## 2 Related Work
### Asymmetric VR  
Asymmetric VR is a relatively new definition that originated from studies on virtual telepresence [54]. It describes a variety of interactions of co-located users in multi-user VE [55; 56; 57]. Lately, the traditional focus on single-user experiences with VR has shifted towards exploring multi-user VR interaction [58], which may occur on different levels of immersion and control among user groups. Despite asymmetry in cooperation being initially reviewed as a challenge to overcome, it delivers benefits in terms of flexibility and freedom in degree of participation [29]. Presence and experience in asymmetric VR were found to be significantly influenced by roles and tasks that were assigned to user groups [58]; therefore, when designing asymmetric VR collaboration, the asymmetry should be leveraged by defining roles in a way to embrace the differences of user groups [27] and extract their advantages [26].  
A variety of research studies demonstrated how to increase immersion and presence of non-HMD users and facilitate the co-located asymmetric collaboration between a variety of devices. [PERSON] et.al. [26] presented the ShareVR proof-of-concept (co-located multi-user VR system), which increases the non-HMD users' enjoyment, presence, and social interaction by immersing them into VE via floor projection and mobile displays in combination with positional tracking. Another article [28] identified the challenges and goals of asymmetric VR based on expert interviews and conducted a co-located user study on collaboration between VR-users and external users who observed VR-users via external tablet and interacted with the virtual environment by directly drawing over it. The presented TransceiVR system was proved to increase the quality of communication and positively affected task completion time, error rate, and task load index. A recent study [59] demonstrated an asymmetric collaboration setup between technicians in VR and experts in a meeting room based on a video stream from VR. Their findings showed the potential of the approach for other use cases and suggested a base virtual collaboration on several spaces, rather than focusing on a single space with rich interactions. Despite the presented positive effects on collaboration, the proposed systems still rely on costly additional technologies and were explored in a co-located setup, where the attributes of the physical world play a significant role [59]. According to the Composite framework for Asymmetric VR (CAVR) [56] in co-located settings, the simultaneous engagement of physical and virtual worlds is the base for facilitating collaboration over a mixed-reality space. The framework further introduced the dimensions of asymmetry: spatial copresence, transportation, informational richness, team interdependence, and balance of power.  
Nevertheless, there is no clear understanding of how asymmetry might occur in distributed settings, when all users are located in different physical spaces and have different levels of interactivity with the virtual space and each other. Furthermore, there is a lack of generalizable knowledge on how VR and other novel technologies affect remote collaboration [30]. To address this gap and further explore the effects of asymmetry in distributed settings, our article explores how VR can be used as an enhancement technology to facilitate collaboration among geographically dispersed departments in an industrial context. Since in some countries access to technology was limited, due to the pandemic situation, we investigated how communication and shared tasks would be performed by VR-users and remote users who observe video feed from VR streamed over Teams. By merging two virtual spaces, an immersive virtual world and a digital space in Teams, we generated a mixed-reality space for asymmetric VR collaboration.