## 2 The MPwise System
### System Software  
The main system software operating on the nodes consists of the following:  
* The operating system is based on a Linux kernel and GNU software, which is open-source, freely available and highly configurable. By default, it contains only the minimum that is required to run Linux without a desktop environment. * SeisComP: The Seismological Communication Processor (SeisComP; Seiscomp3, [[https://www.seiscomp3.org/](https://www.seiscomp3.org/)]([https://www.seiscomp3.org/](https://www.seiscomp3.org/))) is an open-source software package and concept for real-time seismic data acquisition, processing (quality control, event detection and location), distribution and interactive analysis developed by the GFZ. It includes the SeedLink protocol ([[http://www.seiscomp3.org/wiki/doc/applications/seedlink](http://www.seiscomp3.org/wiki/doc/applications/seedlink)]([http://www.seiscomp3.org/wiki/doc/applications/seedlink](http://www.seiscomp3.org/wiki/doc/applications/seedlink))), which is the system devoted to the real-time seismic data distribution, that is, a server protocol based on the Transmission Control Protocol (TCP; TCP/IP, [[https://en.wikipedia.org/wiki/Transmission_Control_Protocol](https://en.wikipedia.org/wiki/Transmission_Control_Protocol)]([https://en.wikipedia.org/wiki/Transmission_Control_Protocol](https://en.wikipedia.org/wiki/Transmission_Control_Protocol))). There is also software embedded within this package for on-site EEW. * Cube_plugin: This program is embedded in SeisComP and handles the data streams from the digitizer board, and then archives them via a SeedLink (see below) or common acquisition protocol (CAPS) server (this has been developed by gampa GmbH; [[http://www.gempa.de/caps/](http://www.gempa.de/caps/)]([http://www.gempa.de/caps/](http://www.gempa.de/caps/))). One of the advantages of CAPS over SeedLink is the greater ease with which one can transfer multi-sensor data from the node to a gateway node, which in turn transmits the information to a data center or end user. For example, this feature allows the optimization of the joint transfer of seismic data and images using a unified protocol. * Optimized Link State Routing (OLSR Project): OLSR (OLSR, [[http://www.olsr.org](http://www.olsr.org)]([http://www.olsr.org](http://www.olsr.org))) is a table-driven proactive routing protocol currently chosen for the wireless mesh network. As a proactive protocol, it periodically assesses and maintains the network topology by sharing information about its direct neighborhood throughout the network. OLSR is capable of operating \begin{table}
\begin{tabular}{c c} \hline CPU & 1.8 Ghz quad core ARM processor and 1.4 Ghz quad core ARM processor \\ \hline RAM (random access memory) & 2 Gbyte LPDDR3 RAM at 933 MHz \\ \hline Operating system & GNU/ Linux \\ \hline Storage & eMMC5.0 HS400 Flash Storage or micro SD \\ \hline Power consumption & 3-5 W \\ \hline User interface & Tri-color RGB LED to display the status of operating system, Standard Micro-HDMI, supports up to 1920 \(\times\) 1080 resolution \\ \hline IO Ports, Possible expansions & 30 Pin : GPIO/IRQ/SPI/ADC \\ \hline Connectivity & USB 3.0 Host \(\times\) 2, USB 2.0 Host \(\times\) 1, Ethernet RJ-45 \\ \hline MEMS sensor & \(\pm\)2 g/\(\pm\)6 g user selectable full-scale, Acceleration noise density (Vdd = 3.3 V; Full-scale = \(\pm\)2 gj: 50 \(\upmu\)g/sqrt(Hz) \\ \hline \end{tabular}
\end{table} 
Table 4: Technical specifications of the microcomputer board. \begin{table}
\begin{tabular}{c c} \hline Number of channels & 3 or 6 \\ AD converter resolution/effective resolution & 24 bit, typ. 21.5 bit @100 Hz sps @gain 1 \\ Gain & 1, 2, 4, 8, 16, 32, 64 \\ Sample rate & 800 (1 ch-mode), 400, 200, 100, 50 sps \\ Input impedance & 100 kOhm \\ Input voltage range & 5–24 V \\ \hline \end{tabular}
\end{table} 
Table 3: Technical specifications of the digitizer board.