Mission-critical Networks Research Articles

Guest Editorial Special Issue on Internet of Mission-Critical Things (IoMCT)

Internet of Things is coming to critical missions such as battlefield, border patrol, search and rescue, critical structure monitoring and surveillance, etc. Internet of Things (IoT) in Critical Missions or Internet of Mission-Critical Things (IoMCT) is propelled by the convergence of sensing, communication, computing, and control. To support IoMCT, the mission-critical networks will need to be flexible and interactive, and still work despite limited bandwidth, intermittent connectivity and with a large number of devices on the network. The focus of IoMCT is to improve surveillance utilizing a network, not fusion of disparate sensor products. Such adaptation, management, and re-organization of information sources, devices, and networks must be accomplished almost entirely autonomously, in order to avoid imposing additional burdens on the humans, and without much reliance on support and maintenance services.

Optimizing the Number of Transmitters and Receivers Per Node for an IoMCT Unmanned Wireless Networking System

To fulfill the needs of Internet of mission critical things wireless networking system, it is necessary that a large number of unmanned aerial vehicles (UAVs) and a large number of unmanned ground vehicles (UGVs) will be a dependable, autonomic, secure, and rapidly deployable network. In our system model, each UGVs and UAVs has only one mobile node, where any of the mobile nodes can communicate with each other directly without any central controller. Each mobile node is connected with a large number of “things.” A mobile node may transmit a large number of messages from its large number of things to a large number of mobile nodes at the same time. Similarly, one mobile node can receive a large number of packets from a large number of mobile nodes. Intuitively, each mobile node should have a large number of transmitters and a large number of receivers, to maintain a very high throughput (inverse of rejection probability) per mobile node. Obviously, a large number of transmitters and a large number of receivers increase the complexity and the cost of each mobile node. Results show that it is not essential that each mobile node should have a higher number of transmitters and receiver to obtain a very higher throughput per node. There are few other options to maintain a very high throughput per node, including the transmitting probability of each mobile node and receiving probability of each mobile node. That may reduce the complexity and cost of each mobile node significantly.

Mobility assisted localization for mission critical Wireless Sensor Network applications using hybrid area exploration approach

Sensor node location information is critical in many Wireless Sensor Network (WSN) applications with random sensor node deployment. In such applications, node localization using a faster area exploration mechanism is needed to initiate precise sensing and communication. In this paper, faster area exploration approach for mobility-assisted localization scheme is proposed for mission-critical WSN applications. Each Mobile Anchor (MA) node embedded with a localization module moves in the sensor field in a coordinated manner while localizing the deployed static nodes. The proposed area exploration scheme is implemented using a hybrid of max-gain approach and cost-utility based frontier (HMF) approach. The paper addresses the issue of sparse anchor node condition during the localization process. The simulation results obtained using Cooja simulator shows that the proposed mobility-assisted localization scheme results in accurate localization with minimum delay. The proof-of-concept of the proposed scheme is demonstrated using Berkeley static nodes and custom designed MA nodes.

A secure wireless mission critical networking system for unmanned aerial vehicle communications

A privacy-preserving secure communication in ad hoc (without infrastructure) mission critical wireless networking system suitable for unmanned aerial vehicle communication systems is introduced and analyzed. It is expected that in a critical condition, few ad hoc (without infrastructure) mission critical wireless networking systems will work together. To make the simple and low cost privacy-preserving secure communication among the same network, each transmitting mobile node generates packets in such a way that its wanted receiving mobile nodes can read the message packets easily. On the other hand, the unwanted receiving mobile nodes from other networks cannot read those message packets. In addition, the unwanted receiving mobile nodes receive ‘jamming packets’ if they try to read them. This mechanism prevents the malicious receivers (readers from other networks) from reading the packets and obtaining information from this network. Results show that the throughput is very high and does not detect any jamming packets, if the receiving nodes of a network try to read packets transmitted by the nodes from the same networks.

Evaluation of Forwarding Efficiency in NFV-Nodes Toward Predictable Service Chain Performance

The concept of network functions virtualization (NFV) has been embodied in commercial networks over the past years. Software-based virtual network functions have forwarding performance concerns in general, and various acceleration technologies have been developed so far, such as DPDK and vhost-user. Existence of several alternatives requires network engineers or operators to select appropriate technologies; however, no pragmatic criterion exists for constructing high-performance NFV-nodes. From their points of view, a lack of common benchmark and understanding of performance characteristics makes it difficult to predict hop-by-hop performance in a service chain, which results in prevention of NFV deployment in mission-critical networks. In this paper, we clarify performance characteristics of packet forwarding in NFV nodes focusing on three types of acceleration technologies; packet I/O architecture, virtual network I/O, and forwarding engine in a practical stage. We examined three packet I/O architectures (NAPI, netmap, and DPDK), three virtual I/O mechanisms (vhost-net, vhost-user, and SR-IOV), and four practical forwarding programs (Open vSwitch, OVS-DPDK, xDPd-DPDK, and Lagopus) with three referential programs (Linux Bridge, VALE, and L2FWD-DPDK). The experiment was conducted on a 40 GbE environment and we examined two device-under-test machines having different CPU performance. We argue performance characteristics of each technology and give quantitative analyses of the result. The key findings are: 1) CPU core speed has impact on both throughput and latency/jitter; 2) DPDK can allow performance prediction; 3) vhost-user is appropriate for real environment; and 4) OVS-DPDK provides a good combination of performance and functionality.

Programmable control plane for mission critical wireless networks

The control plane is an essential element to manage the data plane communications in wired and wireless networks. In a traditional network architecture, the control plane is embedded in the hardware and it lacks programmability. Military wireless networks are historically heterogeneous in nature and require complicated manual setups to create interoperability because of a discontinuous control plane. In the present work, we describe a simple programmable control plane model along with associated network abstractions to create a unified control plane interface that can communicate across heterogeneous wireless networks. We chose an ns-3 based network simulation engine to create, test, and validate the functional fidelity of our models. In addition to the network objects and interfaces available in ns-3, we modified ns-3 codes to capture the characteristics of our proposed model. Furthermore, we proposed a tractable mathematical framework to optimize the performance of the proposed control plane model.

Fault Recovery in Time-Synchronized Mission Critical ZigBee-Based Wireless Sensor Networks

Reliability and precise timestamping of events that occur are two of the most important requirements for mission critical wireless sensor networks. Accurate timestamping is obtained by synchronizing the nodes to each other while reliability can be obtained by eliminating single points of failure (SPF). In this paper, we address the SPF problem of a ZigBee-based wireless sensor network by means of using multiple coordinators with different personal area network identifiers (PAN IDs). We propose a solution where members of a network switch from one coordinator to another in case of failure by changing their respective PAN ID. We verify experimentally that our solution provides gains in terms of recovery speed and, therefore, synchronization accuracy with respect to a solution proposed in the literature.

Distributed REM-Assisted Radio Resource Management in LTE-A Networks

The successful actions of public-safety personnel during disaster recovery depend heavily on rapidly deployable and reliable mission-critical communication networks. As part of the Aerial Base Stat...

Guest Editorial

Guest Editorial

Determining Geographic Vulnerabilities Using a Novel Impact Based Resilience Metric

Various natural and man-made disasters as well as major political events (like riots) have increased the importance of understanding geographic failures and how correlated failures impact networks. Since mission critical networks are overlaid as virtual networks over a physical network infrastructure forming multilayer networks, there is an increasing need for methods to analyze multilayer networks for geographic vulnerabilities. In this paper, we present a novel impact-based resilience metric. Our new metric uses ideas borrowed from performability to combine network impact with state probability to calculate a new metric called Network Impact Resilience. The idea is that the highest impact to the mission of a network should drive its resilience metric. Furthermore, we present a state space analysis method that analyzes multilayer networks for geographic vulnerabilities. To demonstrate the methods, the inability to provision a given number of upper layer services is used as the criteria for network failure. Mapping techniques for multilayer network states are presented. Simplifying geographic state mapping techniques to reduce enumeration costs are also presented and tested. Finally, these techniques are tested on networks of varying sizes.

QRM: A queue rate management for fairness and TCP flooding protection in mission-critical networks

When statistical multiplexing is used to provide connectivity to a number of client hosts through a high-delay link, the original TCP as well as TCP variants designed to improve performance on those links often provide poor performance and sub-optimal QoS properties. Centralised and collaborative resource management tools like C2MLhave been proposed to guarantee intra-protocol fairness, inter-protocol friendliness, low queues utilisation and optimal throughput along with the reliable delivery of packets. However, such tools offer only very limited security guarantees. Both good citizenship and security from flooding attacks are fundamental conditions for the provision of fairness, especially in mission-critical networks. For example, perpetrators of a man-provoked disaster may want to perform a resource exhaustion attack on the network supporting disaster recovery operations, so as to cut out legitimate users from the communications and increase the emergency impact. In this paper we present Queue Rate Management (QRM), an Active Queue Management scheme able to provide protection from traffic overflow attacks in scenarios where access to the shared link is controlled by a tool that assigns to client hosts a bandwidth upper bound. The proposed algorithm checks whether a node is exceeding its allowed rate, and consequently decides whether to keep or drop packets coming from that host. We mathematically prove that with QRMthe gateway queue size can never exceed the Bandwidth-Delay Product of the channel. Furthermore, we employ the ns-3 network simulator to compare QRMwith CoDel, RED and GREEN, showing how QRMprovides better performance in terms of both throughput and QoS guarantees in the aforementioned scenarios.

Applying High Availability Design and Parallel Redundancy Protocol (PRP) in Safety Critical Wide Area Networks

Networks which protect the safety of human lives place special emphasis on network availability and survivability. The nation’s Air Traffic Control (ATC) and First Responder public safety networks used by police departments, fire and rescue, and emergency medical teams are examples of networks that require high availability and survivability. The term mission critical network is often used to describe the characteristics of networks which protect the safety of human lives. There is not a universally accepted standard definition of the term, but much literature on the subject typically identifies three salient characteristics: • Highly Secure • Highly Available • Highly Survivable Highly secure is an important characteristic and needed to design a safety critical network, but the focus of this paper is availability and survivability. It should be noted that mission critical safety networks are private networks and should not be confused with the public Internet simply because they use IP. A private network in itself does not constitute a mission critical network, but it is a significant characteristic of a mission critical network due to the security and performance benefits it supports. The security benefit is risk mitigation from external threats because only authorized internal users can access the network. The performance benefit is similar in that only authorized users have access to the network and their network usage does not have to compete for bandwidth with other external users. Availability and Survivability are related, but they are not the same thing. Availability is simply a measure of the time the network is operating compared to the total time it should be operating. Availability is defined as Uptime divided by Uptime plus Downtime. This same reference defines Survivability as the capability of a system (or network in this case) to perform its mission recognizing that failures are going to occur. As will be explained later in this paper, survivability considers catastrophic events that cannot be easily predicted in an inherent availability model. Specifically, this paper focuses on the availability and survivability of the Wide Area Network (WAN) terrestrial core backbone component of safety critical networks. Much literature on public safety networks for First Responders is devoted to the wireless radio networks including Land Mobile Radio (LMR), P.25 packet radio, cellular telephony and evolution towards broadband 4G Long Term Evolution (LTE) wireless networks. Air Traffic Control networks rely on other wireless forms of communication including narrow-band Air-to- Ground (aircraft to ground based controller) voice and data links in the Very High Frequency (VHF) spectrum. All of these wireless forms of communication rely on a terrestrial core backbone for backhauling and distributing information to the right place. The terrestrial core backbone is a foundational building block for other safety critical network components. This paper also describes some of the differences between legacy Time Division Multiplexing (TDM) technology and modern Internet Protocol (IP) packet switched technology. Historically, networks such as the nation’s Air Traffic Control (ATC) network have relied on point-to-point TDM technology.

Real-Time QoS-Aware Vehicle Tracking: An Experimental and Comparative Study

Abstract Recently, web service became popular for Real-time Communication (RTC). It allows bi-directional, real-time communication between web clients and server. On the other hand, Data Distribution Service (DDS) middleware offers unified integration with high-performance due to its scalability, flexibility, real-time, mission-critical networks and rich QoS features. DDS is based on the publish/subscribe communication model. It improves RTC through its efficient and high-performance data delivery mechanism. This paper studies and investigates that how DDS is better for RTC. Experimental studies are conducted to compare text messaging using socket IO over DDS Web API. The result concerns the throughput satisfaction rate, round trip time and packet loss. In addition, we consider some of QoS of DDS during experimental work e.g. deadline, time based filter etc.

Design and implementation of a hospital wide waveform capture system.

The use of telemetry and invasive monitoring is exceptionally common in modern healthcare. To date the vast majority of this information is not stored for more than a brief duration on the local monitor. This prohibits extensive investigation into waveform data. We describe a system to collect such data in a quaternary care facility. Using standardized "packet sniffing" technology along with routine manual documentation, we reverse engineered the Unity network protocol used to transmit waveform data across the University of Michigan mission critical monitor network. Data was subsequently captured using a proprietary piece of software writing waveform data to local disks. Nightly, this data is post-processed using data from the admit-discharge-transfer system into individual patient waveforms for the day regardless of location. Over a 10 month period, over 2,785 individual patients had a total of 65,112 waveforms captured 15,978 from the operating rooms and 49,134 from the ICUs. The average OR case collected over 11 MB of data. The average single day data collection consisted of 8.6 GB of data. Entire hospital waveform data collection is possible using internally developed software enabling research on waveform data with minimal technical burden. Further research is required to determine the long-term storage and processing of such data.

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Real-Time QoS-Aware Video Streaming: A Comparative and Experimental Study

Due to its flexibility, scalability, real-time, and rich QoS features, Data Distribution Service (DDS) middleware provides seamless integration with high-performance, real-time, and mission-critical networks. Unlike traditional client-server communication models, DDS is based on the publish/subscribe communication model. DDS improves video streaming quality through its efficient and high-performance data delivery mechanism. This paper studies and investigates how DDS is suitable for streaming real-time full-motion video over a communication network. Experimental studies are conducted to compare video streaming using a the VLC player with the DDS overlay. Our results depict the superiority of DDS in provisioning quality video streams at the cost of low network bandwidth. The results also show that DDS is more scalable and flexible and is a promised technology for video distribution over IP networks where it uses much less bandwidth while maintaining high quality video stream delivery.

Distributed node placement algorithm utilizing controllable mobility in mobile ad hoc networks

In this paper, we study a node placement problem in mobile ad hoc networks with controllable mobility. Especially, we consider mission-critical networks in which nodes have their own specific mission whose degree of satisfaction depends on their locations. In addition to accomplish their mission, nodes want to maintain a good communication quality with their neighbor nodes that also depends on their locations. In general, the best location of a node for its mission is not coincident with that for its communication quality, and thus it is important to control the mobility of a node to find its appropriate location jointly considering both its mission and communication quality. Hence, in this paper, we study a joint mission and communication aware node placement problem. We formulate the problem as a potential game and develop a distributed algorithm that converges to the Nash equilibrium. In addition, we also show that if some minor conditions are satisfied, our algorithm provides a global optimal solution that minimizes the weighted sum of costs for mission and communication.

Topology design for on-demand dual-path routing in wireless networks

One way to achieve reliability with low-latency is through multi-path routing and transport protocols that build redundant delivery channels (or data paths) to reduce end-to-end packet losses and retransmissions. However, the applicability and effectiveness of such protocols are limited by the topological constraints of the underlying communication infrastructure. Multiple data delivery paths can only be constructed over networks that are capable of supporting multiple paths. In mission-critical wireless networks, the underlying network topology is directly affected by the terrain, location and environmental interferences, however the settings of the wireless radios at each node can be properly configured to compensate for these effects for multi-path support. In this work we investigate optimization models for topology designs that enable end-to-end dual-path support on a distributed wireless sensor network. We consider the case of a fixed sensor network with isotropic antennas, where the control variable for topology management is the transmission power on network nodes. For optimization modeling, the network metrics of relevance are coverage, robustness and power utilization. The optimization models proposed in this work eliminate some of the typical assumptions made in the pertinent network design literature that are too strong in this application context.

SAFE: A Scalable Autonomous Fault-Tolerant Ethernet Scheme for Large-Scale Star Networks

In this paper, we present a new fault-tolerant, large-scale star network scheme called Scalable Autonomous Fault-tolerant Ethernet (SAFE). The primary goal of a SAFE scheme is to provide network scalability and autonomous fault detection and recovery. SAFE divides a large-scale, mission-critical network, such as the naval combatant network, into several subnets by limiting the number of nodes in each subnet. This network can be easily configured as a star network in order to meet fault recovery time requirements. For SAFE, we developed a novel mechanism for inter-subnet fault detection and recovery; a conventional Ethernet-based heartbeat mechanism is used in each subnet. Theoretical and experimental performance analyses of SAFE in terms of fail-over time were conducted under various network failure scenarios. The results validate our scheme.

Operations support systems for mission critical public safety communication networks

Mission critical communication networks for public safety have very specific operating requirements. The main objective is to maximize system availability and reliability in cases of disaster or large-scale unplanned events. Based on its experience in communications network operations and the unique requirements of public safety communications, Alcatel-Lucent has developed a new solution concept to support public safety communication network operations. The solution focuses on the different user roles and work processes of a public safety network operator. Supported by intelligent fault handling, evolving correlation rules, enhanced help system, end-to-end work process integration, extended test functionalities, real time status and performance views, and other key functionalities, the solution increases usability and applicability for operations organizations. Open interfaces allow future extensions. The basic principles for the technical implementation are the use of commercial off-the-shelf (COTS) software applications in combination with reference to frameworks such as the enhanced Telecom Operations Map (eTOM) and Information Technology Infrastructure Library (ITIL). Successful reference projects have shown that operations organizations can increase their effectiveness by increasing the amount of information they have available. This, in turn, leads to cost savings and better network performance.