Mobile Databases

Mobile Databases


Mobile Databases
􀀹 Mobile computing
􀀹 Wireless technology – establishes communication with other uses & manages their
work while they are mobile.
(eg)
traffic police, weather reporting services, financial market reporting,
information brokering applications.
Problems:
Data management, transaction management, database recovery
Data communication & processing

Mobile Computing Architecture:
􀀹 Fixed Hosts (FS)
Base Stations (BS)
􀀹 Equipped with wireless interfaces
􀀹 Clinet-server paradigm
􀀹 Mobile Units (MU), Base stations communicate through wireless channels
􀀹 Uplink channel, downlink channel
􀀹 Geographic mobility domain
􀀹 Residence latency (RL) – average duration of a user’s stay in the cell
Interconnected through a highspeed
wired network

Types of data in Mobile Applications:
􀀹 Mobile applications
Vertical applications Users access data within a specific cell
Horizontal applications Users access data distributed
throughout the system
􀀹 Data (eg) e-mail
Private data Single user owns & manages the data
Shared data Accessed both in read & write mode by a group of
users. (eg) inventory
Public data Anyone can read data; only one source updates it.
(eg) stock prices, weather bulletins

Data Management Issues:
Distributed data management issues can be applied to mobile databases with the
additional considerations.
􀀹 Data distribution and replication
􀀹 Transaction modes
􀀹 Query Processing
􀀹 Recovery & Fault tolerance
􀀹 Mobile database design
Intermittently Synchronized DataBase Environment (ISDBE)
Intermittently Synchronized DataBases (ISDBs)



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