Joint Tactical Information Distribution System Research Articles

Ultra reliability and massive connectivity provision in integrated internet of military things (IoMT) based on tactical datalink

One of the major challenges arising in internet of military things (IoMT) is accommodating massive connectivity while providing guaranteed quality of service (QoS) in terms of ultra-high reliability. In this regard, this paper presents a class of code-domain nonorthogonal multiple accesses (NOMAs) for uplink ultra reliable networking of massive IoMT based on tactical datalink such as Link-16 and joint tactical information distribution system (JTIDS). In the considered scenario, a satellite equipped with Nr antennas servers K devices including vehicles, drones, ships, sensors, handset radios, etc. Nonorthogonal coded modulation, a special form of multiple input multiple output (MIMO)-NOMA is proposed. The discussion starts with evaluating the output signal to interference-plus-noise (SINR) of receiver filter, leading to the unveiling of a closed-form expression for overloading systems as the number of users is significantly larger than the number of devices admitted such that massive connectivity is rendered. The expression allows for the development of simple yet successful interference suppression based on power allocation and phase shaping techniques that maximizes the sum rate since it is equivalent to fixed-point programming as can be proved. The proposed design is exemplified by nonlinear modulation schemes such as minimum shift keying (MSK) and Gaussian MSK (GMSK), two pivotal modulation formats in IoMT standards such as Link-16 and JITDS. Numerical results show that near capacity performance is offered. Fortunately, the performance is obtained using simple forward error corrections (FECs) of higher coding rate than existing schemes do, while the transmit power is reduced by 6 dB. The proposed design finds wide applications not only in IoMT but also in deep space communications, where ultra reliability and massive connectivity is a keen concern.

TDMA Datalink Cooperative Navigation Algorithm Based on INS/JTIDS/BA

Position information is very important tactical information in large-scale joint military operations. Positioning with datalink time of arrival (TOA) measurements is a primary choice when a global navigation satellite system (GNSS) is not available, datalink members are randomly distributed, only estimates with measurements between navigation sources and positioning users may lead to a unsatisfactory accuracy, and positioning geometry of altitude is poor. A time division multiple address (TDMA) datalink cooperative navigation algorithm based on INS/JTIDS/BA is presented in this paper. The proposed algorithm is used to revise the errors of the inertial navigation system (INS), clock bias is calibrated via round-trip timing (RTT), and altitude is located with height filter. The TDMA datalink cooperative navigation algorithm estimate errors are stated with general navigation measurements, cooperative navigation measurements, and predicted states. Weighted horizontal geometric dilution of precision (WHDOP) of the proposed algorithm and the effect of the cooperative measurements on positioning accuracy is analyzed in theory. We simulate a joint tactical information distribution system (JTIDS) network with multiple members to evaluate the performance of the proposed algorithm. The simulation results show that compared to an extended Kalman filter (EKF) that processes TOA measurements sequentially and a TDMA datalink navigation algorithm without cooperative measurements, the TDMA datalink cooperative navigation algorithm performs better.

Multi-Slots Joint MLE Relative Navigation Algorithm Based on INS/JTIDS/BA for Datalink Network

High accuracy relative navigation (RELNAV) information is crucial for datalink network members in the situation of joint operations, especially the situations that some datalink network members may not be able to obtain their location with absolute navigation. In this paper, relative navigation algorithm based on JTIDS/INS/BA is proposed, in this system datalink joint units(JUs) are positioned in two-dimensional plane with multi-slots joint maximum likelihood estimation (MLE), and altitude is located by a height filter independently, which overcome the problem of poor positioning geometry of altitude. Multi-slots joint MLE convert TOA measurements in different slots to one moment with short-time inertial navigation system(INS) information, which lead to a higher localization accuracy in two-dimensional plane. We simulate a joint tactical information distribution system (JTIDS) network with multiple members, to verify the performance and analyze the influence factors of the proposed algorithm. The simulation results show that compared to EKF that process TOA measurements sequentially in each navigation slot and MLE without multi-slots joint processing, the multi-slots joint MLE relative navigation algorithm based on INS/JTIDS/BA performs better in two-dimensional plane location, and the height filter based on barometric altimeter (BA) improves the relative height positioning accuracy greatly.

The Capacity Analysis of the Orthogonal Frequency Hopping Stacked Nets in the Data Link

The Link-16 can support stacked nets mode for the Joint Tactical Information Distribution System (JTIDS) uses orthogonal frequency hopping networking. The Link-16 can support 127 stacked nets in theory. The number of stacked nets is restricted to 20 in the United States Navy. There are few studies about the impact of the number of stacked nets to the performance. The number of stacked nets has important aspects to network design and planning of data link. Through analysing the architecture of stacked nets, the mathematical model about frequency conflict between sub-networks is established. Under different slot structure, the influences of average delivery are simulated. The simulation results can support the network programming of data link.

Impact Assessment of the L-Band Digital Aeronautical Communications System on the Joint Tactical Information Distribution System

The L-band digital aeronautical communications system (LDACS) is the future air–ground communications technology currently undergoing the International Civil Aviation Organization standardization process. As LDACS is intended to operate in the frequency band 960–1164 MHz, compatibility tests between LDACS and the legacy systems operating in this frequency band are necessary to ensure that no system is harmfully interfered. One of these systems is the joint tactical information distribution system (JTIDS), a technology employed by the tactical data link Link 16. In this paper, we present the results of an impact assessment of LDACS on JTIDS conducted through simulations. The extent of the impact has been quantified by simulating a wide variety of interference configurations, which are expected to cover most realistic interference conditions between LDACS and JTIDS. Baseband simulation models of both systems have been implemented and an interference scenario between LDACS and JTIDS has been defined. To evaluate the impact, the degradation of the signal-to-noise ratio (SNR) of JTIDS by the presence of LDACS has been determined. Default JTIDS transmissions, where the information is repeated at distant frequencies, do not show a significant degradation by the presence of strong LDACS interference, with an SNR loss lower than 1 dB in any considered interference scenario. Comparatively, a certain dependency on the specific LDACS deployment is noticeable for less protected JTIDS transmissions. Based on the observed interdependencies, recommendations for the deployment of LDACS are given in this paper, such that the impact of LDACS on JTIDS is minimized.

A Method for Analyzing the Impact of Intra-System and Inter-System Interference on DME Based on Queueing Theory.

In order to use Distance Measuring Equipment (DME) properly, the impact of intra-system and inter-system electromagnetic interference must be analyzed firstly. However, the error of interference analysis using present methods based on pulse overlap is large when there are more aircraft. The aim of this article is to study a method of analyzing interference on DME whether the number of aircraft is small or not. According to the flow chart of DME signal, we studied the limitations of present methods; then constructed a model of analyzing the collision between duration of desired signal and dead time of receiver based on M/M/1/0 queueing system. Combing this model with other methods, we present a analytic model of analyzing intra-system and inter-system interference on DME. Using this analytic model, we analyzed reply efficiency (RE) and capacity of DME under intra-system and Joint Tactical Information Distribution System (JTIDS) interference. The result shows that the calculation for the probability of overlap between DME dead time and subsequent signals using queueing model agrees well with simulation. Consequently, the analytic model is more accurate than using a single method to analyze interference on DME.

ANALYSIS AND SIMULATION OF RAYLEIGH FADING CHANNEL IN DIGITAL COMMUNICATION

The objective of this paper is to analyze slow, flat, Rayleigh fading channels in modern digital communication systems having different coherent modulation techniques. Most of the packages can only be used to analyze analog communication systems, but modern systems are, increasingly, digital. Improved many-on-many (IMOM) is a two-dimensional, graphical-oriented, radio frequency modeling tool is used to determine probability of channel bit error rather than information bit error, which allows generic solutions independent of the specifics of the system under investigation as long as the particular modulation type is known. Constellation diagram of various modulation techniques, power of faded signal and signal at receiver are plotted in MATLAB environment. The Joint Tactical Information Distribution System (JTIDS) is suitable example of this analysis.

Parametric message passing-based relative navigation in joint tactical information distribution system

Relative navigation is a key feature in the joint tactical information distribution system (JTIDS). A parametric message passing algorithm based on factor graph is proposed to perform relative navigation in JTIDS. First of all, the joint posterior distribution of all the terminals' positions is represented by factor graph. Because of the nonlinearity between the positions and time-of-arrival (TOA) measurement, messages cannot be obtained in closed forms by directly using the sum-product algorithm on factor graph. To this end, the Euclidean norm is approximated by Taylor expansion. Then, all the messages on the factor graph can be derived in Gaussian forms, which enables the terminals to transmit means and covariances. Finally, the impact of major error sources on the navigation performance are evaluated by Monte Carlo simulations, e.g., range measurement noise, priors of position uncertainty and velocity noise. Results show that the proposed algorithm outperforms the extended Kalman filter and cooperative extended Kalman filter in both static and mobile scenarios of the JTIDS.

Simulation and Analysis of Transmission Performance of JTIDS

As a very important part of Link-16, Joint Tactical Information Distribution System (JTIDS) has a good performance. In this paper, the primary technologies of JTIDS are presented and their Transmission performance are simulated and analyzed. And in the different conditions, the bit error rate simulation is tested based on the rationale of JTIDS. In the end of this paper, anti-jamming ability of JTIDS is simulated and the results show that JTIDS has high performance of anti-jamming.

Performance analysis and simulations of 32‐ary cyclic code‐shift keying

AbstractCyclic code‐shift keying (CCSK) is the baseband 32‐ary symbol modulation scheme used by the Joint Tactical Information Distribution System (JTIDS), the communication terminal for Link‐16. CCSK is not orthogonal and an analytic expression for the probability of symbol error for CCSK has thus far been elusive. In this paper, an analytic upper bound on the probability of symbol error of CCSK is derived for the 32‐chip CCSK starting sequence chosen for JTIDS. The analytically obtained probability of symbol error is compared with two different Monte Carlo simulations for additive white Gaussian noise. The results of both simulations match the analytic results very well and show that the analytic method yields a tight upper bound. A new 32‐chip CCSK starting sequence which has a smaller maximum off‐peak cross‐correlation value than the current JTIDS starting sequence is proposed and evaluated both analytically and by simulation. The results obtained for the new CCSK starting sequence compare favorably with the CCSK starting sequence chosen for JTIDS. Published in 2010 by John Wiley & Sons, Ltd.

Network-centric Warfare and the Globalization of Technology: Transforming simple tools into dangerous weapons

Network-centric Warfare and the Globalization of Technology WAR TECH SPRING WAR TECH Transforming simple tools into dangerous weapons New applications of technology, such as sonar and radios to the Internet, GPS (Global Positioning System) and satellite radar, have increased the ease of communication, revolutionizing the technical aspect of war. However, the globalization of the newest technologies brings new mean- ing to the multifunctional power of these devices, making them no longer exclusive to the government and the mili- tary. The utility of such technology is now in the hands of the global masses which can prove progressive, but also dangerous when applied to warfare. The Changing Nature of Technological Warfare ting the target and minimizing civilian casualties (Muller Far infrared technology applied to binoculars and cameras provide visuals at night, making operations in the absence of light possible. An MQ-1 Predator, an unmanned aerial vehicle (UAV), mounted with far infrared surveil- lance cameras, flies over the city to track the motion of troops and enemy activity in urban areas. The UAV can detect whether an automobile or tank engine is running (or has been recently running) solely from the warmth of the engine. Radar, a system of electromagnetic waves, comple- ments infrared in surveillance. A synthetic aperture radar carried on a Predator can take a radar image of several city blocks with a ground resolution of thirty centimeters. It looks like a sharp photo taken from directly above. Using the new Joint Tactical Information Distribution System, the image is delivered to the ground troops in nearly real time by Ann Oh Efficiency and greater access to technology flat- tened the chain of military command, giving soldiers on the ground greater access to information in order to calculate their next moves. Some believed that the recent advance- ments in technological warfare would make war as “pre- dictable as chess” and bring an easy victory (Muller 2002). Unfortunately, the Iraq War exposed the true “…the advent of the internet hor- danger in technological warfare as terrorists wield every- day technology to their advantage. Furthermore, the izontally streamlined this flow of inability to bring stability to the region shattered the faith information for a more efficient and in technology to accelerate the process of war and to bring a quick end. The distribution of technology caused comprehensive response.” by globalization reduces the exclusive advantage of the military by allowing greater access of information to terrorists, enabling them to create vast international net- (Muller 2002). This helps the military to better assess the works and have influence on a global scale. Paradoxically, situation. In terms of communication, cell phones – smaller technology does not simplify war; instead, it complicates it and more reliable than Morse code and radios – have further. Therefore, “network-centric warfare” back-fired on replaced WWI technology to increase connectivity and the military, preventing rational responses while consuming mobility. itself in analyzing massive amounts of data collected to produce a theoretically ideal, yet impractical response. The Internet as a Revolutionary Tool Common Technology and their Military Uses GPS utilizes a constellation of twenty-four satellites that transmit precise microwave signals and enable a GPS receiver to determine its location , speed, direction, and time. Most of the bombs used by the U.S. military are JDAMS (Joint Direct Attack Munitions). These are missiles with inexpensive guidance systems attached to their backs. JDAMs use GPS satellites to guide them to previously pro- grammed locations. They are effective and accurate in hit- Internet proves to be a critical tool in efficient com- munication and in the transfer of bulk data of various medi- ums, such as images and video. Instant communication allows military personnel to be contacted in a matter of sec- onds, which is critical in obtaining immediate battlefield intelligence. According to Thomas Friedman in The World is Flat, the use of basic tools such as the internet flattens the platform upon which the military networks. The stream- ing video transmitted by the unmanned aerial vehicle is fed instantly to flat-screen TVs in the CIA, the DIA, the NSA,

JTIDS relative navigation and data registration

The Joint Tactical Information Distribution System (JTIDS), an integrated communication, navigation, and identification system, provides a solution to the critical data registration problem facing the joint US military services today, namely, the establishment, in real-time, of accurately correlated positions and tracks for all friendly, unknown, and hostile targets in an operational area, thus providing the total situation awareness required for tactical and C/sup 2/ operations. The fundamental relationships of JTIDS navigation and the error analysis for target registration and target hand-off in both geodetic and relative grid coordinates are presented. Simulation results are provided for two scenarios to demonstrate the level of improvement that JTIDS navigation can have on situation awareness, target acquisition, and weapon delivery. Specifically, it is shown that accurate data registration can be achieved by as few as two JTIDS members, with or without accurate knowledge of geodetic position.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Navigation Aspects of JTIDS

AbstractThe United Kingdom's interest in the Joint Tactical Information Distribution System (JTIDS) and its Relative Navigation (relnav) capability began in 1979 with studies into an Electronic Counter-measures (ECM) Resistant Communications System (ERCS). The Singer Kearfott Division (SKD) Time Division Multiple Access (TDMA) JTIDS system, which includes a relnav and position reporting capability, was selected to fulfill this requirement. Early in 1985, approval was also granted to the Royal Navy to procure an ERCS.Technical studies on JTIDS for airborne applications are being directed by RAE Farnborough and by ARE Portsdown for maritime use. Systems Designers Scientific (SD Scientific) is providing technical support in a number of areas including relnav.This paper, which was presented at an Ordinary Meeting of the Institute held in London on 15 January, gives a very brief overview of JTIDS and describes the principles of relnav before outlining the structured approach to JTIDS relnav evaluation which has been adopted.

JTIDS Relative Navigation with Measurement Sharing: Design and Performance

Alternative approaches for conducting relative navigation (relnav) using the joint tactical information distribution system (JTIDS) communication network are presented. The design and performance of the current JTIDS relnav with estimate sharing are discussed, including its shortcomings. We offer first a conceptually simpler alternate design that provides more accurate relnav between any pair of members, provided they have time to maneuver. A second alternative design includes the features of the first plus measurement sharing by designated primary members. It has even better performance including faster more accurate relnav fixes and relaxed maneuvering requirements. Simulation results are presented showing the superior performance of the new designs. The advantages and disadvantages of relnav with measurement sharing compared with relnav with estimate sharing are summarized.

Data Link Communications in Tactical Air Command and Control Systems

Data links in tactical air command and control systems (ACCS's) connect the computers of command and control units to one another and to weapon systems to enable rapid exchanges of real-time tactical information. This paper, presents an overview description of the current and future ACCS data link architecture used by the Services and NATO. This architecture currently consists of various tactical digital information link (TADIL) standards and NATO link standards. In the near future, the Joint Tactical Information Distribution System (JTIDS) will be a major component of the architecture. While the architecture of the far future is speculative, a description of some concepts being considered, such as the role of the International Standards Organization (ISO) reference model, is presented.

Spread spectrum communications - Book Reviews [Cook, C.E., et al., IEEE Press, NY, 1983

This book is a reprint of papers on spread-spectrum communications that appeared in two recent issues of IEEE Transactions on Communications (May 1982 & Jan 1983). As a result, it is another title in the growing list of books on this topic in the IEEE Selected Reprint Series. Whereas the earlier books contain reprints of papers that proved, over time, to be fundamental to the development of spread-spectrum techniques and therefore appealed to a rather broad market, the reviewer feels that this is not the case with this book. The reviewer wonders why the editors restricted their selection of papers to only those that may be classified as dealing with spread spectrum carrier systems. The book's value as a source of research topics in the field would have been enhanced had at least one invited paper on nonsinusoidal waves been included in the last section. He notes that it is also unfortunate that the book contains no tutorial papers on either the Global Positioning System (GPS) or the Joint Tactical Information Distribution System (JTIDS).

Operational Benefits and Design Approaches for Combining JTIDS and GPS Navigation

This paper describes the Joint Tactical Information Distribution System (JTIDS) Navigation Function and the Global Positioning System (GPS), emphasizing their technical similarities and differences. Based on these, the paper discusses the operational benefits, performance, and design approaches for combining the navigational and time data from these two systems. Both JTIDS and GPS are time synchronous, spread spectrum systems which provide high accuracy navigation data through the use of time-of-arrival measurements and pseudo-ranging techniques. Both are subject to Geometric Dilution of Precision (GDOP) effects, though under different conditions; and both are highly resistent to interference, though to different degrees. JTIDS is more a tactical or local system, while GPS is global in nature. Exchanging data between the two systems, under certain constraints, therefore has the potential of great performance and operational benefits with respect to system availability, under a variety of operational scenarios and interference conditions. These benefits and proposed methods for combining the data from the two systems are described in the paper.

Stability of the Decentralized Estimation in the JTIDS Relative Navigation

The joint tactical information distribution system (JTIDS) includes a relative navigation capability with which each member can estimate its own position by utilizing the broadcast position estimates of other members plus the measured times of arrival of the radio signals. Previous simulation studies of the system have shown that unrestricted ranging between members can produce unstable navigation errors, but a covariance-based hierarchy may be stable. We have succeeded in proving, analytically, the stability of a closely related organization?a fixed-rank hierarchy. For all ownstate organizations we present time-domain equations for computing estimation-error covariance and for analyzing stability. A simple simulation is able to demonstrate the stability issues.

JTIDS AIRBORNE ADAPTIVE ARRAY ANTENNA

ABSTRACTThe Navy is developing an airborne adaptive array antenna for the Joint Tactical Information Distribution System (JTIDS). JTIDS is a Tri‐Service multi‐channel, multi‐function system to provide an advanced communication, navigation, and identification (CNI) capability for a wide variety of uses. JTIDS terminals perform multiple digital voice/data functions and relative navigation as well as the standard TACAN and IFF transponder functions. The system uses a low‐duty cycle, spread‐spectrum waveform and advanced coding techniques to provide secure, jam‐resistant, and low probability of exploitation CNI functions. Among the important factors which determine the ultimate utility of a JTIDS terminal is the performance of the antenna system. Inadequate antenna performance could seriously degrade and possibly even negate the primary platform mission. Recent advances in antenna and data processing techndogiea promise to provide JTIDS with adequate gain and pattern coverage as well as substantial AJ (Anti‐Jam) margin to complement JTIDS signal processing. The desired improvement in AJ protection can be achieved by capitalizing on the spatial filtering properties of adaptive array antennas. This paper presents the “trade‐offs” which must be addressed in the design of an adaptive array antenna for airborne JTIDS terminals and the design philosophy currently in development by the Navy.

The Navy's Use of Digital Radio

Since the early 1960's, the Navy has utilized digital data links in support of their Tactical Communication, Command and Control Systems. Most of these systems continue to be used operationally. They include links 4, 11, and 14. These systems, however, lack the ability of combatting the anticipated electronic warfare threat as well as providing the performance required of a modern digital data system. Two new systems are in development that will improve performance as well as meet future threats. They are Fleet Satellite Communications and the Joint Tactical Information Distribution System. The demand of implementing new systems while retaining backward compatibility has suggested using an integrated architecture for the aircraft's communication system. The Tactical Information Exchange System is a communication's system design utilizing programmable multifunction signal processing components interconnected with a BUS architecture that may be the ultimate solution to the Military aircraft communication design problem.