Towards Efficient Wireless Body Area Network Using Two-Way Relay Cooperation

Abstract

The fabrication of lightweight, ultra-thin, low power and intelligent body-borne sensors leads to novel advances in wireless body area networks (WBANs). Depending on the placement of the nodes, it is characterized as in/on body WBAN; thus, the channel is largely affected by body posture, clothing, muscle movement, body temperature and climatic conditions. The energy resources are limited and it is not feasible to replace the sensor’s battery frequently. In order to keep the sensor in working condition, the channel resources should be reserved. The lifetime of the sensor is very crucial and it highly depends on transmission among sensor nodes and energy consumption. The reliability and energy efficiency in WBAN applications play a vital role. In this paper, the analytical expressions for energy efficiency (EE) and packet error rate (PER) are formulated for two-way relay cooperative communication. The results depict better reliability and efficiency compared to direct and one-way relay communication. The effective performance range of direct vs. cooperative communication is separated by a threshold distance. Based on EE calculations, an optimal packet size is observed that provides maximum efficiency over a certain link length. A smart and energy efficient system is articulated that utilizes all three communication modes, namely direct, one-way relay and two-way relay, as the direct link performs better for a certain range, but the cooperative communication gives better results for increased distance in terms of EE. The efficacy of the proposed hybrid scheme is also demonstrated over a practical quasi-static channel. Furthermore, link length extension and diversity is achieved by joint network-channel (JNC) coding the cooperative link.

Solutions and Recent Challenges Related to Energy in Wireless Body Area Networks with Integrated Technologies: Applications and Perspectives

“…The sensed data is related to patient conditions including heart rate, blood pressure and temperature. Routing protocols have main role for data processing (6). The protocols main objectives are to find the shortest path, consume less energy and provide high throughput in the network.…”

Energy Modeling of Wireless Body Area Networks with On-Body Communication Channel Characterization

“…Although this approach is interesting, it fails to take into account the propagation channel conditions. In [17], an analytical expression of energy efficiency was derived by introducing channel specification including signal to noise ratio (SNR) and distance based path loss. However, in this study, there is still a need for considering the body posture influence in the path loss estimation.…”

Analysis and Design of Rateless Two-way Relay Networks Based on a Multiply-and-Forward Scheme

“…Over the past few decades, the two-way relay network (TWRN) [1][2][3][4][5][6][7][8][9][10][11][12][13] has aroused great interest due to the overwhelming development of wireless cellular systems, especially when one-way relaying is of low spectral efficiency because of the half-duplex constraint. In a TWRN system, two source nodes exchange information through a relay node.…”

“…In the three-stage scheme, source nodes send their corresponding messages to the relay in the first two stages, respectively. In the third stage, the relay processes received signals with either a decode-and-forward (DF) approach [1][2][3][4][5][6] or an amplify-and-forward approach [7][8][9][10][11][12][13], and then broadcasts back to the source nodes. In [14], Xu et al proposed a multiply-and-forward (MF) approach, in which the relay multiplies the signals sent from different source nodes.…”