In mobile environment, the replication of data and services will be essential. This is because users and their transactions move from one cell to another while accessing the database. Unless the data moves with the users in the form of a cache or a mobile disk storage, data will need to be retransmitted back and forth. Retransmission wastes the limited communication bandwidth and slow down transaction processing because of transmission delay.
Data can be replicate at three levels-
1. At source system level, where multiple copies are maintained at different station host
2. Data can be cache into the data access agent on base station
3. The data proxy cache can be cached at the mobile unit.
Replication Schemes:
- Follow Me Replication Unconditional
- Follow Me Replication Unconditional on Demand
- Follow Me Replication Conditional
- Follow Me Replication Conditional on Demand
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