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Train Crash Scenario

- a draft spectrum assessment example

-

MESAUser needs and scenarios drive spectrum

requirements

by

Steffen Ring

Chairman Project MESA Steering Committee

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• The Scenario as it developed• Broadband Communication

needs• Spectrum Assessment• Conclusion

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ScenarioA massive train accident in one of the largest cities in the world. A high-speed passenger train and a freight train pulling numerous tank cars of propane and hydrochloric acid have been switched onto adjacent tracks. The center track closed for rail replacements. The scene is set for disaster. And it gets worse...

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The situationA new sports stadium build upon land

reclaimed from a cleaned-up waste site parallels the three sets of railroad tracks that are in daily use for commuter, freight and high-speed passenger operations.

It is late Saturday afternoon. A steady 20 MPH wind is blowing right into the stadium from the direction of the tracks. 65000 people is watching the football game. Parking lots are full. A concert and fireworks show is scheduled for later.....

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The Event• The northbound passenger train approaching the stadium on

the inside track. 10 cars, 400 passengers, dual-tandem engines. Speed 100 Km/h.

• The southbound freight train is rolling through with 4 cars of hydrochloric acid and 8 cars of propane. Total 121 cars pulled by 5 engines in tandem, speed 45 70 Km/h.

• Behind the stadium the freight train is unexpectedly switched to the center track ....

• The entire event unfolds in less than a minute:• First engine reaches the point where the track has been

removed. Five diesel locomotives leave the track pulling 16 cars with them. Acid leaking out producing a deadly fog blowing into the stadium. Propane cars remain upright.

• Engineer of the passenger train is helpless. Engine and 5 passenger cars leave the track. Impact is deadly.....

• Football game stopped. Panic breaks out on the entire stadium...

• 10.000+ cell phones try to call for help at the same time.........

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Mobile Ad-Hoc Network

” The Moving Hot-Spot”

Master Node

Backhaul Link

Full C3 @ scene:•Command•Control•Communication

UPLINK

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Broadband spectrum assessmentExample2:Train Disaster BASIC BROADBAND SCENARIO PARAMETERS

• Hot-spot area: 1 Km2

• No of Paramedical EMS staff: 120– 40 ambulances shuttelling

• No of HazMat Staff: 18• Firefighters: 25

– 5 Trucks

• Rescue Squad Members: 50– 5 Robots deployed for wreckage inspection

• Law Enforcement Officers: 35

1 cell: Circular, r = 500 m

• No of MESA Robots: 5

– Streaming Video Visible Light (MPEG4)

– Control Carrier

CrashArea

• Air Surveillance by video

• Ground Transport Logistics

• Road access and route assistance

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Some relevant applications

• 1) No of active Streaming Video units: 45 (+ 5 Robots with Cameras)

• 2) EMS Still Picture sequencing units: 50 units

• 3) Fingerprint Scanning: 20 Units

• 4) IP Voice Streaming

The M.1390 Methodology calls for separate calculations of spectrum requirements, Uplink and Downlink, application by application.In typical ”hot-spot communications” the upink (information sent FROM the hot-spot)will be the most busy.In this draft example we shall therefore only consider the uplink requirements, and for clarity only calculate 1) and 2)

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Broadband Communication Applications- typical data speeds to accomodate -

• Online Video streaming (MPEG4 Compression @ 700 kBPS

• Stills from scene (Patients) (JPEG @ 250 kBytes)

• Online IP Voice streaming (@20kBPS)

• Fingerprint Scanning remote matching– 500 dpi (AFIS Standard from Police/Law Enforcement)

– 8 bit dynamic range (256 Gray-scale resolution)

– Image 1 x 1 Inch : File size 2 Mbit uncompressed

From FingerprintTo

Mugshot

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Emergency and Medical Services (EMS)

Remote Patient Monitoring

Frontline Medical Assistanceby Broadband Wireless Networking:

Video and Image SequencingElectro Encephalographic data (EEG)Electro Cardiograph (ECG)Blood PressureTemperature

Bit-rates saves lives

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Mobile Robotics• Automated inspection of non-accessible areas• Rescue of people from hazardous areas• Anti terrorist actions• Incident response both tactical and non-tactical

• Urban warfare• Haz-Mat Handling• Airborne control

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The basic equationsRec. ITU-R M.1390

• Fterrestrial - the weighted summation of co-existing individual spectrum components Fes [MHz]– Here we consider Fes as the sole component required

to host the PPDR Broadband requirements as outlined in these examples

FTerrestrial = αesβ Σ Fes

Fes =Tes

Ses

[MHz] ,

Where Tes [Mbit/s/cell] is theTraffic pr Cell, and

Ses [Mbit/s/MHz/cell] is the net system cell capacity

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Geographic ConsiderationsUplink calculation Streaming Video

1) Selection of ”e” – environmental type: Combination of Density and Mobility”e” Dense Urban

2) Cell geometry:Circular, r = 500 m, Cell_Areae = 1 Km2

3) Service type”s” = High Multimedia, Packet SwitchedNet_User_Bit_Rates = 1000 kbit/s (MPEG4 streaming @700 kbit/s) + overhead.

4) Population Density,All Units Operating:Pop_Densitye = 50 [Km-2]

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Geographic and Market Considerations Uplink calculation Streaming Video

5) Penetration Rate, is 100 % as all potential users are active, soPenetr_rate = 100 % or = 1

6) Users per cellUsers/Celles = Pop_Density * Penetr_rate = 50

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Traffic Considerations Uplink calculation Streaming Video

7) Busy_Hour_Call_Attemptss = 1,For Packet Switched systems defined as number of sessions

8) Call_Duration = 3600 [s] or 1 [E]

9) Activity_Factor = 100%The precentage of time the frequency resource is used

10) Traffic/Useres = Busy_Hour_Call_Attemptss * Call_Duration * Activity_Factor = 3600 [call-seconds]

11) Offered_Traffic/Cell = Traffic/Useres * Users/Cell = 36*103

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Technical and System ConsiderationsStreaming Video Uplink final assessment

12) Service_Channel_Bit_Rates = Net_User_Bit_Rates * 1.5 = 1500 kbit/sThe scaling factor accounts for RF channel overhead such as crypto codingAnd error recoverage handling

13) Anticipating 50 service channels per cell we calculate Traffic:Tes = Service_Channels/Celles * Service_Channel_Bit_Ratees = 75 Mbit/s/cell

MESA technology has not been selected yet. However if we considercurrent avaible digital technology such as carriers of Π/4 DQPSKOffering 36000 bps @ 25 kHz (~1.5 bit/s/Hz) we get: Ses = 1.5 Mbit/s/MHz/cell

Fes =Tes

Ses

[MHz] , = 75/1.5 [MHz] = 50 MHz uplink

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Geographic ConsiderationsUplink calculation EMS Still Images

1) Selection of ”e” – environmental type: Combination of Density and Mobility”e” Dense Urban

2) Cell geometry:Circular, r = 500 m, Cell_Areae = 1 Km2

3) Service type”s” = High Multimedia, Packet SwitchedNet_User_Bit_Rates = 250 * 8/5 = 400 kbit/s (1 * 250 kB JPEG image every 5 seconds)

4) Population Density,All Units Operating:Pop_Densitye = 50 [Km-2]

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Geographic and Market ConsiderationsUplink calculation Still Images

5) Penetration Rate, is 100 % as all potential users are active, soPenetr_rate = 100 % or = 1

6) Users per cellUsers/Celles = Pop_Density * Penetr_rate = 50

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Traffic ConsiderationsUplink calculation Still Images

7) Busy_Hour_Call_Attemptss = 1For Packet Switched systems defined as number of sessions

8) Call_Duration = 3600 [s] or 1 [E]

9) Activity_Factor = 100%The precentage of time the frequency resource is used

10) Traffic/Useres = Busy_Hour_Call_Attemptss * Call_Duration * Activity_Factor = 3600 [call-seconds]

11) Offered_Traffic/Cell = Traffic/Useres * Users/Cell = 180*103 [call-seconds]/Cell

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Technical and System ConsiderationsUplink Calculation Still Images final assessment

12) Service_Channel_Bit_Rates = Net_User_Bit_Rates * 1.5 = 600 kbit/sThe scaling factor accounts for RF channel overhead such as crypto codingAnd error recoverage handling

13) Anticipating 50 service channels per cell we calculate Traffic:Tes = Service_Channels/Celles * Service_Channel_Bit_Ratees = 30 Mbit/s/cell

MESA technology has not been selected yet. However if we considercurrent avaible digital technology such as carriers of Π/4 DQPSKOffering 36000 bps @ 25 kHz (~1.5 bit/s/Hz) we get: Ses = 1.5 Mbit/s/MHz/cell

Fes =Tes

Ses

[MHz] , = 30/1.5 [MHz] = 20 MHz uplink

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• Packet Switched Multimedia Environment• Well known Collission Detection principle applied (such as CDMA/CD)• Well known digital wireless technology applied such as a π/4DQPSK

modulated carrier offering 1.5 bits/s/Hz• No degradation in Quality of Service due to spectum congestion tolerated• Ad-hoc high speed interlinking of rescue units not considered part of the

applications requirements for available spectrum

Conclusion

Based on the assumptions below, the Rescue Team and the EMS crew assistance at the scene, some 70 MHz of uplink spectrum wil be needed for their Broad Band needs during this incident