Mobile Phones: Enabling Next Generation Gerontechnologies

Sean J. Barbeau Research Associate Center for Urban Transportation ResearchCollege of Engineering University of South Florida

Topics

Overview of today and tomorrow’s mobile phone technology

Example: The Travel Assistant Device

Challenges with Real-time Mobile Applications

Conclusion

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Opportunities

3.25 billion wireless subscribers (½ of world’s population) Many methods of communication on cell phone (sounds,

pictures, video, touch) for advanced user interfaces Key to reaching the elderly population who are not “digital natives”

Cell Phones can help ease the aging process: Real-time transit navigation for individuals that can no longer drive Bluetooth hearing aids allow phone conversations for hearing-impaired Tracking systems to monitor health/location of early-stage dementia

patients Medication reminders – Instantly update after doctor’s visit Allows individuals to remotely check on elderly parents

Real-time assistance and monitoring can: Enhance individual’s quality of life Prolong the individual’s independence Delay institutionalization and full-time care

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Mobile Technology

Cell Phones are the first widely distributed mobile devices that are: Affordable Programmable

Java for mobile devices = J2ME Always connected

Almost any software application can be adapted for cell phones

Previously separated from Internet, but now connected

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Mobile Technology

Today, many cell phone data communications are IP-based: Browsing the web Accessing email Installed client applications talking to a server

Current Java-enabled cell phones must support HTTP, many also support TCP and UDP

However, most voice calls are not IP-based

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Mobile Technology

Tomorrow: IP Multimedia Subsystems (IMS) Everything-over-IP (Voice, Video, etc..) Network and Technology Agnostic Allows voice and data services simultaneously

Sessions (via SIP) hold information on users: Device Capabilities Presence (Online or Offline) Location (Geographic Coordinates)

A user can move from one device or network to another during a session. Examples:

Cell phone switches from using cellular network to your WiFi network when you arrive home without interruption

You’re on your work phone with a colleague but need to leave the office. Call is instantly transferred to your cell.

Cell Phones become a true mobile extension to the Internet

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Mobile Technology

Network evolution reaching broadband speeds Ex. CDMA data rates (Sprint, Verizon):

CDMA2000 1XRTT

EVDO REV-0 EVDO REV-A WiMAX

(Sprint = “XOHM”)

Download rate Up to 150 kbps

Up to 2.5 Mbps Up to 3.1 Mbps Up to 5 Mbps

Upload rate Up to 150 Kbps

Up to 150 Kbps Up to 1.8 Mbps Up to 1-2 Mbps

Avg. data rate 50 – 75 Kbps

300 –600 Kbps (Download)

50 - 75 Kbps (Upload)

600 – 1300 Kbps (Download)

200 – 500 Kbps (Upload)

End of 2007Now End of 20087

No Network? – No Problem! Bluetooth

Short-range (30ft) technology used to transfer information between 2 devices Phone-to-Phone Phone-to-hearing aid Phone-to-health monitor

Near-Field Communication (NFC) Allows you to “swipe” your cell phone

Buy things, prove your identity, etc. Now available in U.S. phones

Mobile Technology

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Source: Cristina Martinez Byvik

Mobile Technology

Global Positioning System (GPS) Device uses satellite signals to

determine its current location Accurate up to 3-5 meters Small enough to manufacture as

a “chip” inside phone Assisted GPS (aGPS) uses data

provided by the cellular network to reduce time-to-first-fix

Enables Location-Based Services (LBS)

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Travel Assistant Device (TAD)

Helps guide transit riders with cognitive disabilities

Used by Travel Trainers (Employees of transit agencies who introduce new riders to transit)

Keeps rider safe and eases parental anxieties

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Home

Bus Stop B Work

Bus Stop A

“Travel Assistant Device” for Special Needs Riders

Scenario: Joe needs to get from Home to Work and back using transit

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Home

Bus Stop B Work

Bus Stop A

“Travel Assistant Device” for Special Needs Riders

Most of the time Joe gets off at the right stop, but sometimes he forgets to pull the stop handle.

Joe

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Home

Bus Stop B Work

Bus Stop A

“Travel Assistant Device” for Special Needs Riders

Let’s try again, this time with a “Travel Assistant Device”. Joe’s cell phone will ring and vibrate when the bus is approaching the “Reminder A” location, prior to his bus stop.

Reminder A

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Home

Bus Stop B Work

Bus Stop A

“Travel Assistant Device” for Special Needs Riders

When his phone rings, Joe remembers to pull the stop handle. Joe arrives safely at the correct bus stop.

Reminder A

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Home

Bus Stop B Work

Bus Stop A

A second reminder can be established for her ride home.

Reminder A

Reminder B

“Travel Assistant Device” for Special Needs Riders

Home

Bus Stop B Work

Bus Stop A

“Travel Assistant Device” for Special Needs Riders

Joe arrives home safely. The reminders are triggered by his location, so time of day doesn’t matter.

Reminder A

Reminder B

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Home Bus Stop A

“Travel Assistant Device” for Special Needs Riders

Alarms is triggered if a rider deviates from their planned route. Can use multimedia alarms & reminders:

Play a recorded audio message. Show a picture/video of the next stop or landmark.

Alarm A

Travel Trainer

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“Travel Assistant Device” for Special Needs Riders

Travel Trainers and Caretakers can instantly see where the rider is currently located by using a web page.

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Challenges

Cutting-edge and next-generation “Gerontechnology” systems will be driven by real-time access to information

Networked mobile applications are inherently different from traditional networked applications

Need to solve new problems!

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Challenges

Power, a very limited resource, is consumed by: CPU calculations Wireless transmissions GPS fixes

Wireless transmissions: Communication often fails

Reliable protocols (i.e. TCP) cause multiple re-transmissions Retransmissions drain battery, and aren’t useful for real-time LBS

Every bit transferred costs power But so does using compression algorithms

Every bit transferred costs $ GPS

Every fix costs power GPS signals aren’t always available

Attempting to get a fix while indoors can result in large power costs20

Challenges

GPS fix + UDP Transmission every 4 seconds Battery lasts 5.06 hrs Battery Level vs Time

01234

1

1462

2923

4384

5845

7306

8767

1022

8

1168

9

1315

0

1461

1

1607

2

1753

3

Time in Seconds

Bat

tery

Po

wer

Batt. Lv.

Battery Level vs Time

01234

Time in Seconds

Bat

tery

Po

wer

Batt. Lv.

GPS fix + UDP Transmission every 30 seconds Battery lasts 9.6 hrs

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Solutions

“Critical Point Algorithm” – only send GPS points that are required to reconstruct a trip Don’t send coordinate on every fix Vary GPS refresh rate if possible Check cell signal availability before sending

data

Without Critical Point Algorithm With Critical Point Algorithm22

Solutions – “Critical Point”

Without Critical Point Algorithm With Critical Point Algorithm

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Solutions – “Critical Point”

TripNumber of Trip Points

Number of Critical Points

Bytes saved

Financial savings*

1 73 26 5593 $0.17

2 363 56 36533 $1.10

3 489 65 50456 $1.50

4 208 73 16065 $0.48

5 357 62 35105 $1.05

6 2320 159 257159 $7.71

7 1022 139 105077 $3.15

8 811 137 80206 $2.40

*Based on 119 bytes per UDP package and a charge of $0.03 per kilobyte.24

Conclusions

Mobile phones are enabling new “Gerontechnologies”

All IP-based future means cell phones will be seamlessly integrated with networks

However, mobile applications are subject to new problems!

Recognizing these problems and creating solutions leads to successful applications

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Thanks!

Sean J. Barbeau Research Associate Center for Urban Transportation Research University of South Florida 4202 E. Fowler Avenue, CUT100 Tampa, FL 33620-5375

(813) 974-7208 (813) 974-5168 (fax) barbeau@cutr.usf.edu

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