Mobile applications chapter 6
- 1. Mobile Applications Chapter 6 BY MR. A. B. MOMIN ASSISTANT PROFESSOR DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING ATS’S, SANJAY BHOKARE GROUP OF INSTITUTES, MIRAJ
- 2. Geolocation and Maps Mobile Applications Mr. A. B. Momin, Assistant Professor, Department of CSE Location Techniques There are different techniques that we can use to determine the geographical location of a device, based on the platform, the browser, the operator, and so on. • Accuracy Every location technology has some accuracy error. This is usually specified in a distance metric, like meters or kilometres, but in some techniques accuracy is defined according to levels, such as city accuracy or country accuracy. • Indoor Location The idea is that we can offer better services for the users inside the building if we can pinpoint what floor they are on or what department they are in. These services may be local services on the Internet, or even services provided on an intranet with the user using a Wireless LAN connection.
- 3. Client Techniques Mobile Applications Mr. A. B. Momin, Assistant Professor, Department of CSE • GPS The Global Positioning System (GPS) is the first technique most people think of when location detection is mentioned. The United States government created GPS as a system for locating devices, using between 24 and 32 satellites orbiting the Earth. • A - GPS Assisted GPS (A-GPS) is a software-based system available for mobile phones connected to carrier networks that can help the devices to determine their locations. • Cell Information Using the operator network’s cellular towers, the carrier can triangulate the position of a mobile device. The accuracy will depend on how many cell towers are in range. • WIFI Positioning System The WIFI Positioning System (WPS) is a very clever technique that detects your location using the list of wireless routers that are available in your area. This method relies on a pre-existing database of routers and their geographical locations.
- 4. Server Techniques Mobile Applications Mr. A. B. Momin, Assistant Professor, Department of CSE • IP Address The main server technique for locating a user is reading the client’s IP address. IP address we receive may be the operator’s WAP gateway address, a dynamic IP address in the operator’s range, or the IP address of the WIFI connection. • Carrier Connection Some worldwide operators offer developer programs (both open and private) for web portals that allow any request made from a user to your web server to carry additional headers containing information about the user (identity, location, and billing services).
- 5. Detecting the Location Mobile Applications Mr. A. B. Momin, Assistant Professor, Department of CSE There are two options for detecting the user’s geographical location: using the W3C Geolocation API, available under the HTML5 APIs, or using third-party APIs, usually available directly from carriers. • The W3C Geolocation API The W3C standard way to query the user’s position from JavaScript is called the Geolocation API. The Geolocation API doesn’t rely on one location technology. 1. Getting the Position The first way to use the Geolocation API is to get the user’s location using the getCur rentPosition() function of the geolocation object. The coordinates property has the following attributes, defined in the W3C standard: • latitude in decimal degrees • longitude in decimal degrees • altitude (optional) in meters above the ellipsoid • accuracy in meters • altitudeAccuracy (optional) in meters • heading (optional) in degrees clockwise related to true north • speed (optional) in meters per second
- 6. Google Map Mobile Applications Mr. A. B. Momin, Assistant Professor, Department of CSE To invoke the Google Maps application on Android devices we can just point to maps.google.com and optionally send any parameters we want to include, in the basic form http://maps.google.com/?<attributes>. Attributes should be URL-formatted, as in attribute1=value1&attribute2=value2. Possible attributes include: • Q: Query parameter; this can be a comma-separated coordinate preceded by a loc: prefix (loc:lat,long) • Near: Applies a location definition for a query, as in q=starbucks;near=san+mateo+ca • LL: A comma-separated latitude and longitude for the map center. • T: The type of map (m: map, k: satellite, h: hybrid, p: terrain). • Z: The zoom level, from 1 (the whole world) to 23.