Social Network Based
Dynamic Spatial Alarms
Chetan Bhadricha and Alkesh Shah
{bchetan,salkesh}@cc.gatech.edu
ABSTRACT
Over the recent years, location tracking systems like GPS have been developed that
enable mobile devices to keep track of their position in the coordinate system. With a
GPS, mobile devices can identify the coordinates of the location where they are exactly
located. This feature has led to the development of location-based services that utilize this
spatial information obtained from GPS. An example of such a location-based service is
spatial alarms that are set by taking the location as well as the time into consideration.
There are two types of spatial alarms – static and dynamic. Static alarms are set on
objects that are stationary while dynamic alarms as the name suggests correspond to
objects that are in motion. Further, there has been a recent spurt of applications involving
social networks. Social networks model a community of users with relationships amongst
them. One such example is a Friend-of-a-Friend network. Combining the features of a
location-based service with social networks one can create a variety of interesting
applications that are useful to the all the users. In this project, we propose to implement a
framework for using dynamic spatial alarms in conjunction with social network.
MOTIVATION
Existing work in the area of location based services has been involved in developing
static spatial alarms [1]. These static alarms are raised based on the location of a
stationary object. A natural extension to static alarms is dynamic alarms, which as the
name suggests are alarms that are set on moving objects. Such dynamic alarms can be,
for example, used for signaling whether an object (or a friend) has appeared in your
vicinity. Along with social networks (ex. Friend of a friend) interesting applications can
be conjured up that can prove to be beneficial to the community in general. Some
example applications –
1. Meeting Organizer: Imagine that a person is interested in having a casual meeting
with his/her friends at a nearby Starbucks. He/she can simply raise a signal (an alarm)
indicating his/her interest in going to Starbucks. The system will identify all his/her
friends (both stationary as well as moving) within a particular range (say 5 miles) and
send them the signal indicating their friend’s interest. All the interested friends can
then respond back and eventually meet at the Starbucks.
2. Reviews/Deals/Announcements: Assume that a person has seen a steal deal at a
particular store and wants to let his network of friends know about that deal. He/she
can set an alarm on his/her friends such that whenever they are in the vicinity of the
store they would be alerted of the deal. Instead of a deal, reviews of some restaurant
or announcements can also be displayed. Also, similar to the mGraffiti[2] project,
graffiti written by the person’s friends can be displayed.
3. Search: Another application of using social networks is to search for a group of
friends in a particular area. The area boundaries can be defined by the user. By setting
up an alarm on one or more of the friends in that area, the person can pass on some
information or request some activity be performed.
An extension to above examples can be integrating mapping mashups with the alarms
and social networks. Mapping mashups involve obtaining data from different data
sources and presenting them graphically on maps. For example, every friend’s location in
a nearby area can be displayed on a map along with the Starbucks outlets. In this project
our objective is to build a prototype system, which implements dynamic spatial alarms
and utilizes the information from social networks to trigger these alarms accordingly.
RELATED WORK
Recently, there have been location aware applications that have been developed. One
such example is Dodgeball [3], whose main focus is to alert users of fellow users who are
within certain vicinity. This is similar to the concept of dynamic alarms, which are set on
moving objects. Our work additionally involves social networks that provide the
possibility of developing interesting applications like the meeting organizer explained in
the previous section. The work by Prabhakar et al. [4] involves evaluation of continual
queries on moving objects using query indexing and safe regions. Dynamic alarms are
quite similar to continual queries and we plan to use the concept of safe regions for
dynamic alarms.
PROPOSED WORK
1. To begin with the user starts with setting an alarm for his friends in the vicinity he
desires and for the time he wishes the alarm remains effective.
2. In response to this, the server accesses the information about the user’s network of
friends as indicated in the Social Network’s database.
3. The Server (which is assumed to be at the base station in our prototype) maintains a
list of the users who are currently in the specified area.
4. It then sends an alarm to the users which are common to the list of friends of the user
and the available users list.
5. The receiving user on getting the alarm can either decide to ignore it or respond to it.
The response may or may not be forwarded to the user setting the alarm depending on
the application that is being considered.
6. As further extensions to the basic idea, the receiving user can ask for a map showing
him the path to reach the location on which the alarm has been set or a mashup of the
friends who have agreed to join the meet.
Due to lack of hardware we will be using the simulator for demonstration.
Alarm
Database
Network
Outside the
region
Mashup
Module
Central
Server
Map
Server
Other
Databases
Not in
friends list.
No Alarm
Social
Networks
Interface
Anyone for
a coffee
Yes I am
here
System Architecture
Social
Networks
Database
PLAN OF ACTION
The following are the technologies that are planned to be used:
1. Visual Studio 2005 with the Pocket PC Emulator: This will be used for the mobile
device emulation.
2. Microsoft Map point API for obtaining the maps.
3. Web Service for Communication with the server.
4. GeoFrameworks GPS.NET – This is a virtual GPS device along with the necessary
libraries for programming with it.
Timeline:
Feb 13
Submission of proposal
Feb 19 (2 weeks)
Study of the Pocket PC Simulator with Visual Studio 2005
Mar 5 (1 week)
Study of the Virtual GPS and obtaining the user location information
from it
Integrating the user location information with the social network
database
Alarm Activation – the user can set the alarm which is then triggered
based on the social network of the user
Getting the response mechanism working and informing the user
setting the alarm
Documentation and buffer time for completing any delayed work
Mar 12 (1 week)
Mar 19(2 weeks)
Apr 2 (2 weeks)
Apr 16 (1 week)
Deliverables Evaluation and Testing:
Demonstration of dynamic spatial alarms with social networks. We will implement the
solution only for a specific scenario in which the central server is assumed to be at the
Base Station. The user sets an alarm which is notified to his friends (depending on his
social network) inside the area of the same base-station. The user extending the alarm to
regions encompassing multiple base stations will be done if the time permits.
REFERENCES
[1] Spatial Alarms – Anand Murugappan, Sarang Karandikar
[2] mGraffiti – Peter Pesti
[3] Dodgeball – http://www.dodgeball.com
[4] Query Indexing and Velocity Constrained Indexing: Scalable Techniques for
Continuous Queries on Moving Objects – S. Prabhakar et al.