Model Features

Under the Physical Layer, two types of links are modeled in the Satellite communication system.

  1. Abstract Link

  2. Satellite Link

Satellite PHY: Data Rate

Given below is the data rate calculation methodology for both forward and return links. The parameter values used are the default values in NetSim GUI.

\[Symbol\ Rate = \frac{BW}{\left( 1 + (Roll\ of\ factor) \right)}\]
\[Bit\ Rate = Symbol\ rate \times Modulation\ order \times CodeRate\]
\[Bandwidth\ (Hz) = Frame\_ Bandwidth\ (Hz) = 10^{6}\ Hz\]
\[Central\ Frequency\ (Hz) = Base\ Frequency\ (Hz) + \frac{Bandwidth\ (Hz)}{2.0}\]
\[Central\ Frequency\ (Hz) = 26 \times 10^{9} + \ \frac{10^{6}}{2} = 2.60005\mathbf{\times}10^{10}Hz\]
\[Effective\ Bandwidth\ (Hz) = \frac{\ Carrier\ Bandwidth\ (Hz)}{(RollOfFactor + 1.0) \times (SpacingFactor + 1.0)}\]
\[Effective\ Bandwidth\ (Hz) = \frac{10^{6}}{(1.0 + 1.0) \times (1.0 + 1.0)} = 25 \times 10^{4}\ Hz\]
\[Symbol\ Rate = Effective\ Bandwidth\ (Hz) = 25 \times 10^{4}Hz\]
\[Modulation\ Bits = 2\]

The number of Modulation Bits depends on the modulation scheme per the table below:

Modulation

Modulation bits

QPSK

2

8PSK

3

16APSK/16QAM

4

32APSK

5

Table-3: Modulation bits for different modulation

\[Slots = Slot\ Count\ in\ Frame + Pilot\ Header\ (slots) = 360 + 1 = 361\]
\[Data\ Symbols = Slots \times Symbol\ per\ Slot = 361 \times 90 = 32490\]
\[Pilot\ Slot = \frac{Slots}{Pilot\ Block\ Interval} = \frac{361}{16} = 22\]
\[Pilot\ Symbol = Pilot\ Slot \times Pilot\ block\ Size\ (symbols) = 22 \times 36 = 792\ Symbols\]
\[Total\ Symbol = Pilot\ Symbol + Data\ Symbols = 792 + 32490 = 33282\]
\[Frame\ length = \frac{Total\ Symbol}{Symbol\ Rate} \times 1000000 = \frac{33282}{250000} \times 1000000 = 133128\ \mu s\]
\[Pilot\ Block\ Length = \frac{Pilot\ block\ Size\ }{Symbol\ Rate} \times 1000000 = \frac{36}{250000} \times 1000000 = 144\ \mu s\]
\[Slot\ Length = \frac{Symbol\ per\ Slot}{Symbol\ Rate} \times 1000000 = \frac{90}{250000} \times 1000000 = 360\ \mu s\]
\[SuperFrame\ Duration = Frame\ length \times Frames\ per\ SuperFrame = 133128 \times 10 = 1331280\ \mu s\]
\[Bits\ per\ Slot = Symbol\ per\ slot\ \times Modulation\ Bits \times Coding\ Rate = 90 \times 2 \times \frac{1}{2} = 90\]
\[Bits\ per\ Frame = Bits\ per\ Slot \times \ Slot\ Count\ in\ Frame = 90 \times 360 = 32400\]
\[Data\ Rate = \frac{Bits\ per\ Slot}{Slot\ Length} = \frac{90\ bits}{360\ \mu s} = 0.25 \times 10^{6}\ bits/sec = 0.25\ Mbps\]

Analytical throughput estimation

Let us an example in which the Packet Size (App layer) is 1460B which translates to 1488B at the PHY layer after addition of overheads, with QPSK modulation and \(\frac{1}{2}\) coding rate. For this modulation and coding rate the raw PhyRate of the channel is 162249 bps using the formulas given in 3.4. The analytical throughput estimate for such a scenario would be:

\[PacketTransmissionTime = \frac{PacketSize(at\ PHY) \times 8}{PhyRate(bps)} = \frac{1488 \times 8}{162249} = 0.0733687s = 73368.7\mu s\]
\[PacketsPerFrame = \lfloor\frac{FrameTime}{PacketTransmissionTime}\rfloor = \lfloor\frac{133128}{73368.7}\rfloor = \lfloor 1.81\rfloor = 1\]

\(PacketsPerFrame\) is the number of packets that can be packed in a frame, and hence the greatest integer or floor function is used.

\[BytesPerFrame = PacketsPerFrame \times PacketSize(B) = 1488 \times 1 = 1488\]
\[NumberOfFramesPerSecond = \frac{1}{Frame\ Duration(s)} = \frac{1}{0.133128} = 7.51\]
\[PhyThroughput = NumberOfFramesPerSecond \times (BytesPerFrame \times 8) = 7.51 \times (1488 \times 8) = 89399.04\ bps = 0.089\ Mbps\]
\[ApplicationThroughput = \frac{1460}{1488} \times PhyThroughput = 0.087\ Mbps\]

PHY rate for various modulations and coding rates

Modulation

Modulation bits

Slot Count in a frame

Coding Rate

PHY Rate (Mbps)

QPSK

2

360

1/3

0.167

1/2

0.250

1/4

0.125

2/5

0.200

3/5

0.300

2/3

0.333

3/4

0.375

4/5

0.400

5/6

0.417

8/9

0.444

9/10

0.450

8PSK

3

240

3/5

0.450

2/3

0.500

3/4

0.561

5/6

0.625

8/9

0.667

9/10

0.675

16APSK

4

180

2/3

0.667

3/4

0.750

4/5

0.800

5/6

0.833

8/9

0.889

9/10

0.900

16QAM

4

180

3/4

0.750

5/6

0.833

32APSK

5

144

3/4

0.936

4/5

1.000

5/6

1.042

8/9

1.111

9/10

1.125

Table-4: List of support modulation schemes and coding rates, and their respective PHY Rates

Satellite PHY: Land Satellite Channel Model

Propagation

The distance between the ground nodes and the satellite determines the propagation delay and path loss of the radio signal. The distance is computed based on the cartesian distance between the ground nodes and the satellite. NetSim computes the propagation delay of the radio signal traveling from the source node to the destination node at the speed of light. The propagation model calculates the weakening of the radio signal as it propagates from the source node per the pathloss and fading model.

Earth fixed spot beams and cells

NetSim provides three methods for configuring satellite beams:

Standard setup:

The Standard Setup option allows users to quickly configure satellite beams using predefined parameters without manually entering beam coordinates or importing external files. NetSim automatically calculates the beam geometry, radius, and coverage area based on the selected inputs.

  • Number of spot beams.

  • NetSim can presently support configurations of 1, 7, or 19 spot beams.

  • The 7-cell setup consists of a central hexagonal cell surrounded by 6 adjacent cells.

  • The 19-cell configuration has two layers of surrounding cells around a central hexagonal cell

  • NetSim will automatically compute the tessellated beams (cells) based on number of spot beams.

User-defined beam configuration:

This option allows users to upload an Excel/CSV file containing beam parameters such as beam count, Frequency reuse, Satellite altitude(km), HPBW(theta), Aperture radius(m), Band ,Beam centers, Antenna model and Beam radius(km) details instead of relying on automatic or standard setup.

_images/Figure-41.png

Figure-4: User-defined beam configuration.

Manual Placement:

The Manual Placement option allows complete user control over beam locations, coverage regions, and satellite altitude. Unlike the Standard Setup or CSV Upload options, no beam parameters are auto generated. This mode is intended for advanced users who want full flexibility in defining exact beam geometry.

Pathloss Model – Friis Free Space Propagation

The free space propagation model is used to predict received signal strength when the transmitter and receiver have a clear, unobstructed line-of-sight path between them. Satellite communication systems and microwave line-of-sight radio links typically undergo free space propagation. The mathematical expression for free-space path loss is given by the Friis Free-Space Equation:

\[\ PL_{FS} = \ 20\log_{10}{\left( \frac{4\pi d}{\lambda} \right)\ }\]

Where \(\lambda = \frac{c}{f},\)

\(d\) is the slant height meters,

\(\lambda\ \)is the wavelength in meters.

Fading model

NetSim uses a 3 state (state 1, state 2 and state 3) Markov model to simulate fading.

The conditional probabilities of state \(s_{n + 1}\) given the state \(s_{n}\)are described by state transition probabilities \(p_{ij}\)

Where \(S_{1}\), \(S_{2}\), \(S_{3}\) denotes respective channel state, \(P_{ij}\) is the probability the Markov process goes from state i to state j.

_images/Figure-51.png

Figure-5: Switching of three-state Markov process

The switching among each state is described by a transition matrix P, which is

\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ p_{11}\ \ \ \ p_{12}\ \ \ \ p_{13}\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ P = \ \ \ \ \ \ \ \ \ {\ p}_{21}\ \ \ \ \ p_{22}\ \ \ \ p_{23}\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ p_{31}\ \ \ \ p_{32}\ \ \ \ p_{33}\]

Each state of the three-states of the Markov model obeys the Loo distribution with different parameters, while the state transition is modeled as a first-order Markov random process.

The Loo distribution considers the received signal as a sum of two signal components. A log-normally distributed direct signal expresses the slow fading component corresponding to varying shadowing conditions of the direct signal. A Rice distribution characterizes the fast-fading component due to multipath effects.

The Loo parameter triplet consists of the mean, the standard deviation for the log-normally distributed direct signal, and the average multipath power.

\[N\left( \mu,\ \sigma^{2} \right) + R\]

Depending on the current state interval and on the environment of the terminal, a new random Loo parameter triplet is generated. The output of the channel model is a time-series of the received signal in form of a complex envelope.

And finally, the model computes the Loo distributed time-series including Doppler shaping for every new state interval, which is the output of the proposed LMS channel model.

_images/Figure-61.png

Figure-6: The Satellite LMS channel Model

Satellite Antenna Pattern

TR 38.811 Antenna model

The normalized antenna gain pattern, corresponding to a typical reflector antenna with a circular aperture, is considered

\[\ \ \ \ \ \ \ \ \ \ \ \ \ 1\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ for\ \theta = 0\]
\[\ \ \ \ \ \ \ \ \ \ \ \ \ 4\left| \frac{J_{1}(kasin\theta)}{kasin\theta} \right|^{2}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ for\ 0 < \ |\theta| \leq 90{^\circ}\]

where J1(x) is the Bessel function of the first kind and first order with argument x, a is the radius of the antenna's circular aperture, \(k\ = \frac{2\pi f}{c}\) is the wave number, f is the frequency of operation, c is the speed of light in a vacuum and \(\theta\) is the angle measured from the bore sight of the antenna's main beam. Note that ka equals the number of wavelengths on the circumference of the aperture and is independent of the operating frequency. The above expression provides the gain in linear scale and it needs to be converted to dB scale. The normalized gain pattern for \(a\ = \ 10\frac{c}{f}\) (aperture radius of 10 wavelengths) is shown below

_images/Figure-71.png

Figure-7:Antenna gain pattern for aperture radius 10 wavelengths, a = 10 c/f

ITU-R S.672 Antenna model

To model the off-axis behavior of satellite antennas, the ITU-R S.672 recommendation specifies that, for single-feed circular or elliptical beam spacecraft antennas operating in the fixed-satellite service (FSS), the following radiation pattern should be used as the design objective outside the coverage area.

\[G(\psi)\ = \ Gm\ - \ 3\ \left( \frac{\psi}{\psi b} \right)^{\alpha}dBi\ \ \ \ \ \ \ \ for\ \ \ \ \psi_{b}\ \leq \ \psi\ \leq \ a\ \psi b\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (1)\]
\[\ \ G(\psi) = \ Gm\ + \ LN\ + \ 20\log z\ dBi\ \ \ \ \ \ \ \ for\ \ \ \ a\ \psi b\ < \ \psi\ \leq \ 0.5b\ \psi_{b}\ \ \ \ \ \ \ \ \ \ \ (2a)\]
\[G(\psi) = \ Gm\ + \ LN\ \ dBi\ \ \ \ \ \ \ \ for\ \ \ \ \ \ \ \ \ \ \ \ 0.5b\ \psi_{b} < \ \psi\ \leq \ b\ \psi_{b}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (2b)\]
\[G(\psi)\ = \ X\ - \ 25\ log\ \psi\ \ dBi\ \ \ \ \ \ \ \ for\ \ \ \ b\ \psi_{b} < \ \psi\ \leq \ Y\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (3)\]
\[G(\psi)\ = \ LF\ \ dBi\ \ \ \ \ \ \ \ for\ \ \ \ Y\ < \ \psi\ \leq \ 90{^\circ}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (4a)\]
\[G(\psi)\ = \ LB\ dBi\ \ \ \ \ \ \ \ for\ \ \ \ 90{^\circ}\ < \ \psi\ \leq \ 180{^\circ}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ (4b)\]

Where:

\[X\ = \ Gm\ + \ LN\ + \ 25\ log\ \left( b\ \psi_{b} \right)\ \ \ \ \ \ \ and\ \ \ \ \ Y\ = \ b\ \psi_{b}\ 100.04(Gm\ + \ LN\ - \ LF)\]

  • \(G(\psi):\) gain at the angle ψ from the main beam direction (dBi)

  • \(Gm:\) maximum gain in the main lobe (dBi)

  • \(\psi_{b}\): one-half the 3 dB beamwidth in the plane of interest (3 dB below Gm) (degrees)

  • \(LN\): near-in-side-lobe level in dB relative to the peak gain required by the system design

  • \(LF\ = \ 0\ dBi\ :\) far side-lobe level (dBi)

  • z: (major axis/minor axis) for the radiated beam

  • \(LB:\ 15\ + \ LN\ + \ 0.25\ Gm\ + \ 5\ log\ z\) \(dBi\) or 0 \(dBi\) whichever is higher

_images/Figure-81.png

Figure-8: LN selection to get a, b and α.

The numeric values of a, b, and α for \(LN\ = \ - 20\ dB\) and \(- 25\ dB\ \)side-lobe levels are given in above table.

Off Boresight Angle Calculation

Conceptually, the off-boresight angle, \(\theta\), in the antenna gain formula is defined as the angle between two vectors: one along the boresight of the beam (i.e., from the satellite to the beam centre, which corresponds to the sub-satellite nadir point), and the other from the satellite to the UE. In NetSim \(\theta\ \)is computed as the arccosine of the normalized dot product of these two vectors.

Standard ENU-Based Look Angle Computation (Satellite to Earth)

This section describes the standard ENU (East–North–Up) method for computing satellite look angles (azimuth and elevation) as seen from an earth station (user terminal).

Notation

\(\varphi_{t}\) : Latitude of earth station (degrees)

\(\lambda_{t}\) : Longitude of earth station (degrees)

\(H_{t}\) : Altitude of earth station above sea level (km)

\(\varphi_{s}\) : Latitude of satellite (degrees)

\(\lambda_{s}\) : Longitude of satellite (degrees)

\(H_{s}\) : Altitude of satellite above sea level (km)

Step 1: Convert Geodetic Coordinates to ECEF

Convert both earth station and satellite geodetic coordinates to Earth-Centered Earth-Fixed (ECEF) Cartesian coordinates.

  1. WGS-84 ellipsoid constants

WGS-84 defines the Earth as an oblate ellipsoid with:

  • Semi-major axis (equatorial radius):

\[a\ = \ 6378137.0\ m\]

  • Flattening:

\[f\ = \ \frac{1}{298.257223563}\]

  • First eccentricity squared:

\[e^{2} = 2f - f^{2}\]

Numerically:

\[e^{2}\ \approx \ 0.00669437999014\]

  1. Prime vertical radius of curvature

\[ \begin{align}\begin{aligned}N(\phi)\ = \ \frac{a}{\sqrt{1\ - \ e^{2}\sin^{2}(\phi)}}\\This is to compensate for Earth’s flattening.\end{aligned}\end{align} \]

  1. ECEF Conversion formulas (WGS-84)

\[X\ = \ (N\ + \ h)\cos\phi\cos\lambda\]
\[Y\ = \ (N\ + \ h)\cos\phi\sin\lambda\]
\[Z\ = \ N\left( (1\ - \ e^{2})\ + \ h \right)\sin\phi\]

This gives Earth-Centered Earth-Fixed (ECEF) coordinates:

  • X axis: intersection of equator and Greenwich meridian

  • Y axis: \(90{^\circ}\) east on equator

  • Z axis: North pole

Step 2: Line-of-Sight Vector in ECEF

Compute the line-of-sight (LOS) vector from the earth station to the satellite:

\[\Delta r\ = \ r_{s}\ - \ r_{t}\ = \ (\Delta X,\ \Delta Y,\ \Delta Z)\]

Step 3: Rotate LOS Vector into Local ENU Frame

Define the standard ECEF-to-ENU rotation matrix at the earth station latitude \(\varphi_{t}\ \)and longitude \(\lambda_{t}\):

\[\begin{split}\begin{bmatrix} E \\ N \\ U \end{bmatrix}\ = \ \begin{bmatrix} - \sin\lambda_{t} & \cos\lambda_{t} & 0 \\ - \sin\phi_{t}\ \cos\lambda_{t} & - \sin\phi_{t}\ \sin\lambda_{t} & \cos\phi_{t} \\ \cos\phi_{t}\ \cos\lambda_{t} & \cos\phi_{t}\ \sin\lambda_{t}\ & \sin\phi_{t} \end{bmatrix}\begin{bmatrix} \Delta X \\ \Delta Y \\ \Delta Z \end{bmatrix}\end{split}\]

This yields the local ENU components (E, N, U) of the satellite relative to the earth station.

Step 4: Slant Range

The straight-line distance between the earth station and the satellite is:

\[D_{ts} = \ \sqrt{E^{2} + \ N^{2} + \ U^{2}}\]

Step 5: Elevation Angle

The elevation angle (above the local horizontal plane) is computed as:

\[el\ = \ atan2\left( U,\ \sqrt{E^{2} + \ N^{2}} \right)\]

Elevation is in the range −90° to +90°.

Step 6: Azimuth Angle

The azimuth angle, measured clockwise from true North, is:

\[az\ = \ atan2(E,\ N)\]

The result should be wrapped to the range 0°– 360°.

Step 7: Visibility Check

Given a minimum elevation mask angle (maskAngle):

\[visible\ = \ 1\ if\ \ el\ \geq \ maskAngle\]
\[visible\ = \ 0\ otherwise\]

If \(\sqrt{E^{2} + \ N^{2}}\ \approx \ 0\ \)(satellite directly overhead), the azimuth is indeterminate.

Frequency Reuse

NetSim supports FR1 (\(N_{reuse} = 1),\ \)FR2 (\(N_{reuse} = 2)\ \ \),FR3 (\(N_{reuse} = 3)\) and FR4 (\(N_{reuse} = 4)\) configurations.

With NetSim GUI, users can configure the number of beams (1, 7, and 19) and select the frequency reuse factor (FRF) accordingly. When \(N_{reuse} > 1\), NetSim assigns virtual “channel IDs” to the beams. The available resources and bandwidth are then equally divided among the channels. The bandwidth per channel is calculated per the following expression

\[BW_{channel} = \ \frac{{BW}_{Total}\ }{N_{channels}}\]

Interference models

Exact Geometric Interference

Geometric interference arises when multiple beams sharing the same channel ID overlap, leading to co-channel interference at user terminals. The level of interference is influenced by the number of beams and the configured frequency reuse factor. In FR1, interference occurs from all available beams, whereas in FR2, FR3 and FR4 it is limited to beams using the same channel ID.

CIR-based Interference

Per TR 38.821 section 6.1.3.1 the Carrier-to-noise-and-interference ratio (CNIR) of transmission link between satellite and UE can be derived by carrier-to-noise ratio (CNR) and carrier-to-interference ratio (CIR) as follows

\[CNIR\ \lbrack dB\rbrack = - 10\log_{10}\left( 10^{- 0.1CNR\ \lbrack dB\rbrack} + 10^{- 0.1CIR\ \lbrack dB\rbrack} \right)\]

Carrier-to-Interference Ratio(CIR) is the user input and

CNR(dB) is computed from the link budget, based on EIRP, G/T, path loss and the antenna gain.

Interference power calculations for CIR based Interference

\[Interference\ \lbrack mW\rbrack = Noise\lbrack mW\rbrack\ \times \left( \frac{CNR\ \lbrack mW\rbrack\ }{CNIR\ \lbrack mW\rbrack} - 1 \right)\]
\[Interference\ \lbrack dB\rbrack = 10 \times \log_{10}\left( Interference\ \lbrack mW\rbrack \right)\]

Results

Please refer NetSim User manual section 8 for Results and Analysis.

Satellite Log

NetSim Satellite Log file records UT Satellite association, calculated superframe, frame, slot, bandwidth, etc., This log can be enabled/disabled by going to Plots option and checking/unchecking the Satellite Log option under the Network Logs section as shown below:

_images/Figure-91.png

Figure-9: Enabling Satellite Log file.

A log file specific to satellite communication, is generated post simulation as shown in screen shot below,

_images/Figure-101.png

Figure-10: Result Window

On opening, the satellite log file would look like the image below.

_images/Figure-111.png

Figure-11: NetSim Satellite communication log file

This file logs details such as

  • UT – Satellite Gateway association

  • Calculated Super frame, frame, slot, bandwidth, carrier count etc. for each satellite.

  • Frame by frame transmissions with time stamps

Satellite Radio Measurements Log

NetSim Satellite Radio Measurements Log file records Time (ms), Transmitter name, Receiver name, Slant height(km), EIRP (dBW), Elevation Angle(\({^\circ}\)), RXG_T, Pathloss(dB),Fading loss(dB), Additional loss(dB), Total loss(dB), Angular gain( dB), Rx power (dBm), SNR (dB), Thermal noise(dBm), Channel Id, Beam Id, MCS Index and Coding rate. This log can be enabled/disabled by going to Logs option and checking/unchecking the Satellite Radio Measurements Log option under the Network Logs section as shown below:

_images/Figure-121.png

Figure-12: Enabling Satellite Radio Measurements Log file.

The Satellite Radio Measurements.csv file will contain the following information:

  • Time in Milliseconds

  • Transmitter Name

  • Receiver Name

  • Slant height (km)

  • EIRP (dBW)

  • Elevation Angle (°)

  • RXG_T

  • Pathloss(dB)

  • Fading loss(dB)

  • Additional loss(dB)

  • Total loss(dB)

  • Angular gain( dB)

  • Rx power (dBm)

  • SNR (dB)

  • Interference(dBm)

  • Thermal noise(dBm)

  • Channel Id

  • Beam Id

  • MCS Index and

  • Coding rate

Satellite Radio Measurements log files will be available under the Logs in the results window as shown below:

_images/Figure-131.png

Figure-13: Result Window

Users can see Tx Power, Rx power, pathloss, fading-loss, Total loss, Thermal noise, and SNR values in the Log files for each forward and return link.

_images/Figure-141.png

Figure-14: Satellite Radio Measurements log file

Satellite Beam Association Log

The NetSim Satellite Beam Association Log file is useful for observing the values recorded for each beam, including Time (ms), TX Name, RX Name, EIRP (dBW), Beam Id, Channel Id, Theta(\({^\circ}),\) Angular Gain, RXG_T(dB),FSPL(dB),Total loss(dB), SNR(dB), Interference(dBm), Interfering Beam Count, MCS Index, and Coding rate. This log can be enabled/disabled by going to Logs option and checking/unchecking the Satellite Beam Association Log option under the Network Logs section as shown below:

_images/Figure-151.png

Figure-15: Results window

Users can see Angular Gain, Interference and SNR values in the Log files for each forward and return link. These parameters are logged separately for each beam.

_images/Figure-16.png

Figure-16: Satellite Beam Association log file

Omitted Features

  • Regenerative transponder where the signal is demodulated, decoded, re-encoded and modulated aboard the satellite.

  • Impact of Rain/Weather on signal propagation

  • Forward Error Coding in Layer 2

  • IPv6 Addressing

  • No support for LEO, MEO