here is a great divide in mobile computing between what is desirable and what is practical. This divide is inherent and caused by, among other things, constraints in size and power as well as the lack of a reliable network connection. All these compound to make the mobile computing environment a harsh one. None of this, however, has prevented the proliferation of mobile computers, from laptops and personal digital assistants (PDAs) to very small, simple, embedded computing devices that may go almost completely unnoticed. Indeed, the extent to which these devices are embedded means we are already at the stage where people are unaware of how many computers they may use in a day. The integration of this vast array of mobile and embedded computing objects is now the challenge. The prospect is one of a seamlessly orchestrated computing and communications infrastructure. Clearly, there is a large variation in the communication requirements of these very different devices. However, it is our opinion that there must exist, at the very least, a "base level" of connectivity between things. This should be available to even the simplest of embedded sensing and computing objects. By providing just a small amount of wireless connectivity through which communication is possible, we make possible large numbers of new applications. The provision of such connectivity is what we call embedded networking. This article describes the Piconet project underway at the Olivetti and Oracle Research Laboratory (ORL). Piconet is an attempt to understand the implications of the provision of wireless connectivity at the level described here. We recognize that to do this effectively we must build, deploy, and use a system that demonstrates these concepts. This is what we have done. Embedded Mobile Networking E mbedded networking concerns the provision of a network which is so simple and small that it can be used by almost anything. Through embedded networks we would like everyday objects to be able to communicate in a way that has not yet been achieved. Sensors which can monitor and control the environment; telephones, fax machines, photocopiers, printers, portable computers, and PDAs; electronic access control to buildings and roads; banking and public information terminals -many of these already need a network in order to operate, but all would benefit from a common mechanism by which they are made aware of, and can communicate with, other things nearby. The Piconet project at ORL is developing a prototype embedded network. Piconet is a low-rate, low-range, ad hoc radio network. We have developed a Piconet node that can be used to provide a connection to this embedded network. Piconet provides a broad range of mobile and embedded computing objects with the ability to exploit an awareness of, and connectivity to, their environment. Sensors can use Piconet to relay information about the state of the local environment or of a particular device. Personal connectivity is improved because the multitude of mobile and fixed devices used by an individual in a day can be connected by Piconet; it might be used to personalize things nearby or allow two devices near each other to interoperate. Embedded networking is also suitable for smart information services: active diaries, alarms, information points, and electronic business cards, for example. The proximate connectivity that Piconet provides means these applications can be context-aware [1]. T he kind of applications we hope to make possible with an embedded network like Piconet impose certain constraints on the technology used to build it. Primarily the network must be low-powered, simple, and ubiquitous. It must be of reasonably short range to allow proximity to be inferred from connectivity.  Piconet is a general-purpose, low-power ad hoc radio network. It provides a base level of connectivity to even the simplest of sensing and computing objects. It is our intention that a full range of portable and embedded devices may make use of this connectivity. This article outlines the Piconet system, under development at the Olivetti and Oracle Research Laboratory (ORL). The authors discuss the motivation for providing this low-level "embedded networking," and describe their experiences of building such a system. The article concludes with a commentary on some of the implications that power saving, and other considerations central to Piconet, have on the design of the system.
The structural design referred as Piconet is given in REF and this is applicable for low-power ad hoc wireless networks.
Piconet: Embedded Mobile Networking
IEEE Personal Communications
Computer Science