Applications over wireless sensor networks (WSNs) are various and different. Many routing protocols have been proposed for WSNs since a decade. Medium access control protocols can differ from a network to another. The transmission range can also be variable from a sensor to another depending on their battery capacities. All these various protocols have an influence on the WSNs performance, in particular, the quality of service (QoS) they provide. It is worthy to choose the appropriate protocol for each specific situation in order to ensure a high security of the network. In this paper, we show that the type of application, the type of routing protocol, and the transmission range value have a real impact on WSN performance. Indeed, if we do not choose the right protocol in the right situation, the network could provide a low QoS in terms of lost packet rate and energy consumption. We have undertaken a set of experimentations in order to extract a road map that could be useful for any designer who intend to deploy a WSN with a high QoS degree. For the application layer, we have handled three types of applications: regular applications, applications requiring a high communication rate, and burst rate based applications. We have also considered different network sizes. For the routing layer, we have investigated the Ad hoc On-demand Distance Vector, ad hoc on-demand multipath distance vector routing, dynamic source routing, and Destination-Sequenced Distance Vector protocols. Various transmission range values have been used. We have conducted many simulations through the NS-2 simulator in order to analyze two relevant QoS indicators on WSNs: energy consumption and lost packet rate. Copyright © 2014 John Wiley & Sons, Ltd.