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In recent years, a high connectivity demand started being experienced in wireless communication. Practically, everyone and everything needs to be connected because of the huge variety of applications existing today. This is a challenging situation for terrestrial telecommunications infrastructure that they cannot address on their own. Therefore, the 3rd Generation Partnership Project (3GPP) started in 2017 to study the integration of satellites as a part of the 5G ecosystem involving both cellular and satellite stakeholders. The substantial value added by satellites as part of the access technology mix for 5G is now becoming clear, especially for mission critical and other applications where ubiquitous coverage is crucial. For example, NTN can broaden service delivery to unserved or underserved areas, by complementing and extending terrestrial networks (Liolis, K., Geurtz, A., Sperber, R. et al. (2018). Use cases and scenarios of 5G integrated satellite‐terrestrial networks for enhanced mobile broadband: the SaT5G approach. International Journal of Satellite Communications and Networking 37: 91–112; Hofmann, M. (2020). Satellite communication in the age of 5G. Journal of ICT Standardization 8(3). https://journals.riverpublishers.com/index.php/JICTS/article/view/4327/3093 ).In this chapter, we will elaborate on the current standardization of NTN in 5G and further detail the architecture and research challenges toward 6G‐NTN.

Agent‐based models (ABMs) are a powerful class of computational models widely used to simulate complex phenomena in many different application areas. However, one of the most critical aspects, poorly investigated in the literature, regards an important step of the model credibility assessment: solution verification. This study overcomes this limitation by proposing a general verification framework for ABMs that aims at evaluating the numerical errors associated with the model. A step‐by‐step procedure, which consists of two main verification studies (deterministic and stochastic model verification), is described in detail and applied to a specific mission critical scenario: the quantification of the numerical approximation error for UISS‐TB, an ABM of the human immune system developed to predict the progression of pulmonary tuberculosis. Results provide indications on the possibility to use the proposed model verification workflow to systematically identify and quantify numerical approximation errors associated with UISS‐TB and, in general, with any other ABMs., A general solution verification framework for agent‐based models (ABMs) has been proposed. The procedure has been applied to a specific mission critical scenario: the quantification of the numerical approximation error for UISS‐TB an ABM of the human immune system. The proposed approach proved to be affective at identifying and quantifying different sources of errors related to deterministic and stochastic aspects of the model.

Summary Reliability and effectiveness are essential features of satellite transceivers for telemetry and telecommand applications. Modem performance has a strong impact on the success of a satellite mission, in particular, during critical scenarios as the early operation phase, the disposal of a satellite at the end of its life, or the deep-space missions. In these specific mission critical scenarios, fast and correct data reception is even more important than high channel capacity. An unknown and fast variable channel condition, which can be caused by uncertain spacecraft attitude and large Doppler shift with respect to the data rate, requires efficient and innovative receiver architecture. This paper introduces a complete digital implementation of a transceiver for TM/TC application in low Earth orbit mission that is perfectly compliant with aforementioned requirements. Particular attention is dedicated to the definition and selection of the most appropriate frequency recovery technique; 2 open-loop techniques that are derived from ML optimal estimator are presented and compared. Additionally, the performance of the proposed receiver is extensively studied and compared with an incoherent technique that is based on the double differential PSK modulation and is known to be suitable for sat-com in critical scenarios.

In this study, we argue that contract design is a predominant strategy to set contractual expectations among supply chain partners to manage risk. We draw upon resource dependence theory and transaction cost economics to suggest that variation in risk management strategies is dependent upon both the complexity of the procured product or service and the extent to which it is mission critical. In this preliminary study of public-sector supply chains, we find evidence based on an analysis of over 240,000 buyer–supplier contracts that when both mission criticality and service complexity are low, suppliers tend to bear most of the disruption risk by agreeing to fixed-price contracts. When mission criticality is high, we find that the federal government is more likely to share risk with suppliers by utilizing incentive contracts. Evidence suggests that cost-reimbursement and incentive contracts are preferred when service complexity is high.

It is increasingly important to implement a conflict-free access control policies for co-allied networks where different organizations are involve for a common goal. Mobile ad hoc networks are widely used for mission critical situations where teams from different organizational networks cooperate to form a single network to implement their respective operations. These teams or quads have different sets of local policies enforced for their own security resulting heterogeneity in access control. Each team wants to preserve its access control policies at a maximum level. Moreover, a set of allied policies govern the cooperation and interaction between the different teams, which may conflict with their local policies. The policy conflicts arise from the transitivity of policy rules, mobility of the nodes, cooperative behaviors, and so on. In addition, the policy rules may be temporal or static. To achieve the successful completion of the mission, it may be required to compromise with the stringency of the enforcement of the conflicting rules for the quads. In this paper, we propose an automated and formal framework to find the optimal conciliation of the policy rules to preserve the mission and thus ensure minimal compromise with the enforcement of policy for each quad. The efficacy of the work lies on optimizing the enforcement of access control policies to achieve the coalition instead of negating the policy. Copyright © 2014 John Wiley & Sons, Ltd.

An effective maintenance and testing program for readers' mission critical systems is key to protecting the investment. Predictive maintenance, preventive maintenance, and reliability‐centered maintenance programs play an important role in the reliability of the electrical distribution systems. Reliability Centered Maintenance analyzes how each component and/or system can functionally fail. The effects of each failure are analyzed and ranked according to their impact on safety, environment, business mission, and cost. Failures that are deemed to have a significant impact are further analyzed to determine the root causes. The fundamental of maintenance engineering and the role of the mission critical facilities engineer continues to evolve and grow in importance with each new technology applied. Acceptance and maintenance testing are pointless unless the test results are objectively evaluated and compared to standards, and to previous test reports that have established benchmarks.

This chapter contains sections titled: Introduction Risk Assessment Capital Costs Versus Operation Costs Critical Environment Workflow and Change Management Testing and Commissioning Documentation and the Human Factor Education and Training Operation and Maintenance Employee Certification Standards and Benchmarking Conclusion Risk Analysis and Improvement

Businesses that are motivated to plug into the Information Age require reliability and flexibility regardless of whether the companies are large Fortune 500 corporations or small companies serving global customers. The facilities manager was responsible for the integrity of the building. Data center reliability ultimately depends on the organization as a whole weighing the dangers of outages against available enhancement measures. Reliability modeling is an essential tool for designing and evaluating mission critical facilities. The facilities engineering department should be run and evaluated just like any other business line; it should show a profit. In order to design a building with the appropriate level of reliability, a company must first assess the cost of downtime and determine its associated risk tolerance. The Leadership in Energy and Environmental Design is an internationally recognized green building certification system developed by the US Green Building Council and should not be overlooked when designing a data center.

The National Aeronautics and Space Administration's (NASA) Deep Space Network (DSN) was established in the late 1950's, to provide specialized and continuous two-way communications with NASA's deep space and planetary missions. Since then, the DSN has become a “world leader in the development of low-noise receivers, tracking, telemetry and command systems, digital signal processing and deep space navigation.”1 The global configuration of the DSN complexes, the collaboration with foreign government agencies, the complex management and reporting structure, combined with the uniqueness and criticality of the mission data being captured by the DSN antennas all contribute significant challenges to the operation of the network. One of a kind, mission critical science data must be preserved and thus a rigorous risk management approach is critical to ensuring mission success. This paper will describe the risk management process that has been developed and implemented for managing risk within the DSN. The research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

In recent times, dealing with deaths associated with cardiovascular diseases (CVD) has been one of the most challenging issues. The usage of mobile phones and portable Electrocardiogram (ECG) acquisition devices can mitigate the risks associated with CVD by providing faster patient diagnosis and patient care. The existing technologies entail delay in patient authentication and diagnosis. However, for the cardiologists minimizing the delay between a possible CVD symptom and patient care is crucial, as this has a proven impact in the longevity of the patient. Therefore, every seconds counts in terms of patient authentication and diagnosis. In this paper, we introduce the concept of Cardioid based patient authentication and diagnosis. According to our experimentations, the authentication time can be reduced from 30.64 s (manual authentication in novice mobile user) to 0.4398 s (automated authentication). Our ECG based patient authentication mechanism is up to 4878 times faster than conventional biometrics like, face recognition. The diagnosis time could be improved from several minutes to less than 0.5 s (cardioid display on a single screen). Therefore, with our presented mission critical alerting mechanism on wireless devices, minute's worth of tasks can be reduced to second's, without compromising the accuracy of authentication and quality of diagnosis. Copyright © 2011 John Wiley & Sons, Ltd.

This paper describes a bottom-up counterinsurgency strategy in Afghanistan known as Village Stability Operations, as well as some of the contributions information sharing strategies are making to its success. In a “population-centric” strategy, it is essential to understand the people and what is important to them in their world, not ours. In this environment, information about the population, also known as “white” data, can be mission critical, although it wasn't treated as such at the beginning of the Afghan campaign. “White” information is not a panacea; it needs to be blended with enemy (“red”) information and government (“green”) information to form an integrated approach. The paper examines several projects that have been undertaken in Afghanistan, their successes and challenges, and how they have helped the Afghan population while supporting coalition objectives.

This chapter contains sections titled: Introduction The History of the Maintenance Supervisor and the Evolution of the Mission Critical Facilities Engineer Internal Building Deficiencies and Analysis Evaluating Your System Choosing a Maintenance Approach Standards and Regulations Affecting How Safe Electrical Maintenance Is Performed Maintenance of Typical Electrical Distribution Equipment Being Proactive in Evaluating the Test Reports Data Center Reliability

This chapter contains sections titled: Introduction Companies' Expectations: Risk Tolerance and Reliability Identifying the Appropriate Redundancy in a Mission Critical Facility Improving Reliability, Maintainability, and Proactive Preventative Maintenance The Mission Critical Facilities Manager and the Importance of the Boardroom Quantifying Reliability and Availability Design Considerations for the Mission Critical Data Center Mission Critical Facility Start-Up The Evolution of Mission Critical Facility Design

The UPS and the static transfer switch (STS) are the alpha and omega of the power system in mission critical sites. The STS is the last line of power quality defense and removes all power problems that occur in the site between the UPS and the STS. The STS contain only three major components, excluding the sheet metal; these are: protective and isolating circuit breakers or molded case switches; logic, especially Triple Modular Redundant to ensure the safety of the loads; and two sets of silicon‐controlled rectifiers configured as single or three‐phase switches. Fault‐tolerant and abnormal operation must be specified and tested on the purchased STS. There are many iterations of transformer configurations and different tradeoffs made when choosing between stand alone, primary systems, and secondary systems. This chapter outlines some of these tradeoffs are and provides a list of tests that should be performed on a sample or production STS.

This chapter contains sections titled: Introduction Risk Assessment Capital Costs Versus Operation Costs Change Management Testing and Commissioning Documentation and Human Factor Education and Training Operation and Maintenance Employee Certification Standard and Benchmarking

This chapter contains sections titled: Introduction Philosophy Alarm and Notification Early Detection Fire Suppression Systems Design Fire Detection Fire Suppression Systems Conclusion

Today many companies decide to select free/open source software (F/OSS) products for various reasons, for example, economical or quality reasons. For many areas of application, they can choose from a variety of packages provided by different communities. Introducing a software tool into a company—either for supporting a certain business process or for the development of its own products—may be more or less critical depending on the application, which may range from explorative to mission critical. One of the most crucial problems in the usage of F/OSS is the actual decision to use a particular product. Although this is rather similar to the usual investment decisions, the consequences of an involvement in a software project are frequently underestimated. Whether a certain package is appropriate for the intended purposes in the given environment and is suitable to the overall business goals of the company is usually not determined systematically, but often arbitrarily. However, many important hints resulting from the development context of an F/OSS product as well as other technical and economical considerations could be helpful to make the product decision process more transparent and deterministic. In this article, we give a systematic approach for supporting a decision to incorporate a particular F/OSS product into an enterprise. Systematic decision support is provided by a rational approach that facilitates evaluating and interpreting the relevant project circumstances of an F/OSS product to be chosen. By this means, F/OSS projects can be critically reviewed in the light of the particular product requirements of the choosing organisation. The article addresses software managers and engineers in industry and academia. Copyright © 2006 John Wiley & Sons, Ltd.

One of the most important attributes of on-line computer systems that are performing mission or business critical applications is availability. System Engineers are often called upon to predict the reliability of such systems as part of proposal preparation, architecture definition, design reviews, and operation. However, traditional modeling techniques are incapable of handling integrated hardware and software systems with multiple states and redundancy. This paper describes how Markov Modeling and Reliability Block Diagrams can be used together to model a large on-line information system and develop the answers to strategic questions on the configuration and operation of high availability computing systems. The analyses are performed using MEADEP, a reliability analysis tool capable of hierarchical modeling and integrating Markov and block diagram techniques. In the example 3-tier architecture e-commerce site described in this paper, it is shown that (a) the most frequently failing subsystem is not necessarily the availability bottleneck, and (b) that restoration time is often a more important parameter than availability when attempting to maximize system throughput.

SUMMARY In a mission critical collaboration system, a group of roles are assigned to computer nodes connected by a communication network. Role assignment is mission-critical information and needs to be protected. In this paper, we develop methods to effectively and efficiently protect the information of role assignment from traffic analysis, a passive attack. To measure the system security, we introduce a metric of detection probability, defined as the probability that a role assignment can be discovered. A heuristic greedy algorithm is given to minimize the resource consumption while guaranteeing a low detection-probability level. Our performance evaluation shows that the algorithm proposed in this paper performs well in terms of execution time and resource usage compared to an exhaustive search algorithm. We also propose to use additional means (e.g. additional nodes) to further increase the security level of a system at the cost of a mild resource consumption increase. Copyright  2002 John Wiley & Sons, Ltd.

Because the failure of complex, mission-critical systems—such as certain process control and manufacturing operations—can be exceptionally costly to an organization, appropriate management control of these systems is imperative. This paper presents a theory of management control of complex systems that is the potential basis for an intelligent DSS, which would be capable of supporting human agents monitoring complex systems. The theory is derived from field studies of agent decision making under procedural guidance, and it focuses on the most crucial—and interesting—aspect of agent behavior, i.e. the decision to deviate from a procedure when the procedure is considered detrimental to the achievement of organizational goals. The theory is instantiated in a computer model of the agents' decision processes. The computer model in turn embeds a simulation of the agents' situation and goal assessment processes that produce procedural non-compliance. © 2000 John Wiley & Sons, Ltd.

Next generation aircraft computer systems require a major advance in system design practice and associated methods of analysis compared to even the most modern aircraft systems now in service. As well as the ongoing need to demonstrate predictable, real-time behaviour for a wide range of safety critical and mission critical applications, a significant improvement in flexibility is required in order to support cost-effective design-time and in-service modifications to the system. The system design and analysis problem is further complicated by a trend towards increasing functional and physical integration. In this paper, we address the temporal aspects of the problem and propose a design/analysis approach based on resource reservation. This supports top-down development by incorporating only appropriate timing information at each stage of development and defering the use of implementation details until absolutely necessary. At each stage of refinement, the system model supports localised changes with minimal re-analysis, thus minimising the impact (and associated cost) of such changes.

Public Safety (PS) or Professional Mobile Radio (PMR) communications technologies are undergoing significant transformation towards broadband. The Terrestrial Trunked Radio (TETRA) as one of the earliest critical communication systems has evolved from narrowband data in its first release to the current wideband data Tetra Enhanced Data Service (TEDS). TEDS gives higher data rates with up to several hundred kbit/s and very well fits into the existing PMR frequency landscape. The APCO25 suite of standards in North America had a similar evolution. While still providing essential PMR services like voice, group calls and messaging, the evolution of Public Safety communication must include data-rich broadband services to support a wide range of applications to enhance the operational capability of PMR users. Examples of services and applications include remote healthcare, video-streaming and health monitoring of the first responders. In comparison to mobile applications in the consumer market, PMR applications have severe requirements in terms of signal quality, security, reliability, and coverage. In addition, the usage patterns can be significantly different from the consumer market, as public safety officers must often face unexpected situations (e.g. emergency crisis) and still be able to rely on full traffic capacity and high Quality of Service (QoS) from the networks. The design of future PMR communications must take into consideration these requirements and needs. Significant advances have been achieved in the last years and are still under development focusing on the use of advanced signal processing techniques using flexible mul-ticarrier waveforms in PMR bands to satisfy emerging new data service needs in cohabitation with existing networks in the same frequency bands, to facilitate a smooth migration towards broadband systems and to increase spectrum efficiency. One example is Spectrum sharing, which is expected to bring substantial benefits for a better use of the radio spectrum, helping to mitigate the severe spectrum scarcity problem (mainly in the EU PS band). However, there are several issues that put a question mark on the deployment of PMR systems and their integration with fifth generation (5G) communication technologies and vision. First of all, the integration of PS system in LTE-Advanced (LTE-A) is still not optimized for voice calls (and especially not for the group calls), meaning that it will have to coexist for some time with the PMR conventional networks (e.g. TETRA) for basic voice services. Moreover, LTE-A is still not designed as a mission critical system. High availability and security features are not inherent in all the aspects – so some add-ons to the LTE-A standard or implementation scenarios have to be made, especially in the case of future interoperability and usage of commercial 5G networks for PS scenarios. In addition, standards for direct communications, like LTE Device to Device (D2D) or ad-hoc networks, must be still validated on the basis of the requirements of security and reliability. With proper implementation of these concepts, PMR users may rely on future 5G systems in the same manner they rely on the current narrowband PMR systems. Meanwhile, the design and integration of parallel or complementary usage of traditional PMR systems for voice communication and next generation PMR users in 5G systems for mission critical broadband data transfer still remain as open challenges. In particular, the research and standardization for internetworking of heterogeneous networks for PMR is still not completed. This special issue aims to investigate all aspects relevant to the development of the PMR communications systems and networks and their future evolvement in the fifth generation (5G) communication environment. We received over this special issue ten submissions altogether; out of which, eight were accepted through a rigorous peer review process. Note that in the following sections, the terms PMR and PS are used with the same meaning. In this context, the work presented in the paper " Analysis of strategies for progressive 5G emergency network deployment " by Vilhar et al. provides an analysis on network deployment strategies. It is evident that the temporary communication systems for emergency situations have traditionally been provided by a single communication technology. They are typically based on the 2G technologies for mobile radio that cannot meet the data rate requirements of contemporary applications. Emergency systems based on the 3GPP LTE technology are presently under investigation, and there is an increasing interest in including new 5G concepts. 5G may enable the employment of multiple heterogeneous communication systems such as fast deployable areal platforms, ad-hoc portable terrestrial stations and satellite communications, all of which integrated with the preserved part of the existing wireless infrastructure. Such an integrated approach is studied and evaluated in this work, based on the simultaneous use of the remaining terrestrial systems and additional LAPs (Low Amplitude Platforms). Simulations of the system were performed using the GRASS-RaPlaT tool, augmented

Given the temporary nature of radio communications for mission critical scenarios, the existing dedicated public safety network lacks the flexibility of cutting edge technologies to leverage on packet data services. In this context, new challenges arise such as high-capacity demand and low-latency flexible backhaul connection for public safety users. In this paper, we consider a scenario in which 4G LTE radio coverage is provisioned by aerial eNodeBs installed on low-altitude platforms raised in the sky and interconnected through WiFi links. We focus our attention on the critical aspect of theThird Generation Partnership Project handover mechanism studying the handover performance using a X2 interfaces over WiFi links. We develop a novel geometric model of the handover in the context of public safety communications but extensible also to other contexts. Relying on such a model, the handover failure probability is computed taking into account the different handover phases. The coverage area of an aerial eNodeB is studied using a suitable air-to-ground propagation model, while the average handover duration is computed taking into account the delay introduced by the WiFi communication dynamics.

Uncertainty dominates the thinking regarding the threat to be faced by the surface combatant for the 21st Century. However, there is great certainty that affordability, how ever the term is defined, will be a major factor in decisions regarding how many surface combatants, amphibious ships and support ships will be built. What combat and support system mix they will take to sea will also be affordability constrained. Affordable modernization and reduced life cycle costs will be major ship selection criteria. The Vertical Launch System (VLS) innovation represents a major step in a concept that allows for changes in weapon load mix and weapon evolution essential to meeting new threats and execution of varying missions. Currently no parallel breakthrough has been identified for sensors or combat and C4I systems. This paper presents the argument that system architecture and integration engineering for information technology insertion represent the key to a VLS like breakthrough for these other mission critical systems. The paper also argues that system engineering for this technology insertion also provides major potential for more affordable ships. These benefits obtain in both initial construction costs and in system modernization costs over the life of the ship. An included benefit is the potential to off-load non mission critical personnel through automation of support functions and responsive shore based, on line support through the introduction of relevant information technology.

The U.S. Navy introduced the use of digital computers in mission critical applications over a quarter of a century ago. Today, virtually every system in the current and planned Navy inventory makes extensive use of computer technology. Computers embedded in mission critical Navy systems are integral to our strategic and tactical defense capabilities. Thus, the military power of the U.S. Navy is inextricably tied to the use of programmable digital computers. The computer program is the essential element that embodies the system “intelligence”. In addition, it provides the flexibility to respond to changing threats and requirements. However, this very flexibility and capability poses a host of difficulties hindering full realization of the advantages. This paper describes the lessons learned about computer program development over the past twenty five years and discusses a software engineering process that addresses these lessons. It then describes how Ada and its related Ada Programming Support and Run-Time Environments foster this software engineering process to improve computer program productivity and achieve greater system reliability and adaptibility. Finally, the paper discusses how the use of Ada and its environments can enhance the interoperability and transferability of computer programs among Navy projects and significantly reduce overall life cycle costs for Navy mission critical computer programs.

Reliability control for mission-critical items is studied. The purpose of the control is to ensure the attainment during mission time of a required performance level which is based on suitably defined measures. This is achieved by replacing the item during normal operation time as soon as the reliability requirement is violated. We first consider the case of a known life distribution, but the main focus of the work is on the case where the life distribution is not completely specified. A Bayesian approach is taken and a replacement procedure is constructed on the basis of the overall uncertainty we face, namely, the stochastic failure process and our (continuously revised) probabilistic assessment of the underlying life distribution. The resulting replacement policy is investigated and detailed results are obtained for some common life distributions.