The Active Badge Location

Integration of telephone systems with computer systems is an important part of the development of the automated ooce. Much work has already been undertaken integrating digital voice and data into a single network 1] but there has been less commercial eeort invested in improving the telephone interface. Although these interfaces are functionally very sophisticated they are mostly cryptic and their operation is diicult to remember. The features most commonly used by PBX clients arècall transfer' and`call divert' or`follow me'. In the majority of cases the execution of these features could be automated by the PBX if it had information about the current location of its clients. A solution to the problem of determining location information has further application, for example, to help a receptionist locate employees without a public-address system or without telephoning all the possible locations at which they might be found. These kinds of solutions can cause a great deal of irritation and disruption to other employees. Further advantage can be gained from location information by allowing PBX users to deene rules governing when a call transfer is allowed. For instance, where you are and who you are with should aaect this decision. Most people would prefer not to take unexpected telephone calls when they have just been called into their bosses' ooce, and there are many other instances for which call control based on location can be used eeectively. The conventional solution used for personnel location is thèpager system'. In order to locate a person a signal is sent out by a central facility that addresses a particular receiver unit (beeper) and produces an audible signal. In addition, it may display a number to which the called-party should phone back (some systems allow a vocal message to be conveyed about the call-back number). It is then up to the recipient to use the conventional telephone system to call-back connrming the signal and determine the required action. Although useful in practice there are still circumstances where it is not ideal. For instance, if the called party does not reply the controller has no idea if they: 1) are in an area where the signal does not penetrate 2) have been completely out of the area for some time 3) have been too busy to reply or 4) have misheard or misread the call-back number. Moreover, in the case where there are a number of people who could respond …