Driven by Moore’s law (Moore 1965), the microelectronics industry has created ever smaller chips that are consuming less energy, are less costly, and yet are more powerful and capable of things one could hardly imagine before. This has led to a large variety of different devices and terminals, everything from small and simple mobile phones and music players to PDAs, tablet PCs, and computers embedded in virtually every artifact, to advanced mobile multimedia or entertainment platforms.
According to the Wireless World Research Forum (WWRF), by the year 2017, there will be 1000 wireless devices per person on earth. These devices will vary from sophisticated multimedia systems to very simple sensor systems. Many of them will be intimately linked to people. They will be an important ingredient of what has been called ‘the Internet of things’. In principle, this opens up the perspective of using this vast number of personal resources to enhance people’s lives, professional and personal, regardless of where they are. However, the shortcomings of current wireless communication technologies are hampering the development of seamless communication between the multitude of devices a person will own.In order to be successful, future information and communication technology should be centered on the user, improving the quality of life of and adapted to the individual, without the need for the user to be aware of the technical details. In order to achieve this, devices and environments need to become smarter, more responsive, and to accommodate the needs of the individual. Further, personalization and ubiquitous access to information and communication will be essential. Ideally, such a system must adapt to the situation and allow its users to use the most suitable means of communication and to access the most relevant information. As a consequence, new fields of research have emerged that aim to provide users with the same experience independent of user interfaces, terminal capabilities, communication technologies, and network and service providers. Examples of such fields are pervasive and ubiquitous computing as well as ambient intelligence and ambient networking.
The personal network (PN) (Niemegeers and Heemstra de Groot 2003) is such a concept and technology. It is related to pervasive computing with a strong user-focused view. While a PAN connects a person’s devices around her, a PN extends that PAN with other devices and services farther away. This extension will physically be made via any kind of wired or wireless network. This can include devices and networks around her in the car, office, or any other place. However, a PN is more than connectivity. A person’s PN must support her applications and take into account her context, location and, of course, her communication possibilities. A PN must adapt to changes in the surroundings, be self-configuring and be able to incorporate many different types of networks and devices to be as useful as possible. The illustration here shows what a PN could look like for a user. It shows how the user has electronic devices around her that can communicate with each other using WPAN technologies. It also shows how those devices can communicate with the devices of friends in the close vicinity as well as devices in smart buildings. The PN also incorporates devices elsewhere, such as in the office and at home.
There are many different ways of integrating the various communication technologies to achieve one unified system. The best and most complete integration approach is to define a common network layer to be used by all, which is similar to the approach taken by the Internet with the Internet Protocol (IP). Such a general and common network layer architecture that imposes minimal changes to the underlying network types, can bridge different communication technologies and offer a homogeneous and clear view to the end-user. At the same time, the network architecture needs to be future proof, that is able to accommodate all kinds of present and future applications and technologies. In order to be successful, a PN should cater for all of a person’s communication needs. The PN must include not only the person’s wearable and wireless devices but also devices at home, in the car, in the office, or any place where the user may have personal devices. This means that the network layer of the PN must work as a home network at home, a car network in the car, a PAN around a person and glue all these networks together in one PN. At the same time, it must cooperate with existing networks such as the Internet and other infrastructure networks. Take a look at some PN user-case scenarios illustrated here;
