In a mobile computing system, users carrying portable devices can access database services from any location without requiring a fixed position in the networking environment. Some examples of strategies supported by databases in mobile computing include location dependent queries, long-lived transactions that require migration of data into the portable devices, form-based transactions, and online information report. Within a mobile computing environment, the need for a realtime database management model is strong, because one of the basic requirements in mobile data management is to provide real-time response to transactions of the underlying strategies. However, the resource constraints of mobile computing systems make it difficult to satisfy timing requirements of supported strategies. Low bandwidth, unreliable wireless links, and frequent disconnections increase the overhead of communication between mobile hosts and fixed hosts of the system. There are many situations in which we ne...
Ding-Jung Chiang, Hwei-Jen Lin, Timothy K. Shih