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The limited storage and computing capacity hinder the development of cognitive radio ad hoc networks (CRAHNs). To solve the problem, a new paradigm of cloud-based CRAHN has been proposed, in which a CRAHN will make use of the computation and storage resources of the cloud. This paper envisions an integrated CRAHN-cloud network architecture. In this architecture, some cognitive radio users (CUs) who satisfy the required metrics could perform as mobile gateway candidates to connect other ordinary CUs with the cloud. These mobile gateway candidates are dynamically clustered according to different related metrics. Cluster head and time-to-live value are determined in each cluster. In this paper, the gateway advertisement and discovery issues are first addressed to propose a hybrid gateway discovery mechanism. After that, a QoS-based gateway selection algorithm is proposed for each CU to select the optimal gateway. Simulations are carried out to evaluate the performance of the overall scheme, which incorporates the proposed clustering and gateway selection algorithms. The results show that the proposed scheme can achieve about 11% higher average throughput, 10% lower end-to-end delay, and 8% lower packet drop fractions compared with the existing scheme. [ABSTRACT FROM AUTHOR]

Current forecasts predict that the Industrial Internet of Things will account for about 10 billion devices by 2020. Simultaneously, unlicensed low-power wide area networks are gaining momentum due to their low cost, low power, and long range characteristics, which are suitable for many IIoT applications, in addition to the usage of unlicensed bands. In this article, a solution is proposed to seamlessly integrate LoRaWAN, an open and standardized LPWAN technology, with 4G/5G mobile networks, thus allowing mobile network operators to reutilize their current infrastructures. This proposal is transparent to LoRaWAN end devices and to the EPC, since only the LoRaWAN gateway needs to be modified. The gateway acts as an evolved Node B from the core network perspective, implementing part of the eNB protocol stack. All data packets transported over the core network are both encrypted and integrity protected, hence achieving end-toend security. As a proof of concept, this solution has been implemented and validated with an open source EPC. [ABSTRACT FROM AUTHOR]

In this paper, a data aggregation gateway framework (DA-GW) for constrained application protocol (CoAP) group communications is proposed. The DA-GWframework is designed to improve the throughput performance and energy efficiency of group communication to monitor and control multiple sensor devices collectively with a single user terminal. The DA-GWconsists of four function blocks--the message analyzer, group manager, message scheduler and data handler--and three informative databases--the client database, resource database and information database. The DA-GW performs group management and group communication through each functional block and stores resources in the informative databases. The DA-GW employs international standard-based data structures and provides the interoperability of heterogeneous devices used in various applications. The DA-GWis implemented using a Java-based open source framework called jCoAP to evaluate the functions and performance of the DA-GW. The experiment results showed that the DA-GW framework revealed better performance than existing group communication methods in terms of throughput and energy consumption. [ABSTRACT FROM AUTHOR]

This paper presented a new MANET accessing Internet model. In this model, the benefits of three nodes-the source node, gateway node and decision node, were considered synthetically, and gateways were arranged and selected according to the real-time state of accessing network. Otherwise, it simulated the pheromone's update process in ant colony algorithm and computed transmission probability according to the pheromone density on the link, link bandwidth and delay, which are found in searching route.When the gateway pheromone was calculated, it would be added to RREQ. This model was simulated by NS 2. The test result indicated that though it increased average delay, it reduced routing overhead effectively and increased packet delivery radio. The validity of algorithm is validated. [ABSTRACT FROM AUTHOR]

A smart home gateway plays an important role in the Internet of Things (IoT) system that takes responsibility for the connection between the network layer and the ubiquitous sensor network (USN) layer. Even though the home network application is developing rapidly, researches on the home gateway based open development architecture are less. This makes it difficult to extend the home network to support new applications, share service, and interoperate with other home network systems. An integrated access gateway (IAGW) is proposed in this paper which upward connects with the operator machine-to-machine platform (M2M P/F). In this home network scheme, the gateway provides standard interfaces for supporting various applications in home environments, ranging from on-site configuration to node and service access. In addition, communication management ability is also provided by M2M P/F. A testbed of a simple home network application system that includes the IAGW prototype is created to test its user interaction capabilities. Experimental results show that the proposed gateway provides significant flexibility for users to configure and deploy a home automation network; it can be applied to other monitoring areas and simultaneously supports a multi-ubiquitous sensor network. [ABSTRACT FROM AUTHOR]

Mobile Ad-hoc networks have been widely researched for many years. Mobile Ad-hoc Networks are a collection of two or more devices equipped with wireless communications and networking capability. These devices can communication with other nodes that immediately within their radio range or one that is outside their radio range. The Wireless Ad-hoc Networks do not have gateway, every node can act as the gateway. Mobile ad hoc networks have many advantages over traditional networks, such as scalability, mobility and robust city. The network can be formed easily. It is gained more and more attention in recent years for the using in urgent and abrupt occasion, for example communication in military battlefield, salvage, temporary assembly and open country construction, etc. This paper focuses on the study of Ad-Hoc Network and its protocols.The concept of dynamic mobility is also introduced because nodes are moving from one place to another place, within this network any node can join the network and can leave the network at any time. This paper mainly focused upon the architecture, operating principle of Ad-Hoc networks. The various types of Routing Protocols are also discussed in this Paper; and finally applications, advantages and limitations of Ad-Hoc Networks are also discussed. [ABSTRACT FROM AUTHOR]

Sensors and actuators are being increasingly deployed for monitoring and controlling different phenomena and processes in a stand-alone manner or attached to sensor nodes with communication capabilities as part of larger wireless sensor networks (WSN). In addition to the protocols for communication within the WSN, sensor nodes may also provide the gateway functionality towards other networks and/or support communication with other external devices. These devices either represent additional gateways for exposing data and metadata to external networks, or serve as connection points to WSN for instance for the on-site calibration and maintenance. Smartphones as advanced mobile terminals appear particularly suitable for such role. This paper investigates the role a smartphone augmented with WSN gateway functionality can play in WSN with respect to regular dedicated sensor and gateway nodes. As a practical example we show the implementation of a gateway augmented smartphone using a Samsung i8910 phone and a VESNA sensor node connected via Bluetooth. The role of a gateway augmented smartphone is to interface between WSN, which is using a proprietary networking protocol, and the mobile network. The data obtained from WSN can be enriched using smartphone's embedded sensors before being sent to the remote server. We demonstrate this on an example of geo-tagging the collected data from WSN with the smartphone's Global Positioning System-based location data. [ABSTRACT FROM AUTHOR]

This paper looks into the strategic actions of companies who attempt to overcome the technological issue of backwards compatibility through the development of conversion devices. Using an exploratory case study of conversion devices for film analogue photography, the paper demonstrates how market characteristics and the technological characteristics of older products change the hierarchy of benefits sought by users. The paper exposes the significance of accurate strategic actions, such as the simultaneous development of multiple types of gateway devices, to target groups of users effectively. [ABSTRACT FROM AUTHOR]

In this article, we propose a novel abstraction layer for application service implementation compliant with the Java Call Control (JCC) specifications. It simplifies creation of multimedia services using SIP and the Media Gateway Control Protocol. In order to show its effectiveness, we have implemented a JCC resource adaptor for a JAIN service logic execution environment (JSLEE), using the Mobicents application server, which is the only existing open source JSLEE implementation. Experimental results obtained by implementing a complex VoIP service show both a significant simplification of service implementation and improved performance over legacy solutions. [ABSTRACT FROM AUTHOR]

Wireless mesh networks (WMNs) have attracted much attention due to their low up-front cost, easy network deployment, stable topology, robustness, reliable coverage, and so forth. These advantages are suitable for the disaster recovery applications in disaster areas, where WMNs can be advantageously utilized to restore network collapse after the disaster. In this paper, based on a new network infrastructure for WMNs, to guarantee high network performance, we focus on the issue of throughput optimization to improve the performance for WMNs. Owing to selecting different mesh router (MR) as the gateway will lead to different network throughput capacity, we propose a novel gateway selection technique to rapidly select the optimal MR as the gateway, in order to maximize the network throughput. In addition, we take into account the traffic distribution for the MR to eliminate traffic congestion in our method. The performance of our proposed method is evaluated by both numerical and simulated analysis. The simulation results demonstrate that the gateway selection method is effective and efficient to optimize the throughput for WMNs. [ABSTRACT FROM AUTHOR]

A Gateway-oriented Password-based Authenticated Key Exchange (GPAKE) scheme allows a client to establish an authenticated session key with a gateway via the help of an authentication server, where the client has pre-shared a password with the server. The desirable security properties of a GPAKE include session key semantic security, key privacy against servers, and password guessing attacks resistance. Abdalla et al.'s scheme (Asiacrypt 2005) [1] proposed the first GPAKE scheme, and then Abdalla et al. [13] and Byun et al.'s [2] had respectively proposed their improvements to enhance the security. Unfortunately, we find that all the improved schemes fail to commit the security requirements. In this paper, we point out security weaknesses of the improved scheme. To enhance the security, we propose a new GPAKE scheme, and prove its security in an enhanced model. [ABSTRACT FROM AUTHOR]

This paper describes a methodology that allows wireless networking allowing interconnection to the Internet through a Gateway, to interact and obtain products and services delivery. These Wireless Mesh Network(WMN), are based on routers which are programmed to work as nodes of a network. There are certain routers that allow the programming of its firmware to form network nodes. Communication is transmitted between nodes in the network and it is possible to cover long distances. The signal of a distant node, hop from node to node till reach the Gateway. This generates delays and congestion in the network. A path that contains nodes that make more faster connection to the Gateway can be designed as a solution. This is called a backbone, has a different channel frequency of the common nodes. The characteristics of these networks is its fast implementation and low cost. This make them useful for rural areas, for developing countries and remote regions. [ABSTRACT FROM AUTHOR]

In the draft of the IEEE 802.11s standard, a tree topology is established by the proactive tree-building mode of the Hybrid Wireless Mesh Protocol (HWMP). It is used for cases in which the root station (e.g., gateway) is an end point of the majority of the data connections. In the tree topology, the root or central stations (e.g., parent stations) are connected to the other stations (e.g., leaves) that are one level lower than the central station. Such mesh stations are likely to suffer heavily from contention in bottleneck links when the network has a high traffic load. Moreover, the dependence of the network on such stations is a point of vulnerability. A failure of the central station (e.g., a crash or simply going into sleep mode to save energy) can cripple the whole network in the tree topology. This causes performance degradation for end-to-end transmissions. In a connected mesh topology where the stations having two or more radio links between them are connected in such a way that if a failure subsists in any of the links, the other link could provide the redundancy to the network. We propose a scheme to utilize this characteristic by organizing the network into concentric tiers around the root mesh station. The tier structure facilitates path recovery and congestion control. The resulting mode is referred to as Tier-based Proactive Path Selection Mode (TPPSM). The performance of TPPSM is compared with the proactive tree mode of HWMP. Simulation results show that TPPSM has better performance. [ABSTRACT FROM AUTHOR]

This article describes a reliable gateway for in-vehicle networks. Such networks include local interconnect networks, controller area networks, and FlexRay. There is some latency when transferring a message from one node (source) to another node (destination). A high probability of error exists due to different protocol specifications such as baud-rate, and message frame format. Therefore, deploying a reliable gateway is a challenge to the automotive industry. We propose a reliable gateway based on the OSEK/VDX components for in-vehicle networks. We also examine the gateway system developed, and then we evaluate the performance of our proposed system. [ABSTRACT FROM AUTHOR]

Abstract: We propose an adaptive online load-balancing protocol for multi-gateway Wireless Mesh Networks (WMNs) which, based on the current network conditions, balances load between gateways. Traffic is balanced at the TCP flow level and, as a result, the aggregate throughput, average flow throughput and fairness of flows improves. The proposed scheme (referred to as Gateway Load-Balancing, GWLB) is highly responsive, thanks to fast gateway selection and the fact that current traffic conditions are maintained up-to-date at all times without any overhead. It also effectively takes into account intra-flow and inter-flow interference when switching flows between gateway domains. We have found the performance achievable by routes used after gateway selection to be very close to the performance of optimal routes found by solving a MINLP formulation under the protocol model of interference. Through simulations, we analyze performance and compare with a number of proposed strategies, showing that GWLB outperforms them. In particular, we have observed average flow throughput gains of 128% over the nearest gateway strategy. [Copyright &y& Elsevier]

Abstract: The introduction of scalable SNMP agent AgentX into the field of network management expands the control capability of SNMP-based network management system on network devices, important components and applications. The paper designed a kind of applicable network management system based on SNMP protocol and its extended protocol AgentX. The system implemented real-time monitoring and distance configuration of functional running circumstance of aviation data communication gateway server, which provides a practical application mode for network devices management in complicated network environment. [Copyright &y& Elsevier]

Wi-Fi-enabled portable devices have recently been introduced into the consumer electronics market. These devices download or upload content, from or to a host machine, such as a personal computer, a laptop, a home gateway, or a media server. This paper investigates the fairness among multiple Wi-Fi-enabled portable devices in a home network when they are simultaneously communicated with the host machine. First, we present that, a simple IEEE 802.11-based home network suffers from unfairness, and the fairness is exaggerated by the wireless link errors. This unfairness is due to the asymmetric response of the TCP to data-packet loss and to acknowledgment-packet loss, and the wireless link errors that occur in the proximity of any node; the errors affect other wireless devices through the interaction at the interface queue of the home gateway. We propose a QoS-provisioning framework in order to achieve per-device fairness and service differentiation. For this purpose, we introduce the medium access price, which denotes an aggregate value of network-wide traffic load, per-device link usage, and per-device link error rate. We implemented the proposed framework in the ns-2 simulator, and carried out a simulation study to evaluate its performance with respect to fairness, service differentiation, loss and delay. The simulation results indicate that the proposed method enforces the per-device fairness, regardless of the number of devices present and regardless of the level of wireless link errors; furthermore it achieves high link utilization with only a small amount of frame losses. [ABSTRACT FROM AUTHOR]

In Wireless Mesh Networks (WMNs), traffic is mainly routed by WMN Backbone (WMNB) between the mesh clients and the Internet and goes through mesh gateways. Since almost all traffic has to pass through one of the MGs, the network may be unexpectedly congested at one or more of them, even if every mesh router provides enough throughput capacity. In this paper, we address the problem of congestion of gateways while designing WMNs. We propose a simultaneous optimization of three competing objectives, namely network deployment cost, interference between network channels and congestion of gateways while guaranteeing full coverage for mesh clients. We tailor a nature inspired meta-heuristic algorithm to solve the model whereby, several trade-off solutions are provided to the network planner to choose from. A comparative experimental study with different key parameter settings is conducted to evaluate the performance of the model. [ABSTRACT FROM AUTHOR]

This paper presents a System on Chip (SOC) based high-density carrier class Voice over Internet Protocol (VoIP) media gateway. The design exploits three levels of parallelism namely HW/SW partitioning, multiprocessing and instruction level parallelism. The system facilities the carrier class service providers to transform channels on PSTN network to JP network, enabling the consumers to enjoy several value added services, such as voice, data, fax and video all through a uniform network at lower cost. The SoC implements a high-density media gateway switch for carrier class VoIP applications. The solution is synthesized to operate at 266 MHz handling up to OC-3 data rate port density equivalent to 2016 simultaneous calls on a single chip and it can be cascaded to support OC-12 and OC-48 rate port density on single board in different configurations. On each channel the SoC supports up to 128 ms tail length G.168 compliant Line Echo Cancellation (LEC), Voice Activity Detection (VAD), Comfort Noise Generation (CNG) and Discontinuous Transmission (DTX), Dual Tone Multi Frequency (DTMF) detection and generation, variety of G.xxx Voice Codecs, V. 17 Fax and V.34 Data modem standards and MPEG4 Video compression/decompression algorithms. The solution is compared with the existing architectures and commercial products; it offers 3× to 10× cost, size, power and port density performance improvements with IP and PSTN intern etworking support. The media gateway system based on the presented architecture has been used to develop IP-based Automatic Call Distribution (ACD) by etel Pvt. Ltd and installed in Telephone Inquiry Exchange of Pakistan Telecom and its variants are being tested by Buraq Telecom for installation in their service network. [ABSTRACT FROM AUTHOR]

This paper introduces a novel approach for extending DMB service area by making use of existing IP networks. DMBonIP Gateway, which provides RTP/SDP based internet streaming service by generating media streams in real time from the DMB ensemble received from the air, is introduced for this purpose. This paper addresses key functional components of DMBonIP Gateway and how they are designed and implemented. [ABSTRACT FROM AUTHOR]

The LHCb experiment event-building is performed over a Gigabit Ethernet switched network. One specific step of event-building is implemented by a software running on a gateway PC whose role is to gather data packets from data sources, rebuild events and forward them to computing nodes for running trigger algorithms. In this article, we concentrate on the implementation of this component on a Linux system. While implementing the software, we made thorough studies of the kernel and profiled applications, leading to significant performance improvement. More importantly, these studies allowed us to also gain in terms of predictability thanks to a good understanding of the whole system. In this article, we use this application to illustrate possible improvements to system software for data acquisition. We describe in detail implementation choices and related operating system kernel code. These techniques and observations are generic enough to be applied to other similar systems. [ABSTRACT FROM AUTHOR]

We introduce a stochastic model of a bottleneck ECN/RED gateway under a large number of heterogeneous TCP flows, i.e., flows with diverse round-trip delays and session dynamics. We investigate the asymptotic behavior of the system and show that as the number of flows becomes large, the buffer dynamics and aggregate traffic simplify and can be accurately described by simple stochastic recursions independent of the number of flows, resulting in a scalable model. Based on the Central Limit analysis in the paper, we identify the sources of fluctuations in queue size and describe the relationship between the system parameters such as the marking function and variance of queue size. A closed-form approximation for the mean queue size as a function of system parameters is provided from a simple steady-state analysis. Numerical examples are provided to validate our results. [ABSTRACT FROM AUTHOR]

In the last few years, multiprotocol label switching has been successfully deployed by majority of service providers worldwide. The Label Distribution Protocol is used in many MPLS networks for distributing labels to establish the label switched paths. This article focuses on LDP failures, namely failures that may occur in LDP while the underlining Interior Gateway Protocol of choice, and the physical connections are operating normally. Since LDP and MPLS in general do not have intrinsic means for detecting these failures, new mechanisms have to be introduced to handle them. Furthermore, the IGP may remain unaware of the LDP failure, and continue to direct traffic to the faulty path. To resolve this situation, coupling between LDP and the routing protocol may have to be introduced. In this article, we discuss all aspects related to handling LDP failures: discovery, location, notification, recovery, and prevention. [ABSTRACT FROM AUTHOR]

Presents information on Shaman, a Java-based service gateway for networked sensor systems. Features of the Shaman technology; Details on the architecture and implementation of the system; Components of the gateway service.