Adaptive Hierarchical Data Aggregation using Compressive Sensing (A-HDACS) for Non-smooth Data Field

Compressive Sensing (CS) has been applied successfully in a wide variety of applications in recent years, including photography, shortwave infrared cameras, optical system research, facial recognition, MRI, etc. In wireless sensor networks (WSNs), significant research work has been pursued to investigate the use of CS to reduce the amount of data communicated, particularly in data aggregation applications and thereby improving energy efficiency. However, most of the previous work in WSN has used CS under the assumption that data field is smooth with negligible white Gaussian noise. In these schemes signal sparsity is estimated globally based on the entire data field, which is then used to determine the CS parameters. In more realistic scenarios, where data field may have regional fluctuations or it is piecewise smooth, existing CS based data aggregation schemes yield poor compression efficiency. In order to take full advantage of CS in WSNs, we propose an Adaptive Hierarchical Data Aggregation using Compressive Sensing (A-HDACS) scheme. The proposed schemes dynamically chooses sparsity values based on signal variations in local regions. We prove that A-HDACS enables more sensor nodes to employ CS compared to the schemes that do not adapt to the changing field. The simulation results also demonstrate the improvement in energy efficiency as well as accurate signal recovery

Pengembangan Zone Routing Protocol untuk Proses Data Gathering pada Lingkungan Wireless Sensor Network dengan Penghematan Energi

Jaringan sensor nirkabel merupakan jaringan yang terdiri dari node-node sensor yang memiliki fungsi penting tetapi memiliki kekurangan pada bagian daya yang sangat terbatas. Jaringan sensor nirkabel umumnya digunakan untuk mengawasi suatu kejadian dan akan memberikan informasi jika terjadi suatu perubahan pada lingkungan yang diawasinya. Semakin besar dan banyak node yang digunakan dalam jaringan sensor nirkabel, maka akan semakin besar pula energi yang digunakan dalam transmisi. Perlu dilakukan mekanisme tertentu agar energi yang digunakan dapat dihemat tetapi dengan tanpa mengurangi waktu tiba data hasil pengamatan. Pada tugas akhir ini, jaringan sensor nirkabel dibagi kedalam 16 zona berdasarkan posisi dari suatu node. Pada masing – masing zonanya akan dipilih satu node yang akan menjadi cluster head. Data dari setiap node akan dikirim dan dikumpulkan pada cluster head untuk mengurangi jumlah transmisi. Selain dengan menggunakan cluster head, pada setiap node juga terdapat mekanisme aggregasi yang membuat data hasil pengamatan tidak akan langsung dikirimkan melainkan ditampung terlebih dahulu sampai pada batas tertentu. Selain dengan cluster head, penampungan ini akan mengurangi jumlah transmisi. Dengan mengurangi jumlah transmisi data, penggunaan energi dapat ditekan sehingga akan memperpanjang network lifetime. ======================================================================================================= Wireless sensor network is a network that consists of sensor nodes that have important functions but have deficiencies in the power. Wireless sensor network are generally used to monitor an event and will provide information in case of a change in the environment it is watching. The more number of nodes used in the wireless sensor network, the greater energy used in the transmission. A certain mechanism is necessary to use to save energy without reducing the latency of the observed data. In this undergraduate thesis, wireless sensor network is divided into 16 zones based on the position of a node. At each zone will be selected one node which will become cluster head. Data from each node will be sent and collected on the cluster head to reduce the number of transmitions. In addition to using the cluster head, on each node there is also an aggregation mechanism that makes the observation data will not be sent directly but accommodated in advanve to a certain extent to reducing the number of transmission By reducing the number of data transmition, the use of energy can be reduce so that it will extend the lifetime network