Before we talk about wireless communication, there are two important concepts with which you must be familiar: front-end and back-end applications. Front-end and back-end are terms used to characterize program interfaces and services relative to the user of these interfaces and services.

A front-end application is one that application users interact with directly. A back-end application serves indirectly in support of the front-end services, usually by being closer to the required resource or having the capability to communicate with the required resource. The back-end application may interact directly with the front-end or, perhaps more typically, is a program called from an intermediate program that mediates front-end and back-end activities.

The wireless cellular system has been in use since the 1980s. Now, with advanced wireless systems, you can do online chatting, send pictures from one place to another, and if you can afford it, stay globally connected with friends, relatives, etc. all the time. This wireless cellular system reduces distances, offers better services, and makes us able to utilize many advance services more efficiently than before.

Here, the problem is our thirst for better and not with the system. For me, the system is fine, but yes there are some limitations. Adaptability is the core issue. Simply, how adaptable is the system under various environments? Will the system work even if the supporting structure crashes? Can the system work without dependency on any infrastructure? Does the system need an administrator to monitor the whole range of operations? Many other similar issues come up when we discuss the overall adaptability of fixed wireless communication systems.

An old concept, in modified form, has emerged with the invention of technologies like Bluetooth, WiFi, etc. This concept is known as the mobile ad-hoc, or peer-to peer network. The mobile ad-hoc network is one of the new additions in the family of wireless networks. It was first used on an experimental basis in the 1970s to run various military applications. Later, DARPA launched a project to monitor the feasibility of the concept of peer-to-peer networking.

A mobile ad-hoc network is an autonomous system of mobile nodes connecting together in the absence of fixed infrastructure. Mobile ad-hoc networking is an advantageous way of exchanging peer-to-peer information among various types of network devices, such as fixed, portable, and mobile nodes. The use of these networks has increased dramatically, and they're being used for implementing solutions for business, entertainment, and safety applications in business, residential, and industrial areas. The key characteristic of a mobile ad-hoc network is the ability of any mobile node to route traffic for other nodes in the network.