticipate retransmission requests, and use the anticipated retransmission requests to transmit the lost packets prior to requests from other receiving agents. The proposed protocol allows for the receiver to determine if retransmission of lost packets is required, ensuring the greatest flexibility needed for a reliable multicast protocol. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Radio-frequency identification (RFID) technology enables the identification and tracking of objects by means of the wireless signals emitted by a tag attached to the objects of interest. Without adequate protection, however, malicious attackers can easily eavesdrop, scan or forge the information within the tag, thereby threatening the integrity of the system. Previous research has shown that the basic security requirements of RFID systems, i.e. identity authentication, information privacy and location privacy, can be satisfied using conventional cryptographic components. However, such components are expensive, and therefore conflict with the general requirement for low-cost tag designs. Accordingly, this paper presents a low-cost challenge-response security protocol designated as the hidden mutual authentication protocol (HMAP) to accomplish both a mutual authentication capability between the tag and the reader and information privacy. The results show that HMAP provides an efficient means of concealing the authentication messages exchanged between the tag and the reader and is robust toward replay attacks. In addition, it is shown that HMAP is easily extended to provide complete location privacy by utilizing a hash function to generate different tag identifiers in each authentication session. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cities worldwide have planned and implemented large-scale wireless mesh network (WMN) deployments. These mesh deployments are expected to provide broadband mobile access to the Internet at a low cost to the user. This paper considers the fairness problem affecting nodes in multihop WMNs. Many existing approaches to coping with the fairness problem are unsuitable because they necessitate modifications to the IEEE 802.11 MAC protocol or node queueing operations. Such modifications require a change in hardware/firmware at every node in the WMN. Thus, these approaches are less favorable from the points of view of interoperability and cost. Without modifying the lower layer protocols, this study identifies TCP parameters that impact throughput fairness and proposes an adjustment to these parameters to reduce frame collisions and to improve throughput fairness. Using simple mathematical formulations and ns2 simulations, this study shows that the frame transmissions from each node can be effectively controlled by properly controlling the delayed ACK timer and by using a suitable advertised window. The proposed method, in addition to fairness, requires fewer buffer resources than other methods. Moreover, it is not sensitive to the carrier sense range. It is also simple and easy to deploy. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The nodes in a wireless ad hoc network act as routers in a self-configuring network without infrastructure. An application running on the nodes in the ad hoc network may require that intermediate nodes act as routers, receiving and forwarding data packets to other nodes to overcome the limitations of noise, router congestion and limited transmission power. In existing routing protocols, the 'self-configuring' aspects of network construction have generally been limited to the construction of routes that minimize the number of intermediate nodes on a route while ignoring the effects that the resulting traffic has on the overall communication capacity of the network. This paper presents a context-aware routing metric that factors the effects of environmental noise and router congestion into a single time-based metric, and further presents a new cross-layer routing protocol, called Warp-5 (Wireless Adaptive Routing Protocol, Version 5), that uses the new metric to make better routing decisions in heterogeneous network systems. Simulation results for Warp-5 are presented and compared to the existing, well-known AODV ( Ad hoc On-Demand Distance Vector) routing protocol and the reinforcement-learning based routing protocol, Q-routing. The results show Warp-5 to be superior to shortest path routing protocols and Q-routing for preventing router congestion and packet loss due to noise. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Secure multicast is one of the majority services in the near future. The frameworks for IP multicast cannot be directly applied in wireless networks. To address the natural issues of wireless multicast and enhance the efficiency, an adaptive secure multicast framework based on a new primitive called multi-recipient generalized signcryption and a multi-recipient generalized signcryption scheme based on the gap Diffie–Hellman problem (MGSC-GDH) are proposed. The key technologies to construct a high-performance adaptive scheme including identification function, randomness reusing are investigated. The framework provides separate or joint encryption and signature functions according to users' identities and requirements transparently, and has the ability to aggregate multiple unicast besides the common multicast service. Therefore, overheads are reduced sharply for multiple functions which are provided with a single primitive. By the precise reduction, the gap-bridge between the security of a base scheme and the corresponding multi-recipient generalized signcryption scheme is built, which is a direct measure to quantify the security. Analysis shows that MGSC-GDH is a semantic secure multi-recipient generalized signcryption scheme and more efficient than other similar schemes in computational and communicational aspects. It is suitable for dynamic environment for rekeying is avoided when membership changes. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The seamless internetworking among heterogeneous networks is in great demand to provide ‘always-on’ connectivity services with quality of service (QoS) provision, anywhere at anytime. The integration of wireless-fidelity (Wi-Fi) and wireless metropolitan area networks (WiMAX) networks can combine their best features to provide ubiquitous access, while mediating the weakness of both networks. While it is challenging to obtain optimized handover decision-based dynamic QoS information, users can improve their perceived QoS by using the terminal-controlled handover decision in a single device equipped with multiple radio interfaces. The IEEE 802.21 aims at providing a framework that defines media-independent handover (MIH) mechanism that supports seamless handover across heterogeneous networks. In this paper, an multiple attributes decision making-based terminal-controlled vertical handover decision scheme using MIH services is proposed in the integrated Wi-Fi and WiMAX networks to provide ‘always-on’ connectivity QoS services. The simulation results show that the proposed scheme provides smaller handover times and lower dropping rate than the RSS-based and cost function-based vertical handover schemes. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Interference among different wireless hosts is becoming a serious issue due to the growing number of wireless LANs based on the popular IEEE 802.11 standard. Thus, an accurate modeling of error paths at the data link layer is indispensable for evaluating system performance and for tuning and optimizing protocols at higher layers. Error paths are usually described looking at sequences of consecutive correct or erroneous frames and at the distributions of their sizes. In recent years, a number of Markov-based stochastic models have been proposed in order to statistically characterize these distributions. Nevertheless, when applied to analyze the data traces we collected, they exhibit several flaws. In this paper, to overcome these model limitations, we propose a new algorithm based on a semi-Markov process, where each state characterizes a different error pattern. The model has been validated by using measures from a real environment. Moreover, we have compared our method with other promising models already available in the literature. Numerical results show that our proposal performs better than the other models in capturing the long-term temporal correlation of real measured traces. At the same time, it is able to estimate first-order statistics with the same accuracy of the other models, but with a minor computational complexity. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The lifetime of a network is the key design factor of mobile ad hoc networks (MANETs). To prolong the lifetime of MANETs, one is forced to attain a tradeoff of minimizing the energy consumption and load balancing. In MANETs, energy waste resulting from retransmission due to high bit error rate (BER) and high frame error rate (FER) of wireless channel is significant. In this paper, we propose two novel protocols termed multi-threshold routing protocol (MTRP) and enhanced multi-threshold routing protocol (EMTRP). MTRP divides the total energy of a wireless node into multiple ranges. The lower bound of each range corresponds to a threshold. The protocol iterates from the highest threshold to the lowest one and chooses those routes with bottleneck energy being larger than the current threshold during each iteration. This approach thus avoids overusing certain routes and achieves load balancing. If multiple routes satisfy the threshold constraint, MTRP selects a route with the smallest hop count to further attain energy efficiency. Based on MTRP, EMTRP further takes channel condition into consideration and selects routes with better channel condition and consequently reduces the number of retransmissions and saves energy. We analyze the average loss probability (ALP) of the uniform error model and Gilbert error model and give a distributed algorithm to obtain the maximal ALP along a route. Descriptions of MTRP and EMTRP are given in pseudocode form. Simulation results demonstrate that our proposed EMTRP outperforms the representative protocol CMMBCR in terms of total energy consumption and load balancing. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We investigate the behaviour of TCP(α, β) protocols in the presence of wireless networks. We seek an answer to strategic issues of maximizing energy and bandwidth exploitation, without damaging the dynamics of multiple-flow equilibrium. We take a fresh perspective on protocol design: What is the return of the effort that a protocol expends? Can we achieve more gains with less effort? We study first the design assumptions of TCP(α, β) protocols and discuss the impact of equation-based modulation of α and β on protocol efficiency. We introduce two new measures to capture protocol behaviour: the ‘Extra Energy Expenditure’ and the ‘Unexploited Available Resource Index’. We confirm experimentally that, in general, smoothness and responsiveness constitute a tradeoff; however, we show that this tradeoff does not graft its dynamics into a conservative/aggressive behaviour, as it is traditionally believed. We uncover patterns of unjustified tactics; our results suggest that an adaptive congestion control algorithm is needed to integrate the dynamics of heterogeneous networks into protocol behaviour. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An ad hoc network is a collection of nodes that do not need to rely on a predefined infrastructure to keep the network connected. Nodes communicate amongst each other using wireless radios and operate by following a peer-to-peer network model. In this article, we propose a multifold node authentication approach for protecting mobile ad hoc networks. The security requirements for protecting data link and network layers are identified and the design criteria for creating secure ad hoc networks using multiple authentication protocols are analysed. Such protocols, which are based on zero-knowledge and challenge-response techniques, are presented through proofs and simulation results. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Prioritized parallel transmission MAC (PPTM) protocol is proposed for all-IP wireless wide area network (WAN). In this paper, we analyse its performance and compare it with modified channel load sensing protocol (MCLSP). We model PPTM as a non-preemptive priority queueing system and obtain a close form of transmission time delay for each priority class, throughput of the scheme, and number of packets in the queue in the Poisson arrival case. We find that PPTM achieves less transmission time delay than MCLSP does for high priority data. Hence, the overall performance of the system using PPTM is significantly improved. We verify the conclusions with simulation via a simplified all-IP wireless WAN. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper considers the channel assignment problem in a multi-channel MANET environment. We propose a scheme called GRID, by which a mobile host can easily determine which channel to use based on its current location. In fact, following the GSM style, our GRID spends no communication cost to allocate channels to mobile hosts since channel assignment is purely determined by hosts' physical locations. We show that this can improve the channel reuse ratio. We then propose a multi-channel MAC protocol, which integrates GRID. Our protocol is characterized by the following features: (i) it follows an ‘on-demand’ style to access the medium and thus a mobile host will occupy a channel only when necessary, (ii) the number of channels required is independent of the network topology, and (iii) no form of clock synchronization is required. On the other hand, most existing protocols assign channels to a host statically even if it has no intention to transmit [IEEE/ACM Trans. Networks 1995; 3(4):441–449; 1993; 1(6): 668–677; IEEE J. Selected Areas Commun. 1999; 17(8):1345–1352], require a number of channels which is a function of the maximum connectivity [IEEE/ACM Trans. Networks 1995; 3(4):441–449; 1993; 1(6): 668–677; Proceedings of IEEE MILCOM'97, November 1997; IEEE J. Selected Areas Commun. 1999; 17(8):1345–1352], or necessitate a clock synchronization among all hosts in the MANET [IEEE J. Selected Areas Commun. 1999; 17(8):1345–1352; Proceedings of IEEE INFOCOM'99, October 1999]. Through simulations, we demonstrate the advantages of our protocol. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The transmission control protocol (TCP) is one of the most important Internet protocols. It provides reliable transport services between two end-hosts. Since TCP performance affects overall network performance, many studies have been done to model TCP performance in the steady state. However, recent researches have shown that most TCP flows are short-lived. Therefore, it is more meaningful to model TCP performance in relation to the initial stage of short-lived flows. In addition, the next-generation Internet will be an unified all-IP network that includes both wireless and wired networks integrated together. In short, modelling short-lived TCP flows in wireless networks constitutes an important axis of research. In this paper, we propose simple wireless TCP models for short-lived flows that extend the existing analytical model proposed in [IEEE Commun. Lett. 2002; 6(2):85–88]. In terms of wireless TCP, we categorized wireless TCP schemes into three types: end-to-end scheme, split connection scheme, and local retransmission scheme, which is similar to the classification proposed in [IEEE/ACM Trans. Networking 1997; 756–769]. To validate the proposed models, we performed ns-2 simulations. The average differences between the session completion time calculated using the proposed model and the simulation result for three schemes are less than 9, 16, and 7 ms, respectively. Consequently, the proposed model provides a satisfactory means of modelling the TCP performance of short-lived wireless TCP flows. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents a new channel assignment scheme that efficiently improves the spatial frequency–spectrum reuse in a wireless network with heterogeneous demands, in which the cells are partitioned into a lot of clusters. Since the channel demands of each cell are different, this scheme adopts two stages to effectively assign channels. In the first stage, the cluster-based scheme allocates a number of channels to the cells of each cluster for satisfying the requirement of co-channel reuse. The channel demand of majority cells will be satisfied in this stage. In the second stage, when the channel requirement of most cells has been fulfilled, the tree-based assignment scheme allocates channels for the minority cells, which are still lacking of channels. Simulation results showed that the proposed scheme is superior to the previous schemes. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In recent years, a variety of new routing protocols for mobile ad hoc wireless NETworks (MANETs) have been developed. Performance evaluation and comparison of many of these routing protocols have been performed using detailed simulation models. Zone routing protocol (ZRP) is one of these routing protocols, which is a hybrid routing protocol that proactively maintains routing information for a local neighbourhood (routing zone), while reactively acquiring routes to destinations beyond the routing zone. The studies on ZRP have assumed homogeneous scenarios where all mobile nodes have uniform mobility and are statistically identical, lacking the studies on heterogeneous scenarios where mobile nodes move with non-uniform mobilities in the same network. In this paper, we study the performance of ZRP in such scenarios. We propose an efficient scheme for ZRP to adapt to the non-uniform mobilities scenario and study its performance for different mobility scenarios, network loads and network sizes. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Performance enhancing proxies (PEPs) are widely used to improve the performance of TCP over high delay-bandwidth product links and links with high error probability. In this paper we analyse the performance of using TCP connection splitting in combination with web caching via traces obtained from a commercial satellite system. We examine the resulting performance gain under different scenarios, including the effect of caching, congestion, random loss and file sizes. We show, via analysing our measurements, that the performance gain from using splitting is highly sensitive to random losses and the number of simultaneous connections, and that such sensitivity is alleviated by caching. On the other hand, the use of a splitting proxy enhances the value of web caching in that cache hits result in much more significant performance improvement over cache misses when TCP splitting is used. We also compare the performance of using different versions of HTTP in such a system. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Wireless IP networks will provide voice and data services using IP protocols over the wireless channel. But current IP is unsuitable to provide delay or loss bounds and insufficient to support diverse quality of service, both required by real-time applications. In order to support real-time applications in wireless IP networks, in this paper a measurement-based admission control (MBAC) with priority criteria and service classes is considered. First we have shown the suitability of MBAC in wireless IP networks by comparing its performance with a parameter-based scheme. Next, we have investigated the performance of strictly policy-based MBAC and policy plus traffic characteristic-based MBAC schemes in terms of (1) increasing the user mobility, (2) changing traffic parameters and (3) the presence of greedy users. The efficiency and fairness of each scheme are measured in terms of lower class new and handoff traffic performance. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The health status of the control plane and the data plane of a GMPLS-controlled optical network is independent in the physically separated control network implementation. In most control plane designs, besides the topology information, the entities of the routing protocol only record the number of available wavelengths on each link. However, the status of each wavelength is maintained by the entities of the signalling protocol. Without recovery ability of the signalling protocol CR-LDP, a failure in the control plane will result in the permanent loss of the status information of wavelengths. A mechanism to recover the status information of the wavelengths is proposed. A downstream node maintains a label information database (LID) about assignable (free) labels in each incoming link. A copy of LID is redundantly stored in the upstream node as a label information mirror (LIM). A systematic procedure is proposed to synchronize the contents of a LIM and the corresponding LID. The initialization of a new LDP session with the enhanced recovery mechanism will guarantee the revival of the status information of wavelengths. It can recover multiple control channel failures, but it only applies to single node failure among any pair of adjacent nodes. © Crown copyright 2002. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new protocol for wireless mobile ad hoc networks, which establishes a dynamic wireless mobile infrastructure. The proposed protocol, namely, the virtual base stations (VBS) protocol, mimics and maintains the operation of the conventional fixed infrastructure in cellular networks. In the VBS protocol, a mobile node is elected from a set of nominees to act as a temporary base station within its zone. We provide proofs for the correctness of the VBS protocol, and show lower and upper bounds for its global convergence time. Likewise, we study the characteristics and performance of VBS by means of simulation. It is shown that VBS scales well to large networks of mobile stations, and that it outperforms other infrastructure-formation protocols in terms of stability. The VBS protocol would facilitate the development of a comprehensive and promising framework for quality of service (QoS) management in wireless mobile ad hoc networks once the proper integration of the MAC protocol with the routing and call admission control mechanisms is established. The VBS architecture lays the groundwork for assigning bandwidth, and/or implementing priorities, and hence for QoS-based routing by conveying the quality of a path prior to call setup. Copyright © 2001 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The performance of the channel access protocol is a main factor when designing and evaluating the overall performance of a multimedia and multihop radio network. A search in the current open literature shows almost no results or investigation on this subject. The purpose of this research is to design and evaluate several candidates for the channel access protocol. The main objective is to find one, or more, protocol that can meet or exceed the performance requirements for all informed voice service to be provided by a hand-held mobile multimedia terminal (MMT) in a multihop network. Extensive simulation models of MMT have been developed using both asynchronous and synchronous protocol modes. The first one accesses the channel using a suitable random policy. The second one reserves time slots or periods in a fashion similar to conventional time division multiple access (TDMA) techniques. Within each mode there are several options involving various levels of implementation complexity. Based on the simulation results, the following recommendations and conclusions are made: (i) use an asynchronous policy that meets the requirements for all informed voice. At least one of the options studied and simulated meets those requirements; (ii) design a convenient mechanism to reserve channel capacity to ensure promised quality of service. This is particularly important for restricting the channel use for data streams on those nodes which are also handling voice packet streams; (iii) design practical methods to estimate channel capacity; (iv) the level of complexity for implementing any synchronous mode protocol greatly outweighs any potential network performance gain. No performance gain was observed with the synchronous mode procedure implemented in this research work; (v) refine the model to closely match the current design specification for the MMT system at the link layer level. Copyright © 2000 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Nowadays we can access the Internet by carrying a portable computer and using wireless communication. The wireless network with personal handy phone system (PHS) and portable cellular telephone has only rates of tens of Kbps to a few Mbps. Compared with the cable network, the transfer rate cannot generally satisfy a highly developed communication service such as large file transfer and real-time communications. This paper proposes a protocol, SHAKE, for sharing multiple paths in a cluster type network that is a kind of LAN in which some mobile hosts temporarily connect mutually. SHAKE provides the functions for composing a cluster type network, and dispersing traffic efficiently by measuring transfer rate and round-trip time. As a mobile host has only a low transfer capacity for individuals to communicate with the outside, if whole capacities of other hosts which compose a cluster type network are shared, we can get larger transfer capacity and satisfy the required communication services. Copyright © 1999 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The staggered multicast protocol for multihop spread spectrum packet radio networks is suitable for unicasting and broadcasting as well as multicasting. The common-header/transmitter-based spreading code is used for data packet transmission and the receiver-based code is used for acknowledgement packet transmission. By staggering packet transmission the protocol can significantly reduce broadcasting delay. A special addressing method and packet format are also designed to achieve collision-free acknowledgement and multicast capability. Simulation results show that the protocol provides better throughput-delay performance than the common-header/transmitter-based slotted ALOHA protocol. [ABSTRACT FROM AUTHOR]

Summary: Radio‐frequency identification (RFID) is a wireless communication technology. Radio frequencies can cause interference in a dense RFID system, thus decreasing efficiency. In recent years, many protocols have been proposed to reduce reader collisions based on multiple‐access techniques. The main weakness of Time Division Multiple Access (TDMA)‐based schemes is the random selection of resources. Additionally, they do not consider the distance between the interfering readers. Therefore, the likelihood of interference in an RFID system will be increased. To address this problem, we propose a new scheme for allocating resources to readers using a learning technique. The proposed scheme takes into account the distance between interfering readers, and these readers acquire the necessary knowledge to select new resources based on the results of the previous selection of neighboring readers using cellular learning automata. This approach leads to reduced interference in an RFID system. The proposed scheme is fully distributed and operates without hardware redundancy. In this scheme, the readers select new resources without exchanging information with each other. The simulation results show that the percentage of kicked readers decreased by more than 20%, and the proposed scheme also provides higher throughput than do state‐of‐the‐art schemes for dense reader environments and leads to further recognition of tags. In this paper, we propose a new scheme for allocating resources to readers in dense RFID system using a learning technique. The proposed scheme taking into account the distance between interfering readers and readers acquires the necessary knowledge to select new resources based on the results of the previous selection of neighboring readers using cellular learning automata. The major contribution of this manuscript is: In the proposed scheme, resources are selected consciously and not randomly in a dense RFID system.Readers acquire the required knowledge to select new resources to create less interference using a learning model.In the proposed scheme, the distance between readers as a contributing factor in interference is consideredWe conducted a series of experiments to evaluate the performance of proposed approach for different metrics. [ABSTRACT FROM AUTHOR]