**4.2 Model of actively replicated virtual environment**

The data management consistency through active data replication among users/ players is topologically identical to the peer-to-peer architecture. In the case of an actively replicated virtual game environment, consistency sharing is different because it is handled on the side of every user/player separately.

To maintain data consistency, it is necessary to implement a communication node (**Figure 9**). This is important mainly due to the need for global collaboration, as a result of which this model can be considered a hybrid with the client–server architecture [41]. Using the communication node, data consistency and user/player activity can be quickly sent and compared.

The model of an actively replicated virtual environment is controlled by the following algorithm, as depicted in **Figure 9**:


#### **Figure 9.**

*Consistency model of active replication virtual environment sharing.*

The benefits of this consistency model can be considered to be the high efficiency in synchronizing users/players, where the communication level is conducted directly, without processing by a third party [42]. This is desirable for some games. Despite the presence of the communication node, this is not data processing, but only replication to other users/players. Due to the close connection between users/players, it is possible to achieve a faster way of synchronizing and sharing collaborative activities.

Given the negatives, we can state that the growing number of users/players directly increases the requirements for the computing power of their devices. To extend the virtual collaboration systems with XR technology, it is necessary to emphasize that each of them has significantly different computing power. Therefore, the usability of active replication in sharing a virtual environment for a group of XR technologies is insufficient. Another resulting problem is the congestion of the communication level in case the given consistency model would be deployed for global use. In conclusion, this model can be considered effective only if the number of players does not change rapidly during the collaboration as well as the number of players is low.
