COMP 421 /CMPET 401. COMMUNICATIONS and NETWORKING CLASS 5 (4B). TRANSMISSION MEDIA. Overview. Guided - wire Unguided - wireless Characteristics and quality determined by medium and signal For guided, the medium is more important
COMP 421 /CMPET 401
COMMUNICATIONS and NETWORKING
CLASS 5 (4B)
MediumFreq Typical Typical Repeater
Range Atten. Delay Spacing
Today, cables and related components are available in more grade categories than the industry standards specify. You can choose from Cat 5, Cat 5e, Cat 5e+, Cat 6 and yes, even Cat 6+. While there is plenty of hype and confusion surrounding these implied categories
Cat 6 more than doubles the bandwidth of Cat 5e, from 100 MHz to 250 MHz, supporting future emerging applications
Improved EMC performance to reject outside noise from TVs, wireless, and other adjacent applications.
Full backwards compatibility to support all legacy applications
Simpler and less costly installations, due to reduction in electronics needed for echo and NEXT (Near End Cross Talk) cancellation.
Attenuation (dB) = 1.991*sqrt(f) + 0.01785*f + 0.21/sqrt(f)
pr-pr NEXT (dB) = -20log( 10^( -0.05(74.3-15log(f)) ) + 2*10^( -0.05(94.0-20log(f)) ) )
PSNEXT (dB) = -20log( 10^( -0.05(72.3-15log(f)) ) + 2*10^( -0.05(90.0-20log(f)) ) )
pr-pr FEXT (dB) = -20log( 10^( -0.05(67.8-20log(f)) ) + 4*10^( -0.05(83.1-20log(f)) ) )
PSFEXT (dB) = -20log( 10^( -0.05(72.3-20log(f)) ) + 4*10^( -0.05(90.0-20log(f)) ) )
Return loss (dB) = 19 at 1-20 MHz; 19-10*log(f/20) at 20-250 MHz
Phase Delay (ns) = 546 + 34/sqrt(f)
Delay skew (ns) = 50
pr-pr PS pr-pr PS return phase delay
freq atten NEXT NEXT ELFEXT ELFEXT loss delay skew
(MHz) (dB) (dB) (dB) (dB) (dB) (dB) (ns) (ns)
100 21.7 39.9 37.1 23.2 20.2 12.0 549.4 50.0
250 36.0 33.1 30.2 17.2 14.2 8.0 548.2 50.0
To identify the RJ-45 cable type, hold the two ends of the cable next to each
other so you can see the colored wires inside the ends
·Straight-through — the colored wires are in the same sequence at both ends of the cable.
Crossover — the first (far left) colored wire at one end of the cable is the third colored wire at the other end of the cable
8-Wire Jack(10BaseT Data Connections)
8-Wire Jacks(USOC RJ31X Through RJ37X)
6-Wire Jack(USOC - RJ14W)
8-Wire Jack(IBM Token Ring Connections)
8-Wire Jacks(USOC RJ41 Through RJ48)Also TIA 568B(TIA 568A Swaps Pairs 2 & 3)
6-Wire Jack Modified Jack(DEC MMJ)
PER Specification TSB-36 for UTP cable connections for LEVEL 5:
- A terminal jack can be 90M (295ft) from the wiring closet.
- A device can be 10M from a terminal jack at the users location.
- There can be up to 6M of cross-connect patch cords in the wire closet
- Termination of cables must obey the following:
- Twists of actual pairs must be maintained to half-inch of termination.
- Cable sheath should be stripped only as far as necessary to terminate.
- Cables bundles should not nopt tightly bound or cinched
- Cable bundles should not be placed under stress or tension
- Cable bend radii should not be less than 8 times the cable diameter
The outer shield protects the inner conductor from outside electrical signals. The distance between the outer conductor (shield) and inner conductor plus the type of material used for insulating the inner conductor determine the cable properties or impedance. Typical impedances for coaxial cables are 75 ohms for Cable TV, 50 ohms for Ethernet Thinnet and Thicknet. The excellent control of the impedance characteristics of the cable allow higher data rates to be transferred than with twisted pair cable.
CMCommunication wires & cables
CL2Class 2 remote control, signaling, & power-limited cables
CL3Class 3 remote control, signaling, & power-limited cables
FPLPower limited fire protective signaling cables
PLTCPower limited tray cable
xxRIndicates a RISER cable
xxP Indicates a PLENUM cable
Plenum is highest grade. Order is : MPP -> CMP -> CL3P -> CL2P; FPLP -> CL3P & 2P
Riser is next higher grade. Order is : MPR -> CMR -> CL3R -> CL2R; FPLR -> CL3R & CL2R
General Purpose is next. Order is : MP -> CM -> CL3 -> CL2 : FPL or PLTC -> CL3 & CL2
Residential is lowest. The order is : CMX -> CL3X -> CL2X
1Level 1 cable is for basic comm & power limited circuits. VOICE GRADE ONLY.
2Level 2 cable is similar to IBM Type 3 cable for 2 to 25 twisted pair cable. 1MHz max.
8db/1000ft attenuation @ 1MHz; 4db/1000ft @ 256KHz. DIGITAL DATA GRADE
3Level 3 cable is Unshielded Twisted Pair (typical telephone wire). 16MHz max frequency.
7.8db/1000ft attenuation @ 1MHz; 4db/1000ft @ 256KHz. 10Mpbs ENET/ 4Mpbs TR
4Level 4 cable is Low Loss Premises Telecommunication cable, shielded/unshielded, 20Mhz max
6.5db/1000ft attenuation @ 1MHz; 31db/1000ft @ 20MHz for 24AWG wire
4.5db/1000ft atten @ 1MHz; 24db/1000ft @ 20MHz for 22AWG wire. 16Mbps TR.
5Level 5 cable is DATA GRADE up to 100Mbit
1Dual pair STP 22AWG solid, non-plenum data cable, used for long runs in walls of buildings
1PDual pair STP 22AWG, plenum data cable
2Dual pair STP 22AWG data, 4 pair UTP 24AWG solid, telephone(voice) non-plenum cable
2P Dual pair STP 22AWG data, 4 pair 22AWG telephone plenum cable
3Multi-pair (usually 4) UTP 22 or 24 AWG solid data & voice cable for runs in walls
5Two 100/140 micrometer optical fiber in a single sheath
6Dual pair 26AWG non-plenum patch panel data cable, used for patch panels. Attn=1.5xType1
8One flat STP of 26AWG stranded wire for under carpet
9Dual pair STP 26AWG solid non-plenum data cable, Low grade dual pair. Attn=1.5xType1
9PDual pair STP 26AWG plenum data cable
9RDual pair STP 26AWG riser data cable
Based on general description of cable per IBM definitions
Optical fiber consists of thin glass fibers that can carry information at frequencies in the visible light spectrum and beyond. The typical optical fiber consists of a very narrow strand of glass called the core. Around the core is a concentric layer of glass called the cladding. A typical core diameter is 62.5 microns (1 micron = 10-6 meters). Typically Cladding has a diameter of 125 microns. Coating the cladding is a protective coating consisting of plastic, it is called the Jacket.
An important characteristic of fiber optics is refraction. Refraction is the characteristic of a material to either pass or reflect light. When light passes through a medium, it "bends" as it passes from one medium to the other. An example of this is when we look into a pond of water.
If the angle of incidence is small, the light rays are reflected and do not pass into the water. If the angle of incident is great, light passes through the media but is bent or refracted.
Optical fibers work on the principle that the core refracts the light and the cladding reflects the light. The core refracts the light and guides the light along its path. The cladding reflects any light back into the core and stops light from escaping through it - it bounds the medium!
Step index has a large core, so the light rays tend to bounce around inside the core, reflecting off the cladding. This causes some rays to take a longer or shorter path through the core. Some take the direct path with hardly any reflections while others bounce back and forth taking a longer path. The result is that the light rays arrive at the receiver at different times. The signal becomes longer than the original signal. LED light sources are used. Typical Core: 62.5 microns.
Step Index Mode
Graded index has a gradual change in the core's refractive index. This causes the light rays to be gradually bent back into the core path. This is represented by a curved reflective path in the attached drawing. The result is a better receive signal than with step index. LED light sources are used. Typical Core: 62.5 microns.
Graded Index Mode
Single mode has separate distinct refractive indexes for the cladding and core. The light ray passes through the core with relatively few reflections off the cladding. Single mode is used for a single source of light (one color) operation. It requires a laser and the core is very small: 9 microns.
FIBER OPTIC LINK SUMMARY
Splicing technologies may be
divided into two basic categories:
fusion and mechanical.
Mechanical methods may include
products that use mechanical
means to align two cleaved fibers
or products that require polishing
of the fiber ends.
Return loss is the measure of the
level of signal reflected by the
splice back to the source. Return
loss of 40 dB or better is needed
to assure proper performance for
analog video transmission over
DWDM works by combining and transmitting multiple signals simultaneously at different wavelengths on the same fiber. In effect, one fiber is transformed into multiple virtual fibers. So, if you were to multiplex eight OC -48 signals into one fiber, you would increase the carrying capacity of that fiber from 2.5 Gb/s to 20 Gb/s. Currently, because of DWDM, single fibers have been able to transmit data at speeds up to 400Gb/s. And, as vendors add more channels to each fiber, terabit capacity is on its way.
A key advantage to DWDM is that it's protocol and bit-rate independent. DWDM-based networks can transmit data in IP, SONET/SDH, Ethernet, and handle bit-rates between 100 Mb/s and 2.5 Gb/s. Therefore, DWDM-based networks can carry different types of traffic at different speeds over an optical channel.
Testing and certifying fiber optic cable.It's easy to certify fiber optic cable because of its immunity to electrical interference. You only need to check a few measurements:
Attenuation (or decibel loss)—Measured in dB/km, this is the decrease of signal strength as it travels through the fiber optic cable.
Return loss—This is the amount of light reflected from the far end of the cable back to the source. The lower the number, the better. For example, a reading of -60 dB is better than -20 dB.
Graded refractive index—Measures how much light is sent down the fiber. This is commonly measured at wavelengths of 850 and 1300 nm. Compared to other operating frequencies, these two ranges yield the lowest intrinsic power loss. (NOTE: This is valid for multimode fiber only.)
Propagation delay—This is the time it takes for a signal to travel from one point to another over a transmission channel.
Time-domain reflectometry (TDR)—Transmits high-frequency pulses so you can examine the reflections along the cable and isolate faults.
So, in a nutshell, to visualize what happens to radio waves when they encounter an obstacle, we have to develop a picture of the wavefront after the obstacle as a function of the wavefront just before it (as opposed to simply tracing rays from the distant source). Now we're in a position to talk about Fresnel zones. A Fresnel zone is a simpler concept once you have some understanding of diffraction: it is the volume of space enclosed by an ellipsoid which has the two antennas at the ends of a radio link at its foci. The surface of the ellipsoid is defined by the path ACB, which exceeds the length of the direct path AB by some fixed amount. This amount is n /2, where n is a positive integer. For the first Fresnel zone, n = 1 and the path length differs by /2 (i.e., a 180 phase reversal with respect to the direct path). For most practical purposes, only the first Fresnel zone need be considered.
The two-dimensional representation of a Fresnel zone is
In order to quantify diffraction losses, they are usually expressed in terms of a dimensionless parameter , given by:
where d is the difference in lengths of the straight-line path between the endpoints of the link and the path which just touches the tip of the diffracting object (see Fig. 7, where d = d1 + d2 - d). By convention, is positive when the direct path is blocked (i.e., the obstacle has positive height), and negative when the direct path has some clearance ("negative height").
“Knife edge" diffraction means that the top of the obstacle is small in terms of wavelengths. This is sometimes a reasonable approximation of an object in the real world, but more often than not, the obstacle will be rounded (such as a hilltop) or have a large flat surface (like the top of a building), or otherwise depart from the knife edge assumption. In such cases, the path loss for the grazing case can be considerably more than 6 dB - in fact, 20 dB would be a better estimate in many cases. So, Fresnel zone clearance can be pretty important on real-world paths. And, again, keep in mind that the Fresnel zone is three-dimensional, so clearance must also be maintained from the sides of buildings, etc. if path loss is to be minimized. Another point to consider is the effect on Fresnel zone clearance of changes in atmospheric refraction, as discussed in the last section. We may have adequate clearance on a longer path under normal conditions (i.e., 4/3 earth radius)
One common source of reflections is the ground. It tends to be more of a factor on paths in rural areas; in urban settings, the ground reflection path will often be blocked by the clutter of buildings, trees, etc. In paths over relatively smooth ground or bodies of water, however, ground reflections can be a major determinant of path loss. For any radio link, it is worthwhile to look at the path profile and see if the ground reflection has the potential to be significant. It should also be kept in mind that the reflection point is not at the midpoint of the path unless the antennas are at the same height and the ground is not sloped in the reflection region - just the remember the old maxim from optics that the angle of incidence equals the angle of reflection
On long links, reflections from objects near the line of the direct path will almost always cause increased path loss - in essence, you have a permanent "flat fade" over a very wide bandwidth. Reflections from objects which are well off to the side of the direct path are a different story, however. This is a frequent occurrence in urban areas, where the sides of buildings can cause strong reflections. In such cases, the angle of incidence may be much larger than zero, unlike the ground reflection case. This means that horizontal and vertical polarization may behave quite differently When the reflecting surface is vertical, like the side of a building, a signal which is transmitted with horizontal polarization effectively has vertical polarization as far as the reflection is concerned. Therefore, horizontal polarization will generally result in weaker reflections and less multipath than vertical polarization in these cases.
The loss of LOS paths may sometimes be affected by weather conditions (other than the refraction effects which have already been mentioned). Rain and fog (clouds) become a significant source of attenuation only when we get well into the microwave region. Attenuation from fog only becomes noticeable (i.e., attenuation of the order of 1 dB or more) above about 30 GHz. Snow is in this category as well. Rain attenuation becomes significant at around 10 GHz, where a heavy rainfall may cause additional path loss of the order of 1 dB/km.
Trees can be a significant source of path loss, and there are a number of variables involved, such as the specific type of tree, whether it is wet or dry, and in the case of deciduous trees, whether the leaves are present or not. Isolated trees are not usually a major problem, but a dense forest is another story. The attenuation depends on the distance the signal must penetrate through the forest, and it increases with frequency. According to a CCIR report , the attenuation is of the order of 0.05 dB/m at 200 MHz, 0.1 dB/m at 500 MHz, 0.2 dB/m at 1 GHz, 0.3 dB/m at 2 GHz and 0.4 dB/m at 3 GHz. At lower frequencies, the attenuation is somewhat lower for horizontal polarization than for vertical, but the difference disappears above about 1 GHz. This adds up to a lot of excess path loss if your signal must penetrate several hundred meters of forest! Fortunately, there is also significant propagation by diffraction over the treetops, especially if you can get your antennas up near treetop level or keep them a good distance from the edge of the forest, so all is not lost if you live near a forest
Communications satellites are radio relays
in the sky. They receive signals transmitted
from earth-based antennas, amplify the
signals, and return the signals to earth. Satellites
are extremely useful because they can
handle large amounts of different types of traffic,
they offer almost worldwide coverage, and
they can be installed independently and relatively
Satellite systems, which consist of special-
case beyond-LOS equipment, consist of
three parts: the space segment, which includes
the satellite; a ground segment comprising
simple to complex communications terminal
equipment; and a control segment that performs
satellite station-keeping chores and directs
allocation of satellite bandwidth between users.
Satellite systems use different frequencies
for transmitting and receiving information.
A ground terminal transmits the signal on the
uplink frequency; the satellite retransmits the
signal on the downlink frequency to the ground
receiver terminal. A transponder device within a satellite receives the incoming signal, amplifies
it, changes the signal frequency, and retransmits
it to the receiving terminal. Satellite
uplink and downlink frequencies are usually
referred to in pairs, like 6/4 GHz with the first
number the uplink frequency and the second
number the downlink frequency.
Most commercial satellites have more
than one transponder, with bandwidth differing
among various designs. Contemporary C-band
commercial satellites have as many as 34 transponders
each. Each transponder can relay
one color television channel with program sound,
1200 voice channels, or a data rate of up to 50
Mbps. The number of channels a satellite can
provide is related to the available bandwidth
and how it is used. This number may be increased
by improving the efficiency of the transponder
or increasing its power. However, because
more power requires more weight, the
number of channels is related to the satellite’s
size and weight.
0.25ms each way
The technical/operational performance characteristics that are to be used in
conjunction with the possible services are:
1. Standard T-2
Earth Stations having a nominal G/T of 37 dB/K and operating in the 11/14 GHz frequency bands via the EUTELSAT II satellite system for international public telephony and high quality television transmissions or international public telephony only. (Note: The T1 standard applied to TDMA transmissions on EUTELSAT-I has been replaced by the T2 standard)
2. Standard V-1
Earth Stations having a nominal G/T between 26 dB/K and 30.5 dB/K (depending upon location) and
operating in the 11/14 GHz frequency bands via the EUTELSAT II satellite system for international
high quality television transmissions only.
3. Standard S-1
Earth Stations having a nominal G/T of 30 dB/K and operating in the 12/14 GHz frequency bands via the EUTELSAT I/II satellite system for international SMS services (SMS Open Network).
Generally, commercial systems operate
within different parts of the UHF and SHF bands
than do military systems. The accompanying
chart shows the relation of frequency bands
with letter frequency designators used in the
telecommunications industry. L-, C-, and Kuband
systems are currently available for lease;
all can provide communications services to most
of the world. Wide geographic coverage by Cband
is more prevalent than that by Ku-band
because Ku-band satellites tend to use very
narrow beam antennas to support high population
density regional locations. L-band, which is
associated with small terminals and mobile applications,
is used by INMARSAT and is available
FDMA (Frequency Division Multiple
Access): A static multiple access technique
where transponder bandwidth is subdivided into
smaller frequency bands, or sub-channels, in which
each subchannel is assigned to a specific user.
TDMA (Time Division Multiple Access):
A static multiple access technique where
the transponder bandwidth is assigned to each
user during a specific time slot in a cyclic time
CDMA (Code Division Multiple Access):
A dynamic multiple access technique,
also known as spread spectrum, where total
transponder bandwidth employs a separate and
distinct code for each user to access a traffic
channel at any instant of time in sharing the
overall bandwidth with other users.
Polling (Roll Call and Round Robin):
A dynamic multiple access technique where
total transponder bandwidth is made available
to a user for the duration of time the user
requires. Upon transmission completion, channel
access is passed to the next user on the
polling list in a cyclic manner.
DAMA (Demand Assigned Multiple Access):
A family of dynamic multiple access
techniques where each user reserves channel
space based upon individual need.
Contention: A family of dynamic multiple
access techniques where users compete
with each other for channel space by transmitting
when required. If separate transmissions
collide, the corrupted transmissions are re-attempted
after a random delay.
Each of the multiple access channel
control techniques has advantages and disadvantages.
The selection of a multiple access
technique depends upon network application,
traffic generation profiles for each network subscriber,
and user tolerance to traffic throughput
Currently, FDMA and TDMA techniques
are static and do not adapt readily to changing
traffic loads. Polling techniques are not suitable
for networks with exceptionally large numbers
of users due to the time needed to cycle through
the polling list. CDMA has an inherent electronic
countermeasure resistance, but is expensive
to implement. DAMA is most efficient
for networks of users with varying traffic loads,
but the automated reservation (control) system
technology is complex.
The signal level on any contour line is
derived from the satellite’s EIRP at that location,
with values of EIRP measured in decibels
referenced to one watt of power or dBw. The
higher the EIRP value, the better the signal
quality. For example, the EIRP level of a satellite
signal could range from 18 dBw at beam
edge to 21 dBw at beam center. The G/T gain-to-
noise temperature ratio of the ground station
determines the quality of the received signal.
To achieve successful satellite communications,
several technical considerations must
be satisfied. Considerations include the
geolocation of the terminal with respect to the
satellite beam coverage or “footprint” on the
earth’s surface, the frequency band, the signal
bandwidth, the antenna transmit gain expressed
as its Effective Isotropic Radiated Power (EIRP),
the size of the antenna dish, and the antenna
receive performance “figure of merit,” expressed
as G/T (the ratio of antenna receive gain to
system noise temperature in decibels per degrees
Kelvin, or dB/K).
Basic technical constraints affect system
performance and dependability of satellite
communications. Antenna size and polarization
influence system performance in terms of
radio receiver sensitivity G/T and transmitter
output power EIRP. Besides these physical
characteristics, other factors such as atmospheric
“noise” and temperature play significant
The EIRP of an earth terminal is a key
parameter in determining system performance.
The EIRP required depends on the communications
traffic that the earth terminal needs to
support. The recently introduced micro earth
terminals and very small aperture terminals
(VSAT) with low ElRPs are not able to support
the communications traffic volume that a large
earth terminal with a high EIRP can support.
There is a trade-off in a communications link
between the transmit EIRP and the receive G/T
required to support a given data rate. There is
also a trade-off in available power versus bandwidth
allocated by the satellite resource manager,
as well as between transmitter power and
Noise is the principal enemy of a
satellite receiver because it affects the receiver’s
ability to accurately separate the downlink radio
signal from ever-present random electrical energy.
Noise can be natural cosmic background
static, can come from heat generated by the
antenna’s own amplifier, or can originate from
other electronic parts of the receiver. Noise is
also caused by the sun’s RF energy falling on
the antenna. Fortunately, this phenomenon is
relatively short-lived, amounting to several minutes
a day and occurring seasonally in the fall
and spring, when, during the solar equinoxes,
the sun’s transit contributes to these disturbances.
Sun spots and solar flares can also
affect receiver performance at any time.
C-Band Medium EIRP Coverage
Ku-Band EIRP Coverage
C-Band High EIRP Coverage
Determines the dish
size, output power,
frequency, and other
physical radio parameters
& Reception of
FROM: DURRES TO: BELGIIUM
*Availability (%): 99.900 *Satellite INTELSAT 705
*Required Eb/No (dB): 5.50 Satellite West Long : 18.0
*Bit Error Rate : E-08 *Transponder SPOT-SPOT
*Modulation Type : QPSK !Usable Trnspndr BW (MHz): 72.00
*Info. Rate (Kbps): 256.00 !SFD @ 0 dB/K (dBW/M^2): -97.10
*FEC Rate : 0.69 *Transponder Atten (dB): 12.0
*Spread Spectrum Factor : 1.00
*Modem Step Size (kHz): 1.00
TRANSMIT E/S RECEIVE E/S
North Lat: 41.3 West Long: 39.0 North Lat: 51.0 West Long: 23.0
Frequency (GHz): 14.20 Frequency (GHz): 11.20
*Satellite G/T (dB/K): 4.20 *Satellite EIRP (dBW): 42.10
*Antenna Diameter (m): 2.4 *Antenna Diameter (m): 3.8
Antenna Gain (dBi): 49.40 Antenna Gain (dBi): 51.80
Antenna Elevation (Deg): 37.69 Antenna Elevation (Deg): 31.42
Carrier EIRP (dBW): 43.72 *LNA Noise Temp (K): 65.00
*Power Control (dB): 0.00 *Loss betw.LNA & Ant.(dB): 0.06
*Output Circuit Loss (dB): 0.00 System Noise Temp. (K): 107.94
Path Loss (dB): 207.11 Station G/T (dB/K): 31.47
Other Losses (dB): 0.70 Path Loss (dB): 205.16
(other loss = atm,pol,ant point) Other Losses (dB): 0.60
C/Io Adj Sat U (dB-Hz): 71.92 #C/Io Intermod (dB-Hz): 75.41
C/Io Adj Sat D (dB-Hz): 78.52 C/No Thermal Up (dB-Hz): 68.71
C/Io Crosspol (dB-Hz): 80.28 C/No Thermal Dn (dB-Hz): 69.62
C/Io Adj Channel (dB-Hz): 79.42 C/Io Total (dB-Hz): 68.79
C/Io Adj Trans (dB-Hz): 83.67 C/No Therm Total (dB-Hz): 66.13
C/Io Microwave (dB-Hz): N/A C/No Total (dB-Hz): 64.25
Overall Link Margin (dB): 4.67 *Rain Model : CRANE
Uplink Availability (%): 99.912
Rain Margin (dB): 4.67 *Uplink Rain Zone : D2
Dnlink Availability (%): 99.988
Rain Margin (dB): 4.47 *Dnlink Rain Zone : C
G/T Degradation (dB): 4.36
*Number of Carriers : MULTIPLE *Number of Carriers : 1.0
*Total OPBO (dB): 3.50 *Total HPA OPBO : 0.00
Total IPBO (dB): 7.00 HPA Power/Carrier (dBm): 24.32
Carrier OPBO (dB): 26.78 Required HPA Size (dBW): -5.68
Carrier IPBO (dB): 30.29 Required HPA Size (W): 0.27
FCC Req: 1) Uplink Flange Density (dBW/4kHz): -22.34 File: I705DBE
(@46.0) 2) Downlink EIRP Density (dBW/4kHz): 2.56
Transponder BW Used Per Carrier (x1.35) (%): 0.35 # = deltas used
Transponder Power Used Per Carrier (%): 0.47 ! = modif. default
Transponder Bandwidth Allocation (MHz): 0.251 * = user's input
RADIO COVERAGE REQUIREMENTS
RADIO HORIZON IS
150NM AT 15,000ft
213NM AT 30,000ft
Freq.= 126 MHz
RF FEED LOSS = 2.5dB
ANTENNA GAIN = 0dBd
TRANS. ERP = 14W
RCVR SENSIT.= -90dBm
NOTE: DISTANCE TO HORIZON IS
HF Radio Systems
100 x 100mm
100 x 100mm
150 x 150mm
150 x 150mm
200 x 200mm
This lens provides a beam divergence of 0.5 degrees, giving a large beam footprint. This is to avoid problems of loss of signal due to building movement, atmospheric distortions, ease of installation and long-term reliability. A coarse optical filter is placed in front of the lenses to reduce the effect of sunlight on the APD.
The size of the transmit aperture provides a wide area of emission to avoid safety and scintillation problems.