Radio Training Slides

8/16/2019 Radio Training Slides

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Public Safety Radio Bands

• VHF-Low Band: 25 MHz to 5 MHz

• VHF-Hi!": #$% MHz to #&' MHz

• (HF: '% MHz to 5#2 MHz

• & MHz )new*

• % MHz• '+, Hz )new*


2/62

."y is t"is a /0oble1

• Radios only o/e0ate in one band3

4 Multi-band 0adios a0e 0a0e and

e/ensi6e

• 7f 8!ency 8 uses VHF and 8!ency Buses (HF9 t"ey cant tal; to eac"

ot"e0 (• >?"ey "a6e /lanned a"ead3

4 ?wo 0adios in a 0i!9 etc+


3/62

P0o/a!ation Basics- F0ee S/ace Pat"

Loss• Pat" Loss )in dB* @ 2 Lo!A'πdλC

4 ."e0e: d is distance in 1ete0s

λ is wa6elen!t" in 1ete0s

λ @ s/eed of li!"tf0eDuency

• So: as f0eDuency inc0eases9 /at" lossinc0eases

• ?"is 1eans t"at if e6e0yt"in! else we0e eDual9

a syste1 at a lowe0 f0eDuency would 0eac"fa0t"e0 t"an a syste1 at a "i!"e0 f0eDuency

• But>ot"e0 facto0s a0e at /lay as well


4/62

P0o/a!ation E Band

"a0acte0istics• VHF Low Band )$-5 MHz*4 Best /0o/a!ation in unde6elo/ed and "illy te00ain4Poo0 buildin!

/enet0ation

• VHF Hi!" Band )#5-#&' MHz*4 Ve0y !ood /0o/a!ation in unde6elo/ed and "illy te00ain4Mode0ate

buildin! /enet0ation• (HF )'5-5#2 MHz*

4 ood /0o/a!ation in unde6elo/ed and "illy te00ain4ood buildin!/enet0ation

• &% MHz4 Poo0 /0o/a!ation in unde6elo/ed and "illy te00ain4Ve0y !ood buildin!

/enet0ation44 & cu00ently subGect to incu1bent tele6ision stations in so1e a0eas

4 % cu00ently subGect to inte0fe0ence f0o1 co11e0cial ca00ie0s

• '+, Hz4 Mic0owa6e /0o/a!ation used fo0 s"o0t 0an!e ).i-Fi ty/e* o0 /oint-to-/oint lin;s


5/62

F0eDuencies 6s+ "annels

• 8 f0eDuency is a /oint in t"e 0adios/ect0u1

4 /a0t of w"at desc0ibes a c"annel• 8 c"annel is a set of /a0a1ete0s t"at

can include one o0 1o0e f0eDuencies9?SS tones9 na1e9 etc+

• =a1/le: V8LL is a c"annel wit"t0ans1it and 0ecei6e f0eDuency#55+&525 MHz9 ?SS tone of #5+& Hz


6/62

?SS )PL* ?ones

• PL stands fo0 P0i6ate Line9 a Moto0olat0ade1a0;

• It"e0 na1es include ode ua0d9 ?one SDuelc"9 all ua0d9 "annelua0d9 Juiet "annel9 P0i6acy ode9Sub-audible ?one9 etc+

• Kene0ic te01 is ?SS 4ontinuous ?one oded SDuelc"Syste1


7/62

."at 80e ?"ese ?ones

• 8 PL tone is a sub-audible )ba0ely audible*tone t"at is sent alon! wit" t"e t0ans1ittedaudio

• 8 0ecei6e0 t"at "as ?SS decode )a+;+a+ a0ecei6e PL tone* acti6ated will only o/en itss/ea;e0 if t"e co00ect tone is 0ecei6ed

• PL tones a0e diferent t"an tones used to set

o /a!e0s )two-tone seDuential /a!in!*• Re1e1be0>PL tones a0e sub-audible andcontinuous>t"ey a0e bein! sent t"e enti0eti1e a 0adio is t0ans1ittin!


8/62

Standa0d ?SS ?one

?able


9/62

."at 80e ?"ey (sed Fo0

• PL ?ones a0e used to MASK inte0fe0ence

• ?"ey NI


10/62

."at 80e ?"ey (sed Fo0

)cont+*• (sed to acti6ate 0e1ote lin;s

• (sed to access 0e/eate0s


11/62

NS 4 Ni!ital oded

SDuelc"• 8+;+a+ Ni!ital P0i6ate Line )NPL*• Si1ila0 to ?SS9 but uses a di!ital

code instead of an audio tone• (sed on analo! 0adio syste1s9

e6en t"ou!" it is a di!ital code


12/62

=ncode 6s+ Necode

• PL )o0 NPL9 et+c* Encode 1eans to t0ans1itt"e tone

• Decode 1eans t"at t"e 0ecei6e0 will listenfo0 t"e tone and not let anyt"in! t"0ou!"unless t"e co00ect tone is 0ecei6ed

• ?Q and RQ tone can be die0ent

• Radio can be set to ?Q tone but "a6e no RQtone )all t0aOc is 0ecei6ed*

• 7f in doubt9 dont /0o!0a1 RQ tone

• KMonito0 function by/asses RQ tone


13/62

Si1/le

• Ve0y Reliable

• Li1ited Ran!e

• Radio "annel uses # f0eDuency


14/62

Nu/le

• Radio "annel usin! 2 f0eDuencies9 F0eD # total; f0o1 0adio 8 to 0adio B9 and F0eD 2 to tal;f0o1 0adio B to 0adio 8

• =ac" use0 1ust be line of si!"t wit" eac" ot"e0

• =a1/les: o0dless ?ele/"one syste1s9 w"ic"bot" /a0ties can tal; at t"e sa1e ti1e andlisten at t"e sa1e ti1e+

f#

f2


15/62

Base Station 4 Hei!"t 71/0o6esRan!e

(nit#

Dispatch

Center

(nit

2 (nit

(nit'

So1e unitsdont "ea0t0ans1issionbecause ofobst0uctions


16/62

Base Station 4 Hei!"t 71/0o6esRan!e

(nit#

Dispatch

Center

(nit

2 (nit

(nit'

Nis/atc"e00elays 1essa!e4 "ea0d by allunits


17/62

Re1ote Base I/e0ation

(nit#

(nit

2 (nit

(nit'

DispatchCenter

Re1oteLin;

Mic0owa6e9P"one Line9etc+


18/62

on6entional Re/eate0

• Recei6es a si!nal on one f0eDuency and0et0ans1its )0e/eats* it on anot"e0 f0eDuency

• Placed at a "i!" location

• 7nc0eases 0an!e of /o0table and 1obile 0adioco11unications

• 8llows co11unication a0ound obst0uctions)"ills9 6alleys9 etc+*

• (se0 0adios 0ecei6e on t"e 0e/eate0s t0ans1itf0eDuency and t0ans1it on t"e 0e/eate0s0ecei6e f0eDuency )se1i-du/le*


19/62

f#f2 f2

f2

f2f#RQ ?Q

on6entional Re/eate0

8ll units wit"in 0an!e of0e/eate0 "ea0 allt0ans1issions t"0ou!"t"e 0e/eate0

(nit#

(nit

2 (nit

(nit'

DispatchCenter

f2

Re/eate0


20/62

PN 2

PN #

PN $

PN '

FN #

FN 2

FN $

P. #

P. 2P. $

on6entional Syste1s

When one user is talking, other users on that

channel are cannot talk, even though other

repeaters in the area may be idle.o11unicatin!

7dle

7dlePD 3 cannot talk to PD 4because PD 1 is using the

repeater

Public works repeater

may be idle 9! o" the

time, which means that

"re#uency is largely

wasted


21/62

?0un;in!

• ?0un;in! is a 1et"od of co1binin!0e/eate0s at t"e sa1e site to

Ks"a0e f0eDuencies a1on! use0s• S/ect0ally eOcient

• 8llows 1any 1o0e K6i0tual

c"annels )called tal;!0ou/s* t"ant"e0e actually a0e f0eDuencies

• o1/ute0 cont0olled


22/62

f#

f2

f2

f2f#RQ ?Q

?0un;ed Syste1

f'f$RQ ?Q

ff5RQ ?Q

PN #

PN 2

S"a0ed Re/eate0

PN $

FN #

FN 2

f$

f'

$%re#uencies are dynamically

assigned by system controller $&ser radio may be on a di""erent

"re#uency every time it transmits$'alkgroups are (virtual) channels$Possible to have many more

talkgroups than actual "re#uencies$*tatistically, not all talkgroups will

be active at the same time

Syste1ont0olle0


23/62

?0un;ed Syste1 I/e0ation

• (se0 0adios continuously 1onito0 a dedicated Kcont0ol c"annel

• ."en a use0 wants to t0ans1it9 t"e use0s 0adio 1a;es a

0eDuest to t"e syste1 cont0olle0

• 7f a 0e/eate0 is a6ailable9 t"e syste1 cont0olle0 te1/o0a0ily

assi!ns t"at 0e/eate0 c"annel to t"e tal;!0ou/ 1a;in! t"e0eDuest

• ?0ans1ittin! use0s 0adio will !i6e a Ktal; bee/9 indicatin! t"ata 0e/eate0 "as successfully been assi!ned>use0 can tal;

• 8ll use0 0adios 1onito0in! t"at tal;!0ou/ auto1atically switc" to

t"e f0eDuency of t"e assi!ned 0e/eate0 and "ea0 t"et0ans1ission

• ."en t"e t0ans1ission is co1/lete9 all 0adios 0etu0n to1onito0in! t"e cont0ol c"annel


24/62

Multi-Site Syste1s

• on6entional

4 Re/eate0s on sa1e out/ut9 die0ent in/ut

4 Lin;ed 0e/eate0s on die0ent f0eDuencies4 Re1ote Recei6e Sites

• Votin!

4 Si1ulcastin!

• ?0un;in!4 Roa1in!

4 Si1ulcastin!


25/62

Re/eate0s on sa1e out/ut f0eDuency9 die0entin/ut f0eDuency )o0 PL tone*

(se0s 1ust 1anually c"an!ec"annel to die0ent 0e/eate0de/endin! on t"ei0 /"ysical

location

Inly one 0e/eate0 acti6e at a

ti1e


26/62

Re/eate0s on sa1e out/ut f0eDuency9 die0entin/ut f0eDuency )o0 PL tone*


location

Inly one 0e/eate0 acti6e at a

ti1e


27/62

Lin;ed 0e/eate0s on die0ent f0eDuencies


location

Lin;)1ic0owa6e9/"one line9etc+*

Bot" 0e/eate0sacti6e at t"esa1e ti1e wit"sa1e t0aOc9 but

on die0entf0eDuencies


28/62

Votin! Recei6e0s

(se0s do not need to c"an!ec"annel de/endin! onlocation+ Syste1 )6ote0*

auto1atically /ic;s best0ecei6e towe0 site+

Lin;)1ic0owa6e9/"one line9etc+*

RX OnlySite

Vote0

CentralTransmitt

er

Vote0 )co1/a0ato0* c"oosesbest 0ecei6ed si!nal and sendst"at si!nal to t"e t0ans1itte0


29/62

Si1ulcastin!

?0ans1itte0s 1ust be ca0efullysync"0onized to /0e6entinte0fe0ence in o6e0la/ a0eas

Bot" 0e/eate0s t0ans1it at t"esa1e f0eDuency at t"e sa1eti1e

Lin;

)1ic0owa6e9/"one line9etc+*


30/62

8nalo! 6s+ Ni!ital

Modulation


31/62

o11on 8nalo!

Modulation Sc"e1es• FM 4 F0eDuency Modulation

• 8M 4 81/litude Modulation

• SSB 4 Sin!le Sideband 8M

• 8l1ost all analo! /ublic safetyco11unications use FM

• 8M is used fo0 B 0adio9 ai0c0aftco11unication


32/62

F0eDuency Modulation

)FM*• ?o 1odulate 1eans Kto c"an!e o0 Kto

6a0y

• F0eDuency Modulation 1eans c"an!in!t"e f0eDuency of t"e t0ans1itte0 in/0o/o0tion to t"e audio bein! /ic;ed u/by t"e 1ic0o/"one

• ?"e 0ecei6e0 detects t"e c"an!e int0ans1itte0 f0eDuency and uses it to0e/0oduce t"e audio si!nal at t"e s/ea;e0


33/62

F0eDuency Modulation 4 8n

7llust0ation

'ime +milliseconds,

- o l t s

1

1

'ime +milliseconds,

% r e # u

e n c y + / 0 1 ,

124.32

124.312

124.192

Mic0o/"one Iut/ut: ?0ans1itte0 Iut/u


34/62

FM Radio Bloc; Nia!0a1s

)si1/lied*

/odulator % 5mpli"ier /ic*ound

Waves

5udio *ignal % *ignal

5mpl"ied %

*ignal

5udio

5mpli"ier Demodulator *pkr

5mpli"ied

5udio *ignal 5udio *ignal

% *ignal

?0ans1itte0

Recei6e0


35/62

Ni!ital Modulation

• Si!nal f0o1 1ic0o/"one is con6e0tedf0o1 a 6olta!e into nu1be0s t"0ou!"

a /0ocess called sa1/lin!• ?"ose nu1be0s a0e /0ocessed by aco1/ute0

• Bina0y info01ation )ones and ze0os*

is sent o6e0 t"e ai0 instead of analo!)continuous 6olta!e* info01ation


36/62

Sa1/lin!

112 3 1 63 2 12 7

11111 11111 1 111 11 111 111111 111

1 199 63 189 17 7411 11111 11111 111 1111 11111 111

'ime +milliseconds,

322

112

3

1

63

2

12

7

1

199

63

189

17

74


37/62

F0eDuency S"ift eyin! 4

8n 7llust0ation

'ime +milliseconds,

- o l t s

2

1 1 1 1

'ime +milliseconds,

% r e

# u e n c y + / 0 1 ,

124.32

124.312

124.192

Ni!ital Bitst0ea1: ?0ans1itte0 Iut/ut:


38/62

Vocodin!

• Vocodin! is used to 0educe t"e a1ountof data t"at needs to be sent o6e0 t"e ai0

•(sed to 0educe necessa0y bandwidt" 4conse06es s/ect0u1

• Ko1/0esses di!ital audio 4 analo!ousto +1/$ 6e0sus +wa6 audio les

• (ses ;nown "u1an s/eec"c"a0acte0istics to Kll in !a/s of datat"at is 0e1o6ed


39/62

Ni!ital Radio Bloc;Nia!0a1s

)si1/lied*

*ampler +5D :onverter,

/odulator % 5mpli"ier /ic*ound

Waves

aw 5udio

*ignal

aw Digital

*ignal% *ignal

5mpli"ied %

*ignal

100111010011

-ocoder

1100101

;ncoded

Digital *ignal

D5

:onverter Demodulator *pkr

*ound

Waves

econstructed

5udio *ignal

Decoded

Digital *ignal% *ignal

100111010011

-ocoder

1100101

;ncoded

Digital *ignal

?0ans1itte0

Recei6e0


40/62

?"e Ni!ital Radio

KP0oble1• Pa0a1et0ic 6ocode0 uses ;nown "u1an 6oice

c"a0acte0istics to encode and decode data

• ."en bac;!0ound noise )non-"u1an noise* is

/0esent9 6ocode0 doesnt always ;now "ow to0es/ond

• (n/0edictable 0esults )!a0ble9 loss ofco11unication9 etc+*

• 7n a si1ila0 situation9 an analo! 0adio would

t0ans1it t"e bac;!0ound noise 0i!"t alon! wit"t"e intended audio )bac;!0ound noise 1i!"to6e0/owe0 6oice9 but so1e audio is still 0ecei6ed*


41/62

Possible Pe01utations• VHF 8nalo! on6entional Si1/le

• (HF 8nalo! on6entional Si1/le

• % MHz 8nalo! on6entional Si1/le

• VHF 8nalo! on6entional Re/eate0

• (HF 8nalo! on6entional Re/eate0

• % MHz 8nalo! on6entional Re/eate0• VHF Ni!ital on6entional Si1/le

• (HF Ni!ital on6entional Si1/le

• % MHz Ni!ital on6entional Si1/le

• VHF Ni!ital on6entional Re/eate0

• (HF Ni!ital on6entional Re/eate0• VHF 8nalo! ?0un;in! Re/eate0 )6e0y 0a0e*

• (HF 8nalo! ?0un;in! Re/eate0 )0a0e fo0 /ublic safety*

• % MHz 8nalo! ?0un;in! Re/eate0

• VHF Ni!ital ?0un;in! Re/eate0

• (HF Ni!ital ?0un;in! Re/eate0

• % MHz Ni!ital ?0un;in! 0e/eate0


42/62


43/62

."at is


44/62

."at is


45/62

=istin! VHF Syste1s: 8l0eady a /0oble1+


46/62

#55+&'5 #55+&

#55+&&5

2HzBandwidt"

2Hz

Bandwidt"

2HzBandwidt"

O#erlapO#erlap

#55+&52 #55+&&

8


47/62

#55+&'

5 #55+&

#55+&&

5 #55+&52 #55+&&

7.5K!Channe

lSpacin

"

11K!$an%&i%t

h

?"is 0e/0esents analo! 6oice wit" a ##Hz necessa0ybandwidt"

8


48/62

Still a 6e0y 1ino0 o6e0lay in t"e VHF band+(HF band will "a6e no o6e0lay because of #2+5Hz "annel S/acin!+

#55+&'

5 #55+&

#55+&&

5 #55+&52 #55+&&

7.5K!Channe

l

Spacin"

'.1K!Bandwidt

"

N77?8L


49/62

."at No 7


50/62

."y


51/62

Mi!0ation P0oble1s

• P0oble1s can occu0 w"en bot" wideband and na00owband a0eused to co11unicate on t"e sa1e c"annel+4 "annels a0e /0o!0a11ed fo0 eit"e0 wide o0 na00owband+4 "annels 1ust be /0o!0a11ed consistently fo0 all 0adios in use+

•


52/62

Syste1 Reliability

Failu0e Modes E Bac;u/ Plans


53/62

Rebandin!

% MHz Inly


54/62

."at is Rebandin!

•


55/62

Syste1 Failu0e9 Reliability9Bac;u/ Plans


56/62

Possible Points of Failu0e

• (se0 Radio4 Vocode0

4 Loss of Powe0 )dead batte0y*

• Re/eate04 Loss of Powe0 )downed /owe0 line*

4 8ntenna Failu0e )windsto01*

4 atast0o/"ic Site Loss )?o0nado*

• Lin; )?# line9 1ic0owa6e lin;9 etc+*4 Loss of Powe04 8ntenna Failu0e

4 (tility Iuta!e )/"one line*


57/62

ey 4 "oose t"e 1ost 0eliable co11unication/at" /ossible fo0 t"e Gob at "and

(atr)l O*cer t)Dispatch

• Most 0eliable /at" isa 0e/eate0 because1any ti1es t"eoOce0 will be out of

0an!e of t"edis/atc" cente0

+ire,"hter t) -C

• Most 0eliable /at"is si1/le becauseof t"e s"o0t 0an!ein6ol6ed+ Re/eate0failu0e is no lon!e0

an issue9 no0 isbein! out of 0an!eof t"e 0e/eate0+


58/62

Miti!ation ?ec"niDues

• Ha0dened Sites

• Bac;u/ Powe0

• RedundantBac;u/ Sites

• I6e0la//in! o6e0a!e

• P0e/lannin! )i+e+ 0adio /0o!0a11in!*

• Po0table?0ans/o0table Syste1s

• (se0 ?0ainin!


59/62

7nte0o/e0ability E Mutual8id


60/62


61/62

P0e/lannin! is ey to

7nte0o/e0ability• Radios 1ust be /0o!0a11ed wit" 1utual

aid E inte0o/ c"annels befo0e"and

• ."en t"e Kbi! one "its9 its too late

• P0o!0a1 as 1any 1utual aid c"annels into0adios as you "a6e ca/acity fo0

• =stablis" co11unications )1a;e su0e t"ey

wo0;* befo0e !oin! into t"e eld• o11on na1in! con6ention is i1/o0tant


62/62

P0actical ?i/s

• Hold 0adio in "and fo0 1ai1u1 0an!e )0adio on beltwit" s/ea;e0 1ic !0eatly 0educes 0an!e unless 0e1oteantenna is used*

• Nont swallow t"e 1ic 4 2 inc"es away

• Nont yell 4 causes o6e0de6iation9 disto0ts audio9un0eadable

• now "ow t"e 0adio wo0;s 4 scan9 /0io0ity scan9 scan0esu1e9 tal;a0ound9 1onito09 etc+

• =nsu0e t"e c"annel is co00ectly /0o!0a11ed fo0na00owband o0 wideband o/e0ation )if t"is isnt an o/tionin t"e 0adio9 its /0obably not na00owband ca/able*

• (se consistent c"annel na1es w"en /0o!0a11in!

Documents

Radio Training Slides