Many routing, power aware and data diffusion protocols have been designed especially for WSN, which are reliability and network operation based. The presentation of various ideas on multi-hop reliability and network operation based routing protocols is given here. Unattended sensor nodes deployed randomly in the network area require reliable routing. In recent years, an extensive research has addressed various issues for the coordination and management of nodes for efficient operations and efficient routing. The mission of maintaining and finding routes is nontrivial as sudden changes in status of nodes lead to unpredictable consequences. In this chapter, comparative study of various routing protocols has been presented to pave new ways to researchers. In this chapter, we have classified reliability and network operation routing in to five types (i) coherent based, (ii) QoS based, (iii) multipath based, (iv) query based and negotiation based.Keywords Multi-hop routing Á Reliability Á Network operations Á Query Á Quality of service (QoS) Á Coherent
Brief HistoryDesigning of Routing protocols for demands of existing and developing applications is an important issue. Multi-hop routing protocols are classified into five categories under network operation and reliability (Fig. 3.1). Many protocols are proposed in literature based on single path communication without considering the increased load on that path. Routing through single path requires less computation but it reduces the network throughout [1,2]. In case of the single path failure, new routes need to be searched, which can waste the resources and energy of the nodes. Due to resource constraints and limitations of single path routing, multipath routing became the promising solution to exploit the benefits of WSN. Wireless sensor network is different from other networks in operation as it needs some global address scheme to identify the location of the sensor nodes for communication. In