IoT browser is a useful tool for the Internet of Things (IoT), which provides a novel way for people to interact with daily life objects through the Internet. Comparing with traditional web browsing environment, IoT browsing environment has some distinctive features such as the way of interacting with the physical objects, the importance of spatial-temporal information of objects, and the necessity of resource reuse. In this demonstration, we present a prototype of a proposed IoT browsing system architecture with a semantic-based learning-capable middleware for IoT browser and demonstrate the applicability of the system in a browsing scenario. The learning scheme is able to suggest users the next possible events when the users design their own service flows through web interface. The prototype shows that with the help of the IoT browsing system, heterogeneous devices can cooperate with each other to provide IoT services.

In long term evolution-advanced (LTE-A) networks, the carrier aggregation technique is incorporated for user equipments (UEs) to simultaneously aggregate multiple component carriers (CCs) for achieving higher transmission rate. Many research works for LTE-A systems with carrier aggregation configuration have concentrated on the radio resource management problem for downlink transmission, including mainly CC assignment and packet scheduling. Most previous studies have not considered that the assigned CCs in each UE can be changed. Furthermore, they also have not considered the modulation and coding scheme constraint, as specified in LTE-A standards. Therefore, their proposed schemes may limit the radio resource usage and are not compatible with LTE-A systems. In this paper, we assume that the scheduler can reassign CCs to each UE at each transmission time interval and formulate the downlink radio resource scheduling problem under the modulation and coding scheme constraint, which is proved to be NP-hard. Then, a novel greedy-based scheme is proposed to maximize the system throughput while maintaining proportional fairness of radio resource allocation among all UEs. We show that this scheme can guarantee at least half of the performance of the optimal solution. Simulation results show that our proposed scheme outperforms the schemes in previous studies.

When accidents or disasters happen, emergency response time is always crucial. Most procedures in the existing emergency vehicle dispatching systems rely heavily on manual assignments. In this paper, we propose a novel emergency vehicle dispatching system to reduce emergency response time, which includes automatic emergency resource assignment and driving path planning to reduce unnecessary time delay caused by human misjudgment or the delay caused by traffic jam. As the traffic condition varies from time to time, the traffic information employed in the proposed method needs to trace back to several weeks prior to the dispatching time. Furthermore, we also propose a lane reservation scheme for emergency vehicles to minimize the crash risks. Before an emergency vehicle arrives at each road segment, Road Side Units start to disseminate the warning message at suitable time, so that other drivers could have enough time to take proper actions such as speed acceleration or switching lanes. Simulation results show that the proposed approach can largely reduce the traveling time of emergency vehicles comparing to the shortest path approach with sirens and lights to alert other drivers. With the traveling time as well as emergency resource assignment time being reduced, the emergency rescue teams would gain edges in rescuing lives and property.

Wireless sensor networks have been widely used in many applications. One of them is indoor guiding service for emergency evacuation whose goal is to assist moving objects in escaping a hazardous region safely and quickly when an emergency occurs. In this paper, we propose a distributed and adaptive guiding protocol that takes several factors such as hazardous regions, distance to exits, width of exits, and congestion degree of each location into consideration. This protocol guides moving objects with load balancing among multiple navigation paths to multiple exits and avoids congestion to reduce the evacuation time. Simulation results show that the proposed protocol can guide moving objects (e.g., people) to exits in shorter time and have higher survival rate in comparison to those without balancing the traffic load on navigation paths and exits.

Vehicular Ad-hoc Networks (VANETs) has been regarded as an emerging and promising network for transportation because it can provide safety and useful traffic information for passengers. VANET employs IEEE 802.11p standard as transmission protocol that defines media access control (MAC) and physical layers, where provide one control channel and six service channels. IEEE 802.11p MAC protocol is a contention-based protocol that has low channel utilization under heavy traffic load. In this paper, we propose a Distributed Channel Assignment Scheme (DCAS) to increase the successful rate of channel reservation and avoid hidden terminal problem to increase the channel utilization. Besides, we also propose an emergency state transition mechanism when VANETs need to transmit emergency messages. Through state transition, vehicles in normal state using non-safety applications will enter emergency state to rapidly forward emergency message to reduce transmission delay. Simulation results show that the proposed scheme can improve 27% channel utilization in average comparing with random channel selection scheme.

Guiding navigation is an important application in wireless sensor networks to make moving objects leave dangerous areas safely and quickly. However, guiding policy without considering congestion problem will postpone the escape time. In this paper, we propose a distributed flow-based guiding protocol for indoor environments to evacuate mobile objects from dangerous area to exit. Our goal is to construct less congested paths to minimize the escape time and the congestion time. Each sensor in the network holds an artificial potential value determined by the moving speed of object on a path monitored by it, the distances to exits, and the capacity of exits that have the maximum potential values, and objects are directed to paths with higher potential values. Nevertheless, our approach also solves the local maximum problem that objects are trapped at a non-exit location holding a local maximum potential value. In addition, we adopt a traffic flow model for transforming object density of a road into object's velocity to reduce the computational cost and the communication overhead. Simulation results show our proposed protocol can efficiently decrease the escape time and congestion time.

One important goal of surveillance systems is to collect information about the behavior and position of interested targets in the sensing environment. Traditional video surveillance systems usually cannot provide complete information of interested targets since they are limited by single and fixed monitoring directions. Recently, surveillance systems combining wireless sensor networks with video cameras have become more and more popular. In this demonstration, we show a multi-view surveillance system consisting of several rotatable video cameras and objects. By implementing the proposed visual sensor selection algorithm, our system can provide more meaningful information from multiple rotatable cameras.

Because of shortage of raw materials, the energy-saving issues become popular in Vehicular Ad-hoc Networks (VANETs). A VANET is formed by traveling vehicles with communicating capability and thus it brings various applications. Navigation system is one of important applications in VANETs. The traditional navigation system usually plans a shortest path for users according to geographic maps but the planned path may become a slower one due to the traffic congestion. A congestion path not only delays the traveling time but wastes fuel. So the real-time traffic information should be considered while constructing a navigation path. In this paper, we propose a navigation system to find a fuel-saving navigation path by considering real-time traffic information. In order to estimate the traffic load on the future path, we maintain a table of historical traffic information by Intelligent Transport Systems (ITS). Furthermore, our system can dynamically change the navigation path by updating traffic information. In the simulation results, our approach can save more than 20% fuel consumption when vehicles travel in a traffic congestion environment.

Traffic congestion is a serious problem in urban areas of many countries due to the increasing amount of vehicles on surface streets and accompanies fuel-wasting and air-pollution. This problem can be alleviated by adopting a ride-sharing service. The main idea of ride-sharing service is to collect travelers whose travel destinations are nearby into one vehicle. In doing so, we can reduce the amount of vehicles on surface streets and meantime save fuel. In this paper, we focus on the taxi-sharing service and propose a dynamic taxi-sharing system based on Intelligent Transportation Systems (ITS) technology. In the proposed system, we can immediately serve each irregular ride-sharing request and find a fuel-saving taxi for it. The simulation results show that our solution can exactly select a fuel-saving taxi for each ride-sharing request and outperform in responding time, the number of compared taxis, and fuel-saving while comparing with existing solutions.

This paper proposes a new application framework for group tour guiding services based on RFIDs and wireless sensor networks. We consider a sensing field mixed with multiple independent tourist groups, each with a leader and several members. Members of a group will follow the moving path of their leader, but may occasionally roam around randomly on their own interests. Sensor nodes have to track leaders' locations and maintain guiding paths from members to leaders. A member may inquire where his/her leader is, and a leader may "recall" his/her members. We propose a feasible solution to such an application by using existing technologies and off-the-shelf components. A group guiding protocol is presented. The design enables reliable group guiding at low cost and low traffic load. Our prototyping system is reported and system performance is discussed.

One of the major applications of wireless sensor networks is guiding navigation service with its goal to assist moving objects in leaving a hazardous region safely and quickly. In this paper, we propose a distributed guiding navigation protocol that can guide moving objects to multiple exits with load balancing among multiple navigation paths to the exits. With the assistances of sensor nodes, moving objects are guided to different navigation paths so that they can move to exits as soon as possible without causing congestion. In some traditional navigation algorithms, a sensor may select a wrong guiding direction when an information- updating packet has not flooded through the whole network. Hence, the guiding direction of the sensor may oscillate in a short time and guided objects will confuse with this phenomenon, called direction oscillation problem. This problem will be eliminated in our proposed protocol. Simulation results indicate that our protocol can guide moving objects to exits in shorter time and solve the direction oscillation problem effectively.

One of the major applications of wireless sensor networks is guiding navigation service whose goal is to find a way to guide moving objects across a hazardous region covered by sensors. Sensor networks maintain safe paths by which the moving objects can be guided safely to exits. In this paper, we propose a distributed guiding navigation protocol for constructing area-to-area optimal guiding paths that do not traverse through the hazardous areas and to guide the moving objects to escape from this area safely and quickly. Our protocol also allows multiple exits and multiple emergency events in the sensor networks. Moreover, we propose a load-dispersion algorithm including an additional AP layer for moving objects registration and path assignment in multi-exits scenario. Hence, the moving objects can be properly dispersed to multiple paths leading to multiple exits to avoid congestion in the same exit. Simulation results show that our protocol can guide moving objects along shorter paths to reach nearest exits and operate in different scenarios or environments.

One important goal of surveillance systems is to collect information about the behavior and position of interested targets in the sensing environment. These systems can be applied to many applications, such as fire emergency, surveillance system, and smart home. Recently, surveillance systems combining wireless sensor networks with video cameras have become more and more popular. In traditional video surveillance systems, the system performance and cost is proportional to the number of deployed video camera. In this paper, we propose a real time video surveillance system consisting of many low cost sensors and a few wireless video cameras. The system allows a group of cooperating sensor devices to detect and track mobile objects and to report their positions to the sink node in the wireless sensor network. Then, the sink node uses the IP cameras deployed in the sensing area to record these events and display the present situations. We also propose a camera control scheme to initialize the coverage distribution of cameras and support the inter-task handoff operations between cameras. We have implemented the proposed system with 16 sensor nodes and two IP cameras, and evaluated the system performance. The result shows that our surveillance system is adaptable to variant environments and provides real time information of the monitored environment.

This paper proposes a new application framework for group tour guiding services based on RFIDs and wireless sensor network. We consider a sensing field mixed with multiple independent tourist groups, each with a leader and several members. Members of a group will follow the moving path of their leader, but may occasionally roam around randomly based on their interest. Sensor nodes have to track leaders' locations and maintain following paths from members to leaders. A member may ask where his/her leader is, and a leader may "recall" his/her members. We propose a feasible solution to such an application by using existing technologies. A group guiding protocol is presented. The design enables reliable group guiding at low cost and low traffic load.