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OCR for page 132
A.~.3 Wireless Communication
Wireless communication has significant ITS applications:
1. Any vehicle-to-infrastructure communication (i.e., mobile applications)
2. Temporary communication faciiides including rapid deployment when required
3. Cations where wire or fiber are not options:
a. canyon, ever, other geographic obstacles
b. Business or traffic disruptions for installation are unacceptable
4. Situations where more cost effective Han wire or fiber
5. Diversity~ot-standby for reliability
Wireless offers bandwidths and bit rate capabilities comparable to wire and, to a lesser extent, to
fiber. Vanous wireless options are available to support virtually any llS link, including low-
speed local links, high-speed backbones, and TOC-to-TOC links.
Wireless communication has unique characteristics compared win wire and fiber:
1. Wireless communication requires installation of only terminal equipment. In addition, up to
Me repeaterless propagation limits of We installation, has fixed (constant) cost per link
regardless of distance, compared USA fiber/wire which must include approximate linear
cost/un~t of distance. This comparison is depicted in Figure A.13-~. Ri~t-of-way~site
acquisition costs are only incurred at terminal locations, not between as with fiber/wire.
2. Wireless requires FCC licensing for guaranteed interference-free operation or careful
design/operation considerations in Be unlicensed bands.
L:W~h~c2~t N~3-51e P~2F~Re~n A1-124
OCR for page 133
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r
3. Wireless propagation and coverage characteristics vary widely based on frequency, antenna
heights, intervening terrain, weaker, allowable power, etc., which makes design of wireless
systems more complex than wire or fiber design.
Wireless, like fiber and wire, has link budget criteria for successful operations. Table A.~.3 lists
typical wireless little parameters. Because wireless has different propagation modes and widely
varying weaker, atmospheric, terrain, etc., lim~tabons, repeaterIess distances and achievable bit
rates are highly vanable.
Table A.~.3
Typical Wireless Link Budge! Parameters
I Parameter T Example
Transmit Power | 50,000 WaNsAM Broadcast Stat on (77 dbm)
Transmission Loss* -6 dB/Octave Free Space (Octave is double the distance)
-6too18dB/Octave inMultipath
Receiver Sensitivity -80 to -120 dam
*Actual Transmission Loss is highly variable depending on many factors as discussed In text.
A.~.3.! Wireless Propagation and Coverage
At Me most fi~nd~mental level, wireless propagation and coverage can be modeled by He free
space transmission (i.e. Line of Sight propagation) formula (Equation A.~.3.~-~) (adapted from
lakes, Microwave Mobile Communications).
LW~h~2.~t NC~3-51e P0e2F~Re~n A1-126
OCR for page 135
Equation A.1.3.1-1
Pr = Pt (4 d) g&, or
Pr ~ ,1 2
L = - = if_ gtgr
where: L = pad loss
P. = Receive Power
P'= Transmit Power
A = wavelength =
c - 10 "meters /see
d = distance between
g2. = gain of transmit antenna
gr = gain of recede antenna
c = speed of light, f = frequency
transmit Id receive antennas
For an antenna that receives or transmits equally In all directions over a sphere, grge = I. This is
generally referred to as an isotropic antenna Needless to say, directional antennae are frequently
employed to Improve wireless system performance. Equation A.~.3.~-1 is often converted to
Lab (]OSS expressed in decibel or dB) with antenna gates, gigs = I, and the loss equivalently
expressed as:
c
Equation A.1.3.1-2
LdB = - 92.4 - 20 x log ~.O(fGNz) ~ 20 X log ~o~dk,,')
In free space line-of-sight propagation, Here is a loss of 6 dB for each doubling of distance and
6 dB per doubling of frequency. Thus, propagation distance, or coverage, is less at higher
frequencies (assuming all other factors are equal).
Free space (or spaces) propagation is usually only consistently achieved in outer space, although
many earthbound applications under favorable conditions, closely approximate free space
propagation. Generally, actual propagation losses are more severe Man free space and must be
modeled (usually stadshcally) accordingly. Free space propagation is typically "line-of-sight,"
t.:\.NCHRP`.Phase2.rp~ NCHRP 3-51 · Phase 2 Ftnal Report
A1-127
OCR for page 136
but may include refraction (i.e., sometimes creating multiparty), and some diffraction over terrain
or obstacles (e.g., buildings). Free space propagation occurs at all RF frequencies and is
dominant at hider frequencies.
Another mode of propagation is ground (or surface) wave propagation which is the dominant
component at frequencies less than 2 megahertz. This is a secondary component up to He very
high frequency range (30-300 MHz) and can usually be neglected at frequencies above 300
MHz. Ground waves usually combine with direct (free space) signals and other reflected signals
in a manner such Hat He received signal has greater attenuation Han a free space signal;
however, at very low-frequencies, ground waves dominate and therefore are used by the rnilit.ary
for worldwide commun~cabon with submarines and for other cndcal missions. Propagation is
very good at these low frequencies and literacy provides worldwide communication. The AM
broadcast band propagates via ground waves (as wed as other modes).
Skywaves, another mode of propagation, is the bending of a wave as it passes from one medium
to another because of different propagation speeds in He two mediums. This bending causes
radiowaves Hat would normally propagate into space to bend back toward He earn. This
bending typically occurs in the ionosphere region which is approximately 30 to 260 miles above
the earths surface. Depending on He frequency employed, time-of-day (night is best), plus
other factors; skywave propagation can support communication link distances from 60 to over
6000 miles. Skywave propagation is the dominant mode of propagation in the 2 to 30 MHz
frequency range.
Figure A.~.3.~-1 illustrates these modes of propagation. Propagation characteristics are highly
dependent on frequency and can be classified into frequency bands with each band having
essentially similar propagation charactenstics. Table A.~.3.~-! lists the generally accepted
frequency band cIassificabons, range of frequencies, propagation characteristics, and typical
uses.
~;\NC~Phasc~rp ~NCHRP 3-51 · Phase 2 final }report A1-128
OCR for page 137
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In RF (wireless) system design, coverage is estimated based on propagation loss between
transmitting and receiving antennae. For frequency reuse based on geographic separation, signal
attenuation of a potential interfering transmitter due to propagation loss at a receiving antenna
must be sufficient so that the interfering signal level is significantly less Can the desired signal.
Obviously, at lower frequencies that support over-the-honzon propagation modes such as
groundwave and skywave, frequency reuse distances will be great. Conversely, LOS
propagation to the horizon, which is the dominant propagation mode above 30 MHz, permits
much shorter frequency reuse distances and smaller direct coverage areas, but greater system
capacity through frequency reuse.
In addition to slywave, ground/surfacewave, and free space LOS propagation modes, over
factors influence propagation:
1) In free space propagation, multipath attenuation, (where reflected and direct signals
combine) can be greater or less. A typical multiparty loss profile is depicted in
Figure A.~.3.~-2. Up to a distance prior to onset of multiparty, the loss profile is He typical
6 dB/km and Hereafter has a steeper loss profile greater Han 6 dB/km. Under more severe
multipath conditions, multiple breakpoints may exist with successively steeper loss per unit
Of distance. Multiparty is a dominant factor in mobile wireless communication (e.g., cellular,
unlicensed spread spectrum).
2) Above VHF, traditional suggests theory is that propagation is limited to He LOS honzon.
Experience, often He result of unexpected interference, has proven overwise. Current
theory suggests that weaker produces venous select conditions Hat actually enhance
propagation. These conditions include tropospheric scatter, rain scatter, dusting, radiation
inversion, reflection from objects, etc. When these conditions anse, propagation can extend
significantly beyond LOS. These conditions can occur virtually anywhere, but seem to be
most prevalent over wann water areas such as Florida, He Gulf Coast, and California, In He
U.S. These conditions also often create undesired interference; however, RF communication
propagation engineers usually understand local conditions and often have mesons to
address these problems and/or use to their advantage.
L:~h=~.~t NC^P3^51 · P~e2F~Re ~A1-131
OCR for page 140
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Wireless propagation modeling and design is not an exact science. Many variables exist so
detailed RF propagation and coverage design should be accomplished by communication
engineers who have access to many models. Rough planning estimates, however, can be
calculated using the free space model of Equation 1, modified as appropriate, by Me actual
antenna gain.
A.~.3.2 FCC Rules
RF spectrum for wireless communicators is a scarce resource ~at, except for some unlicensed
bands, is allocated to service providers and/or users on exclusive or shared bases, though
licensing administered by the Federal Communications Commission (FCC). The mles governing
licensed and unlicensed wireless operations are contained in the Code of Federal Regulations
(CFEt) Title 47, Telecommunications, consisting of parts 0 Trough 101 (currently). Table
A.1.3.2-1 lists Me parts of CFR 47 relevant to ITS. Their titles provide an indication of the
services addressed. Table A.1.3.2-2 provides more detail on some of the Parts significant to ITS
and includes services, comments, pending FCC Notices of Proposed Rule Malting (NPRM) and
Reports and Orders wig ITS impact, and ITS applications.
A. l.3.2. ~ FCC Licensing and Coordination
FCC licensing procedures and rules are generally described in Part ~ of CRF 47. These
procedures and rules are complicated, partly because of many years of evolution and upgrade.
This section is not intended to be an in-depth discussion of the details of licensing and
coordination, but a general overview of Me concepts of Importance to ITS.
FCC licenses/au~onzations may be required in the following situations:
I) Operator/station license to operate a transmitter at a given site or within a specified
geographic area
L~\NCHRP\Phas~p' NCHRP 3-51 · Phase 2 Final Report
A1-133
OCR for page 142
Table A.~.3.2-1
Code of Federal Regulation (CFR) 47 ~ Telecommunications
Parts Relevant to ITS
FCC Part
(partial list of Communication Organization
relevant parts)
Part 1 Practice and Procedures
Part 2 Frequency Allocations and radio treaty matters; general rules and regulations
Part 5 Experimental radio service (other than broadcast)
Part 13 Commercial radio operator
Part 15 Radio Frequency devices
Part 17 Construction, marking, and lighting of antenna structures
Part 18 Industrial, scientific, and medical, devices (ISM)
Part 21 Domestic public fixed radio services
Part 22 Public mobile services
Part 23 International fixed public radio communications see/ices
. _
Part 25 Satellite communications
Part 68 Connections of terminal equipment to the telephone network
Part 73 Radio broadcast services
Part 74 Experimental, auxiliary, and special broadcast and program distributional services
Part 76 Cable television services
.
Part 79 Cable television relay service
Part 80 Stations in the maritime services
Part 87 Aviation services
Part 90 Private land mobile radio services
Part 94 Private operational-fixed microwave services
Part 95 Personal Radio services
Part 97 Amateur radio services
..
Part 99 ~
Part 100 Direct broadcast satellite service
. . . .
Part 101 Terrestrial Microwave Fixed Radio Services
(will replace Part 94 and Parts of Part 21)
L:\NCHRP\Phase2~pt NCHRP 3-51 ~ Phase 2 Fmal Report A1-134
OCR for page 187
Table A.1.3.5.1-1 lists the selected amended Part 90 frequency bands including the refarm~ng
bands as well as others. Included In the table are channel spacings and au~onzed channel
bandwidths. As opposed to requ~nng users to upgrade, He new rules encourage upgrade over an
anticipated lO-year nonnal replacement cycle by not type accepting new equipment for the
refanning bands unless it meets He new rules. After August I, 1996, type acceptance win be
granted only if one of He following is met:
Single or multimode equipment with a maximum banded of 12.5 kHz;
25 MHz of bandwidth for multimode equipment that is also capable of operating on channels
of 12.5 kHz or less; or
25 kHz bandwidth operation equipment is permitted by employing spectrum efficiency
standards of at least one voice channel per 12.5 kHz of bandwidth or data channel operations
supporting at least 4800 bps per 6.25 kHz of bandwidth (i.e., .768 bits/second/hertz). This
will permit spectral efficient TDMA equipment to be deployed.
On January 1, 2005 the spectral efficiency requirements win be reduced from 12.5 to 6.25 kHz.
The refarniing order contains a Further Notice of Proposed Rulemaldug (FNPRM) to consolidate
frequency coordination. Currently, the refanning bands are divided into 20 services for He
purposes of frequency coordination. These current services are listed in Table A.~.3.5.~-2, as:
· The number of transmitters as of December, 1994;
\
The number of assigned 25 kHz channels (some channels are shared by different services in
both the Vim and UHF bands); and
The frequency coordinator.
It should be noted that this definition of services for frequency coordination purposes is close, but
not the same, as the definition of services under Subparts B. C, D, and E (see Table A.~.3.5-~.
The FNPRM directs He PLUM users community to assess their needs and submit a consensus
L:~h~.~t NC~3-51 · Ph~2F~Re~n A1-179
OCR for page 188
Table A.~.3.5.~-1
Amended Part 90, PROS Standard Channel Spacing/Bandwidth
.
Frequency Band (MHz) Channel Spacing (kHz) Authorized Bandwidth (kHz)
25 - 50 ~20 ~20
72 - 76 20 20
150 - 174 1 (25 kHz) 7.52 25/11.25/623
220 - 222 5 4
421 - 430 (25 kHz) 6.52 25/11.25/623
.
450 - 470 1 (25 kHz) 6.52 1 25/11.25/6~3
470 - 512 1 (25 kHz) 6.52 1 25/11.25/623
806 - 821/851-866 1 25 20
._ .
821 - 824/866 - 869 1 12.5 1 20
896 - 901/935 - 940 12.5 13 0
929 - 930 1 25 1 20
proposal within Free months of He effective date of Be Report and Order on how to consolidate
frequency coordination arid create a consolidated real-dine database of assigned frequencies. The
FNP~M cites a goal of 24 coordination categories based on Me user proposal justifiable
categones. The reasons for Me consolidation are:
More efficient and effective frequency assignments among low and high use groups;
Simplify interservice shanng;
2 Prior to August 16, 1995. For stations authorized on or after August 16, 1995, type acceptance of
equipment after August 16, 1996 must be capable of operating on channel bandwidths of 12.5 klIz or less and
support one voice channel per 12.5 kHz of bandwidth and a minimum data rate of 4800 bps per 6.25 Adz of
bandwidth (i.e. about .768 b/s}Hz).
3 Multimode capable of operating on He old 25 kHz and He new channel spacing/bandwid~ can be type
accepted after August 1, 1996
.~NCHRP\.Phase:.rp ~NCHRP 3-51 · Phase 2 Penal Report Al-180
OCR for page 189
Table A.~.3.5.~-2
Private Land Mobile Radio Services and Frequency Coordinators
Description of Private Land Mobile
Radio Services Below 470 MHz
Number of Number of Frequency
Transmitters Channels Coordinator (see
list below)
VHF UHF
3,575,223 109 289 NABER(PCIA)
1,550,394 75 86 APCO
1,382,647 80 78 APCO
843,747 815 30 ITA
826,773 38 48 IMSA
768,551 40 UTC
742,454 119 20 MR
419,436 19 74 IMSAIIAFC
NABER(PCIA)
356,607 58 38 MSHTO
..
340,913 103 36 PFCC of API
335,109 43 38 MSHTO
308,227 52 48 MRFAC
182,598 56 30 ATA
137,640 10 36 TELFAC
123,864 36 24 ITLA
Business: educational, religious,
hospital, small business, etc.
Police: protection of citizens in
emergency and non-emergency
situations
Local Government: official functions of
governmental activities
Special Industrial: heavy construction
(roads/bridges), farming, and mining
Fire: fire protection services by state
and local entities
Power: electricity, natural or
manufactured gas, water, and steam
Railroad: rail transport of passengers
and freight
Special Emergency protection of life and
property for emergency medical care
Forestry Conservation: protection and
conservation of forests and wildlife
Petroleum: production, collection, and
refining petroleum products by pipeline
Highway construction and maintenance
of highway activities
Manufacturers: plants, factories, mills,
and shipyards
Motor Carrier: trucking (short and long
haul) and public buses
Telephone Maintenance: daily repair and
emergency restoration
Taxi Cabs: nonscheduled passenger
land transportation
L.\NCHR~Phasc2.rpt NCHRP 3-51 · Phase 2 Final Report A1-181
OCR for page 190
Description of Private Land Mobile Number of Number of Frequency
Radio Services Below 470 MHz Transmitters Channels Coordinator (see
list below)
VHF ~ UHF
Forest Products: logging,hauling,and ~119,428 | 106 | 50 | FIT l
manufacturing of lumber products
Automobile Emergency: dispatching of 35~877 23 4 MA
repair trucks, tow trucks, etc.
Relay Press: publication and operation of 22,017 12 4 AN PA
newspaper and press
Video Production: producing, 12,794 18 O AMPTP
videotaping, filming of movies and
television programs l l l l l
Totals: 20 Radio Services (includes 553 324
EMRS) I 12,084,299 1 1 1 1
AAA Amencan Automobile Association
AASHTO American Association of State Highway and Transportation Officials
AAR Association of Amencan Railroads
AMPTP Alliance of Modon Picture and Television Producers
ANPA AmencaD Newspaper Publishers Association
APCO Association of Public Safety Communications Officials - International, Inc.
API Amencan Petroleum Institute
FIT Forest Industries Telecommunications
LAFC International Association of Fire Chiefs
IMSA International Municipal Signal Association
ITA Industnal Telecommunications Association, Inc.
1TLA International Taxicab and Lively Association
MRFAC Manufacturers Radio Frequency Advisory Committee
NABER National Association of Business and Educational Radio (merged win PCIA)
PCLA
PFCC
Personal Communications Industry Association
Petroleum Frequency Coordinadng Committee
TELFAC Telephone Maintenance Frequency Advisor Committee
UTC
L:\NCHRP\Ph;~se2.rpt
Ublides Telecommunications Committee
NCHRP 3-51 ~ Phase 2 final Report
A1-182
OCR for page 191
Organize channel allocation to more easily use advance technology;
More effectively allocate He newly created channels; and
· Provide a mechanism for exclusive channel use of He expanded channel capacity. This urn
also allow more efficient enlacing.
If a consensus user proposal cannot be reached, the FCC says it win make a decision. Competing
frequency coordination services will be allowed in each coordination category (or group).
Refarming could have important ITS implications:
Access to lower frequencies wad greater coverage potential. (This might be essential for
rural applications.~;
Substantially greater number of channels becoming available for new applications;
Streamlined technical rules permitting more efficient trundling and TDMA. (Spread spectrum
will be allowed, but only for police applications.~;
· It promotes interoperability with 12.5 kHz equipment used by Federal Government users
(e.g., FBI, DOD), and He new APCU-25 standard developed by the public safety community;
It promotes upgrades of existing PEMA systems (e.g., highway maintenance). (Some will
require network reconfiguration due to new technical rules reducing maximum allowable
powers and lower maximum antenna heights.~; and
The data rate capacity of the channels ranges from 4,800 bps (6.25 kHz bandwidth) to
19,200 bps (25 Lutz bandwidth) at BERs between i0~3 and lo-6
.
The ITS community needs to actively promote its needs during He transitional period.
L:\NCHTWhase2.rpt NCHRP3-51e Phase2F'nalReport A1-183
OCR for page 192
A.~.3.~.2 Transportation /nfrastruefure Radio Service {T/RSJ - AVW[MS
~ February, 1995, the FCC adopted rules (FCC 9541, February 5, 1995) for Automatic Vehicle
Monitoring (AVM) under a new Subpart M stardng at Part 90.350. These new rules replace
interim (1970) AVM rules in 90.239 (deleted). The title of Subpart M is "Transportation
Infrastructure Radio Service" AIRS) and is intended to allow new radio-based technologies for
ITS applications. The AVM name is changed to Location and Monitoring Service (LMS) and is
Me first radio-based technology service under this subpart.
The LMS will share spectrum in the 902-928 MHz band with over users (see Table A.~.3.4-~.
The FCC 9541 Report and Order (R&O) modifies and eliminates outdated regulations that have
not kept pace with technological evolution that is supportive of ITS applications. The key
elements of Me R&O are as follows:
Defined two general categories of EMS technologies multilateration, or w~deband Including
direct sequence spread spectrum, and non-muldIateration, or narrowband. The subbands and
ban dwid~s are in Table A.13.S.2~.
Table A.~.3.5.2~1
EMS Frequency Subbands
Subband(MHz) ~ System LicenseBandwidths tMHz) ~ Power(Watts)
902.00 - 904.00 Non-multilateration2.00 MHz 30
904.00 - 909.75 I Multilateration 5.75 MHz | 30 l
909.75 - 921.75 | Non-multilateration 12.00 MHz | 30 l
919.75 - 921.75 Both (shared equally) 2.00 MHz 30
921.75 - 927.25 1 Multilateration 5.75 MHz 1 30
927.25 - 928.00 i Multilateration (Forward links, 250 KHZ) | 300
Permit Multilateration LMS systems to locate any object (i.e., vehicle or not).
· In addition to locations and monitoring information, permit LMS systems to transmit about a
mobile unit, status and instructional inflation including voice and non-voice. Under
~ :\NC~Whase2.rp ~NCHRP 3-51 · Phase 2 Fmal Report Al-184
OCR for page 193
certain conditions related to public safety or special emergency radio service, L`MS systems
may interconnect with the Public Switched Network (PSN).
Expand EMS license eligibility to all entices eligible under Part 90 and to allow licensees,
under qualifying critena, to provide commercial service to paying subscnbers. Establish
exclusive license for multilateration systems in Major Trading Areas (MTAs) Trough
competitive bidding, but provide a mechanism for existing operators to godfather current
licenses.
License non-multilateration systems on a shared basis in designated subbands.
Clarify what constitutes harmful interference from Part 15 device and amateur operations as
defined In Part 90.361. (Basically, indoor operations and operations with low antenna heights
win not be considered hannfill interference.)
Make provisions for furler testing of muldlateradon systems to ensure that interference to
Me existing, widely deployed, and expanding Part 15, unlicensed operation is minimized.
These rules have been defined to accommodate various EMS services from multiple vendors.
The multilaterabon, or wideband, licenses will support vehicle location using a broad band signal.
Technically, a w~deband signal can be received with better time resolution
(Time Resolution
B0tdwid~
that can employ several techniques to accurately locate a signal source, typically a vehicle. Pulse
ranging techniques are typically employed. Thus, LMS services will be available for:
Vehicle location within approximately 50-200 feet depending on infrastructure and
interviewing te~Ta~n/obstacles;
Bit rates for voice/data from 1200 bps to in excess of 400,000 bps; and
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· If voice is not supported, packet technology can be employed and packet size can be tailored
for short, efficient, location messages.
Unlike GPS band location systems, these multilateration services can offer two-way and other
communication and integrated fleet management, emergency, vehicle secunty, smart/probe,
communication services. These EMS services should not be as susceptible as satellite to
shadouang/facing in urban areas. Additionally, EMS services ability to integrate location and
communication services should prove cost-effective when available.
The non-multilateration cards, essentially narrowband, are intended for non-commercial
applications and shared spectrum usage. Toll/RF tags are the best examples. Many of these
applications can be implemented under the Part 15 unlicensed rules, but can increase power and
achieve some interference protection benefits by licensing under Part 90.
It should be emphasized that Part 90 EMS operations in 902-928 MHz band have primary status
and Part 15, unlicensed, operation has secondary status. Thus, in Me event of interference,
Part 15 applications must cease operation or change installation or configuration to eliminate
interference.
A. 1.3.5.3 Meteor Burst Communications
the 1930s, researchers observed that ionized trails of meteors entering Me ear~'s atmosphere
win reflect radio waves. In the 1940s and 1950s, much research was conducted on meteor burst
propagation charactenstics. In Me 1950s and 1960s, as satellite technology emerged for '`beyond
line-of-sight" communication, interest in meteor burst communication waved. Nevertheless,
meteor burst communication has achieved cost effective application primarily in government
sponsored remote sensor data collection. The U.S. Forestry Service has placed snow/weather
sensors on remote western mountaintops to measure snow depths and melting to predict spring
river~creek flow. This "SNOTEL" program uses meteor burst communication from remote
mountaintop sites to communication hubs. The mutiny uses it as a backup to potentially
vulnerable satellite long range links. Meteor burst technology is also employed for truck fleet
management applications.
~:wCHRP`Phasc2.rps NCHRP3-51. Phase2FinaIReport
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The meteor burst communication channel phenomenon is illustrated in Figure A.~.3.53-~. When
a meteor trail sweeps into the earths atmosphere and is properly oriented, the transmit signal is
reflected to We receiver for as long as the trait persists. The occurrence of a properly oriented trail
is a statistical phenomenon in both start time, total time of occurrence, and channel
characteristics. This statistical nature makes meteor burst communication unsuited for tight real-
time applications. Table A.~.3.5.3-1 illustrates typical parameters for meteor burst
communication channels. The ITS applications for meteor burst focus on rural locations where
data sources and destinations can be sparsely located over an extended- geographical area. The
specific applications include:
· Automated weather stations;
· VMS;
Non-real-time control data such as timing plans;
· Kiosk database updates (not remotely interactive);
Non-real-time sensor data (monitored, but not control); and
Fleet management (e.g., CVO, transit).
;
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Table A.~.3.5.3~1
Typical Meteor Burst Communication Parameters
Parameter | Value
Coverage Distance 2000 km (1250 miles - maximum)
Carrier Frequency 40- 100 MHz
Transmit Power 200 - 2999 Watt
Bandwidth 100 kHz
Typical Bit Rates 1200- 19,200 bps(intermittent)
Trail Duration 0.2 - 1.0 seconds
Information Duty Cycle 2.5 - 5.0 percent
.
Average Message Delay 10 - 80 seconds
.
Worst Message Delay ~ ~ em_
The FCC rules for meteor burst are in 90.250 and only authorizes operations for the state of
Alaska. Coterminous U.S. operation is by FCC developmental authorization defined in
Subpart Q of Part 90.
L:~h~.~t NCH~ 3-51 · PI 2 Few Ream A1-189
Representative terms from entire chapter:
bit rates
