NrBAlone Class Code: EEL 6788 Instructor: Dr. DamlaTurgut Native Community Search Mobile Application Date: 04-18-2011 Presenter: Taranjeet Singh Bhatia
Abstract An urban sensing smart phone application which enables new arrivals into a cosmopolitan community to locate people of their own native country. The application, which runs on Android phones, detects and displays the other members of the community which are in 200 meter proximity of the user.
Application Usage Scenarios A student who has recently entered into foreign land for education somehow manage to get living resource but do not feel at home. The display on his device reinforces his senses to integrate within his neighborhood, and reassure him that native country people are nearby. But he does not have any idea to approach or even find out how many are surround him A new immigrant family is looking for secure and familiar living neighborhood in foreign land. They visited a quiet and sophisticated township for buying new home but they do not have any immediate idea about number of families’ who are their country-native living in that township During long distance journey we normally find co-country familiar stranger sitting next to us but due to lack of confidence about their origin we gain hesitation in starting conversation
Application overview Download manager Map Display GPS Sensor Update Service Uploading manager Back Light Status Accelerometer Sensor
Application Feature • Optimized power consumption using adaptive GPS interval • No past data saved on server reducing the risk of tracking users location history • User identity saved on server in non-reversal encrypted form • Maximum of 20 user will be visible on map which reduces the data download • Proximity of user is restricted to 200m distance • User can see common information shared by other users
System Requirement • Continuously monitoring User Location • Reduced Power consumption by Sensor such as Accelerometer and GPS sensor • Reduced data transfer usage • User Privacy
Power Consumption Tests And Results: 1. Test 1: GPS ON without loading a GPS enabled application Result: 5 hours later: 92% battery remaining 2. Test 2: GPS ON with continuous GPS tracking application running in the background Result: 5 hours later: 30% battery remaining 3. Test 3: Accelerometer ON by Elixir app accelerometer test function Result: 5 hour later: 1% battery remaining
Optimizing power consumption using adaptive GPSinterval Case 1: Condition: If less than 5 meter of distance is covered by user in two consecutive GPS coordinates with update frequency of 20s Assumptions: User is not using mobile phone or sitting or standing Action: 1. Start Accelerometer 2. When the device is in static condition such as kept on a table (and obviously not accelerating), the accelerometer reads a magnitude of g = 9.81 m/s2 on Z- axis. In this circumstance we can reduce the frequency of GPS update by the exponential factor of 2seconds in next iteration of GPS location fetch. This reduction in GPS update occurs continuously until maximum value of 10 min is reached. At this upper limit, it will be assumed that user is sleeping and so shut down GPS update. Start polling for other event such as screen backlight turn on or keypad unlock event to start GPS update again with initial update frequency of 20s.
Optimizing power consumption using adaptive GPSinterval 3. When the user is in static condition and not moving very frequently such as at community gathering or Waiting for bus, the accelerometer reads a magnitude of g on Z axis other than 9.81 m/s2. In this condition, we can reduce the frequency of GPS update by the constant increment of 10 seconds in next iteration of GPS location fetch. This reduction in GPS update occurs continuously until GPS update maximum value of 10 min is reached. 4. Whenever new GPS coordinate occur it will be update on server too
Optimizing power consumption using adaptive GPSinterval Case 2: Condition: If 1-10 meter of distance is covered by user in two consecutive GPS coordinates with update frequency of 20s Assumptions: User is walking or running or playing some sports such as basketball or football. Action: No changes require in GPS update frequency. As application covers the 200 meter of radius we need to keep the track of user location in this case. As this condition will not last for long time we do not need to change the GPS location update frequency. Whenever new GPS coordinate occur it will be update on server too
Optimizing power consumption using adaptive GPSinterval Case 3: Condition: If more than 10 meter of distance is covered by user in two consecutive GPS coordinates with update frequency of 20s Assumptions: User is bicycling or driving or using transport Action: In this circumstance we reduce the frequency of GPS update by the power of 2 in next iteration of GPS coordinate fetch. This reduction in GPS update occurs continuously until maximum value of 10 min is reached. In this case, we are not uploading the GPS coordinate on server because user is moving fast and will exist shorter at one place which make his location difficult to appear in the proximity of other users.
Future Implementation Ability to initiate chat, SMS or email from within the NrBAlone application. Ability to broadcast notifications to all the nearby members of a specific community. This would enable application scenarios such as car pooling for shopping trips, car pickup for commute, organization of instant events and special offers from merchants and restaurants of interest to a specific community. The tools will be used to collect statistical data about the geographical and temporal distribution of members of communities as well as their interaction patterns.