A Survey of Routing Protocols in Wireless Body Area Networks for Healthcare Applications

Introduction

In the last few years, wearable monitoring systems (Cypher, Chevrollier, Montavont, & Golmie, 2006) have gained the attention of various researchers, especially in the healthcare (Rodrigues, 2009). An important task of such systems is to collect physiological parameters like the heartbeat, body temperature, etc.

A WBAN (Moutinho, 2009; Baker, Armijo, Belka, Benhabib, & Bhargava, 2007; Barth, Wilson, Hanson, Powell, Unluer, & Lach, 2008; Chen, Gonzalez, Vasilakos, Cao, & Leung, 2010; Ullah et al., 2010) is made up out of several kinds of low powered miniaturized wireless devices. As shown in Figure 1, the most common devices are the sensors and actuators. The former measure physiological data, while the latter can undertake a specific action according to the received data from the sensors or via interaction with the user.

Figure 1.

Example of patient monitoring in a Body Area Network

The WBAN provides a wireless connection between these devices and a Personal digital assistant (PDA) or a smart phone, which is responsible for the connection with other networks. For example, the obtained data can be forwarded to a hospital server. Therefore, it is clear that forwarding data is an important challenging task in WBANS. These challenges must be taken in consideration and overcome in proposed routing approaches.

Although there are previous efforts for surveying WBANS (Moutinho, 2009; Ali, Sarker, & Mouftah, 2010; Ameen, Liu, & Kwak, 2010; Chipara, Lu, Bailey, & Roman, 2010; Hsua et al., 2010) in many aspects, to our best knowledge, none of them was only devoted to surveying routing protocols. Thus, due to the importance of this topic in such type of network this paper is a dedicated study and classification of the body of literature on WBANS routing protocols. In addition, it illustrates a comparison of these protocols, which reveals the important features that need to be taken into consideration while designing and evaluating new routing protocols for WBANS.

The rest of this paper is organized as follows. In Section 2, we discuss routing challenges and design issues in WBANS. In Section 3, we illustrate the WBAN architecture. A classification and a comprehensive survey of WBANS routing approaches are presented in Section 4. In Section 5, a discussion and a comparative study are elaborated. Finally, Section 6 concludes this paper and highlights the future works that will be carried related to this topic.

2. Design Issues Of Routing Protocols

Developing efficient routing protocols in WBANs is a nontrivial task due to diverse characteristics of the WBANs environment. Thus, the design challenges of WBANs routing protocols involve the following main aspects.