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TopBackground
Advancements in wireless and mobile technologies have enhanced the capabilities of wireless (or mobile) devices. With increasing number of users owning wireless devices and developments in grid, scientists and engineers have paved the way for wireless grid evolution. A future enterprise with wireless grid may request other enterprises (equipped with either a wireless grid or a wired grid or a combination of both) for service, on some agreement or payment basis. Some devices (such as camera, printer) provide only specialized services, whereas others (such as mobile phones, laptops) can provide multiple services. A device can request other devices to do some job on its behalf in a wireless grid.
Figure 1 shows wireless grid, where some wireless devices can also have access to wired grid infrastructure. It is comprised of wireless devices like wireless PCs, laptops, PDAs, cell phones, etc., which are resource constrained having limited battery power, bandwidth, processing capacity and memory. However, due to continuous increase in device capabilities and number of users, an aggregated resource pool can offer a tremendous capacity such that any complex application can execute. Wireless devices communicate with BTS (Base Transceiver Station) using wireless communication technologies such as IEEE 802.11x, IEEE 802.16x, IEEE 802.15x, IEEE 802.20x, Bluetooth, Zigbee, wireless ad hoc networks, cellular networks, etc.. The BTS is connected to the wired grid. Using a particular user interface wireless devices get connected with a grid service providers or applications via BTS.
TopClassification Models Of Wireless Grids
Based on different factors, wireless grids ARE classified into three categories as follows:
- 1.
Geographical distribution or organizational scope,
- 2.
Type of service they offer, and
- 3.
Predominant devices and their mobility.
Figure 2 shows various types of wireless grids in each of this category.
Key Terms in this Chapter
Grid: Computing : It is a type of parallel and distributed system that enables the aggregation and sharing of geographically distributed resources such as Computers (e.g., PCs, clusters, ...), Softwares (e.g., special purpose applications), Databases (e.g., access to human genome database), Special Instruments (e.g., radio telescope), and People (e.g., researchers, scientists) across the Internet and presents them as an unified integrated (single) resource.
Wireless Grid: wireless grid is an extension of the capability of grid computing to wireless devices such as laptops, mobiles, PDAs, sensors, etc. to support sharing of resources within the virtual organizations. Thus it represents a large scale, complex, heterogeneous, distributed wireless network environment in which wireless devices from different administrative domains have different policies, preferences, and goals for resource sharing.
Actual Organization (AO): It refers to an autonomous organization equipped with some necessary infrastructure (hardware, software, human resources, etc) to manage its functions.
Virtual Organization (VO): It refers to a network of independent organizations that join together, often temporarily, to offer or obtain particular services. All these organizations share some commonality among them, including common concerns and requirements, but may vary in size, scope, duration, sociology, and structure.