The innovation lies in the interaction of several properties and factors. The project uses various existing technologies and approaches to develop solutions to problems of public facilities related to the Corona pandemic. These are:

• Small, networked NDIR sensors
• LoRaWAN wireless technology for data transmission over several kilometers
• Easy-to-understand visualization of the measured data
• Open data and open licenses for public use of the project results
• In addition, the project was developed and implemented in the interaction between civil society, companies, science and public administration.

The COMO pilot project ends on September 30, 2022. During the project, we distributed around 45 sensors in Berlin institutions and integrated them into the local LoRaWAN network. Likewise, three outdoor gateways and five indoor gateways were installed to support data transmission. The sensor data show publicly on the COMo website, if the institutions have agreed. The evaluation of the data and results is not yet complete, but it is already clear that reliable operation of a network of sensors with LoRaWAN technology only makes sense if this infrastructure is expanded and operated professionally. The number of sensors installed in an institution must also be increased significantly in order to enable models to forecast ventilation intervals. All findings are published and given to the Berlin Senate as recommendations for expanding the IoT infrastructure. The Berlin Senate is funding the project and is currently working on expanding the Smart City infrastructure.

The project is funded and co-developed by Berlin Senate Chancellery. They are developing the Smart City strategy in Berlin.
The Technologiestiftung Berlin is a non-profit NGO. It runs several digitization projects with substantial community participation from various sectors. KOING GmbH initiated the project and is contributing its technical expertise in LoRa technology.
Berlin University of Applied Sciences (HTW) is developing the models for ventilating the rooms and forecasting the air quality

The project supports several groups in society, as described above:

• Operators of the respective publicly accessible premises such as cultural institutions, educational institutions, restaurants, etc.
• Potential users of said premises
• The project also provides information for the Berlin Senate on the expansion of Smart City infrastructures

What results and effects have been observed from the innovation so far? For the first time, COMo allows non-technicians to control their air quality based on measured values. This is relevant to facilities with many visitors (e.g. clubs, cinemas...). But also, it is evident that the number of installed sensors for single participants is still too small for general statements and forecasts on the development of indoor air quality.

How were the results and impacts measured? The number of transmitting sensors and the connection quality is continuously monitored, the individual sensors are marked. The air quality data are collected and are therefore available for further scientific evaluation. The operators were also asked about their experiences with the sensors by the HTW using interview guidelines.

What outcomes and impact do you expect in the future? A significant increase in the number of participating institutions and installed sensors as well as an improvement in LoRaWAN coverage.

Main challenges that arose in the project were:

• Due to the tense work situation during the pandemic, the interested operators of the rooms were often not able to give dates for the sensor installation in a timely manner. Since LoRa technology currently does not allow plug and play, support is required for the installation and registration process. This has made it difficult to fully deploy existing sensors quickly.
• The unexpected patchy coverage of the urban area with LoRa gateways has caused a high maintenance effort for the sensors, since poor coverage causes high power consumption of the batteries used.
• Finally, delivery bottlenecks caused by the pandemic have led to sometimes very long delivery times for the necessary devices.
  Overall, these obstacles have led to delays in the project process. This could only be partially compensated for by additional work, so that an extension of the project period was applied for and approved.

For the implementation of the project, it was essential that an intensive exchange process was carried out between the participants (TSB, HTW, KOING GmbH and last but not least representatives of the Senate Chancellery) in order to achieve a common understanding of the project goals and the possible results. This common understanding was the prerequisite for funding the project from public funds. Another important prerequisite for reaching the possible participants for the project was the network of the TSB in civil society.

There are known approaches to monitoring indoor air quality in order to reduce the risk of infection for restaurant visitors (in Brussels, for instance). Schools have also already used corresponding CO2 sensors, but rarely with comprehensive networking and central control options. DIY sensor projects are also known. However, the sensors used in these decentralized projects are often only technically suitable to a limited extent to generate permanently valid values. Today, the sensors used in heating and air conditioning often are able to measure the CO2 concentration in order to exchange the room air accordingly. However, these systems are currently not operated under the aspect of infection protection, the data collected are not used or published to visualize the CO2 concentration. It is probably possible to read out this data via interfaces of existing air conditioning systems and publish it as in COMo, in order to document compliance with indoor air hygiene standards.

In general, the communication of the project idea between those potentially involved and the target group is pivotal for the success of such a project. The communication is greatly encouraged if there is a physical location as a meeting point for communication and experimentation for those involved - in our case the CityLAB Berlin. Unexpectedly, the participating operators had few concerns about the privacy of the transmitted sensor data. This was expected of us in advance and we had sought advice from a lawyer. In fact, questions arose about the energy consumption of the sensors and gateways, or whether the sensors color can be changed to match the wall. The example shows that a previous survey and involvement of potential participants, anchored in urban society, helps to avoid false expectations of the participants. Furthermore, due to currently very long delivery times of hardware, it makes sense to consider and test several alternative systems to avoid delays in the project.