Database replication i Mobile Ad Hoc networks
Publish date: 2010-12-27
Report number: FOI-R--3144--SE
Pages: 27
Written in: Swedish
Keywords:
- distributed database
- data dissemination
- mobile wireless networks
- ad-hoc networks
- command and control service
- soldier status information
- video distribution
- positioning distribution
- caching
- replication
Abstract
Many of the services presumed to be vital in a mobile, tactical network can take advantage of a distributed database system with effective data dissemination. Investigated are methods for effective data replication from one of the producer databases in such a database system to the databases of the consumers in a mobile ad hoc network, i.e., a network with constantly changing topology. Four services are treated; a command and control service, a service for soldier status information, a service for video distribution, and a service for positioning distribution. These services are classified according to their principle properties in order to determine which of the data dissemination methods that is suitable. In this report we compare two possible methods for data dissemination. One design utilizes caching of requested data along the transmission path and the other pre-emptively disseminates data to the units where it's in highest demand. Furthermore, we also compare with two reference methods; one where no data is transmitted unless a specific request from a unit has occurred and one with total data dissemination, i.e. all data is relayed to all units. The methods are compared with respect to their capacity demands. The properties of the service determine which of the methods that works best. However, in most cases is the best method the one with caching.