In this paper, we present an overview of IEEE 802.15.4 and 802.15.6 standards. Thereafter, in view of their various strengths and many similarities, we study the possibility of using one of these two norms to implement the body area network (WBAN) of CANet (an innovative ehealth project) scenario according to the nature of the studied sensors. To do so, we considered an hybrid differentiation layer, previously proposed, based on 802.15.4 and we made a classification of CANet ehealth sensors based on IEEE 802.15.6 native superframe periods and priority and service differentiation systems. Each choice between them has its advantages and disadvantages. Thus, it will be necessary to analyse in detail the simulation and prototyping results of 802.15.4 and 802.15.6 norms once implemented in CANet context in order to decide about the standard providing the optimal QoS.