Various servers, which are relatively powerful computers that anchor the network by performing computationally-intensive services for less powerful computers on the network, will manage the personal networks and their data stores. These servers will be shared among a number of personal networks, but individual personal networks will remain logically separated.
The personal networks can connect among themselves, especially those of family members, friends and groups having a common interest or those who are together in a shared environment such as home or office, thus making the system very powerful. A combination of wired and wireless communications makes it possible to establish links to any personal network anywhere in the world, if required.
One of the biggest technology challenges is the user interface. The personal network is required to communicate with people in a human-to-human manner, which comes naturally to us. It means making adjustments as per our computer literacy. Also, voice identification and speech synthesis by the computer are some areas on which a lot of research is happening. There are many complexities such as speech patterns that could change for the same individual depending on his or her mental condition, mood, physical health, etc.
Speech recognition is based on identification of phonemes—the smallest acoustical components of language, and spoken English comprises approximately 80 phonemes. Human speech is sampled by the computer with digitised audio signals and compared with those that it has stored. There is some scope to accommodate disparities in individuals’ pitches and word duration. In addition, probability of a particular word following another will lead the computer towards finding a match. Finally, the need is that you should be able to interact with your personal networks simply by talking and listening to these.
Apart from human-to-machine communication, reliable machine-to-machine communication is also important, especially if the personal network is to be able to interact effortlessly with other people’s personal networks. Channels of communication comprise chiefly the physical links between machines like home LANs, infrared links among devices located in very close proximity, short-range radio links used in cordless phones, long-range radio links as in mobile phones and cable or high-speed connections to the rest of the world.
Wireless communication techniques form the hub to the personal network mobile computing. While for in-room communication infrared systems offer links of up to 4Mbps across a distance of about one metre, wide-area usage demands radio links.
Complexities of wireless communications are far greater than those posed by wired links. Key communication parameters such as transmission speed, error rate, reliability and delay can change considerably and rapidly during the course of a single wireless communication. This instability is driven by the variability of radio frequency noise and the signal attenuation that is caused by natural phenomenon such as storms or due to interference from various electronic devices.
Mobility further brings in more uncertainty. For example, radio-wave propagation is abruptly interrupted when a skyscraper, vehicle or some other large object comes between the transmitting and receiving devices. Therefore transmission speeds available in wireless communications tend to be much lower vis-a-vis wired links.
Access to personal network devices will be increasingly protected by biometrics—use of physiological features such as pattern of a voice, fingerprint or iris to permit activation. Biometrics are unique to an individual. For example, no other human being on Earth has the same fingerprint as yours and, hence, your thumb or finger swipe allows you and only you to access your laptop.
Traditional protection such as passwords will exist but only to supplement biometrics. However, public-key cryptography—a mathematical system that will be used to secure owner control over the personal network and allow for intra- as well as inter-network privacy—will form the hub of the security system. Encryption systems known as RSA and PGP are examples of public-key cryptography.
Public-key cryptography works by assigning each person two different keys, which really are two numbers linked with each other. The two keys are several digits in length and next to impossible for most humans to memorise. These are generally saved on the computer’s hard drive or on a disk. The public key is accessible to anyone who wants to send you a secure message. The private key, however, is only available with you. Public-key cryptography guards with encryption and ensures privacy. A sender can encrypt a message to you that could be an account number or a debit card number using your public key. However, this message can be decoded only by using both the public and the private key, and only you have the private key.
Apart from security, another critical aspect is software. Programs need to be such that these cater to multiple computers and operating systems. Software will need to be written in a language like Java that can translate commands into readable instructions and is device agnostic.