This document provides an overview of satellite communications, including how satellites work, different types of satellite orbits like GEO, LEO, and MEO, frequency bands used, and capacity allocation methods like FDMA and TDMA. Satellites act as relay stations, receiving uplinks from earth stations and sending downlinks. Advantages include wide coverage areas, while disadvantages include high launch costs and bandwidth limitations. Different orbits trade off factors like signal strength, coverage area, and visibility duration.
This slide is regarding satellite systems, which come under Communications and network, explains the various satellites and their advantage and disadvantage
This slide is regarding satellite systems, which come under Communications and network, explains the various satellites and their advantage and disadvantage
Foundations of Satellite Communication: Understanding the Basics.pptxpritamlangde
Basics of Satellites:
Satellites are objects that orbit around larger bodies in space. They are primarily used for communication, navigation, Earth observation, weather monitoring, scientific research, and more. Satellites can be categorized based on their orbits, functions, and sizes. They are launched into space using rockets and placed into specific orbits, depending on their intended purpose
1. Geostationary Earth Orbit (GEO) Satellites:
GEO satellites orbit the Earth at an altitude of approximately 35,786 kilometers (22,236 miles) above the equator.
They have an orbital period that matches the Earth's rotation, allowing them to remain stationary relative to a fixed point on the Earth's surface.
GEO satellites are commonly used for communication, broadcasting, and weather monitoring because they provide continuous coverage of a specific region.
2. Low Earth Orbit (LEO) Satellites:
LEO satellites orbit the Earth at altitudes ranging from about 160 kilometers (100 miles) to 2,000 kilometers (1,200 miles) above the Earth's surface.
They complete an orbit around the Earth in a relatively short amount of time, typically ranging from 90 minutes to 2 hours.
LEO satellites are used for various purposes, including Earth observation, remote sensing, satellite imaging, scientific research, and satellite constellations for global communications.
3. Medium Earth Orbit (MEO) Satellites:
MEO satellites orbit the Earth at altitudes ranging from about 2,000 kilometers (1,200 miles) to 35,786 kilometers (22,236 miles) above the Earth's surface.
They have orbital periods longer than LEO satellites but shorter than GEO satellites.
MEO satellites are often used for navigation systems, such as the Global Navigation Satellite Systems (GNSS) like GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), and Galileo.
4. Molniya Orbit Satellites:
Molniya orbit is a specific type of highly elliptical orbit with a high inclination angle.
Satellites in Molniya orbits have a long dwell time over high latitudes, making them suitable for communication and observation services in polar regions.
These satellites are used for applications like communication in northern latitudes, remote sensing, and reconnaissance.
5. High Altitude Platform Stations (HAPs):
HAPs are not traditional satellites but rather platforms stationed at high altitudes in the Earth's atmosphere, typically in the stratosphere.
They are used to provide communication and surveillance services over a specific area.
HAPs can be equipped with telecommunications equipment, antennas, and other technologies to relay signals between ground stations or act as relays for satellite communication systems. capacity allocation in satellite communications are Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA).
This is the slide of Satellite Broadcasting commonly useful for Satellite and Broadcasting describing different orbitals of satellite, frequency allocation, its use for broadcasting, Components of Broadcasting and many more. Feel free to comment but do add source if you are using it as a reference.
This is the presentation slide of Satellite Broadcasting. It contains the topic covering satellite and its broadcasting. Its beneficial for the students and lecturers for this topic. This covers the topics as:
Satellite
Broadcasting
Satellite broadcasting
Typical components of satellite broadcasting
Satellite Orbits
Different earth orbits
Frequency bands
Capacity Allocation
FDMA
TDMA
Advantages
Disadvantages
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
3. Basics: How do Satellites Work
Two Stations on Earth want to communicate through
radio broadcast but are too far away to use
conventional means.
The two stations can use a satellite as a relay station
for their communication
One Earth Station sends a transmission to the
satellite. This is called a Uplink.
The satellite Transponder converts the signal and
sends it down to the second earth station. This is
called a Downlink.
4. Basics: Advantages of Satellites
The advantages of satellite communication
over terrestrial communication are:
The coverage area of a satellite greatly exceeds
that of a terrestrial system.
Transmission cost of a satellite is independent of
the distance from the center of the coverage area.
Satellite to Satellite communication is very
precise.
Higher Bandwidths are available for use.
5. Basics: Disadvantages of
Satellites
The disadvantages of satellite
communication:
Launching satellites into orbit is costly.
Satellite bandwidth is gradually becoming used
up.
There is a larger propagation delay in satellite
communication than in terrestrial communication.
6. Basics: Factors in satellite
communication
Elevation Angle: The angle of the horizontal of the
earth surface to the center line of the satellite
transmission beam.
This effects the satellites coverage area. Ideally, you want
a elevation angle of 0 degrees, so the transmission beam
reaches the horizon visible to the satellite in all directions.
However, because of environmental factors like objects
blocking the transmission, atmospheric attenuation, and the
earth electrical background noise, there is a minimum
elevation angle of earth stations.
7. Basics: Factors in satellite
communication (cont.)
Coverage Angle: A measure of the portion of
the earth surface visible to a satellite taking
the minimum elevation angle into account.
R/(R+h) = sin(π/2 - β - θ)/sin(θ + π/2)
= cos(β + θ)/cos(θ)
R = 6370 km (earth’s radius)
h = satellite orbit height
β = coverage angle
θ = minimum elevation angle
8. Basics: Factors in satellite
communication (cont.)
Other impairments to satellite communication:
The distance between an earth station and a satellite (free
space loss).
Satellite Footprint: The satellite transmission’s strength is
strongest in the center of the transmission, and decreases
farther from the center as free space loss increases.
Atmospheric Attenuation caused by air and water can
impair the transmission. It is particularly bad during rain
and fog.
9. Basics: How Satellites are used
Service Types
Fixed Service Satellites (FSS)
• Example: Point to Point
Communication
Broadcast ServiceTelevision/Radio
• Example: Satellite Satellites (BSS)
• Also called Direct Broadcast Service
(DBS).
• Example: Satellite Phones
Mobile Service Satellites (MSS)
10. Types of Satellites
Satellite Orbits
GEO
LEO
MEO
Molniya Orbit
HAPs
Frequency Bands
11. Geostationary Earth Orbit (GEO)
These satellites are in orbit 35,863 km above
the earth’s surface along the equator.
Objects in Geostationary orbit revolve around
the earth at the same speed as the earth
rotates. This means GEO satellites remain in
the same position relative to the surface of
earth.
12. GEO (cont.)
Advantages
A GEO satellite’s distance from earth gives it a
large coverage area, almost a fourth of the earth’s
surface.
GEO satellites have a 24 hour view of a particular
area.
These factors make it ideal for satellite broadcast
and other multipoint applications.
13. GEO (cont.)
Disadvantages
A GEO satellite’s distance also cause it to have
both a comparatively weak signal and a time
delay in the signal, which is bad for point to point
communication.
GEO satellites, centered above the equator, have
difficulty broadcasting signals to near polar
regions
14. Low Earth Orbit (LEO)
LEO satellites are much closer to the earth
than GEO satellites, ranging from 500 to
1,500 km above the surface.
LEO satellites don’t stay in fixed position
relative to the surface, and are only visible
for 15 to 20 minutes each pass.
A network of LEO satellites is necessary for
LEO satellites to be useful
15. LEO (cont.)
Advantages
A LEO satellite’s proximity to earth compared to a
GEO satellite gives it a better signal strength and
less of a time delay, which makes it better for
point to point communication.
A LEO satellite’s smaller area of coverage is less
of a waste of bandwidth.
16. LEO (cont.)
Disadvantages
A network of LEO satellites is needed, which can
be costly
LEO satellites have to compensate for Doppler
shifts cause by their relative movement.
Atmospheric drag effects LEO satellites, causing
gradual orbital deterioration.
17. Medium Earth Orbit (MEO)
A MEO satellite is in orbit somewhere between 8,000
km and 18,000 km above the earth’s surface.
MEO satellites are similar to LEO satellites in
functionality.
MEO satellites are visible for much longer periods of
time than LEO satellites, usually between 2 to 8
hours.
MEO satellites have a larger coverage area than
LEO satellites.
18. MEO (cont.)
Advantage
A MEO satellite’s longer duration of visibility and
wider footprint means fewer satellites are needed
in a MEO network than a LEO network.
Disadvantage
A MEO satellite’s distance gives it a longer time
delay and weaker signal than a LEO satellite,
though not as bad as a GEO satellite.
19. Other Orbits
Molniya Orbit Satellites
Used by Russia for decades.
Molniya Orbit is an elliptical orbit. The satellite
remains in a nearly fixed position relative to earth
for eight hours.
A series of three Molniya satellites can act like a
GEO satellite.
Useful in near polar regions.
20. Other Orbits (cont.)
High Altitude Platform (HAP)
One of the newest ideas in satellite
communication.
A blimp or plane around 20 km above the earth’s
surface is used as a satellite.
HAPs would have very small coverage area, but
would have a comparatively strong signal.
Cheaper to put in position, but would require a lot
of them in a network.
21. Frequency Bands
Different kinds of satellites use different frequency
bands.
L-Band: 1 to 2 GHz, used by MSS
S-Band: 2 to 4 GHz, used by MSS, NASA, deep space research
C-Band: 4 to 8 GHz, used by FSS
X-Band: 8 to 12.5 GHz, used by FSS and in terrestrial imaging, ex:
military and meteorological satellites
Ku-Band: 12.5 to 18 GHz: used by FSS and BSS (DBS)
K-Band: 18 to 26.5 GHz: used by FSS and BSS
Ka-Band: 26.5 to 40 GHz: used by FSS
23. FDMA
Satellite frequency is already broken into
bands, and is broken in to smaller channels
in Frequency Division Multiple Access
(FDMA).
Overall bandwidth within a frequency band is
increased due to frequency reuse (a
frequency is used by two carriers with
orthogonal polarization).
24. FDMA (cont.)
The number of sub-channels is limited by
three factors:
Thermal noise (too weak a signal will be effected
by background noise).
Intermodulation noise (too strong a signal will
cause noise).
Crosstalk (cause by excessive frequency
reusing).
25. FDMA (cont.)
FDMA can be performed in two ways:
Fixed-assignment multiple access (FAMA):
The sub-channel assignments are of a fixed
allotment. Ideal for broadcast satellite
communication.
Demand-assignment multiple access (DAMA):
The sub-channel allotment changes based on
demand. Ideal for point to point communication.
26. TDMA
TDMA (Time Division Multiple Access)
breaks a transmission into multiple time slots,
each one dedicated to a different transmitter.
TDMA is increasingly becoming more
widespread in satellite communication.
TDMA uses the same techniques (FAMA and
DAMA) as FDMA does.
27. TDMA (cont.)
Advantages of TDMA over FDMA.
Digital equipment used in time division
multiplexing is increasingly becoming cheaper.
There are advantages in digital transmission
techniques. Ex: error correction.
Lack of intermodulation noise means increased
efficiency.