LCESM:Location-aware Context Event Subscription Mechanism

Traditional location-aware publish/subscribe systems mainly limit at event publication and matching,and couldn't support the frequent context events that happen in the same event source.A location-aware context event subscription mechanism that consists of location-aware context event subscription language(LACL) and dynamic binding approach was presented in the paper.Based on LACL,location event and event source event were defined and made the system capable of location awareness and event source awareness separately;dynamic binding consists of the mapping between the available context event source and the subscriptions and the dynamic binding relationship between agents and subscriptions.The former converts the matching between events and subscriptions to the matching between event sources and subscriptions,and reduces the matching and improves the system performance;agents' dynamic operations to subscriptions avoid redundant monitoring cost.The mechanism was implemented in context-aware middleware CTK.Experiments show effectiveness of the mechanism.