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Safeguarding helicopter communications
Safegu lteJico e : oillmtlnlcatl oils C
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Are Your Sensitive Transmissions Being Illicitly Monitored? by Lance Hillhouse
very flight program and public safety a g e n c y has s e n s i t i v e information that would compromise public safety and the patient's privacy. However, refraining from broadcasting sensitive information is no longer the only option available. The scenario below will illustrate an ideal system. A request for aeromedical evacuation is received at the communications center, and the helicopter responds to the scene. While en route, the flight crew has been updated on all information available via their Mobile Data Terminal. The dispatcher has updated the location data with LORAN coordinates. As the helicopter lands, the time and LORAN coordinates are logged simultaneously at the helicopter communications center and at the calling public safety agency. When the helicopter lifts off, the time, destination and the ETA are logged automatically. Total elapsed time is now 20-25 minutes. The flight crew gives a patient report to the receiving facility. This is the first voice t r a n s m i s s i o n of the flight. This scenario, with slight alteration, c o u l d d e s c r i b e a l m o s t any s c e n e response. You may wonder how this
E
Lance Hillhouse is a senior dispatcher f o r Methodist Hospitals o f Dallas EMS Communications/CareFlite. He has been an EMT a n d involved in EMS f o r 14 years. He is also an EMS instructor~examiner a n d an emergency medical dispatch instructor.
18
MAYOUNE1987 AMJ
may affect your service. We are all plagued with the problem of "Scanner Buffs." The security of public safety c o m m u n i c a t i o n s has always b e e n a concern. One of the methods to secure p u b l i c safety c o m m u n i c a t i o n s has been to establish "Code" systems. This does not always work, since there are n o t e n o u g h possible codes to cover every situation. It is not impossible or even difficult for an average person to obtain a copy of codes. Furthermore, by
comparing the plain language information to the blank spaces, a determined person can break the code. Radio security can also be assured by voice s c r a m b l i n g . The original scramblers available used simple speech inversion. This resulted in a signal referred to by many people as the "Donald Duck Speech." Not only did this device greatly reduce the radio range, it was not very secure. By careful monitoring, a scanner buff could
You should not discuss sensitive patient information over public airways without some form of radio security.
d e c i p h e r q u i t e a f e w words. S o m e t i m e s t h e s e w e r e e n o u g h to figure o u t w h a t t h e c o n v e r s a t i o n w a s a b o u t . T h e curr e n t g e n e r a t i o n of scramblers uses digital e n c r y p t i o n t e c h n i q u e s . T h e casual l i s t e n e r w i l l o n l y h e a r static w h e n t h e s y s t e m is w o r k i n g as d e s i g n e d . This p r o v i d e s a h i g h level o f s e c u r i t y w i t h out reducing the effective range of the r a d i o s y s t e m . T h e r e are m i l l i o n s o f p o s s i b l e c o d e c o m b i n a t i o n s available, r e d u c i n g to a l m o s t z e r o t h e c h a n c e s o f anyone breaking the code. However, w i t h t h e p r o p e r e x p e n s i v e a n d sophisticated equipment, any code can be broken. A second way of securing voice communications is b y t r u n k i n g . T r u n k i n g c o m b i n e s a n u m b e r o f freq u e n c i e s (usually five o r m o r e ) to maximize the spectrum efficiency. The r a d i o s c a n s c a n all c h a n n e l s a n d select a n u n u s e d c h a n n e l as t h e t r a n s m i t butt o n is d e p r e s s e d . C h a n n e l availability n o r m a l l y takes 0.3 s e c o n d s . ' This syst e m c a n a c c o m m o d a t e 3-5 t i m e s as m a n y r a d i o s as a c o n v e n t i o n a l system with the same number of channels available. It is e x t r e m e l y h a r d to m o n i tor b e c a u s e e a c h t i m e a m o b i l e u n i t t r a n s m i t s , it m a y u s e a d i f f e r e n t channel. The most promising method of increased spectrum efficiency and v o i c e s e c u r i t y is to e l i m i n a t e t h e voice.
Mobile data terminals placed in the ground vehicles and/or helicopters can communicate with a host computer p l a c e d at t h e c o m m u n i c a t i o n s center. This is a l m o s t totally s e c u r e as w e l l as being extremely spectrum efficient. C o m b i n e this w i t h a n A u t o m a t i c Vehicle L o c a t i o n S y s t e m (AVLS) a n d t h e n e e d for v o i c e t r a n s m i s s i o n s c a n b e f u r t h e r r e d u c e d . T h e M a g n a v o x Syst e m for e x a m p l e , t r a c k s t h e v e h i c l e l o c a t i o n b y LORAN C a n d d e a d recko n i n g . This i n f o r m a t i o n is t r a n s m i t t e d a u t o m a t i c a l l y o v e r e x i s t i n g r a d i o syst e m s to t h e h o s t c o m p u t e r . 2 O f f s h o r e N a v i g a t i o n Inc. (ONI) h a s a h e l i c o p t e r o p t i o n . W h e n e v e r t h e h e l i c o p t e r lifts o f f o r t o u c h e s , t h a t i n f o r m a t i o n is t r a n s m i t t e d a l o n g w i t h LORAN Coord i n a t e s to t h e h o s t c o m p u t e r . 3 T h i s o p t i o n c o u l d b e e x p a n d e d to use for f l i g h t f o l l o w i n g . At p r e d e t e r m i n e d intervals, a p i l o t w o u l d o n l y h a v e to press a b u t t o n to t r a n s m i t his p r e s e n t c o o r d i n a t e s to t h e h o s t c o m p u t e r . Receiving hospitals could be prog r a m m e d i n t o a s p e e d d i a l e r to facilitate easy a n d r a p i d t r a n s m i s s i o n . Most p r o g r a m s h a v e o n l y a f e w h o s p i t a l s to which they might transport scene r e s p o n s e victims. S h o u l d t h e local p u b l i c safety agencies use t h e s a m e o r c o m p a t i b l e AVLS a n d also b e c o n n e c t e d to t h e EMS or aeromedical agency by computer,
automatic updates of the exact location as well as p r o g r e s s o f e l e m e n t s r e s p o n d ing to s c e n e s c o u l d b e t r a n s m i t t e d a n d s h a r e d b y all i n v o l v e d a g e n c i e s simultaneously. M a n y systems a l r e a d y use c o m p u t e r s a n d s o m e f o r m o f AVLS. S o m e systems are u s i n g m o b i l e data t e r m i n a l s . Some systems are c o n n e c t e d b y c o m p u t e r to l o c a l p u b l i c s a f e t y a g e n c i e s . In t h e f u t u r e w e will see all t h e s e systems b e c o m e i n t e r c o n n e c t e d . This is n o t to b r i n g a b o u t a "Big B r o t h e r is W a t c h i n g " situation, b u t s i m p l y t o m a x i m i z e our scarce resources while providing o p t i m u m s e r v i c e a n d p u b l i c safety. The t e c h n o l o g y is h e r e , t h e f u t u r e is now. I Footnotes 1. Johnson, EF: Technical System Specifications. Clearchannel Ltr. 2. Sales Brochure: "Magnavox Automatic Vehicle Location System." Magnavox Advanced Products and Systems Company, 1986. 3. Sales Brochure and Specifications: "Fleet-Trak Automatic Vehicle Positioning System." Offshore Navigation Inc., 1987. 4. "Two Way Radio Technology." Communications News, August 1986. 5. Farris, CR: "Mobile Data Dispatch: the LA Project." Personal C o m m u n i c a t i o n s Technology, July/August 1986. 6. Szezutkowski, CF: "Voice Guard, A Digital System Approach to Speech Security." Personal Comm u n i c a t i o n s Technology, July/August 1986. 7. Noreen. GE: "Vehicle Location Technology, Evaluating Your Options." Personal Communications Technology, July/August 1986.
Mark Regan Productions
Broadcast Betacam Field Production
FULL SERVICE AEROMEDICAL VIDEO PRODUCTION COMPANY
H
WING ~ii
!i~il ¸
W munications, etc. tdors. Id procedures utilizing
; ~ a r k ~ i n g and Pubiic • All Video Productions your aircraft and flighl • ASHBEAMS Guidelim IDEAL FOR: FIRSTRESPONL
INCREASEDREVENUES.
* 10 years broadca,'
~adcast Quality.
CLIENTS SUCH AS: SAMARITAN AIR EVAC, STANFORD/SCVMC LIFE FLIGHT & GOOD SAMARITAN TRAUMA CENTER
3799 West Surrey Avenue
Phoenix, Arizona 85029
(602) 978-2020
AMJ
MAY/JUNE 1987
19
@
~@
,
Are Your Sensitive Transmissions Being Illicitly Monitored? by Lance Hillhouse
very flight program and public safety a g e n c y has s e n s i t i v e information that would compromise public safety and the patient's privacy. However, refraining from broadcasting sensitive information is no longer the only option available. The scenario below will illustrate an ideal system. A request for aeromedical evacuation is received at the communications center, and the helicopter responds to the scene. While en route, the flight crew has been updated on all information available via their Mobile Data Terminal. The dispatcher has updated the location data with LORAN coordinates. As the helicopter lands, the time and LORAN coordinates are logged simultaneously at the helicopter communications center and at the calling public safety agency. When the helicopter lifts off, the time, destination and the ETA are logged automatically. Total elapsed time is now 20-25 minutes. The flight crew gives a patient report to the receiving facility. This is the first voice t r a n s m i s s i o n of the flight. This scenario, with slight alteration, c o u l d d e s c r i b e a l m o s t any s c e n e response. You may wonder how this
E
Lance Hillhouse is a senior dispatcher f o r Methodist Hospitals o f Dallas EMS Communications/CareFlite. He has been an EMT a n d involved in EMS f o r 14 years. He is also an EMS instructor~examiner a n d an emergency medical dispatch instructor.
18
MAYOUNE1987 AMJ
may affect your service. We are all plagued with the problem of "Scanner Buffs." The security of public safety c o m m u n i c a t i o n s has always b e e n a concern. One of the methods to secure p u b l i c safety c o m m u n i c a t i o n s has been to establish "Code" systems. This does not always work, since there are n o t e n o u g h possible codes to cover every situation. It is not impossible or even difficult for an average person to obtain a copy of codes. Furthermore, by
comparing the plain language information to the blank spaces, a determined person can break the code. Radio security can also be assured by voice s c r a m b l i n g . The original scramblers available used simple speech inversion. This resulted in a signal referred to by many people as the "Donald Duck Speech." Not only did this device greatly reduce the radio range, it was not very secure. By careful monitoring, a scanner buff could
You should not discuss sensitive patient information over public airways without some form of radio security.
d e c i p h e r q u i t e a f e w words. S o m e t i m e s t h e s e w e r e e n o u g h to figure o u t w h a t t h e c o n v e r s a t i o n w a s a b o u t . T h e curr e n t g e n e r a t i o n of scramblers uses digital e n c r y p t i o n t e c h n i q u e s . T h e casual l i s t e n e r w i l l o n l y h e a r static w h e n t h e s y s t e m is w o r k i n g as d e s i g n e d . This p r o v i d e s a h i g h level o f s e c u r i t y w i t h out reducing the effective range of the r a d i o s y s t e m . T h e r e are m i l l i o n s o f p o s s i b l e c o d e c o m b i n a t i o n s available, r e d u c i n g to a l m o s t z e r o t h e c h a n c e s o f anyone breaking the code. However, w i t h t h e p r o p e r e x p e n s i v e a n d sophisticated equipment, any code can be broken. A second way of securing voice communications is b y t r u n k i n g . T r u n k i n g c o m b i n e s a n u m b e r o f freq u e n c i e s (usually five o r m o r e ) to maximize the spectrum efficiency. The r a d i o s c a n s c a n all c h a n n e l s a n d select a n u n u s e d c h a n n e l as t h e t r a n s m i t butt o n is d e p r e s s e d . C h a n n e l availability n o r m a l l y takes 0.3 s e c o n d s . ' This syst e m c a n a c c o m m o d a t e 3-5 t i m e s as m a n y r a d i o s as a c o n v e n t i o n a l system with the same number of channels available. It is e x t r e m e l y h a r d to m o n i tor b e c a u s e e a c h t i m e a m o b i l e u n i t t r a n s m i t s , it m a y u s e a d i f f e r e n t channel. The most promising method of increased spectrum efficiency and v o i c e s e c u r i t y is to e l i m i n a t e t h e voice.
Mobile data terminals placed in the ground vehicles and/or helicopters can communicate with a host computer p l a c e d at t h e c o m m u n i c a t i o n s center. This is a l m o s t totally s e c u r e as w e l l as being extremely spectrum efficient. C o m b i n e this w i t h a n A u t o m a t i c Vehicle L o c a t i o n S y s t e m (AVLS) a n d t h e n e e d for v o i c e t r a n s m i s s i o n s c a n b e f u r t h e r r e d u c e d . T h e M a g n a v o x Syst e m for e x a m p l e , t r a c k s t h e v e h i c l e l o c a t i o n b y LORAN C a n d d e a d recko n i n g . This i n f o r m a t i o n is t r a n s m i t t e d a u t o m a t i c a l l y o v e r e x i s t i n g r a d i o syst e m s to t h e h o s t c o m p u t e r . 2 O f f s h o r e N a v i g a t i o n Inc. (ONI) h a s a h e l i c o p t e r o p t i o n . W h e n e v e r t h e h e l i c o p t e r lifts o f f o r t o u c h e s , t h a t i n f o r m a t i o n is t r a n s m i t t e d a l o n g w i t h LORAN Coord i n a t e s to t h e h o s t c o m p u t e r . 3 T h i s o p t i o n c o u l d b e e x p a n d e d to use for f l i g h t f o l l o w i n g . At p r e d e t e r m i n e d intervals, a p i l o t w o u l d o n l y h a v e to press a b u t t o n to t r a n s m i t his p r e s e n t c o o r d i n a t e s to t h e h o s t c o m p u t e r . Receiving hospitals could be prog r a m m e d i n t o a s p e e d d i a l e r to facilitate easy a n d r a p i d t r a n s m i s s i o n . Most p r o g r a m s h a v e o n l y a f e w h o s p i t a l s to which they might transport scene r e s p o n s e victims. S h o u l d t h e local p u b l i c safety agencies use t h e s a m e o r c o m p a t i b l e AVLS a n d also b e c o n n e c t e d to t h e EMS or aeromedical agency by computer,
automatic updates of the exact location as well as p r o g r e s s o f e l e m e n t s r e s p o n d ing to s c e n e s c o u l d b e t r a n s m i t t e d a n d s h a r e d b y all i n v o l v e d a g e n c i e s simultaneously. M a n y systems a l r e a d y use c o m p u t e r s a n d s o m e f o r m o f AVLS. S o m e systems are u s i n g m o b i l e data t e r m i n a l s . Some systems are c o n n e c t e d b y c o m p u t e r to l o c a l p u b l i c s a f e t y a g e n c i e s . In t h e f u t u r e w e will see all t h e s e systems b e c o m e i n t e r c o n n e c t e d . This is n o t to b r i n g a b o u t a "Big B r o t h e r is W a t c h i n g " situation, b u t s i m p l y t o m a x i m i z e our scarce resources while providing o p t i m u m s e r v i c e a n d p u b l i c safety. The t e c h n o l o g y is h e r e , t h e f u t u r e is now. I Footnotes 1. Johnson, EF: Technical System Specifications. Clearchannel Ltr. 2. Sales Brochure: "Magnavox Automatic Vehicle Location System." Magnavox Advanced Products and Systems Company, 1986. 3. Sales Brochure and Specifications: "Fleet-Trak Automatic Vehicle Positioning System." Offshore Navigation Inc., 1987. 4. "Two Way Radio Technology." Communications News, August 1986. 5. Farris, CR: "Mobile Data Dispatch: the LA Project." Personal C o m m u n i c a t i o n s Technology, July/August 1986. 6. Szezutkowski, CF: "Voice Guard, A Digital System Approach to Speech Security." Personal Comm u n i c a t i o n s Technology, July/August 1986. 7. Noreen. GE: "Vehicle Location Technology, Evaluating Your Options." Personal Communications Technology, July/August 1986.
Mark Regan Productions
Broadcast Betacam Field Production
FULL SERVICE AEROMEDICAL VIDEO PRODUCTION COMPANY
H
WING ~ii
!i~il ¸
W munications, etc. tdors. Id procedures utilizing
; ~ a r k ~ i n g and Pubiic • All Video Productions your aircraft and flighl • ASHBEAMS Guidelim IDEAL FOR: FIRSTRESPONL
INCREASEDREVENUES.
* 10 years broadca,'
~adcast Quality.
CLIENTS SUCH AS: SAMARITAN AIR EVAC, STANFORD/SCVMC LIFE FLIGHT & GOOD SAMARITAN TRAUMA CENTER
3799 West Surrey Avenue
Phoenix, Arizona 85029
(602) 978-2020
AMJ
MAY/JUNE 1987
19