Communication Mediums for Signal, ITS, and Freeway Surveillance Systems Final Report (1996) / Chapter Skim
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A.1.3 Wireless Communications
A.1.3 Wireless Communications
Pages 132-197
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From page 132... ...
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 lowspeed local links, high-speed backbones, and TOC-to-TOC links.
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From page 133... ...
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From page 134... ...
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!
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From page 135... ...
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)
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From page 136... ...
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.~-!
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From page 137... ...
N / / ~ \ l ills LLJ 11 I CY A: at: o C' o m z At: z to o In V \ ~ me N e.
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From page 138... ...
In I: o · · 4I~ 0 In As o cO - ~ ~as ', ~ a' Is ce o cn CL o 0 It m = 0 ._ {d Of CO CtS ° ~ E ~ c Q ° C ~ c O U)
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From page 139... ...
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)
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From page 140... ...
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From page 141... ...
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)
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From page 142... ...
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 .
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From page 144... ...
o ~ -o a' o · it ~ o ~ it ~ ~ o · -~ ~ -~ · ce ~ o i - -~ an D: · ~o ~ o ~ t: ~d 1~ Tore 1~ ~ ~K id ~: ~ 0 ~ O U
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From page 145... ...
. Within a CF~ Part, one or more of Be following may be defined for transmitters: Transmitter power, Types of emission and bandwidths allowed, Antenna heights, Antenna gain, Pu~poses/organizabons eligible for licenses, Frequencies of operation and frequency coordination requirements for application, Location or area of transmitter operation, Requirements for type cer~ficadon of equnpment employed, Ground rules for use (exclusive, shared, etc.)
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From page 146... ...
, Me FCC: typically requires applicants to submit frequency coordination data win Me applications. Certain frequency bands are licensed, but require no coordination.
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From page 147... ...
bands; and 3) Over operations in Me ISM bands such as Automatic Vehicle Identification Systems (AVIS)
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From page 148... ...
The Part 15 regulation typically specifies that field strength measurements, when specified, be measured at a specified distance from Me transmitter antenna. Obviously, an increase or decrease in the transmit power will increase the field strength at any distance, but the field strength unroll also be determined by the antenna type, antenna gain, frequency, cabling/connector losses, etc., that are fixed once installed.
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From page 149... ...
o By - Z LtI En 9\ Lao J o > z F At: ~7 is At: .
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From page 150... ...
o O it| > 11 > Hi ~\ - ~; > - ~ c: J LLJ ~ Q I_ Z ~ L.I in g o · _ '18 o 18 · _ N a ~ I I ev O O 8 8 Z Be O 1 ad: lo :e an I Cal O A)
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From page 151... ...
It should also be noted Hat Part 15.205, "Restncted Bands of Operation," lists frequency bands where only spurious emissions are permitted (as opposed to fundamental or intended emissions) which include harmonics, residual out-of-band, etc.
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From page 152... ...
Part 15.219 defines rules for Part 15, AM band operations and at no more Man 100 milliwatts of power and provided that He total length of transmission line, antenna, and ground (if used) not exceed 3 meters.
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From page 153... ...
. The frequency bands of operation are 2.9-3.26 GHz, 3.267-3.332 GHz, 3.339-3.458 GHz, and 3.358-3.6 GHz.
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From page 154... ...
4. Supports bit rates from low speed to over 600 Mbps.
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From page 155... ...
He U.S., He FCC regulations for microwave in CF~ 47 are in the following parts: I Part 21-Domestic public fixed radio services (common camera)
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From page 156... ...
(3) Supportable Bit rates: Very low: below ~ Mbps; Low: below 45 Mbps; Medium: 45 - 135 Mbps; High: Above 135 Mbps.
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From page 157... ...
3. Practical bit rate capabilities by frequency band.
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From page 158... ...
. Frequency Bands, Radio Service MHz Common Carrier Private Radio Broadcast {Part 101)
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From page 159... ...
CARS: Cable Television Relay Service (Part 78) CAR, SAT SAT CARS TBD L:\NCHRP\Pha=.rpt NCHRP3-51 a Phase2FmalReport A1-151
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From page 160... ...
MDS: Multipoint Distribution Service (Part 21) OFS: Private Operational Fixed Point-to-Point Microwave Servicef Part 101, Subpart C and H)
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From page 162... ...
, Telecommunication System Bulletin TSB-IO-F, entitled 'interference Cr~tena for Microwave Systems." Applications to the FCC for new licenses must include frequency coordination data demonstrating that the new system win not interfere with existing systems and can operate win anticipated interference from existing systems. In fact, new applicants must notify existing system operators and provide an opportunity for comments concerning Me new instaBation.~ Microwave can be employed for venally any ITS link, similar to wire or fiber, as it can support bits rates from the low speed RS 232 bit rates of 1200 to 19,200 BPS to SONET OC-3 rates (155 Mbps)
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From page 163... ...
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From page 164... ...
/ z lo At: z z z to o ~ > ~L cn Q O ~ Q go Q A)
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From page 165... ...
. Maximum bandwidth 25 or 50 MHz _ Supportable bit rates - Standard RS 232 rates and up to 4 DS-1 (4 x 1.544 Mbps)
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From page 166... ...
Table A.~.3.3-5 Cost Components of Fiber and Microwave Fiber Microwave TerminaUmultiplexing equipment ~ ~ e I= Right-of-way- Tower cost = Site real estate ~ ~~ Site building/shelters Fiber costs ~ _ I ~ Fiber installation costs Tower, antenna, waveguide installation costs Power plant costs Power plant costs ~ Microwave is ~e w~eless ophon ~at can support higher bandw~ requ~rements of backbone links, video, and TOC-to-TOC links. Table A.~.3.3-6 presents a comparison of fiber versus riicrowave links.
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From page 167... ...
· Interference-free · No r~ght-of-way operation problems · No license required, · Compatible non-shared bandwidth/bit rates operation unless · Mobile/temporary/ planned flexibility · Can be low cost requirements option (high · Licensing available bandwidth/bit rate with desired and/or short distance bandwidth requirements) · Near line-of-sight · Right-of-way available available and cost effective Note ]
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From page 168... ...
x x x x 1 1 1 1 ~ O _ ~ O I I l 1 1 ~ ~u, O ~ I WI-F01 ~l L~l ~ o~l ~ XX' X~X~' 1 1 - ~to c ~tn ca 1 1 ~ ~o c' z ~r y z ~r z ~ c]
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From page 169... ...
The ITS community typically refers to Part 15, unlicensed, spread spectrum as "spread spectrum." This shortening is probably an incorrect oversimplifictibon because spread spectrum is applicable to virtually any frequency band: licensed or unlicensed. Currently, most legacy FCC regulations do not accommodate spread spectrum, although the FCC seems to be open to suggested rule changes Cat improve efficiency of spectrum utilization Cat might eventually allow wider deployment of spread spectrum.
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From page 171... ...
Table A.~.3.4-2 Part 15.247 Frequency Hop/Maximum Supportable Bit Rates Maximum ~ Modulation Maximum Bit rate Maximum Bit rate Maximum Bit rate Band Bandwidth .5 bitsiseclHz 1/bit/secondlHz 2 bit/secondlHz 902-928 MHz 500 kHz 250 MbiVsecond 500 k bibsecond 1 MbiVsecond 2.4-2.485 GHZ 1 MHz 500 k bits/second 1 MbiVsecond 2 MbiVsecond 5.7-5.8 GHz Most use substantially less modulation bandwidth supporting He typical RS 232 bit rates of 300, 1200, 2400, 4800, 8600, 19,200 bits/seconds.
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From page 172... ...
3. Ratio of pseudorandom bit rate to data bit rate (always an integer)
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From page 175... ...
users, Men multiple users can share (i.e., coexists on Be same frequency band in the same geographic area. This technique can be employed to provide what is referred to as "Code Division Multiple Access" or CDMA.
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From page 176... ...
Part 15.247 requires FHSS or DSSS to use ~ watt of transmit power essential for greater range. Spread spectrum has essentially the same range as non-spread spectrum assuming no interference or mul~pa~.
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From page 177... ...
Table A.~.3.4-6 Part 15.247 Spread Spectrum Maximum Repeateriess Distances | Parameter l Band | 2.4 GHz Band 5.8 GHz Band | Transmit Power, Pt. dBm l 30 dBm | 30 dBm 30 dam l | Receiver Sensitivity, P., dBm l -90 dBm | -90 dam -90 dam Link Budget, Pb, dB l -120 dB | -120 dB -120 dB Frequency,GHz | 0.915 GHz | 2.41675 GHz 5.8 GHz Range, km, O dbi gain Antenna | 26.22 km | 9.93 km 4.14 km l Range, km, 6 dbi gain Antenna 52.31 km 19.80 km 8.25 km 1.6 km = 1 mile L;\NCHRP`Phasc2.'p ~NCHRP 3-51 · Phase 2 FmaI Report A1-169
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From page 178... ...
Thus, Me Tree ISM bands in Part 15.247 can support approximately Me following maximum bit rates as shown in Table A.~.3.4-7. Table A.~.3.4~7 Maximum Theoretical Direct Sequence Spread Spectrum {DSSS} Bit Rate Band (Bandwidth)
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From page 179... ...
Supported bit rates F Jurisdictions considering spread spectrum should carefully evaluate the current and future impact of unlicensed operations, which provides no legal protection from interference whether unintentional or malicious. Current unlicensed applications in the band include: 1.
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From page 180... ...
Table A.~.3.4~S Part 15 ISM Bands, Shared Service Priority List Band Service Applicable FCC Shared Priority Rules 902 - 928 MHz ISM Part 18 1 US Government Radar 2 US Gov. Fixed & Mobile Radio 3 Location Monitoring Part 90 4 Amateur Part 97 5 ~ Unlicensed ~Part 15 ~6 2.400 - 2.4835 GHz ISM Part 18 1*
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From page 181... ...
PEMR services are important to ITS for He following reasons: The allocated frequencies are in legacy bands below 512 MHz, In He 800/900 MHz bands, and to a lesser extent in hider microwave bands. The lower frequency bands can often support significantly greater repeaterless ranges by sky wave or ground wave propagation.
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From page 182... ...
~,, The combinations and details of these multiple and shared assignments are based on more Man 50 years of legacy evolution, especially in Me lower frequency bands below 512 MHi. Thus, it is not possible to easily present a concise listing of all frequency assignment and application.
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From page 184... ...
Ad If Q ~9 ._ On G ~: tg _ ~ o )
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From page 185... ...
220-222 MHz 1 Subpart T 421 - 430 MHz | Radio location services 450 - 470 MHz Industrial, road transportation, public safety 570 - 512 MHz | Subpart L (TV broadcast sharing) 806 - 821 M Hz | Specialized Mobi le Radio ( S M R)
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From page 186... ...
· Consolidate Me current 20 radio services into fewer services (ideally less than 5) to create more efficient allocation frequency pools (e.g., currently no forestry service in NYC, but unused frequencies)
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From page 187... ...
to consolidate frequency coordination. Currently, the refanning bands are divided into 20 services for He purposes of frequency coordination.
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From page 188... ...
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.
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From page 189... ...
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)
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From page 190... ...
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.
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From page 191... ...
. (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)
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From page 192... ...
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~.
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From page 193... ...
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 ~:\NCHRP`Phase~rp ~NCHRP 3-51 · Phase 2 final Report Al-185
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From page 194... ...
Nevertheless, meteor burst communication has achieved cost effective application primarily in government sponsored remote sensor data collection.
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From page 195... ...
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 realtime applications.
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From page 196... ...
l in o LO / /~ An J o 1' L\= / an \ oo of of oo ~3 ,`1 Z r lo ME Be O Z _ CL z z a: a: z lo 1 Be _ Cot Z ~ lo C,8 m lo
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From page 197... ...
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.
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