Wireless sensor network transport layer: State of the art

Abstract

This chapter describes the essence of a generic transport layer of a Multi-hop Wireless Sensor Network (WSN). The transport layer of the Internet handles the congestion generated due to the network traffic and the end-to-end reliability of individual packets. Similar to the Internet, many WSN applications require a congestion control mechanism to regulate the amount of traffic injected within the WSN to avoid packet loss and to guarantee end-to-end reliable packet/event delivery. WSN researchers thus argue the presence of a transport layer for WSN similar to the Internet. Because of the resource constraint nature of sensor devices, researchers however admit that an Internet-scale transport layer will indeed be a matter of challenge. Literature reveals detailed analysis of the requirements and constraints of a WSN transport layer. The advancements in microprocessor technology, high speed and large memories, high speed networks, Ultra Wide Band frequency spectrums, very efficient sensor network Operating Systems and miniaturization of many heterogeneous sensor devices, to name a few, have led to the development of many transport layer protocols. This chapter addresses the unique characteristics of a WSN transport layer, classifies the attributes that characterize different functionalities offered by a transport layer, presents the most popular transport layer protocols based on the attributes found in each protocol, and finally, points out open research issues of this domain, which need further attention to overcome the aforementioned challenges. © 2008 Springer-Verlag Berlin Heidelberg.