QoS improvement in TCP/IP-based wireless sensor networks using cross-layer optimization

Dissertação de Mestrado, Engenharia Informática, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Internet of Things (IoT) is becoming a reality and new and advanced applications are expected to emerge. For applications with reliability needs to work well in IoT environments, robust data transportation is required. Approaches like TCP are known for not being adequate in sensor network environments, while UDP has been included in the 6LoWPAN stack allowing low-power and limited processing devices to participate in the IoT. However, UDP provides no reliability. One way of providing reliability is to use link-layer acknowledgements but this mechanism may lead to an inefficient use of resources if used unconditionally throughout all the network. Another way is to request the confirmation of messages sent, done at the application layer, but this is an end-to-end process that can only be applied for specific message type transactions. If used for all data then there will be long delays and inefficient use of resources also. Here we address the design of a cross-layer reactive mechanism that improves reliability of data delivery, in order to support applications that require some reliability level when delivering data notifications. This mechanism introduces link layer reliability at specific nodes, gradually and only when needed, having no scaling problems. Results show that this mechanism can improve data delivery and improve the use of network resources.

Erasmus Mundus Iran Iraq Yemen (EMIIY)