Research On Address Configuration And Head Compression Based On6LoWPAN For LoTs

People have poured more and more attention into the research of Internet of Thingssince the day it is brought up, especially the key technologies. As the research deepens,gradually scholars argue that it is the top priority to complete a global uniqueidentification for each thing with IP address if we want to put the Internet of Things intoapplication in real sense. It is defined that sensors in wireless sensor networks collectinformation and do comprehensive perception, all these works are done in the perceptionlayer of the Internet of Things. Then the question lies ahead is what we can do to applyIP into LR_WPAN with the hard-swallowing truth that LR_WPAN is based onIEEE802.15.4protocol while the other is Internet protocol, which means the twonetworks above are heterogeneous. We need make the two networks work as onealthough they are different obviously. Fortunately,6LoWPAN is the technology we arelooking for, with which we can transmit an IP packet in network using an IEEE802.15.4.It works as an adaptation layer that shields all the differences between the two networksabove. It is a new concept relatively, though the working group has done a huge amountof jobs about the way how it works. Still, a lot of works in6LoWPAN need to be done inthe future, like addressing configuration, packet fragmentation and packetremade, header compression, routing etc. Therefore, the paper focused on the addressconfiguration and head compression under the circumstance of6LoWPAN in order tomake it work better.Firstly, the paper came to a conclusion that the stateless addressing scheme is betterfor6LoWPAN after knowing there are two schemes for IP addressing. Unfortunatelythere is also a downside about the stateless one, it is that the address conflict detection in the scheme may increase the cost in the whole system. Based on the problem above, thepaper proposed a cluster_tree hierarchical addressing scheme, in which nodes aregrouped into clusters. All nodes will establish a logical tree in each cluster and the nodeworking as a parent will assign addresses for its children, in which each node needscheck the other nodes within the same cluster only. The consumption is down in somesense by reducing the searching and comparing range. Finally, the problem, the cost ofaddress conflict detection in stateless addressing, is solved.Secondly, the paper did plenty of works on the research of the existing ways of headcompression under6LoWPAN. Then we know that LoWPAN_HC1does a great job inlocal link networks. Meanwhile, LoWPAN_IPHC rules what can be done when theaddress is a multiple one, and it considers the stateful addressing. Moreover it works wellespecially when the nodes are not in the same link. Considering the limitation ofLoWPAN_HC1and the high complexity of LoWPAN_IPHC, the paper gave an evolvedscheme by adding control bits, which makes wise choice between the schemes aboveaccording to the context.Thirdly, the paper gave simulations on the schemes we had brought up. Thesimulations were done in three groups. The first one was done for the addressing, thesecond one was for head compression, the last was a compressive one which was aboutaddressing and head compression. Finally we came to a conclusion that the evolvedschemes in this paper are better than traditional ones according to the simulations.