Research On Dynamic Quality Guarantee Methods For Internet Of Things Services

The emerging of IOT technologies helps the Services Computing to open up a new application area. The IOT services is a product of the organic combination of both. In the new environment, quality guarantee for IOT services faces new challenges. For this issue, from the perspective of architecture, we have done some further studies on quality guarantee for IOT services. We discussed and refined the Event-Driven Service-Oriented Architecture proposed by our research group for services provisioning in IOT environments. In order to guarantee the data distribution quality of IOT services, we proposed a low-delay, light-weight publish/subscribe architecture. For guaranteeing the data transmission quality of IOT services, we proposed a cluster-based packet acknowledgement approach in wireless sensor network. In our opinion, the explorations and practices of quality guarantee for IOT services in terms of architecture are meaningful attempts, have more direction and guiding significance for the emerging IOT service systems, and help to quickly build IOT demonstration applications.Researches and achievements of this paper are summarize as follows:(1) Service Oriented Architecture and Event-Driven Architecture are complementary, and event-driven SOA is the transformation of the traditional SOA. In the new IOT environments, IOT services face heterogeneous, dynamic and many other challenges. To address these challenges, our research group proposed an Event-Driven Service-Oriented Architecture to provide IOT services. We refined, supplemented and improved this architecture, especially the access agent, publish/subscribe based unified message distribution network, complex event processing engine and operational processes. This architecture integrates respective advantages of SOA and EDA, enhances the system flexibility. IOT service systems therefore can effectively distribute sensor information and achieve the event-driven dynamic service coordination cross domain in an open, distributed computing environments.(2) A scalable, low-delay information distribution architecture is needed for the large-scale, distributed, loosely coupled IOT environments, and will asynchronously distribute sensor information. Therefore, we proposed an efficient and scalable publish/subscribe architecture. As a key component of the EDSOA, Based on the concept of grid quorum mechanism, this architecture organize publish/subscribe brokers into a broker-to-broker grid overlay network for efficient topic searching. It also leverages a topic searching algorithm and a one-hop caching strategy to minimize the search latency. Light-weight RESTful interfaces make this architecture more suitable for IOT services. Cost analysis and experimental study demonstrate that the architecture achieves a significant performance gain in search satisfaction without compromising search cost.(3) In order to support guaranteed data transmission quality of IOT services, we proposed a cluster-based packet acknowledgement approach in wireless sensor network. This approach cumulates multi-packets of multi-nodes into a Cumulative Acknowledgment, which can reduce more packet ACKs naturally than traditional approaches. Simulation results demonstrate that this approach effectively increase the packet delivery ratio, and reduce average end-to-end delay and the total length of ACKs which decreases the network load.