WIRELESS LANDSCAPES: MAKING THE INVISIBLE INTELLIGIBLE A practical guide for wavespotters An Inspiration "There are some kinds of knowledge too that cannot be obtained from books, but must be gathered by actual observation. The inspection of a formation in nature, which is pointed out to you, will teach you more in regard to it in a few minutes that you could learn from lectures or from reading books in as many hours, and the lesson so received will be better remembered. "How lonely would be a journey on which you would see not a single face that you know, and how different it would be if every one you meet were an old friend. So to the tourist new charms must be given to scenery, however attractive it may already be, if he knows something about its geology. The rocks, mountains, valleys and plains, although he sees them for the first time, are old friends in perhaps new and interesting forms. He meets them with a certain pleasure, for he understands what he sees and he is given the materials for many a happy hour of quiet and profitable reflection at home, on what he has seen on his railway journey." From An American Geological Railway Guide, by James R. MacFarlane, Ph.D., New York: D. Appleton and Company, 2nd edition, 1890, pp. 3-4. Rick Prelinger Made for the "ART on BART" Tour San Francisco, October 1, 2005 http://www.prelinger.com WIRELESS LANDSCAPES 1 Introduction Though BART leaves a conspicuous footprint over much of the Bay Area, it retreats into tunnels, jumps onto aerial right-of-ways, and hides behind tall fences. It inflicts a measure of sensory deprivation on its passengers, distancing the landscapes it penetrates through thick, sound- dampening windows. But one environmental attribute is harder to shut out: the wireless landscape. Imagine a totally sensory-deprived spectator, unable to sense sight, sound, smell, touch, taste or movement, but able to receive and demodulate radio-frequency (RF) emissions. What would this spectator perceive? And, as BART passed by, what would RF sniffing reveal about the people, their activities and the infrastructure supporting them? This tour will mark, identify and interpret the rich quilt of wireless transmissions through which our BART journey passes. It will describe the characteristics of this invisible landscape and relate it to the human activities occurring around the places we pass by and through. It will also propose "wirelessness" as a sixth sense that we can mobilize as a way to navigate and understand our emerging environments. This guide follows the order of the ART on BART itinerary. It is intended to be an introductory guide to the wireless landscapes that the BART system penetrates and is neighbor to. It avoids overly technical information, and certain specific details of some communications systems have purposely been omitted. For specific information on two-way radio communications systems operated by federal, state, county, municipal and other government agencies throughout California, I recommend the Government Radio Systems guides published by Mobile Radio Resources, 1224 Madrona Avenue, San Jose, Calif. 95125-3547; 408 269-5814 (no website). The BART official station designators are used in official communications between BART employees, and are included here to add coherence to these communications when we or others listen. WIRELESS LANDSCAPES 2 Civic Center (BART official designator: M40) can be received for many miles. Setting up a computer in United Nations Plaza to "stumble" We begin our observations at the BART station wireless networks will reveal dozens, and closest to San Francisco's city, state and federal conceivably hundreds. Prominent networks government buildings. Great rewards await careful receivable in the vicinity include that of the Public and patient observers in this area, where a rich RF Library, many networks at nearby Hastings College environment prevails. of the Law, and the network operated by a commercial contractor within the Superior Court Immediately above the station is United Nations building at 400 McAllister street, intended for the Plaza, commemorating the founding (in S.F.) and use of attorneys and jurors waiting to be called for further achievements of the United Nations, trial. supporting farmers' markets and crafts vendors on various days of the week, and serving as a resting Nearby is also the Federal Office Building bounded place and agora for working-class and poor people by Hyde, Turk, Golden Gate and Larkin. As far as at other times. The plaza is also frequently we know, no Wi-Fi networks operate within this populated by San Francisco police (SFPD) building, as the ease of intercepting traffic on these enforcing quality-of-life offenses and the Mobile networks constitutes a security vulnerability for the Assistance Patrol (MAP), whose members pick up agencies in the building, including the FBI, DEA homeless and distressed people often under the and various divisions of the Department of influence and transport them to various public Homeland Security. A look at this building's roof, facilities. The SFPD is a major user of the though, reveals a generous number of transmitting Emergency Communications Department trunked antennas, many of which operate in the two radio system (see below), and MAP operations may exclusive government frequency bands of 162-174 be heard on the Public Works Department trunked and 406-420 Mhz. Shortwave networks also exist radio system. to back up other communications nets in case of disaster, and some antennas for this may be located At the intersection of Grove, Hyde, Market and 8th atop the FOB. Many transmissions in these bands streets is the Orpheum Theater, patrolled by are now digitally encrypted and will appear to the security guards whose walkie-talkie transmissions civilian listener lacking the proper equipment are easy to monitor yet devoid of much interest. simply as white noise. Others may be picked up by Inside the theatre, stagehands and ushers use other anyone with the proper equipment. For many years, radios, and wireless microphones are often in use. the San Francisco FBI field office operated a complex radio network that was easily monitored, It’s reported that concert bootleggers have presenting a fascinating and often cryptic panorama sometimes smuggled radios into venues and of surveillance activities. In the early 1980s, this recorded the high-fidelity output of wireless mics network was updated to support digital encryption, worn by performers, then later remixed these tracks and now only occasional plain-language with field recordings to obtain a higher-quality transmissions can be heard. bootleg. Wireless mic frequencies are generally standardized and well-known, but this method of This and other federal facilities are protected by the obtaining high-quality audio seems difficult, and the Federal Protective Service Police, continually transmitters are quite low in power. It is unlikely present in and around this building. Their primary that transmissions from the Orpheum's stage dispatch channel on 417.200 Mhz may be heard penetrate the foundation and issue into the BART throughout the Bay Area and is interesting station. listening, especially when demonstrators convene to disrupt the normal flow of government business or Across Hyde from the Orpheum is the San to petition for redress of grievances. Francisco Public Library, which recently installed a free wireless computer network for its patrons. Nine blocks from the BART station is the five-year- Such networks, commonly known as "Wi-Fi" or old building housing the San Francisco Emergency 802.11 networks, provide high-bandwidth, high- Communications Division, at 1001 Turk street. speed Internet access to anyone with 802.11 This modern building houses the city's 911 call and compatible equipment. These networks operate on dispatch center for police, fire and other public unlicensed spectrum in the 2400 Mhz range (most safety activities. It is a high-security, seismically- microwave ovens use a frequency in this range, hardened environment. Microwave links and 2450 Mhz, for cooking by heating up water telephone lines connect this building to molecules in food) and, though very low in power, approximately 13 city radio transmitter sites, said WIRELESS LANDSCAPES 3 to be atop 555 California street, Bernal Heights, particular frequencies for the use of state California Pacific Medical Center, Clay and Jones, transportation agencies and private construction Twin Peaks, Embarcadero Center, Sunset Heights, companies, it is now often the case that Fort Miley, the Hall of Justice, McLaren Park, construction crews use cheap, unlicensed Family South Hill (Daly City), Sutro Tower, and within the Radio walkie-talkies available for as little as $15 underground Muni tunnels along Market street. apiece in chain stores. These radios typically use The public safety trunked system occupies 23 14 frequencies in the 462 and 467 Mhz range, and channels in the 800 Mhz band. Transmissions most models can be used to scan all channels in the emanating from this building are a major portion of group. total RF activity occurring in the city at any one time, and carry information often of great urgency Many millions of these radios are now in use for and importance. In addition to their immediate every imaginable purpose, from child's play to the pertinence, messages from the ECD dispatch site coordination of combat operations in Iraq. (Special reveal many patterns and structures of life and models using government-only frequencies in the social interaction in San Francisco. The city also 380 and 390 Mhz range are manufactured for the operates a separate trunked radio system for Public Department of Defense.) Those interested in a fast Works and other city departments. and inexpensive means of monitoring the nearby wireless environment, as well as a continuous Five blocks south of Civic Center station is San source of informal commentary on nearby Francisco's Hall of Justice, a courthouse and happenings and events, and not fearful of the detention facility administered by the San Francisco vernacular, quotidian or banal, might well acquire Sheriff's Department, who operate a 16-talkgroup one of these radios for listening purposes.