Overview of Mobile Computing (2): Applications and Services

The iMode Story: It is About Services! 27M Internet-capable cell phone sub-scribers (10/01); 50K iMode Web Sites World’s largest ISP, first to deploy 3G “Freedom of Multimedia Access” (FOMA) Not just about Japanese teenagers Applications UsedUser Ages Economist Magazine, 13 Oct 2001

In the post-PC age… Not just about gadgets or access technologies About services and applications, and how the network can best support them Increasing, not decreasing, diversity Bottlenecks moving from core towards edge Enabled by computing embedded in communications fabric: wide-area, topology-aware, distributed computing

Services for Mobile Networks How to build services for end users in a mobile and wireless networking environment: Issues and service types One example: universal interactor,

Grand Goal of “AAA” Mobile Services AAA Service: “Any time, Any where, Any form” service Any time: it is about wireless (time-domain quality) Any where: it is about mobility (space-domain quality) Any form: it is about device diversity (systems quality)

Issues in building mobile services Mobility induced issues: –Seamless services: service migration –Location services: location itself is a service Heterogeneity induced issues: –Hardware diversity Client devices & different networks –Software diversity System software: OS, networking protocols Application software Wireless induced issues: –Time-varying network connectivity: disconnection, partial connection, full connection

Possible services types 1.Location service 2.Location-transparent services – Hide locations from users: same as old Internet 3.Location-dependent services – Services “local” to a geographic location – Not available globally 4.Location-aware services – Services are globally available, but multiple instantiations of the same service are a function of locations – Service adapts to a location

How to Provide Location Services GPS at every node GPS at a few reference points –Build recursive location services through reference hierarchy Geometric triangle computation –Cricket system Identify the current cell What about location tracking?

Services Location transparent services: –If lower-layer provides mobility support, this is not a big issue Location-dependent services: Local currency exchange when visiting foreign country Location aware services: –example: finding a nearby bookstore while driving –Issue: service migration from old server to the new server –Solution: location-adaptive

Building context-aware applications? Context is a key factor for mobile computing –Typical context: time, location coordinate, personal profile, etc.

Typically: Identity, location, time Rest is implied Not much else used: activity, mood, etc.

Design Process Using Tools? For your information only Not required for the exam