Avlite AvMesh User manual

V1.0
INSTALLATION & TROUBLESHOOTING GUIDE
AvMeshTM
RF Communications Systems

2
Version No. Description Date Author Reviewed Approved Design
1.0 Manual Launch April 2019 P. Naidu J. Ohle W. Evans M. Sugars

AvMesh® RF Communications Systems
Installation & Service Manual
Latest products and information available at www.avlite.com 3
Table of Contents
1.0 Glossary of Terms.......................................................................................................................5
2.0 Background..................................................................................................................................6
3.0 RF Fundamentals ........................................................................................................................ 7
3.1 Elements of a Radio Frequency communications system........................................................................7
3.2 Modulation and Demodulation.................................................................................................................................. 8
3.3 Intermodulation.................................................................................................................................................................. 8
3.4 Antennas................................................................................................................................................................................ 9
3.4.1 Gain................................................................................................................................................................................10
3.4.2 Direction......................................................................................................................................................................10
3.4.3 Polarization................................................................................................................................................................. 11
3.5 RF Propagation................................................................................................................................................................... 11
3.5.1 Line-of-sight propagation..................................................................................................................................12
3.6 Interference.........................................................................................................................................................................13
3.6.1 Fresnel zones............................................................................................................................................................13
3.6.2 In-band interference............................................................................................................................................15
3.7 Spectrum Analyzers.......................................................................................................................................................16
3.7.1 Types of Spectrum Analyzer...........................................................................................................................16
3.7.2 The Decibel formula............................................................................................................................................. 17
3.7.3 Signal to Noise Ratio (SNR or S/N)...............................................................................................................19
4.0 AvMeshTM Communications System: Theory of Operation...............................................20
4.1 Node Information............................................................................................................................................................. 20
4.2 Network set-up procedure.........................................................................................................................................21
4.3 Network bridging ............................................................................................................................................................24
5.0 Avlite Wireless Remote Controller.........................................................................................27
5.1 Radio Controller Menu................................................................................................................................................... 27
5.1.1 Operation Mode....................................................................................................................................................... 27
5.1.2 Advanced Op Mode.............................................................................................................................................28
5.1.3 Light Group ...............................................................................................................................................................28
5.1.4 Intensity .......................................................................................................................................................................28
5.1.5 Timeout Mode.........................................................................................................................................................28
5.1.6 Timeout Duration...................................................................................................................................................29
5.1.7 Diagnostic...................................................................................................................................................................29
5.2 Controller Menu (Advanced).................................................................................................................................... 30
6.0 Direct Connection...................................................................................................................... 31
6.1 To force a primary node ...............................................................................................................................................31
7.0 Rotary Switches ........................................................................................................................32
7.1 To force a Reserve node...............................................................................................................................................32
8.0 Maintenance/Housekeeping of the AvMeshTM Communications System ......................32
9.0 Troubleshooting ........................................................................................................................33
9.1 Identifying the Problem.................................................................................................................................................33
9.2 Single Fixture Non-functional...................................................................................................................................34
9.3 Whole Runway Non-functional...............................................................................................................................35
9.4 Multiple Fixtures Non-functional.............................................................................................................................36
9.4 Multiple Fixtures Non-functional Continued ....................................................................................................37

4
Table of Figure
Figure 1: Hub and Spoke architecture (left) and Mesh Network (right) .................................. 6
Figure 2: Radio Communications System.................................................................................................7
Figure 3: Wavelength is inversely proportional to frequency.......................................................7
Figure 4: Creation of intermodulation products ................................................................................... 9
Figure 5: Radiation pattern of Isotropic (left) and Dipole (right) antennas ..........................10
Figure 6: Unidirectional (left), Bi-directional (center) and Omnidirectional (right)
antennas......................................................................................................................................................................10
Figure 7: Vertically (left) and Horizontally (right) polarized antennas...................................... 11
Figure 8: The first (red), second (green) and third (blue) Fresnel zones between the
transmitting and receiving antennas ......................................................................................................... 14
Figure 9: The first node to turn on will become a primary node............................................. 21
Figure 10: The nodes are configured as primary if they are not within range of at
least 3 other primary nodes........................................................................................................................... 22
Figure 11: If the node is within range of at least 3 other primary nodes, it will
become a reserve node.................................................................................................................................... 22
Figure 12: If a node is within range of at least 3 other primary and 3 other reserve
nodes, it will remain as a listen only node.............................................................................................. 23
Figure 13: Resulting mesh network .......................................................................................................... 23
Figure 14: Creation of 2 different network IDs, one at each end of the runway ............ 24
Figure 15: The next nodes to turn on will be independent of the nodes at the other
end of the runway................................................................................................................................................ 25
Figure 16: Node 5 will become a primary node in network 4 if node 9 accepts the
bridging....................................................................................................................................................................... 25
Figure 17: Other primary nodes within range of node 5 will also join the new
network....................................................................................................................................................................... 26
Figure 18: All primary nodes will adopt the better network....................................................... 26

AvMesh® RF Communications Systems
Installation & Service Manual
Latest products and information available at www.avlite.com 5
1.0 Glossary of Terms
Attenuation - The negative ratio of the output power to the input power in decibels
(dB). It is the reduction in power of a signal as it propagates through space.
Carrier signal - a pure wave of constant frequency, amplitude and phase.
Centre frequency - The central frequency of a filter or channel, centered between the
upper and lower cutoff frequencies.
Fresnel Zone - A theoretical elliptical region between the transmitting and receiving
antennas. The size of the ellipse is determined by the frequency of operation and the
distance between the transmitter and receiver. If 80% of the first Fresnel Zone is free of
obstacles, the propagation loss is said to be equivalent to free space loss.
Gain - The positive ratio of the output power to the input power in decibels (dB).
Interference - Any external factor (such as physical obstacles, noise or other radio
signals) that degrade or reduce the clarity of the desired radio signal.
Light group - A way to group lights in an area so that they can be controlled in unison.
This allows the airfield to independently control different areas such as multiple run-
ways, taxiways and helipads.
Listen only light - A light that will receive commands and act upon them, but will not
pass the commands on.
Mesh network - A local network architecture in which the nodes connect to as many
nodes as possible and cooperate with one another to transfer data from point to point.
Noise floor - This is the measure of signal created from noise sources and unwanted
signals, with noise defined as a signal other than that being monitored. It may include
atmospheric noise, thermal noise and cosmic noise.
Passband - The range of frequencies that can pass through a filter without attenuation.
Primary Node - A light that is part of the primary AvMeshTM network. This light will
receive commands from a controller, other primary node or a reserve node. This light
will act upon the commands and pass them on to other nodes in the network.
Reference level - The top most line in the spectrum analyzer display.
Reserve node - A light that is part of the reserve AvMeshTM network. This light will
receive commands from a controller, a primary node or another reserve node. This
light will act upon the commands and pass them on to other nodes in the network.
RF Propagation - The behavior in which radio waves travel from one point to another.
Sensitivity - The smallest signal that can be detected by the receiver.
Selectivity - The ability of a receiver to differentiate between signals that are close
together in frequency.
Span - The range between the measured start and stop frequencies.
Spectrum analyzer - An electronic measurement device that helps to determine the
type and frequencies of interfering RF signals.
Transmit Power - The power that is input to the antenna cable, before cable loss and
antenna gain are considered.

6
2.0 Background
The AvMeshTM Communications System is a wireless communication platform which
operates by broadcasting signals from the Avlite wireless remote controller to the lights in
the system via a 2.4GHz encrypted mesh network.
A typical network architecture (e.g. networks used to connect devices such as phones,
computers and routers) uses a ‘hub and spoke’ arrangement in which points on the
network (the spokes) are all connected to a single center device known as the hub. The
hub serves as an access point through which all devices in the network connect to one
another. This architecture is not as flexible as a mesh network.
Instead of connecting to all other devices through a single centralized point, the lights, also
known as nodes, act as centralized points and connect to all other nodes that are nearby
in the mesh network. The nodes send signals to other nodes that are within range and
the signals are passed from node to node until the final destination is reached. This allows
all the lights in the system to be controlled wirelessly, even if the final destination is out of
range of the wireless controller.
Figure 1: Hub and Spoke architecture (left) and Mesh Network (right)
The AvMeshTM Communications System is self-realizing meaning that once deployed, the
airfield lights will undertake a period of network mapping, whereby the system determines
how many lights need to repeat commands and be ‘nodes’ to provide the airfield enough
coverage.
The sections in this manual cover the necessary fundamentals of Radio Frequency
(RF) Communication Systems to provide an understanding of how the AvMeshTM
Communications System operates as well as provide troubleshooting information relating
to the AvMeshTM Communications System.

AvMesh® RF Communications Systems
Installation & Service Manual
Latest products and information available at www.avlite.com 7
3.0 RF Fundamentals
3.1 Elements of a Radio Frequency communications system
A typical radio frequency communication system consists of the following elements:
• Transmitter - Feeds the signal to a transmitting antenna by first encoding the data
into RF waves (signals) with a certain signal strength (known as the power output) to
project the signal to the receiver.
• Receiver - Accepts and decodes the RF signals that come through the receiving
antenna and rejects unwanted ones via the use of a filter.
• Environment - The physical space between the transmitter and receiver over which
the radio waves propagate. The environment through which communication is
occurring can be affected by interference and physical obstructions such as walls,
buildings and vegetation.
• Antennas or other focusing elements - Devices that focus the radio frequency
energy in a particular direction.
Figure 2: Radio Communications System
In radio frequency communication, electromagnetic waves (signals) are created and
radiated from a source (i.e. transmitting antenna at the transmitter) and then travel through
the air at the speed of light after which they are picked up at a particular destination (i.e.
receiving antenna at the receiver). The higher the frequency of an electromagnetic wave
(signal), the shorter the wavelength. Signals with longer wavelengths are typically able
to travel a greater distance and bend around objects better than signals with shorter
wavelengths.
Figure 3: Wavelength is inversely proportional to frequency
Transmitter
Receiver
Transmitter
Receiver
Transmitting
Antenna
Receiving
Antenna
Env ir on me nt
Transmitter
Receiver
Transmitting
Antenna
Receiving
Antenna
Env ir on me nt
Lower frequency-
longer wavelength
Lower frequency-
longer wavelength
Higher frequency-
shorter wavelength
Higher frequency-
shorter wavelength
Higher frequency-
shorter wavelength Lower frequency-
longer wavelength
Lower frequency-
longer wavelength
Higher frequency-
shorter wavelength
Higher frequency-
shorter wavelength
Higher frequency-
shorter wavelength

8
3.2 Modulation and Demodulation
Modulation occurs in the transmitter, where the input signal (also known as the modulating
signal) is intentionally ‘mixed’ with a sinusoidal carrier wave (a wave of constant frequency,
amplitude and phase). Through this process, one of the three parameters (i.e. amplitude,
frequency or phase) of the carrier wave is modified by the input signal according to a
predefined method known as the modulation technique. This encodes the carrier wave
with the required information from the input signal before the carrier wave is transmitted
to the receiver. The information contained in the input signal is able to travel over a much
larger distance when encoded into the carrier wave.
After the modulated carrier wave is received and amplified by the receiver, the transmitted
information is extracted from the carrier wave through a process known as demodulation.
The type of demodulation used to remove the carrier wave depends on the technique
used during modulation. It is important to note that the receiver must be able to identify
the received modulated carrier signal from other signals which may be using the same
channel.
For a two-signal input into a modulator (or non-linear mixer or amplifier), an input signal
of frequency f1 is mixed with a carrier signal (or other competing signal) of frequency
f2. These signals will be present at the output along with additional signals called
intermodulation products which are at the sum and difference and integer multiples of the
original frequencies. The frequencies of the intermodulation products can range in order
from second order (e.g. 2f1, 2f2, f1-f2 or f1+f2), third order (e.g. 3f1, 3f2, 2f1-f2, 2f1+f2, 2f2-f1,
2f2+f1), fourth order (e.g. 4f1, 4f2, 2f2+2f1,2f2-2f1,2f1+2f2, 2f1-2f2) up to the nth order and
usually arise from non-linearity in the signal processing equipment.
When many transmitters are placed at the same location, intermodulation may become
an issue. Typically, it is the third odd order intermodulation products which are of most
concern because they are the closest in frequency to the fundamental frequencies and
therefore cannot be effectively filtered out of the system (although this is not limited to
only third order products). This results in a spectrum of products that are spread out either
side of the fundamental frequencies which increases the bandwidth of the signal. In some
cases, the bandwidth of the signal is increased to a degree where it causes sideband
splatter in which the channels either side of the operating frequency are impinged by the
wider bandwidth of the signal. This causes interference with other systems operating in
these directly adjacent channels, otherwise known as co-channel interference.
3.3 Intermodulation

AvMesh® RF Communications Systems
Installation & Service Manual
Latest products and information available at www.avlite.com 9
Figure 4: Creation of intermodulation products
Furthermore, the third order intermodulation products can potentially pass through the
receiver since they are close in frequency to the fundamental frequencies. Consider the
situation in which 3 signals are present at the input of a non-linear amplifier or mixer; one
is the signal of interest at frequency f3 (e.g. 140 MHz) and the other two are competing
signals at frequencies f1 (e.g. 100MHz) and f2 (e.g. 120MHz). There are 15 combinations
of third order intermodulation products (including harmonics) from the interactions
between the signal of interest (f3) and the competing signals (f1 and f2). One of these
intermodulation products (i.e. 2f2-f1=2x120 – 100=140MHz) is equal to the frequency of the
signal of interest (f3) and as a result, this intermodulation product will enter the receiver
and interfere with the signal of interest. As a consequence, the receiver is at risk of
extracting and processing the incorrect information.
It is therefore essential to calculate the 3rd order harmonics and intermodulation products
for all combinations of competing frequencies in a site to determine if there is a possibility
of interference.
Antennas are a key component of any radio frequency communications system as they
enable the transfer of information from the transmitter to the receiver. For this reason, poor
antenna performance limits the performance of the overall system.
Antennas provide a radio communication system with three main properties; gain,
direction and polarization. A description of each is given in the following sections.
Typically, antennas do not transmit or receive radio frequency energy uniformly in all
directions and instead, transmit or receive more in some directions compared to others.
The antenna gain can be defined as a ratio of the highest signal strength transmitted or
received in a particular direction to that of a reference antenna. The two main types of
reference antenna are either the isotropic antenna which radiates the radio frequency
energy uniformly in all directions or the dipole which does not.
f1-f2
f1 f2
Frequency
Amplitude
2f1-f2
2f2-f1
2f1
f1+f2
2f2
3f1
2f1+f2
f1+2f2
3f2
f1-f2
f1 f2
Frequency
Amplitude
2f1-f2
2f2-f1
2f1
f1+f2
2f2
3f1
2f1+f2
f1+2f2
3f2
3.4 Antennas
3.4.1 Gain

10
Figure 5: Radiation pattern of Isotropic (left) and Dipole (right) antennas
A higher gain typically indicates that the signal (transmitted or received) is concentrated
over a smaller beam width and can therefore cover a larger distance. However, the
effectiveness of a high gain antenna depends on the application. Typically, a high gain
antenna is most suitable for applications where the source or destination of the signal is
known in order to isolate a specific signal and avoid external interfering signals.
A lower gain typically indicates that the signal (transmitted or received) covers a wider
beam width and hence, a wider area. A low gain antenna is generally most suitable for
applications where either the source or the destination of the transmitted signal is not
known and hence, coverage in all directions from the antenna is required.
Antennas operate by concentrating the radio frequency energy they radiate or receive in
a beam of a particular width. The width of the beam is known as the antenna direction or
directivity.
The directional qualities of an antenna are known as being either unidirectional, bi-
directional or omnidirectional and each possesses its own coverage capabilities. A
unidirectional antenna is able to transmit or receive radio frequency energy in one
particular direction whereas a bi-directional antenna is able to do so in two particular
directions. An omnidirectional antenna is able to transmit or receive radio frequency
energy equally in all horizontal directions and is therefore able to achieve 360-degree
coverage.
Figure 6: Unidirectional (left), Bi-directional (center) and Omnidirectional (right) antennas
3.4.2 Direction