Browse Topic: Telecommunications systems
Kraus Hamdani Aerospace, Emeryville, CA
It has been nearly five years since the International Telecommunication Union (ITU) released ITU-R M.2083-0, with a roadmap to release IMT-2020 to address the anticipated future of 5G performance that would greatly eclipse that of IMT-Advanced and then-planned 4G technology.
It has been nearly five years since the International Telecommunication Union (ITU) released ITU-R M.2083-0, with a roadmap to release IMT-2020 to address the anticipated future of 5G performance that would greatly eclipse that of IMT-Advanced and then-planned 4G technology. In 2017, the 3rd Generation Partnership Project (3GPP) rushed to release a preliminary version of their 5G standard (Release 15) so telecommunications companies would begin developing hardware and deploying 5G infrastructure according to their guidelines. The result was the new radio (NR) standard for 5G that includes a non-stand-alone (NSA) millimeter-wave spectrum capability and additional sub-6 GHz cellular bands. Release 15 has provided enhanced mobile broad-band (eMBB) specifications, with future updates to Release 16 and a Release 17 to provide more definition of massive machine-type communications (mMMC) and ultrareliable low-latency communications (URLLC).
As the military has moved toward network-centric operations, unmanned aerial vehicles (UAVs) have become increasingly valuable for capturing realtime information for joint operations on the ground. Several attributes inherent in electronic systems architecture, however, contribute to issues in using these systems today. Enhancing the capabilities of electronic systems requires reinforcing the command and control cycle and supporting the frontline mission.
General Atomics Aeronautical Systems, Inc. Poway, CA 858-312-2810
Delta Digital Video Horsham, PA (215) 657-5270
This eLoran transmitted signal standard provides technical descriptions of the data channel using ninth pulse modulation techniques. The eLoran transmitted signal standard, to which this data channel technique applies, is part of the SAE9990 family of standards covering data channels, receiver specifications, and recommended practices for eLoran.
This eLoran transmitted signal standard provides technical descriptions of a data channel based on the tri-state pulse position modulation technique. The eLoran transmitted signal standard, to which this data channel technique applies, is part of the SAE9990 family of standards covering data channels, receiver specifications, and recommended practices for eLoran.
ABSTRACT This paper describes an approach to aid the many military unmanned ground vehicles which are still teleoperated using a wireless Operator Control Unit (OCU). Our approach provides reliable control over long-distance, highly-latent, low-bandwidth communication links. The innovation in our approach allows refinement of the vehicle’s planned trajectory at any point in time along the path. Our approach uses hand-gestures to provide intuitive fast path editing options, avoiding traditional keyboard/mouse inputs which can be cumbersome for this application. Our local reactive planner is used for vehicle safeguarding. Using this approach, we have performed successful teleoperation nearly 1500 miles away over a cellular-based communications channel. We also discuss results from our user-tests which have evaluated our innovative controller approach with more traditional teleoperation over highly-latent communication links.
One of the biggest challenges connected cars pose is the integration of information and consumer electronics into the car and ensuring connectivity among them. Connected-car technology has become a key differentiator for car makers and their Tier 1 suppliers. One of the biggest challenges connected cars pose is the integration of information and consumer electronics into the car and ensuring connectivity among them. Connected-car applications such as telematics, driver assistance, and infotainment require seamless connectivity to and from the vehicle. Modern cars are built with embedded computers called ECUs (electronic control units) that are further connected to sensors for data acquisition. The in-vehicle network is further divided into sub-networks such as CAN (controller area network), MOST (media-oriented safety transport), and FlexRay. The choice of the bus network depends on the communication requirements of the connected ECUs and the baseline vehicle platform out of which a new vehicle line is derived.
As demand for computing and communication capacity surges, the global communication infrastructure struggles to keep pace. The problem is that light signals transmitted through fiber-optic lines must still be processed electronically, creating a bottleneck in telecommunications networks.
The TDM-to-packet network transformation has been underway in transport/ telecommunications networks for some years now, fueled primarily by two trends: (a) the advent of triple-play (voice, video, data) for enterprise and residential customers and, lately, the explosion in video and mobile data services, and (b) the evolution in both packet- and transport-network equipment.
Communications and, more recently telecommunications, are needs deeply engrained in human history. These needs have significantly evolved over time enabling today’s content-rich (text, music, images and video, etc), real-time and multi-location exchanges through electrical, optical or, more broadly, electromagnetic signals conveyed by different media. Among the more versatile is optical fiber.
Multi-Mission Telecom Analysis Tool (MMTAT) is a C-language computer program for analyzing proposed spacecraft telecommunication systems. MMTAT utilizes parameterized input and computational models that can be run on standard desktop computers to perform fast and accurate analyses of telecommunication links. MMTAT is easy to use and can easily be integrated with other software applications and run as part of almost any computational simulation. It is distributed as either a stand-alone application program with a graphical user interface or a linkable library with a well-defined set of application programming interface (API) calls. As a stand-alone program, MMTAT provides both textual and graphical output. The graphs make it possible to understand, quickly and easily, how telecommunication performance varies with variations in input parameters. A delimited text file that can be read by any spreadsheet program is generated at the end of each run. The API in the linkable-library form of MMTAT enables the user to control simulation software and to change parameters during a simulation run. Results can be retrieved either at the end of a run or by use of a function call at any time step.
A report describes a prototype system interface assembly (SIA) that performs the functions of a compact, radiation-hard application-specific integrated circuit (ASIC) to be built subsequently. The SIA ASIC would be installed in a spacecraft, where it would function as a peripheralcomponent interface (PCI) with (a) four scientific instruments that generate highspeed serial data streams and (b) either of two spacecraft telecommunication systems — the Small Deep Space Transponder (SDST) or the Space Transponding Modem (STM). Once configured, the serial uplink and downlink channels would conform to the SDST serial interface protocol or the STM modified serial peripheral interface protocol. In the SDST configuration, the downlink could be further configured for Reed-Solomon coding, for turbo coding, for bypass mode, and/or to enable a pseudo-randomizer. The SIA ASIC would operate in conjunction with a bus controller/remote terminal/monitor ASIC (United Technologies BCRTM or equivalent) to provide the control and status interfaces to the telecommunication systems and/or other systems that conform to MIL-STD-1553 devices. The ASIC would control, and would serve as an interface to, memory circuitry configurable by the user as external first-in/first-out buffers for each of the telecommunication and instrument interfaces.
A computer program facilitates the analysis and design of a radio-communication system for transmitting data from an orbiting spacecraft to ground stations. Input data provided by the user include primarily (1) parameters of the spacecraft orbit (including parameters that specify its position and orientation with respect to a coordinate system that translates with, but does not rotate with, the Earth); (2) either a specification of the gain pattern or else parameters needed to calculate the gain pattern of the antenna aboard the spacecraft; (3) type of spacecraft antenna aiming (nadir-pointed or articulated); (4) locations of the ground stations; (5) downlink bit rates and frequencies; (6) spacecraft instrument data rates; and (7) the angle (relative to the horizon) below which the line of sight from the spacecraft to each ground station is deemed to be blocked. The program calculates the spacecraft trajectory, the times when the spacecraft is visible from each ground station, the times (as functions of visibility and the antenna gain pattern) when radio communication is possible, the number of bits that a ground station can receive from the spacecraft during a given orbit, and the spacecraft data-storage capacity needed to hold data that are generated between communication intervals.
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