Science and Technology

All Circuits Are Busy

How do we implement Article 26 of the law of July 17, 2001, which permits proprietors and managers of cinemas, theaters, cabarets, and other entertainment spaces to install cell-phone “scramblers”? This is the delicate issue on which the Telecommunications Regulating Authority (ART) presented proposals to the Consultative Commission of Radio Communications after public hearings.

There are several categories of scramblers, which may be classified into two larger families. First, there are those that scramble the emission frequencies of cell phones by creating a level of interference so intense that mobile network can no longer initiate or maintain communication. Next, there are systems that can act upon the mobile units by using a filtering mechanism, which can force them into a change of status (restricted usage). They can change the channels, modify their contents, and finally block communication by sending incoming calls to subscribers’ voice mails.

Differences exist within these two broad groups. There are simple scramblers (these emit a permanent signal that creates interferences on the frequencies allocated to the mobile phone). Then there are “smart” scramblers, which emit only a parasitic signal when they determine that another cell phone is about to initiate communication. When a cell phone is called, it does not ring immediately. Its base station sends a generalized call, or page, to locate precisely (to the exact cell) the particular mobile phone that is being sought. It is when the latter signals its presence in response to the page that the scrambler detects the phone and launches the signal preventing ringing and communication.

The systems that use filtering are harder to develop and are still within the realm of theory. They are more intrusive, given that they are capable of distinguishing between different channels within the signal (signaling channels, data channels, etc.). They cannot be implemented without the technical engagement of the network providers, who, naturally, are not interested in this.

Industry experts believe that these systems—the objects of a few patents—will not be available for two to five years. Yet both simple and intelligent scramblers that merely create an interference signal are already available in France, even though they remain illegal. In theory, they are reserved for security or military applications.

The casual overseas shopper (in Israel, Japan, South Korea, or China) will find low-grade scrambling devices of a few milliwatts in specialized shops or on the Internet. These are James Bond-type gadgets, which can be hidden within a Nokia or Siemans cell-phone carrying case. At the other end are highly powerful suitcase units (30 watts or more), ranging in price from 100 to several thousand euros, which can scramble the entire Global System for Mobile Communications or other base stations. One can well understand why the ART and the network providers are worried about the proliferation of such systems. In the hands of ill-intentioned or simply ill-informed persons, they could prove dangerous.

The debate rages regarding the feasibility of achieving isolation inside entertainment spaces as defined by law—places where artistic works are performed and broadcast. This definition, however, is very broad. Does a temporarily raised tent fit this definition? What about entrance lobbies or bars at intermission? For Hortense de Labriffe, representative of the Union des Cinémas, there is nothing to argue about, “Only the performance space itself is affected by this law.”

To avoid the proliferation of scramblers, this point of the law ought to be clarified. In all cases, isolation presents a problem. The inclusion of adjacent spaces in the scrambling rules will have economic consequences for network providers. Communications in the performance hall during shows may be scrambled, but what about calls made and received from lobbies? The owners of entertainment venues, accustomed to strict regulations regarding public spaces, do not see any problems with restrictions that would exclude adjacent areas (lobbies, backstage areas, bars) from scrambling (if an efficient isolation system could be implemented).

Next comes the issue of emergency phone calls. For the scramblers are not able to distinguish the wheat (emergency call) from the chaff (casual phone call). A doctor on call, attending the opera in a scrambler-equipped theater, will not receive emergency phone calls or text messages (SMS). “This is not actually an issue,” replies Hortense de Labriffe. “The doctor in question can simply let us know before going inside the theater that he or she might be called. If necessary, the theater managers will alert him or her. Likewise, in the case of an emergency in the performance space (fire, sick spectator), we can call emergency services without using spectators’ cell phones, just as we have always done. The ART specifies, however, that regulations oblige network providers to transmit emergency calls free of charge in areas they cover. This will have to be revised.”

ART has another argument against scramblers: norms regarding the levels of public exposure to electromagnetic fields. The addition of a scrambler might augment these levels. This seems unlikely given the weakness of the equipment already in place (illegally), or of the kind performance space proprietors seek to acquire. Finally, if the law is implemented, even according to strict regulations, network providers can be expected to demand a cut in the fees they pay for the exclusive use of frequencies employed by the Special Mobile Group and Universal Mobile Telecommunications System, prorating them to reflect the artificially created shadow areas.