Research On WBAN Lifetime Optimization By Resource Allocation

In recent years, with the development of information a nd technology, wireless sensor network applications dabble in a variety of fields. As one of these important applications, wireless body area network(WBAN) which is applied to the field of medical and healthcare attracts more and more attentions. WBAN is composed of wireless sensor nodes which are attached to or inside the human body and a coordinator. The sensor nodes collect human's actual physiological signals and transfer them to the coordinator which has a certain computing capabilities and then the coordinator transfers the data to the handling system like in hospital via the mobile network. Since the sensor node's energy is extremely limited, it is a key issue to improve the energy efficiency to prolong the lifetime of WBAN.According to the characteristics of the wireless body area network, we make a research on the resource allocation methods. The mathematical model of resource allocation which is solved subsequently in WBAN is established. The major works in this paper are in the following :Firstly, research on system model of WBAN. The system model which includes the signal source, topology, channel path loss model and the operating mode are studied and analyzed which is the background of the thesis.Secondly, network static energy minimization model of WBAN. Under the background of the network structure, the transmission characteristics of medical monitoring and the time-invariant frame, from the perspective of resource allocation, we optimize the allocation of transmission power(transmit rate) a nd transmission time simultaneously from the perspective of resource allocation in WBAN. Finally, the static energy minimization model is established which is proved to be a geometric programming. After that, we can achieve the optimal result and the energy efficiency of WBAN is improved accordingly.Thirdly, dynamic network lifetime maximization model of WBAN. Based on the static energy minimization model, the characteristics of WBAN and the time-varying frame, after several tranings of the global energy allocation for every node, the network lifetime maximization model was proposed. According to the simulation, it can be concluded that energy efficiency can be obviously promoted by the proposed methods and also prolong the lifetime of the WBAN.