Research On Techniques Of Handoff And Recovery Of Mobile Transaction Processing

This dissertation addresses the techniques of handoff and recovery of mobile transaction processing in the Mobile Transaction Service Networking (MTSN).Handoff of mobile transaction, in general, means the procedure of completing connection transfer for mobile client from the old server/coordinator to a new one during execution of the mobile transaction. In some cases, the transaction handoff is called service handoff as well. The data routing switching and the migration of the execution context must be taken into account during transaction handoff because the physical distance between cells may be inconsistent with the logical distance. Usually, the physical distance is larger.My dissertation classifies the applications in the mobile computing environment (MCE) and analyses the features of architectures of several typical mobile information access systems, and then the architecture of the MTSN is presented which supports the mobile transaction handoff.During execution of the mobile transaction, the mobile client (MC) may disconnect from the MTSN, keep moving across different cells. In addition, the mobile transaction may be long-lived, location-dependent, data sources are independent each other and et al. Consequently, the processing procedure and control mechanism must adapt to these features and especially support the deadline of invalidation of mobile transaction.The open nested transaction model with time constraint (TC-ONTM) is used in this dissertation to describe the behavior of mobile transaction in MTSN. The ONTM model is able to support the mobile transaction in nature and certain realtime characteristics is introduced into it in order to terminate the execution of the mobile transaction to release the system resource.Three types of models are discussed in my dissertation. The basic reference model is the zone-based mobile transaction handoff model (ZMTHM) which can effectively handle the handoff processing of the TC-ONTM mobile transaction. This model consists of a set of connected subMTSNs by zone and the processing of...