Location-Based Service Application

Question

I need to be able to locate the user in a building, show the route that can be taken, and optionally download the building's map, and use the turn-by turn navigation without any internet/GPS access after that.

My main questions are; 1) How do I get a building's map? For example I wanted to have a map of my university campus, where do I get the map from? Google Map? 2) How to implement the turn-by-turn navigation without any internet/GPS? Only the graphical is enough, no need for sound support. 3) How do i obtain user's location using Wi-Fi connection instead of GPS?

I am not hoping for source codes, I just need guidance and directions on where should I look, and what I need to study.

Answer 1

That seems like a tough assignment. I imagine you have to create the building map yourself. Perhaps to start off, you can write an application which records the signal strengths of all wifi signals in a given building while you walk around in it. So, say there are 7 wifi access points you will have a database of signal strength vectors {w_i_1,w_i_2,...,w_i_7}.

With this database you can then compare to a new unknown signal {v1, v2, ..., v7} so you have some idea of where you are (find the minimal norm of w-v for each w_i).

Finally store 'special' locations (where you reach a left/right/straight decision point and have your app guide the user which way to go to get to their destination.

Answer 2

1) How do I get a building's map? For example I wanted to have a map of my university campus, where do I get the map from? Google Map?

Unless your campus is huge enough, Google static maps won't be practical enough. There is no place where you can download the blueprint of a building. That only happens in Hollywood movies.

• You draw it yourself.
• Download it from The internet.
• Talk to some lecturer from your campus, he might know where the map for you campus lies.

2) How to implement the turn-by-turn navigation without any internet/GPS?

Without Internet or GPS, you only have Wifi and Gyro sensors to help you. Here is a paper that compares Route Navigation algorithms. You'll have to study map matching algorithms. Here is a java project that you may use as a reference.

3) How do i obtain user's location using Wi-Fi connection instead of GPS?

You will need an access to a WiFi database to triangulate your position. Once you get a lat, lon fix. You do what Arnoud suggested and create your own WiFi positioning system.