- Peer-to-Peer (P2P) network of office computing devices
- VOF document contains data and workflow information
- Each device can send, receive and process VOF documents
- VOF document routed according to workflow
A VOF-Node in general is the system’s representation of an end device (e.g. Laptop, PC, Mobile Phone, PDA etc.) for users in the Virtual Office. Figure 1 displays the conceptual view of a VOF-Node. The VOF-Platform on top of the operating system is the core component. It is responsible for the communication with other VOF-Nodes in the environment. The VOF-Platform acts as the communication middleware for each node in the VOF-Infrastructure. Further, the platform manages and provides executable services and also an interface for VOF-Applications. These applications are able to use all deployed services within the VOF-Environment.
A Virtual Office Service (VOF-Service) is a service, which can be deployed or undeployed on the VOF-Platform. After the deployment, a service is executable from local and remote VOF-Nodes using its underlying VOF-Platform. A VOF-Service contains program logic to support a user during his work in an office. By means of several criteria given a VOF-Application, a VOF-Service chooses a matching underlying Basic Service and delegates the execution. A Basic Service is a fundamental service without a logic block. It is also executable and discoverable but only from VOF-Services. Figure 2 illustrates this concept means of a location based print service. First this VOF-Service requests the current location of the VOF-Platform, afterwards it discovers all Basic Services, which are able to print documents. In the last step the VOF-Service delegates the print job to the underlying Basic Service, which maps to the nearest location.
VOF-Environment and Infrastructure
The VOF-Environment is a distributed system based on a decentralized network topology. This means that every member of the VOF-Environment has equivalent capabilities and responsibilities, which is realized as a peer-to-peer (P2P) solution. Inside the system, each VOF-Node provides different executable VOF-Services and Basic Services for other VOF-Nodes in the system. Within the Environment, each provided service can be discovered and executed other VOF-Nodes. Figure 3 displays an example of a VOF-Environment, containing four peers (VOF-Nodes) and their deployed services. The following example illustrates a service call in the VOF-Infrastructure: C is able to discover a VOF-Service located on peer A. The logic containing in those service, discovers a Basic Service on D and delegates the call for execution. The Feedback of D is sent back to C via A.
More information can be found in [1,Chapter 4] and [2,Chapter 4]. Formal models of VOF constructed used during evaluation can be found in .
 Requirement Elicitation, August 2009. Deliverable 5.1 of project FP7-231620 (HATS), available at http://www.hats-project.eu/sites/default/files/Deliverable51_rev2.pdf#page=29.
 Evaluation of Core Framework, August 2010. Deliverable 5.2 of project FP7-231620 (HATS), available at http://www.hats-project.eu/sites/default/files/Deliverable52.pdf#page=42.
 Supplementary models of D5.2, August 2010, available at http://www.hats-project.eu/sites/default/files/Deliverable5.2Models.zip