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added value to the duration example

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jensjensenjens 2020-06-20 16:15:02 +02:00
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solution_architecture.md
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@ -211,7 +211,8 @@ The information listed above is not visible to the user, but is used internally
*Figure 12* displays how the total risk score is being calculated. The application is provided with a set of parameters, which are marked in blue within the figure.
Those parameters are regularly downloaded from the CWA Server, which means they can be modified without requiring a new version of the application (see [`exposure-config.yaml`](https://github.com/corona-warn-app/cwa-server/blob/eb8be6c3e9c723c62c619784e41889d10054cc93/services/distribution/src/main/resources/master-config/exposure-config.yaml) for details).
Each of the four risk categories (days since exposure, exposure duration, weighted signal attenuation, and the transmission risk factor) receives an input value from the event which is then mapped to a predefined input value interval. As an example: an exposure duration of D=15.3 minutes is mapped to the interval 15 < D <= 20. Note: the transmission risk category does not use input intervals and instead just consists of the values 1-8. Each of those input value intervals is then assigned a risk score from 0-8, where 0 represents a very low risk and 8 represents a very high risk. This means that from each of the rows in the figure, one value is selected according to the input value for the corresponding category. The product of the four risk scores is used as the **total risk score** of the individual exposure.
Each of the four risk categories (days since exposure, exposure duration, weighted signal attenuation, and the transmission risk factor) receives an input value from the event which is then mapped to a predefined input value interval.
Each of those input value intervals is then assigned a risk score from 0-8, where 0 represents a very low risk and 8 represents a very high risk. This means that from each of the rows in the figure, one value is selected according to the input value for the corresponding category. As an example: an exposure duration input value of D=15.3 minutes is mapped to the interval 15 < D <= 20, which in the current implementation has a value of 1 assigned to it. The product of the four risk scores is used as the **total risk score** of the individual exposure.
According to the [documentation of the framework](https://developer.apple.com/documentation/exposurenotification/enexposureconfiguration), "the attenuation is weighted by the duration at each risk level and averaged for the overall duration". In order to incorporate the time spent within the ranges of attenuation buckets mentioned before, each of those three buckets is assigned a weight value as shown in *Figure 13*.
The individual time values are multiplied with their according weight (*weight_1*, *weight_2* and *weight_3*).
@ -228,7 +229,8 @@ While by default there is no minimum value set, this value is being configured a
![Figure 13: Calculation of the combined risk score](images/solution_architecture/figure_13.svg "Figure 13: Calculation of the combined risk score")
Note that the transmission risk level plays a special role in the above calculations: It can be defined by the app and be associated with each individual diagnosis key (i.e. specific for each day of an infected person) that is being sent to the server. It contains a value from 1 to 8, which can be used to represent a calculated risk defined by the health authority. As an example it could contain an estimate of the infectiousness of the potential infector at the time of contact and, hence, the likelihood of transmitting the disease. The specific values are defined as part of the [app](https://github.com/corona-warn-app/cwa-app-android/blob/ddb1f94f1d577f08863ae319c195d80cacf0bc3e/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/ProtoFormatConverterExtensions.kt) - a motivation of the parameter choices is found in the document [Epidemiological Motivation of the Transmission Risk Level](https://github.com/corona-warn-app/cwa-documentation/blob/master/transmission_risk.pdf).
Note that the transmission risk level plays a special role in the above calculations: It can be defined by the app and be associated with each individual diagnosis key (i.e. specific for each day of an infected person) that is being sent to the server. It contains a value from 1 to 8, which can be used to represent a calculated risk defined by the health authority. As an example it could contain an estimate of the infectiousness of the potential infector at the time of contact and, hence, the likelihood of transmitting the disease. The specific values are defined as part of the [app](https://github.com/corona-warn-app/cwa-app-android/blob/ddb1f94f1d577f08863ae319c195d80cacf0bc3e/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/ProtoFormatConverterExtensions.kt) - a motivation of the parameter choices is found in the document [Epidemiological Motivation of the Transmission Risk Level](https://github.com/corona-warn-app/cwa-documentation/blob/master/transmission_risk.pdf). Note also that the transmission risk category does not use input intervals and instead directly uses the values 1-8.
### Data Transfer and Data Processing