A Taxonomy of Routing Protocols for Wireless Sensor Networks
                                              

                                               

                                            Gergely´Acs,Levente Buttyan

                                Laboratory of Cryptography and Systems Security(CrySyS)

                                          Department of Telecommunications

                               Budapest University of Technology and Economics, Hungary

                                             {acs, buttyan}@crysys.hu

                                                January 12, 2007




 

  Wireless sensor networks are large scale networks consisting of a large number of tiny sensor nodes and a few base stations, which communicate using multi-hop wireless communications. The design of energy


efficient routing protocols for such networks is a challenging task, which has been in the focus of the sensor network research community in the recent past. This effort resulted in a huge number of sensor

 
network routing protocols. The proposed protocols show a high variety, which stems from the diverse requirements of the various envisioned application scenarios.In this work, we propose a taxonomy of sensor

 
network routing protocols, and classify the mainstream protocols proposed in the literature using this taxonomy. We distinguish five families of protocols based on the way the next hop is selected on the ro_


ute of a message,and briefly describe the operation of a representative member from each group.

  Sensor networks are composed of resource constrained sensor nodes and more resourced base stations. All nodes in a network communicate with each other via wireless links, where the communcation cost is much
 

higher than the computational cost. Moreover, the energy needed to transmit a message is about twice as great as the energy needed to receive the same message.Consequently, the route of each message destined 


to the base station is really crucial in terms network lifetime: e.g., using short routes to the base station that contains nodes with depleted batteries may yield decreased network lifetime.On the other hand,


using a long route composed of many sensor nodes can significantly increase the network delay.


  Unfortunately, some requirements for the routing protocols are conflicting. Always selecting the shortest route towards the base station causes the intermediate nodes to deplete faster, which results in a d_


ecreased network lifetime (if we measure the network lifetime by the time that lasts until the first node dies in the entire network). At the same time, always choosing the shortest path may result the lowest 


energy consumption and lowest network delay globally. Ultimately, the routing objectives are tailored by the application; e.g., real-time applications require minimal network delay, while applications perfor_


ming statistical computations may require maximized network lifetime. Hence, different routing mechanisms have been proposed for different applications [1]. These routing mechanisms primarily differ in terms 


of routing objectives and routing techniques, where the techniques are mainly influanced by the network characteristics.


  In this paper, we propose a taxonomy of sensor network routing protocols, and classify the mainstream protocols proposed in the literature using this taxonomy. We distinguish five families of protocols based 

on the way the next hop is selected on the route of a message, and briefly describe the operation of a representative member from each group.

 
  In order to select the most suitable routing mechanism for a sensor application, we have to classify all routing protocols according to a well-defined taxonomy. Using this classification, all protocols become 


comparable for an application designer. As a part of this taxonomy, we define a system model that describes the network and operational characteristics of the routing protocols, and an objective model that des_


cribes the routing objectives of the protocols. Furthermore, the system model encompasses the definiton of the network model as well as the operation model of routing protocols.