Implementation and evaluation of the sensornet protocol for Contiki

Sensornet Protocol (SP) is a link abstraction layer between the network layer and the link layer for sensor networks. SP was proposed as the core of a future-oriented sensor node architecture that allows flexible and optimized combination between multiple coexisting protocols. This thesis implements the SP sensornet protocol on the Contiki operating system in order to: evaluate the effectiveness of the original SP services; explore further requirements and implementation trade-offs uncovered by the original proposal. We analyze the original SP design and the TinyOS implementation of SP to design the Contiki port. We implement the data sending and receiving part of SP using Contiki processes, and the neighbor management part as a group of global routines. The evaluation consists of a single-hop traffic throughput test and a multihop convergecast test. Both tests are conducted using both simulation and experimentation. We conclude from the evaluation results that SP's link-level abstraction effectively improves modularity in protocol construction without sacrificing performance, and our SP implementation on Contiki lays a good foundation for future protocol innovations in wireless sensor networks

Joint Congestion Control and Scheduling in Wireless Networks with Network Coding

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A Routing Algorithm To Reduce The Queueing Complexity In Communication Networks

A new adaptive routing algorithm built ahead the widely studied back-pressure algorithm. We decouple the routing and scheduling components of the algorithm by designing a probabilistic routing table that is used to route packets to per-destination queues. The scheduling decisions in the case of wireless networks are made using counters called shadow queues. The results are also extended to the case of networks that employ simple forms of network coding. The routing algorithm is considered to decrease the average number of hops used by packets in the network. This idea along with the scheduling/routing decoupling leads to setback decrease compared with the traditional back-pressure algorithm. The algorithm can be applied to wire line and wireless networks. Wide simulations show spectacular improvement in delay performance compared to the back-pressure algorithm.  When network coding is employed per-previous-hop queues may also be essential but this is a requirement compulsory by network coding not by our algorithm.