it first has to be clear what the capacity of each device is and what the storage need is. As said, there are many techniques to describe certain resources but there is not one technique that is able to provide this service for all resources. The available techniques combined, however, cover most of what is needed. Grid Computing Grid computing came into existence as a manner of sharing heavy computational loads among multiple computers to be able to compute highly complex mathematical problems (a good real-world example being the SETI@Home project). However, it developed rapidly into a way of sharing virtually any resource that is available on any machine on the grid. Wired grids are now used to share not only computing power, but also hard disk space, data, and applications. The grid topology is highly flexible and easily scalable, allowing users to join and leave the grid without the hassle of time and resource hungry identification procedures, having to adjust their devices or install additional software on them. The goal of grid computing is described as "to provide flexible, secure and coordinated resource sharing among dynamic collections of individuals, institutions and resources" (McKnight, Howison, 2004). It is intended to be a dynamic network without geographical, political, or cultural boundaries that offers real-time access to heterogeneous resources and still offer the same characteristics of the traditional distributed networks that are in use everywhere in our houses and offices. These characteristics being stability, scalability, and flexibility as the most important ones. Ian Foster offers a checklist for recognizing a grid. A grid allows: Coordination of resources that are not subject to centralized control Use of standard, open, general-purpose protocols and interfaces Delivery of nontrivial qualities of service The Wireless Grid One of the biggest limitations of the wired grid is that users are forced to be in a fixed location as the devices they use are to be hard wired to the grid at all times. This also has a negative influence on the flexibility and scalability of the grid; devices can only join the grid in locations where the possibility exists to physically connect the device to the grid (i.e. there is the need for a hub or a switch to plug into). One description of the wireless grid is "an augmentation of a wired grid that facilitates the exchange of information and the interaction between heterogeneous wireless devices" (Argawal,