View Preface Permissions. Review Article. Research Article. Aseri DOI: International Journal of Sensors, Wireless Communications and Control, Volume 9 - Number 4 This issue is in progress but contains articles that are final and fully citable. View Biography. View Abstract Permissions. This issue is in progress but contains articles that are final and fully citable. Futane DOI: Deshpande DOI: Anwar Hussain DOI: Kulkarni DOI: Articles Ahead of Print.
Arif DOI: Abstracts Ahead of Print. H Wandra DOI: Suppose mobile multi-agent systems consist of. Based on the Lypunov stability theory, the consensus of multi-agent systems with pinning control is analyzed. Finally, computer simulations are used to show the validity of the result.
This research analyzes inertia as a metaphor to explain organizational change and innovation by adopting system dynamics modeling of the organizational inertia of knowledge-intensive business services KIBS. KIBS are regarded as the main study object in virtue of more uncertainties and complicatedly ever-changing environments and their winning inertia for the survival is a buzzword.
This study aims at making out the specific component of organizational inertia of KIBS, which have the prominently different characteristics from the traditional industries. It highlights the level and rate model to illustrate the dynamic evolutionary processes of organizational inertia and works out the input and output graphs of organizational inertia in Vensim that demands the relevant system modeling foundations in the empirical practice.
With the rapid increase on requirement of the cross-platform distributed imaging technology, and the common, stable imaging lib, SUN provided a complete solution based Java platform technology. Especially, it details the image operators, the core classes and the programming framework of Java Advanced Imaging. At last, the paper gave out two imaging examples included the programming codes and the result images, which can be used in project.
At last, some simulations are made to validate the results. There may be some defects in elaborate results by using traditional methods because different analyzers usually have different views on the goals and turn to different elaborate results. This article quotes domain rules to instruct goals elaborate process upon the traditional methods. Analyzers answer such questions which can instruct the elaborate process. Through learning from the energy multi-path routing protocol of WSN and the hybrid genetic algorithm, this paper presents a novel routing protocol to find the optimal path.
The Algorithm consists of two stages: single-parent evolution and population evolution. The initial population is formed in the stage of single-parent evolution by using gene pool, then the algorithm continues to the further evolution process, finally the best solution will be generated and saved in the population.
The simulation results show that the algorithm is effective. It can optimize the network path, balance energy consumption of the network and extend the network life cycle. In this paper, three-dimensional elastic contact problem is discussed. Based on traditional boundary element method BEM , mixed boundary integral equation is presented to solving several bodies contact problem with friction.
It is not only reducing the dimension from domain to boundary, but also solving the displacement and stress independently at the same time. A new judgement criterion of contact state is established to judge the contact state of separate, adhere and slip. Infrared imaging guidance is a guidance system with strong anti-interference ability. It is a technology with high efficiency-cost ratio which increases the missile power.
It also is one of precision guided munitions development directions nowadays. It is first step that studies on the infrared radiation characteristics of target region to study on infrared imaging guidance, in which the key is how to obtain the infrared information of target region. This paper presents a kind of target IR scene simulation methods based on aerospace information. Firstly, three-dimensional scene model is generated based on terrain data, target 3D data and remote sensing image data. Secondly, the value of target and scene surface temperature is computed with different methods.
Finally, target region IR scene 24h image sequence is produced. After comparative analysis, the IR scene image sequence produced by this method reflects target region infrared radiation characteristics in truth, and has a good fidelity. The sensor nodes in wireless sensor network have limited capacities, complete complex tasks through collaboration.
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In multi-agent system, the agents complete their work through collaboration. Collaboration is one of the key issues in multi-agent system research. Taking into account the similarities between multi-agent systems and wireless sensor networks, it is possible to use agent collaboration in wireless sensor network. In this paper, we use the role-based agent collaboration to help sensor nodes, and construct a Wireless Data Acquisition and Analysis System with role-based agent collaboration.
Simulation experiment results show that, when the number of nodes is large, the use of role-based agent collaboration can help it to effectively improve the system load, and reduce channel congestion. However, in the area of role definitions, roles dynamically added and so on, there are great challenges. Color information carried by the matting components in spectral matting is used in our method to solve the matting problem.
By comparing the color similarity of each matting component, the matting components were separated into two groups: the foreground and the background.
The Fifteenth International Conference on Wireless and Mobile Communications
There are two advantages of doing so. Firstly, there is no need to use the trimap which is a necessary tool in traditional matting solving methods to accomplish the process of semi-supervised learning. Instead, the color similarity information could be used as constrain or heuristic cue in finishing the process of unsupervised learning to lower the blindness of automatically extracting the foreground object. Secondly, combining the color similarity information with a little user provided foreground and background cue could further reduce the number of matting components whose group have not been known yet, and thus a semi-supervised learning process which could only be done by using a lot user provided cue in traditional matting solving methods could be accomplished.
This paper investigates the correlation properties of original sunspot series and their conditional time series. The conclusions indicate that the Hurst exponents value H decrease from 1. In this paper, we introduce moving average method to estimate the Hurst exponent of the Hang Seng Index data for the year period, from December 31, , to June 6, in the Hongkong stock market, a total of trading days.
Further, we present a detailed comparison between the regular rescaled range method and the moving average method. We find that the long-range correlations are present by both the new method and the regular method. Chord is one of the peer-to-peer systems that searching algorithm for resource,simplicity stabilize and scalable.
But its reckon without properties of node while mapping out. Every node is equal under the system. This leads to some problems. In this paper, considering instance of application in practice, we propose a scheme that improved Chord Model Grouping by Property GP-Chord. And results show that its satisfactory through simulation. First, established submersible vehicle movement mathematic model; then analyzed disadvantage of PID autopilot effect. Mainly, a multi-controller method with a neural network control and PID control was adopted, and researched the submersible vehicle autopilot control technology, then a neural network identification NNI was designed, and to identify the submersible vehicles space mathematical models on line, though the submersible vehicle mathematical models can not fully determine, the submersible vehicles approaching mathematical models also can be identified on line by NNI through the real time input and output of the submersible vehicle under large interference.
At the same time, the multi-layer prior neural network as neural PID controller NNC was adopted, and it improved accuracy. The simulation results show that neural network PID control autopilot has very good performance and is better than traditional PID autopilot in robustness and practicability. Electronic systems are widely used in many engineer and civil fields, such as aviation, energy, communication, military and automatic etc. Usually the more the components that a system includes the poorer the system reliability is. But the failures of components are usually dependent.
In this paper, a reliability model of dependent failure of electronic system is built and the influences of strength decentrality and load decentrality is discussed. The results of two examples prove the validity and superiority of the method in the application of the reliability modeling and assessment of system and the model that considered failure dependent is more reasonable than those conventional reliability models.
The introduction of authentication protocols for RFID system provides the security to it, authentication protocol based on hash function is one of the most commonly used authentication protocol, which the hash function they used is a unilateral function, with a relatively high security, and it is easy to implement in the tag of RFID, so it has a wider application in RFID system. As the hash function, the characteristics of its own will have hash table conflicts, and thus would have resulted in security vulnerabilities, aim at the hash table conflict, this paper proposes a specific solution, and simulate the improved authentication protocol.
Routing data messages in a wireless sensor network is different from traditional networks because sensors do not have a unique IP address, knowledge of the network topology or routers and routing tables. Also, the limited power resource places restrictions on the number of messages sent and received within a network. The purpose of this article is to develop an algorithm based on small world networks, to route sensor data to the nearest sink node. A wireless sensor network, with optimally placed sink nodes, does lead to efficient routing of data between nodes while preserving battery lifetime.
China is on the important accelerating step to industrialization country, taking a new road of industrialization of integrating information technology application with industrialization is a very crucial job for our economy. The traditional industrialization that relies on resources and high capital input accelerated the rapid economic growth and at the same time, inevitably, caused a number of problems.
For example, the overall efficiency of the national economy was dragged down, all sectors of society slackened the drive to promote technological innovation and efficiency, the development of service industry was suppressed and the shortage of basic resources like water, land, coil, electricity and oil was intensified and the ecological environment was worsened. All of these make the traditional way difficult to carry on and call for a new type one.
In this paper, take HeBei Province for an example, to discuss how to increase the industrialization from the angle of integration of information technology and industrialization. The volatility of financial asset return is getting more and more drastic in recent years. This situation makes regulators and investors pay more attention to high loss risk of portfolio. Conditional value at risk CVaR is an effective tool to measure the risk of high loss.
In order to control the large loss risk of portfolio, the paper established mean-CVaR portfolio optimization model, and presented pivoting algorithm to solve the model. Based on the real trade data of composition stocks of SZ50 Index, we calculated the efficient frontier of the mean-CVaR model. The computational results showed that the pivoting algorithm has high calculation efficiency which can satisfy the computing demand of investment practitioner. An ontology-cored emotional semantic retrieval model was proposed and constructed in order to overcome the current situation that it is difficult to implement emotional semantic search in the course of image searching.
A method Combines Mpeg-7, theory of concept lattices and ontology construction together to construct the kernel ontology library was put forward. The difficulty of this method lies on how to integrate the Mpeg-7 standard descriptor with image emotional ontology properties, and how to auto-generate new concept results. Related experiments were carried out of which the results validated the feasibility of this model on image emotional semantic search.
Task allocation is the core problem of MAS. Based on capability, this article present an auction-based task allocation algorithm. Each agent gives a reasonable tender price to select perfect task, according its capability and its preferences for different tasks, and mission requirements. Finally, we make a simulation experiment for transporting problem, and the results show that the algorithm is reasonable and effective, Superior NeA-MRTA algorithm.
In this paper, the global error bound estimation for the generalized complementarity problem in engineering and economic equilibrium modeling GCP is established. The results obtained in this paper can be viewed as extensions of previously known results.
At the basis of an in-depth study on the popular ALOHA algorithm and binary search algorithm to solve the tags collision problem, the basic principles and a variety of improvements of the two algorithms is described in detail, and the emergence of new research trends of Tag anti-collision technology is summarized. Finally, anti-collision technology development tendency is forecasted.
An improved medium access control algorithm based on energy conservation is proposed in this paper because the energy is constrained in wireless sensor network.
International Journal of Wireless & Mobile Networks (IJWMN)
In this algorithm, each code can adjust its sleeping probability by its remaining energy, balance energy consumption of net codes, so the life time of whole network is enlarging. The simulating result shows that comparing with traditional algorithm, the max life time can be increased from 1. At sometime, the data groups also can be improved more in life time with the same energy of each code. Central to the standard are the concepts of risk and safety functions. The risk is a function of the frequency or likelihood of the hazardous event and the event consequence severity.
IEC defines safety integrity level SIL as a discrete level one out of possible four , corresponding to a range of safety integrity values, where SIL 4 is the highest level of safety integrity and SIL 1 is the lowest. The standard has its origins in the process control industry. It covers the complete safety life cycle, and may need interpretation to develop sector-specific standards. In fact, the standard lies at the root of a number of specific domains e. The development of Co-CPS poses challenges on safety issues that are not adequately addressed by existing practices and standards exposed above.
One of the primary objective of SafeCOP is to propose an approach to the safety assurance of Co-CPS which will facilitate their certification and market release. A safety-case is a well-documented body of evidence, in the form of a clear argument, assuring that the system is acceptably safe. Building the safety case requires ensuring not only that identified failures have been addressed, but also that any unwanted interactions between the system parts as well as the environment have been managed.
SafeCOP applies the Safety Assurance approach to manage functional safety activities during the life-cycle of the machine, i. As the contracts capture safety-relevant behaviors, they are used during system development for generating system-specific safety cases.
It is necessary to assure that the system relates to the runtime assurance claim of whether the system is still sufficiently safe whether the contracts are violated in the current environment or not. A continuous Runtime Manager checks for contract violations. Contracts must be always satisfied in any environment condition, thus their violation during runtime indicates that a failure occurred in the environment, i. On the other hand, if the contract assumptions are not violated, then the runtime manager should check if the system offers the promised guaranteed behavior. If the guaranteed behavior is not provided, then an internal failure exists.
Beyond the safety, the overall system dependability relies on security: there are many subtle interactions and interdependencies among safety, QoS and security as introduced in previous sections. Often, security is conflicting with safety and performances, thus requiring to evaluate a quantifiable trade-off between the three.
One of the key issues that allows the trade-off evaluation is the definition of a metric [ 35 , 36 ]. Metrics are also suitable for security assessment of services, applications, as well as users and communication channels. Several strategies have been proposed in the area of communication channels security to secure protocols and messaging schema. A SSL connection is established, between two pair nodes, exchanging identification parameters in the form of digital certificates.
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Defense mechanisms against possible threats, either malicious or due to environment, are also defined. In particular, wireless communications are subject to physical layer attacks, like, e. These require specific measures known as physical layer security mechanisms aimed at increasing the robustness and secrecy capacity of the wireless channel [ 37 ]. The main issues are related to the enhanced flexibility and scalability of the networks, especially in the case of Co-CPSs, where different systems could participate to a cooperative group with different roles and the group dimension can vary over time, like in vehicular use cases, where a platoon is a high dynamic set of cars continuously entering and exiting the platoon itself.
Vision and details on these items are available in, e. While the security approaches proposed in the literature mainly focus on the trustiness of the information flowing through the network, enforcing the network access and utilization e. SafeCOP aims to extend the current wireless protocols for both safe and secure cooperation. In general, such technologies have been designed to meet communication requirements and significant progress has been done to secure the channels, but they cannot satisfy the safety requirements imposed by the selected use cases.
Therefore, SafeCOP is working to enhance current wireless communication protocols to ensure that safety requirements are preserved, together with security, in the highly dynamic scenarios envisaged for Co-CPSs, where traditional safety assurance methods may not be sufficient. Details on communication technologies adopted by each use case and the protocol enhancements proposed within SafeCOP project are presented in Section 3 and Section 4. However, attention is taken to the technology evolution of mobile networks since the future 5G technologies will address most of the challenging network issues, e.
Network virtualization increases the flexibility of 5G networks, and improves their adaptability to the specific communication requirements of Co-CPSs. Moreover, the storage capability of the cloud allows to collect a wide range of sensors data and to support the application logic with data analytics. A deeper discussion on 5G is available in Section 5.
To reach this objective it is driven by five representative use cases that span from hospital applications with low-speed movements, vehicular applications with high speed movements, to maritime applications. In what follows, we briefly introduce the use cases addressed in the SafeCOP project. To reduce the risk of contamination and spread of disease, hospital beds are thoroughly cleaned before being used by a new patient. In most hospitals, the cleaning is performed manually on site in each patient room, even in hospitals where they have a centralized bed-washing facility CBWF.
This is because moving the bed to and from the CBWF takes about the same amount of time as cleaning the bed in the ward. Both manually cleaning a bed and transporting beds to the CBWF are tasks that require hard physical labor and non-ergonomic motions and positions. To avoid unnecessary strain on hospital workers, and to free up a large amount of their time, this use case proposes an automated solution using two small mobile robots, designated MiR A MiR will be attached to each end of the bed, and coordinate and synchronize their movement through the use of safe communication.
As the MiRs are small, their vision is quite limited. To assist in navigation and obstacle detection, a network of cameras will be installed in the hospital hallways. Figure 1 provides the layout of the hospital beds testbeds, where two individual mobile robots are moving in the corridor covered by wireless access points. International Maritime Organization IMO, London, UK has received a proposal supported by a number of countries to include autonomous ships on its agenda.
The IMO Maritime Safety Committee will establish a new international legal framework for the safe operation of autonomous vessels. It is evident that safety considerations are crucial in this respect. The main barrier to the development of autonomous shipping is represented by the concerns related to the risk of collision between manned and unmanned vessels.
Moreover, as the number of cyber threats are increasing, a great concern is raised on specific cyber-attacks targeting the control of autonomous vessels [ 43 ]. To reduce inherent risk, cybersecurity should be taken at a high priority when developing autonomous ships. Among various explorations of autonomous ships, bathymetry Bathymetry is the study of underwater depth of lake or ocean floors. Bathymetric charts are typically produced to support geophysical exploration and environmental monitoring is a very attractive application [ 44 ]. Bathymetry is usually performed by sailing a boat with a multi-beam sonar in a rather repetitive lawn-mover pattern.
USV application to bathymetry will result in a twofold gain: saving costs and reducing HSE risk for survey personnel [ 45 ]. This gain increases for bathymetry measurements in extreme conditions like the Arctic Ocean, where USV may replace a fully-crewed ship and shows better performance in adverse environments and inclement weather. At the current stage, the USV has to be remotely controlled by a human operator who is located on another vessel.
Such cooperation between the USV and the manned vessel can dramatically increase navigation safety while heavily relying on wireless communications between them, as illustrated in Figure 2. The USV and manned vessel have to periodically exchange critical information, such as vessel speed, course and position, to maintain a certain formation. The USV receives instructions and commands from the manned vessel to maneuver or stop. When safety-critical events occur e.
Therefore, packets carrying critical information and safety control commands are subject to very low latency requirements. During the bathymetry measurements operation, the boats and the unmanned surface vehicle USV communicate wirelessly for coordination. Safety, comfort and efficiency of both roads and vehicles have improved considerably over the last decade.
However, our transportation system still suffers from many problems. The fast growth of urban areas causes an increasing trend of vehicular traffic and road accidents, resulting in serious socioeconomic problems. According to the latest report from the United States U. Moreover, in , highway users in the U. To address these problems, there have been worldwide efforts by automotive companies, universities, and governments to provide applications, services, and technologies that connect a vehicle to its surroundings. Examples of such applications and services may include adaptive cruise control, automate braking, remote vehicle diagnostics, hazards, and blind spot warnings.
Typically, a connected vehicle CV includes interactive advanced driver-assistance systems ADAS and cooperative intelligent transport systems C-ITS , where vehicle awareness concerning its current traffic context is aided by information exchange with surrounding vehicles through vehicle-to-vehicle V2V communication, close roadside units through vehicle-to-infrastructure V2I communication or people through vehicle-to-pedestrian V2P communication, collectively referred as V2X.
These technologies are anticipated to offer significant benefits, including: reduced driver stress and possibility for passengers to rest and work while traveling; reduced driver costs of paid drivers for taxis and commercial transport; mobility for non-drivers including disabled people, therefore reducing the need for motorists to chauffeur non-drivers, and to subsidize public transport; increased road safety and therefore crash costs and insurance premiums; reduce high-risk driving, such as when impaired e.
SafeCOP defined three use cases related to the vehicular applications, as described in the following. The goal of this use case is to demonstrate how we can apply and extend wireless technologies to support automotive cooperative V2x-based systems such as auto-braking in vehicle platooning. Besides inter-vehicle networking, this use case is also exploring intra-vehicle communication. Upon detection, the system should send a CLW alert to the other elements involved in the process, e.
The operation in this use case is illustrated in Figure 3. In case of control loss of any vehicle the blue vehicle in the figure , CLW alert is delivered from car to car forward and backward using the V2V communication infrastructure, and eventually each vehicle gains knowledge about the CLW and can react in a pre-defined manner, by entering in a safe mode. In addition, a wireless network of in-vehicle sensors and actuators is exchanging data with the on-board unit to inform about the status of different automotive systems.
This use case has been built upon the data exchange between the roadside road weather station and a passing vehicle. Road weather stations RWS are typically installed to fixed locations beside the road, collecting different measurement parameters related to weather and traffic, and delivering this data to a single data collection point, typically being the road administrator. During the RWS pass, the vehicle receives up-to-date local road weather information.
As an exchange, vehicle can also deliver its own observational information back to RWS, to be used as local supporting data in meteorological services. In this vehicle-roadside unit interaction, we must ensure that the delivered data is not altered or violated by a third party or some communication malfunctioning.
The primary scenario in this use case is data exchange between vehicle and RWS, when and where the vehicle is passing the RWS. The basic scenario is introduced in [ 50 ]. This scenario is extended to cover also data exchange between two vehicles scenario 2. In this case, both vehicles share the data received from the latest RWS, and as a result both vehicles will obtain up-to-date road weather data from the area ahead. The communication in this scenario is naturally local area communication.
In the final extension scenario 3 , we employ an IoT cloud as communication entity, and instead of direct data exchanges between vehicles and RWSs, the IoT cloud shares the location-based relevant data with vehicles and RWSs. The architecture of these resulting three scenarios are presented in Figure 4.
A vehicle and a roadside unit are participating in the first scenario vehicle-to-infrastructure , two vehicles in the second scenario vehicle-to-vehicle and, finally, a service provider, a vehicle and a roadside unit to the final third IoT-cloud scenario. VCA consists in the acquisition from video cameras referred to as RSU-C in Figure 5 and subsequent elaboration through appropriate algorithms.
The probability of traffic accidents will decrease by providing assistance to drivers exploiting both ARS e. A-TLSs change the traffic lights signaling plan the duration of red, yellow and green phases according to a set of control parameters, e. A-TLS improvements enabled by VCA allow the optimization of the signaling plan according to the changing traffic conditions, usually by extending the green phase when vehicles are closely spaced.
Figure 6 shows the architecture of the envisaged system. It integrates several SafeCOP framework components, including runtime mechanisms for safety assurance and distributed safety-critical cooperation techniques based on extensions to IEEE This system will represent one of the SafeCOP demonstrators. Communications between the parts of the demonstrator system are performed through radio frequency front-ends which transmit and receive on-the-air, or through attenuators and noise generators for testing purposes. The OBU integrates radio communication and inertial sensors, allowing additional information on vehicle behavior to be received by the RSU.
The RSU acquires video from the camera and performs the necessary initial elaboration to reduce communication times, aggregates information from vehicles in its operating range, and transmits the information over a wired connection to the remote Control Center. Communication technologies vary for different Co-CPS use cases. For different use cases, we can use different protocols, open and proprietary, and technologies.
Here, we give a brief overview of the most common communication technologies and protocols in each of the five use cases. Notably, we consider existing technologies that can be suitable candidates per use case because match the design requirements better. This use case will employ two different wireless protocols, namely Wi-Fi and XBee. The IEEE Wi-Fi infrastructure is already installed in some hospitals, and provides good coverage with relatively high data rates needed for transmission of live video streams. In addition, since both MiRs are connected to the same network, non-safety related information and data will be transmitted between the MiRs over the Wi-Fi connection.
The Wi-Fi network can also be used for future communication between MiR and other hospital information systems of interest. This link will be used to safely coordinate and synchronize the movements of the two MiRs. Although the over-the-air data rate of the XBee is limited to kbps, this should be sufficient for this purpose. The proposed setup of the autonomous hospital beds illustrated also in Figure 1 has been considered in some previous works that we discuss below.
In [ 53 ], the authors provide an experimental testbed with mobile robots that can receive their position through a centralized camera. The images are processed in a central PC unit, which is able to send the position information to each robot over ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation, where robots communicate to its neighbors only at event times.
In [ 54 ], the authors provide a similar testbed setup that is used for localization and tracking using CMUcam3 modules mounted on static WSN nodes. A partially distributed approach was adopted and image segmentation was applied locally at each WSN camera node. The output of each WSN camera node, i. To a similar direction, authors in [ 55 ] proposed a testbed setup, where the images captured synchronously by the cameras are processed at each node with the objective of extracting the essential information of the object.
The measures from all the cameras are integrated using information fusion methods such as maximum likelihood and extended Kalman filters. Finally, in [ 56 ], the authors also provide a cooperative control system of multiple robots using infrared cameras and image processing to facilitate the cooperative formation control. The above mentioned works are benchmarked in terms of distance among the mobile robots and their estimated location in a formation control. Due to the heterogeneity of the considered formation controls for each case, we can not compare their results. However, a general outcome is that localization errors could exist depending on demanding formation control and in case of traveling longer distances [ 57 ].
This use case sees a bathymetry system based on a set of USV in addition to a manned vessel that drives and controls the measurement campaign. Since s, the mobile satellite communication has been used to the maritime community as well. Taking into consideration the cost and signal coverage, the bathymetry platoon uses the VHF radios as the primary communication channel.
To ensure the reliability of communication, both the USV and manned vessel are also equipped with the transceiver for communication via the mobile network. Although the available data rate of the VHF channel is low, it is sufficient when transmitting the critical information e. Since message transmission between the USV and manned vessel requires the hard delay bound to ensure the safety of the cooperative bathymetry platoon, TDMA is a better option. It guarantees the worst-case end-to-end E2E delay through appropriately configuring the relevant parameters, such as TDMA frame length and slot size.
TDMA requires synchronization among all users who access the shared channel to avoid interference caused by data transmission in consecutive slots. Synchronization can be realized referring to either some external clocks e. ITS-G5 generally refers to a wireless technology used for automotive and intelligent transportation system applications via short-range exchange of information among onboard units OBUs located inside the vehicles, RSUs placed on the side of the road, or handheld devices carried by pedestrians.
Cellular networks provide an off-the-shelf solution for this type of communications. Quality-of-Service QoS can also be guaranteed e. On the other hand, some drawbacks that have been recognized e. ProSe, similarly to ITS-G5, allows user equipment to discover and communicate with each other directly within communication range, regardless of whether they are in or out of network coverage.
The ProSe specifications do not cover the whole V2X requirements it has been designed with the requirements of public safety and commercial consumer applications in mind. Enhancements are required for high speeds e. From the application point of view, the 5G integrated architecture will allow new business models characterized by services and applications ensemble with an increasing interaction, cooperation and complexity level as well as a great level of flexibility for service tailoring on customer demands.
At the infrastructure level, the research aims to satisfy most vertical use case requirements, improving and enhancing the current technologies in an evolutionary scenario, thus solving the foreseen weakness of LTE and ProSe for the vehicular use case. To support the requirements of different vehicular applications, each vehicle must be aware of the position, status and intention of its surrounding vehicles through message broadcasting. CAMs include information such as geographical location, speed, and acceleration, and are only sent to a close neighborhood, as the validity of the information they contain is very limited in time.
A large variety of C-ITS based safety applications are built upon the periodic exchange of CAMs, and their timely and reliable transmission is vital as a vehicle that continuously fails to deliver its beacon becomes invisible to its neighbors, which may result in potentially hazardous situations.
Based on American standardization, CAMs are periodically generated, while ETSI recently decided upon a set of kinematic CAM triggering rules that trigger beacons when needed rather than keeping it strictly periodic. On the other hand, DENMs are only generated when an event of common interest occurs, and it is spread within an area of interest for the duration of the event.
An IEEE This is the main benefit of IEEE The supported ad hoc mode reduces delay, as messages do not have to take the detour around the access point or base station. ETSI is responsible for developing the whole protocol stack including vehicle-centric road traffic safety applications, whereas applications orienting towards road traffic efficiency utilizing road infrastructure are under the responsibility of CEN.
Non-safety related applications are directed to a 20 MHz band at 5. The dedicated frequency bands have been divided into 10 MHz frequency channels. Due to the proximity of these bands to the frequency band used for ETC in Europe 5. There is no cost associated with using this frequency band it is license free. However, EN standard specifies requirements on output power limits, spectrum masks, etc.
A MAC protocol for a typical vehicular application has to be flexible enough to cope with high mobility and frequent topology changes. Therefore, the IEEE This will ensure that data traffic with higher priority e. However, the different QoS classes will not ensure timely channel access and thus, there will still be problems with collisions, especially during high utilization periods.
The protocol defines the physical and data-link layers and to complement it, several proposals such as the ZigBee, RPL, or 6loWPAN protocols were presented since its first release. More recently, to satisfy the requirements of emerging IoT applications, particularly in the industrial domain, the IEEE Hence, it improves its flexibility in accommodating different kinds of application requirements.
SafeCOP use cases are representative of real application scenarios where safety and security play the key role. In the following, we analyze the safety and security requirements and solutions that are proposed for the five use cases of SafeCOP. An initial safety analysis of the concept has concluded that the network of external cameras is an enhancement to the basic functionality of the MiRs, and should not be considered as part of the safety system.
The MiRto-MiR communication, on the other hand, is an integral part of the safety system, and must be certified as safe according to the relevant safety communication standard. Unfortunately, there is currently no relevant safety standard for small, autonomous robots with wireless communication operating in a hospital environment.
However, in the railway domain, there are similar challenges in signaling systems and train communication, where wires cannot be used due to the mobility of the application. The safe communication architecture will thus be based on the requirements of EN [ 62 ]. In addition, since wireless communication by definition is an open communication system, which is vulnerable to attacks from actors with malicious intent, information security mechanisms authentication, cryptography are a prerequisite for achieving safe communication.
The combination of threats random failures and external attacks will lead to one or more of the following basic message errors: repetition, deletion, insertion, resequence, corruption, delay and masquerade.
Wireless Communication Technologies for Safe Cooperative Cyber Physical Systems
In line with EN , the XBee communication shall be enhanced with a safety layer implementing defenses against these threats. They consist of a protocol with the following parameters and functionalities: sequence number, time stamp, time-out, source and destination identifiers, feedback message, safety code, identification procedure, and cryptographic techniques. The primary scenario defined in this use case deals with one USV that is remotely controlled by a human operator located on another vessel.
The wireless link connection between the USV and the manned vessel is maintained active by the continuous transmission of mode command messages from the manned vessel to the USV, to improve the reliability of the communication. If the message is not received within a given time-frame, the USV considers that the communication with the manned vessel is lost. Then, the USV will enter in fail-safe mode e. This mechanism is implemented at application level and independent of the underlying communication protocol. A crucial safety requirement that the cooperative bathymetry platoon has to fulfill is to guarantee that a safe distance is maintained between the USV and the manned vessel.
The acceptable distance between the USV and manned vessel is calculated as the maximum distance that allows messages carrying vessel voyage information be reliably and timely transmitted over the wireless network. Since the signal strength in maritime wireless networks is subject to perturbations due to the sea movement, safety messages are subject to packet loss at communication level. Therefore, sending messages in a periodic manner is applied to compensate packet loss.
The vessels speed is typically slower than other transportation systems e. Thus, missing one message is acceptable if the following one can be received correctly and timely.