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. Since system on the city's trunked radio system. The they are often sold in packs of two, it is easily traffic on this system is one measure of the city's possible to combine the roles of observer and pulse and degree of distress. participant.

Entering the station takes you from a rich RF environment into a subterranean gallery also rich with RF signals.

The BART station platforms and tunnels run one level below the "Muni Metro" level, used by light- rail cars operated by the San Francisco Municipal Railway. The Muni uses radio for operations and security, and operates an automatic polling system by which streetcars and buses communicate automatically with base stations. In order for these radio systems to work underground, a "leaky cable" relays signals from above into the tunnels and stations. These cables can be easily seen on the Muni level. This system also relays police and fire radio from the surface.

On the BART level, a similar system relays transmissions on the BART trunked radio system, a complex area-wide system that serves the BART system fairly well but is difficult to hear as the distance from the actual tracks increases. About 50 miles of RADIAX "leaky-cable" relays signals from 75 local nodes into tunnels and stations.

Between Civic Center and 16th Street Mission, BART passes under the US 101 freeway reconstruction project, which was completed on September 9th, 2005. During the lengthy construction period, Caltrans and its contractors deployed many portable radios to coordinate this complex project. Though the FCC allocates

WIRELESS LANDSCAPES 4 16th Street Mission (BART official designator: M50)

Above and east of the station is the Redstone Building (at 2926-2948 16th Street), home of the Lab performance and exhibition space and many community and political organizations. One is Enemy Combatant Radio (ECR), currently webcasting news, talk, music and events. At one time, ECR operated an unlicensed over-the-air radio station from various sites in the Bay Area, and served an avid audience with news and updates of political and community actions motivated by the U.S. invasion of Iraq in 2003.

Many demonstrations, include recent antiwar marches, begin or end in this area or in nearby Dolores Park. March coordinators often use generic Family Radio walkie-talkies, while tactical police commanders and squads use police talkgroups A9, A10 and A11. Other information relating to large demonstrations is often transmitted over the Golden Gate Traffic air frequency on 124.300. Audio recordings of tactical police radio transmissions played a significant role in Whispered Media's videotape We Interrupt This Empire (2003), which documented antiwar demonstrations and activities in San Francisco after the U.S. attack on Iraq.

The Bay Area has been home to a large number of unlicensed or "pirate" radio stations for many years. Some, like Free Radio Berkeley (check) can easily be received from the BART system while traveling aboveground, as long as headphones are used.

The 16th street area is a busy part of the city with a rich RF environment. Much of it is generated by cellphones and other personal communications devices, which have become ubiquitous in recent years, especially among people of post-college age who form a large part of the crowds in this area. Many who have recently taken up residence in the US also use cellphones as a primary means of personal communication, as is evidenced by the large number of cellphone stores targeting non- English speaking customers. Many of these stores emphasize prepaid services, which carry a higher per-minute calling cost.

The Mission district is particularly rich in Wi-Fi networks. In early 2004, a Wall Street Journal reporter "wardriving" (navigating a vehicle equipped with a computer, wireless card, antenna and wireless "stumbling" software) reported finding over 10,000 networks in the immediate Mission area.

WIRELESS LANDSCAPES 5

24th Street Mission horn-shaped antennas (known as the TD-2 relay (BART official designator: M60) system). Otherwise, the site is in active use by the city of San Francisco, various federal government Like 16th street, 24th street is a rich personal agencies, and a number of private users. communications environment. In addition to the decentralized RF traffic created by hundreds or There is a proposal to build a 30th Street Mission thousands of portable transmitters, the 24th street BART station, but construction has not yet begun. area is overshadowed by two hilltop transmitter sites: Twin Peaks, altitude approx. 920 feet, home of the city's Central Radio Station; and Mount Sutro, altitude 834 feet, on whose summit a stinger-shaped tower, 977 feet from base to top of mast, has been built. This tower hosts transmitting antennas for many radio and television services, including commercial and government two-way networks and analog and digital transmitters for most Bay Area television stations (most located between 657 and 977 feet above the base). Lower on the tower, at approximately 187 feet above ground level, reside standby antennas for the area's TV and a few FM stations, which would be used in case of failure or damage to the primary antennas.

Mount Sutro, operated by a corporation known as Sutro Tower, Inc., reflects great design and engineering ingenuity. Many of its immediate neighbors take exception to the presence of such a high-power RF emitter in their vicinity, and have expressed concern about the biomedical effects of high-density RF fields. The research in this area is complex and often specific to individual situations, and many of the investigators in this field have close ties to the communications industry. There have also been concerns that Sutro Tower, Inc. has not closely observed regulations or obtained proper city permits for all of the transmitters on the tower.

Even at some distance from the tower, the high- power transmitters affect radio reception throughout the city, throwing out interference and spurious signals that affect the ability to receive certain services clearly. In addition, Sutro's central location and high power combine to raise the RF "floor" level throughout San Francisco, making it difficult to use RF sniffers and "near field" receivers, equipment that can enable hobbyists and artists to pursue many engaging and instructive projects.

South and slightly east of 24th Street station and less than a mile away is Bernal Heights Park, where offleash dogs run freely and American Kestrels, our smallest raptors, hunt small mammals. Atop the hill is what appears to be an abandoned AT&T Long Lines microwave relay site, one example of the nationwide network that carried long distance telephone calls until the widespread deployment of fiber optic lines and satellite networks. These sites are easily distinguished by the presence of large

WIRELESS LANDSCAPES 6 Glen Park (BART official designator: M70) drivers, is being gathered at such points, as frequent commuters sometimes receive traffic survey At Glen Park, our route begins to leave the tunnels; questionnaires asking them about their travel sunlight is visible at the south end of the station. patterns. BART then parallels I-280 (also known as the Southern and Foran Freeway) until south of the Daly City station. Balboa Park (BART official designator: M80)

Freeways are hotbeds of RF activity. In addition to This station, whose platforms are illuminated by transmitters in vehicles, such as two-way radios, natural light, is close to the San Francisco cellular phones, two-way pagers and Blackberry Municipal Railway car shops (the Curtis E. Green wireless data devices, freeways utilize radio Light Rail Center) and to San Francisco City networks extensively for police and patrol, College. maintenance, the transmission of traffic information, and polling vehicles to manage traffic After Balboa Park, the route wends back more effectively. underground, surfacing with the vast panorama of the Excelsior district and the slopes of San Bruno I-280 is patrolled by the California Highway Patrol, Mountain to the east. On the west is the outer which utilizes a combination of car radios, hilltop Mission district and Bernal Heights. BART follows transmitters and relay stations, most operating in a long, languid curve in a generally southwestern the 42 and 39 Mhz range. These "lowband" direction until it curves further southwards just frequencies can be received at great distances, before the San Francisco/San Mateo county providing the receiver and transmitter are within boundary. Just before the city line, BART passes a line of sight. In addition, when sunspot activity 7-11 convenience store sporting a satellite dish and (which peaks on 9-year cycles) is at high levels, 2400 Mhz Wi-Fi vertical antenna on its roof. lowband frequencies are subject to a phenomenon These Wi-Fi antennas are typically seen on many known as "skip," and can be received at great California 7-11 stores. 7-11 stores and other distances. I have received CHP transmissions (and locations that sell California state lottery tickets are SFPD dispatches, when that agency was on connected by local wireless networks whose hub is a lowband) in Connecticut. 7-11 or other business which aggregates transactions on the ticket terminals and transmits Caltrans provides construction, maintenance, repair them to a central computer, perhaps via satellite. and other services to this and other state highways, This arrangement saves connectivity costs, since using mountaintop transmitters, which in this only one location within the cluster of sales agents immediate area are located on San Bruno Mountain is actually connected to the central computer at all (see below). times.

Television cameras are mounted at many freeway locations to transmit pictures of strategic spots to traffic management centers (TMCs) and the CHP. While some of these cameras may transmit wirelessly, others use landlines. There is a growing tendency in the U.S. to use unlicensed spectrum, sometimes Wi-Fi or Wi-Fi-like radios, to transmit surveillance camera pictures.

At many points along Bay Area freeways, small Yagi (fishbone-style) antennas "ping" FastTrak transponders located in private vehicles, polling them for information which is then channeled to TMCs and used to compile aggregate data on traffic congestion. These can, for instance, be seen on US 101 northbound at the Waldo Grade, just north of the Golden Gate Bridge, and on I-80 eastbound in San Francisco, just before the entrance to the Bay Bridge. It is apparent that data on individual transponders, and thus on individual cars and

WIRELESS LANDSCAPES 7

Daly City (BART official designator: M90) South San Francisco (BART official designator: W20) Daly City station, just a block south of the San Francisco city/county line, is just southeast of I- BART serves the east end of South San Francisco, 280. At the north end of the station, a tall tower known to many as "The Industrial City" from the holds antennas for the BART communications whitewashed lettering on the side of Sign Hill Park. system and for one or more cellphone providers, an The station, though underground, receives natural example of colocation (when a tower is shared by light through skylights, and, like the other recently more than one user). By the station is Pacific constructed San Mateo County stations, is filled Plaza, an office complex with several restaurants with public artworks. and a movie theater, which is also the home of DigiDesign, the developer of the well-known South San Francisco is a working-class town that ProTools audio editing software. Theater seems in many places to belong to an earlier era. employees communicate via low-power walkie- Its west side is residential, and its east side contains talkies, probably in the UHF range, and servers in many support businesses for the nearby San the restaurants receive reminders via short-range Francisco International Airport. Much radio traffic unlicensed tone-only pagers when dishes are ready in the area is generated by hotels, car rental to be picked up at the kitchen and brought to tables. agencies, trucking companies, limousine services, and the frequent Caltrain passenger and freight trains along the Southern Pacific line. Colma (BART official designator: W10)

Lying southwest of San Bruno Mountain, Colma is San Bruno (BART official designator: W30) a town of 1.9 square miles. It is home to approximately 1,200 living and an estimated two For the first time on this leg of the tour we see blue million dead, with 17 cemeteries dedicated to the sky above the station platforms. This station serves needs of deceased humans and those who remember the modestly-sized town of San Bruno, whose them, and one for pets, well worth a visit. Besides downtown preserves the image of a 1960s its quieter districts, Colma is also home to two California town. San Bruno station is located at shopping malls (280 Metro Center and Serra Tanforan Park Mall, which was formerly the Center) and just across I-280 from a larger mall, Tanforan Park racetrack. In the early days of Serramonte Center, technically located in Daly City. World War II, Japanese Americans were concentrated into buildings built to temporarily The presence of so many stores and the proximity of house animals at the racetrack, prior to their San Bruno Mountain, whose ridge is topped by ten relocation to and internment in remote camps large towers with hundreds of transmitters, throughout the rural West. Today, Tanforan Park including many for local FM and TV stations, serves working-class and middle-class shoppers makes for a rich and often chaotic RF environment. from San Francisco and the northern Peninsula, with a mixture of big-box stores, a multiplex movie Big-box stores such as Target, Mervyn's and Bed, theater and restaurants, all of which generate the Bath and Beyond, all in the area, use low-power kind of RF smog we previously experienced in two-way radios extensively for security, inventory Colma. control/replenishment and maintenance. Many fast- food outlets in the area also have drive-through After the San Bruno station we dive into a tunnel, windows, where cashiers speak to drivers via a two- then out again to an elevated structure, and then frequency radio link, usually on frequencies east on one arm of the Y-shaped spur to San reserved for low-power use or wireless mics. Many Francisco International Airport (SFO). newer scanners feature search capability for these low-power frequencies, and a search in the Colma area will immediately turn up quite a number of conversations about what seem to be highly ephemeral concerns. Members of the public using portable Family Radios are also highly present on air in this vicinity.

South of Colma BART enters another tunnel.

WIRELESS LANDSCAPES 8 San Francisco International Airport its wireless manifestations is beyond the scope of (BART official designator: Y10) this guide, but suffice it to say that arriving and departing aircraft first communicate with an ATC The airport spur passes through an unused tract of Center (in this case Oakland), one of 21 that land that during BART construction was discovered handles air traffic over a sector of the United to be habitat for the endangered blue, green and red States, then are handed off to a TRACON (Terminal San Francisco garter snakes. Nearby is a white Radar Approach Control), which in San Francisco's dome mounted on a short tower that I surmise case identifies as SIERRA control and handles a contains a NEXRAD automatic weather radar number of Bay Area airports. When an aircraft is observation system to supply real-time weather 10 miles from SFO, SIERRA control hands it off to information to aircraft and controllers. This San Francisco Tower, which communicates with it information is available by subscription and on as it orients itself to the runway and lands. Further several websites. We then pass over busy US 101 communications occur on special ground control and into the stem of the Y, then into the relatively frequencies. A continuous recorded broadcast new International Terminal, where the BART known as ATIS (Airport Terminal Information station is located. You may hear the train operator Service) repeats weather, barometric corrections announce directions to specific airlines, a kind of and current information for aircraft in the vicinity. announcement not often heard on American transit All of these communications occur in the VHF systems. As the train pulls into the station, aircraft aircraft band (118-137 Mhz) which uses AM parked at gates 89 through 91 may be seen being modulation, unlike conventional two-way radio loaded and serviced. ground communications that utilize FM.

The International Terminal offers a number of Commercial airlines speak to aircraft in flight using interesting destinations for the nonflying visitor. On VHF airband frequencies, known as "company" the lower level, right outside the BART paid area, is channels. These are generally assigned by airline the Meditation Room. This relatively luxurious and and the messages they carry can range from the RF-free room forbids the use of radios or cellular painfully banal to the urgently pertinent. telephones, and is a place where the visitor or harried traveler may relax. After some meditation In addition, there are a number of navigation the visitor will realize that this is a dual-purpose services that transmit what would appear to the ear room, designed both to serve the spiritual needs of as tones and pulses. There are also air traffic visitors and as a secluded facility for relatives and control services provided over UHF military air survivors of airplane crashes. Upstairs is the frequencies by the same controllers, which may or airport museum, which currently features may not be repeated over the VHF control interesting displays of passenger air transport frequencies. On higher frequencies, typically in the advertising and memorabilia. On the concourse, microwave range, are a number of radar systems behind the check-in kiosks, is a free-standing that provide imagery of the air traffic environment exhibition space which at last visit was displaying and local weather conditions. highlights from the excellent David Rumsey map collection. Finally, there are two food courts with One aircraft frequency of special interest in the Bay restaurants that serve generally better-quality food Area is 124.300, known as "Golden Gate Traffic." than is available at most U.S. airports. All of these Low-flying aircraft and helicopters use this facilities reside outside the sterile secure area and frequency to self-announce their presence to one may be visited by anyone complying with general another, and as a kind of "intercom" on which to airport conduct regulations. A visit to the airport compare notes about air and ground conditions. on a nonflying day can be delightful and free of the Typically present on this frequency are the CHP tension that often accompanies travel in the jet age. helicopters (known as "Eureka" units), traffic observation aircraft working for radio and TV The radio-equipped visitor will find a great deal of stations, the regular Coast Guard port and harbor interest at this busy airport. Airports are security patrols, and tourist excursion helicopters. fascinating RF environments with activity in many This frequency is an excellent indicator of major portions of the radio spectrum, much of which can events and activities in the region. For example, easily be heard by hobbyists. during the antiwar demonstrations of spring 2003, much useful information about activities on the Perhaps most prominent are the various kinds of air ground and the positions of demonstrators and traffic control communications. A detailed police was exchanged between airborne members of taxonomy and description of air traffic control and the media and law enforcement air units, in what

WIRELESS LANDSCAPES 9 was probably a common example of cooperation transmitted, and can easily be received with a between the press and police. receiver and computer equipped with free software. ACARS sounds like little "burrs" of audio, each a Beyond air-to-air and air-to-ground channels, the burst of data, and uses a few nationwide airport is a hotbed of wireless activity. An frequencies, especially 131.550. incomplete list of radio users on the ground includes:

• ground personnel handling baggage, controlling the movements of passengers, and solving problems. Each airline has its own frequencies, which make interesting listening when the traffic involves your own plane

• airport police and fire crews

• security officers. The Transportation Security Administration (TSA) uses frequencies assigned to the FAA in the 172 Mhz range

• Immigration and Customs Enforcement officials, who use radios in the federal frequency bands

• San Francisco police officers and firefighters, who have special bureaus established at the airport. San Mateo County sheriffs, California Highway Patrol officers, FBI, Secret Service, and State Department Bureau of Diplomatic Security officers all percolate through the airport on various specific assignments, making it a hotbed of law enforcement, much of it invisible to the unsensitized eye

• Passengers with personal voice and data wireless devices and users of the many Wi-Fi nodes at the airport.

Finally, one of the most interesting wireless communications networks that operates at SFO may also be heard throughout the Bay Area and the world, provided that the listener makes a small investment in equipment and finds a sensitive antenna. It's the ACARS network, operated by Aeronautical Radio, Inc. ACARS (Aircraft Communications and Reporting Service) is a data- only service that's sometimes jokingly called "email for planes." All commercial passenger and many general aviation aircraft are equipped with ACARS terminals, which allow crew to transmit and receive text messages from ground stations. During a given flight, an airplane may send and receive many messages, some of which are completely automated (machines talking with machines about status of the aircraft systems, weather reporting and forecasts, etc.) and others of which are keyed in. Messages about health emergencies onboard, sensitive information involving passengers and crew, and other operations-related information are all

WIRELESS LANDSCAPES 10 Millbrae (BART official designator: W40) Powell (BART official designator: M30)

After an all-too-brief visit to SFO, we proceed along BART's four downtown stations occupy a region the other leg of the Y in a southeasterly direction to filled with dense electromagnetic energy, which Millbrae station. This station lies adjacent to the some critics of wireless network expansion have Caltrain right-of-way, formerly the Southern Pacific called "RF smog." Without the "leaky-cable" system Railroad's commuter and freight line along the that distributes public safety and BART operational Peninsula. Direct platform-to-platform transfers communications throughout the Market street between BART and commuter rail are possible here. tunnels, the underground stations would be radio quiet zones, but on the street an observer would find Caltrain, like most railroad operations, is a heavy busy and chaotic activity on most frequency bands. radio user (there are 96 weekday trains), and many railroad buffs carry scanners to monitor railroad In past years much of the traffic was voice: "loss operations, similar to many railroad workers who prevention" officers in the nearby stores, taxi carry handie-talkies. Voice communications dispatchers, security and housekeeping workers at concern movement and safety issues, and can be the hotels in and around Union Square, and more. very interesting when you are a passenger caught in The 1990s ushered in a wide switch to digital the midst of a service disruption. Private telephone communications, and though some of these voices communications (PBX) are also carried on these can still be heard, powerful digital signals from cab channels, all in the 160 Mhz region. Trains dispatch systems, paging networks, digital cellular communicate internally (from engines to end of transmitters, telemetry from Muni buses and trolley trains, and between engines and helper engines) coaches and other wireless data services beep, buzz using data-only telemetry networks at 452 and 457 and burr continuously, creating an agreeable Mhz, which humans perceive as short bursts of cacophony that's unintelligible without the proper noise. decoding software.

The Bay Area's busy freight railroad system also Older buildings with unused radio transmission uses an automated data system operating in the 900 masts can be seen up Powell and the other hilly Nob Mhz region. This system tracks movement of Hill streets. These masts held antennas for early trains, status of signals and switches, and the AM, possibly some FM stations and shortwave location of equipment over many thousands of transmitters before AM transmitters were located square miles. Hobbyist software is available to outside city centers. track trains and build a real-time representation of rail operations, and the advanced rail buffs who have experimented with this system find it Montgomery (BART official designator: M20) remarkable. Serving the heart of San Francisco's once- The Union Pacific and other railroads also use preeminent financial district, Montgomery is microwave "backbone" networks that link their another communications nexus. Atop many operating regions with central dispatch centers, in highrises in this area are microwave dishes the UP's case located in Omaha, Nebraska. These transmitting highspeed data communications to elaborate systems, operating at 6.6 Ghz, permit data centers and satellite corporate facilities workers in the field to speak with dispatch located outside the city. Many data links that were thousands of miles distant. once point-to-point terrestrial microwave now use satellite dishes or fiber networks, which has relieved At the north end of the Millbrae BART platform, we congestion in the microwave bands to some degree. see a high tower bearing antennas for BART's own trunked system and various cellular providers. The wardriver will note that a high percentage of the wireless networks in this area use encryption. Our return train will carry us to Pittsburg/Bay Point, and the next station not previously described North and slightly west of Montgomery station is is: the first large Chinatown in San Francisco, another RF-rich area, whose merchants make heavy use of Family Radio walkie-talkies to conduct business.

WIRELESS LANDSCAPES 11

Embarcadero (BART official designator: M16) small Yagi-style antennas point eastward and upward. These antennas, part of a UC Berkeley Embarcadero is San Francisco's last station before geophysical monitoring network, are connected to our train enters the 3.6 mile transbay tube. The seismic sensors on the island and transmit signals station lies below the Hyatt Regency Hotel and indicating ground movements in the area. close to the Embarcadero Center and Golden Gateway building projects, both of which generate At the Bay Bridge toll plaza, hundreds of short substantial radio traffic for security and wireless transmissions occur every minute as maintenance purposes. At the end of Market street, vehicles equipped with FastTrak devices pass several blocks beyond the station, is the newly through the tollgates. The FastTrak transponders remodeled Ferry Building, where ferries arrive from are not active transmitters, but passive devices that and depart for various destinations. are "pinged" by transmitters at tollgates and other locations. When pinged, they each transmit a BART's transbay tube (construction commenced unique code, which when sent to a central computer 1965, opened September 16, 1974) joined other indicates whose toll account is to be charged. infrastructure built to span the Bay. In addition to the tube, which lies 135 feet below the surface at its deepest, there's the San Francisco-Oakland Bay Bridge (opened 1937, currently being seismically upgraded and in part replaced) and various underground communications cables.

While in the tube, BART passes under and adjacent to a number of interesting radio transmitters and networks.

Though San Francisco's port handles only a fraction of the passengers and cargo it did in the past (most of the freight traffic is now handled through the Port of Oakland), there is considerable marine traffic inside and outside of the Golden Gate, and marine radio channels at 156-157 Mhz are still very busy. The Vessel Traffic System (VTS), dispatched from a high-security center atop Yerba Buena Island in the middle of the Bay, controls the movements of large vessels, and they can be heard checking in with VTS outside the Golden Gate and as they enter the Bay. The Coast Guard's stations are quite active with rescue traffic and notices to mariners, as well as law enforcement and security operations (many of which are coordinated via encrypted radio channels). Coast Guard HH-65 helicopters in telltale orange regularly patrol the ports and Bay shoreline, and can be seen and heard flying throughout the Bay Area every day. Their operations are easily heard on 124.300 ("Golden Gate Traffic"), on the military air frequency 345.000, and others. Commercial fishing vessels and pleasure boats also chat heavily on marine channels.

Caltrans maintains the Bay Bridge and operates a busy trunked radio system with several subsystems audible throughout the Bay Area. The California Highway Patrol patrols the bridge and reports delays, accidents and incidents occurring there. On Yerba Buena Island, much of which has been closed to public exploration even before 9/11/2001,

WIRELESS LANDSCAPES 12 Oakland West (BART official designator: M10) Oakland City Center – 12th Street (BART official designator: K10) The Oakland West station, which in the 1970s primarily served a small local population and BART passes under downtown Oakland, stopping workers in the neighborhood, has become a busy first at the 12th Street Station. transfer station in recent years. Downtown Oakland, home of a few corporate West Oakland is a historically African American headquarters, a major hotel, a large Chinese working-class and working-poor neighborhood that American community, a city and regional museum is now experiencing gentrification and a population of art, culture and science, an antiquarian increase as artists and middle-class people move bookstore, numerous interesting art exhibition and into new or remodeled buildings, many of industrial performance venues and the location of Philip K. origin. Like many neighborhoods near Dick's disturbing realistic novel Humpty Dumpty in manufacturing areas and transportation facilities, Oakland, presents a wireless profile much less West Oakland is traversed by a high density of congested than downtown San Francisco's but still wireless communications. In the 1960s, African interesting. American activists discussed the theoretical possibility of gaining funding for unmet community Amtrak passenger and freight trains pass through needs by charging tolls to suburbanites passing downtown Oakland in the Jack London Square area, through their neighborhoods on the way to the generating interesting traffic on the radio and central city. Today, the extreme gap between the traffic jams on the streets. The city of Oakland value of the communications services physically operates an EDACS-type trunked public safety located in poor and working-class communities and radio system that is engineered so as to be the low wealth held in these communities suggests extremely difficult to hear outside the Oakland city that residents might take a look at the invisible limits. Because of budget constraints that have services that their neighborhoods provide without limited the city's ability to employ workers, the compensation. system is often much quieter than municipal communications systems in cities of similar size. The Oakland Army Terminal, commissioned as the Family Radios are very active in the Chinese “Oakland Sub-Port of the San Francisco Port of American community, located just east of the Embarkation" on December 8, 1941 and closed in downtown core. And since residences and 1999, was probably the largest generator of businesses are located close to one another, cordless wireless communications in West Oakland during its telephone signals and Wi-Fi networks mix with time of operation, especially during the Vietnam business radios. war. This facility, plus the Naval Supply Center Oakland and several other facilities, lie largely unused, waiting for political consensus and economic development to converge so as to support new uses. Some nonprofit organizations such as the Alameda County Food Bank and a few commercial tenants use the facility, but it is largely a quiet spot on the wireless map.

Near the station are many railroad yards, whose wireless communications are described under Millbrae, and the U.S. Postal Service's large Oakland Processing and Distribution Center, where international mail that is to be sent by sea and other bulk mail is processed. The Postal Service uses radio extensively for trucking and loading operations.

A large cellular telephone tower is located on the south side of the BART line between Oakland West and the downtown Oakland tunnel.

WIRELESS LANDSCAPES 13

19th Street Oakland transmissions through the car radios and into the (BART official designator: K20) dispatch centers. Most CHP cars continuously repeat transmissions over a mile radius, sometimes 19th Street is close to the southern end of Oakland's more, on this channel, and so continuously "Auto Row," a twenty-block stretch of automobile monitoring 154.905 will indicate when one is near dealers and services. Automobiles are becoming a CHP vehicle. At accident and disaster scenes, the wireless transmission platforms in their own right. traffic on this channel is often quite informative. Consider a new car: it is possibly equipped with Bluetooth short-range wireless technology, so that Near MacArthur is a complex of hospitals, in the the occupants can talk "hands-off" on their cellular district sometimes known as "Pill Hill." Hospitals phones; the driver may be using a wireless are hotbeds of radio activity, with traffic ranging transmitter on an iPod or similar device so that the from cardiac telemetry (in which ambulatory unit can play through the dashboard stereo; the patients carry small transmitters relaying their vehicle may be equipped with OnStar, a system that heart activity to remote receivers so that their vital integrates car sensors, an onboard cellphone and signs can be observed by nurses), to the special satellite technology so that a driver in distress (or a cordless phones that are approved for in-hospital stolen car) can "talk" directly to a central dispatch use, to security and maintenance networks, to center; or it may be LoJack equipped. LoJack, a communications with air ambulances and Life technology operating on 173.075 Mhz, is activated Flight helicopters transporting in trauma victims when a car is stolen; the hidden LoJack transmitter and to the interesting ambulance-to-hospital sends out signals that can be received by any police channels, ubiquitous throughout the U.S. These patrol car with a telltale array of four vertical channels permit paramedics to communicate antennas on its roof, enabling the car to determine directly with emergency room physicians and staff, the direction and strength of the signal. It is to provide initial exam and triage data before claimed that LoJack-equipped cars are almost arrival, and to send EKG data to the hospital. So always discovered. In addition to contributing to as to comply with recent health privacy (HIPAA) congestion and pollution, therefore, cars also add to regulations, these channels are encrypted in some radio spectrum congestion. The radio spectrum, cities so as to prevent the public from hearing fortunately, is not a limited resource. patient names and details of their physical and mental condition.

MacArthur (BART official designator: K30) Rockridge (BART official designator: C10) MacArthur station, a busy transfer point, is located in the middle of a freeway, CA 24, which generates BART proceeds from MacArthur to Rockridge a great deal of wireless traffic as described earlier. along the center of CA 24. The University of Close to the station is the Oakland office of the California Berkeley campus is visible on the left California Highway Patrol (CHP), transmitting (North) side of the line, about two miles north. regular dispatches on 42 Mhz, links to tower sites on 72 Mhz and in the microwave range. Rockridge is an increasingly affluent residential neighborhood and many homes are equipped with The CHP operates a complex radio system broadband Internet access. Many use wireless stretching the length and breadth of California. routers that emit the characteristic Wi-Fi signals. Most communications to and from the familiar black-and-white (and occasionally all-white) Leaving Rockridge, we near the Berkeley Hills. vehicles take place in the low VHF band on 39 and Along the ridgeline are several hilltops that host 42 Mhz. Listening to the CHP provides a detailed major communications sites, including Grizzly picture of the pulse of transport, weather and law Peak, Vollmer Peak (where the Berkeley Police enforcement activity throughout California, and is radio system primary site is located) and KPFA recommended for the long-distance highway Hill, transmitter site of the often-contested and traveler not contented with music and news. The contentious Pacifica FM station. lowband channels, which are color-coded (Oakland operates on "Green," San Francisco on "Pink" and We enter the 3.5-mile long Berkeley Hills tunnel, Hayward on "Aqua") may be heard at great passing into Contra Costa County along the way. distances. Individual CHP officers also carry walkie-talkies that operate on 154.905 and other frequencies, communicating directly with mobile extenders in the patrol cars that repeat handheld

WIRELESS LANDSCAPES 14 Orinda (BART official designator: C20) encompassing the northern Central Valley, the Sacramento Valley and the Sierras, though Orinda, a bedroom community of 17,599 people, is interference from nearby transmitters can be a protected from many of the diverse RF emitters of problem. the San Francisco Bay basin. Its topography is characterized by rolling hills and thus is well suited for the VHF radio systems used by the Contra Costa Pleasant Hill (BART official designator: C50) police, fire and local government agencies. Along I-680, which parallels BART as we approach BART follows the freeway median until Walnut Pleasant Hill, we can see traffic cameras. Some, Creek, serving (and in many cases sustaining) the though not all, of these cameras transmit pictures narrow spine of commercial and higher-density to Traffic Management Centers and CHP dispatch development that surrounds the freeway and transit centers via wireless links. Others are hardwired. line. On the south (right) side of the line between Orinda and Lafayette, the house of an amateur By Pleasant Hill station is a large Embassy Suites radio operator (ham) with the characteristic array hotel equipped with highspeed Internet access. of antennas can be seen. A cross-yagi antenna for Hotel wireless networks are extremely active. satellite operation is pointed towards the sky. Though the content of transmissions is generally uninteresting and their privacy should in any case be respected, their density characteristics can Lafayette (BART official designator: C30) reveal a great deal about the guests and their activities. Idle hotel guests having a moderate level BART continues to follow the freeway median. of technical awareness and some freely available Between Lafayette and Walnut Creek on the North software can monitor network activity (though (lefthand) side of the line, a hilltop radio site stands usually not the content of computer-to-computer with many masts, towers and antennas, all transmissions) and gain insight into the intangible enveloped and partly hidden by a eucalyptus grove. networks that exist in these singular places. This effect is similar to that sought by cellular system operators when they camouflage their towers Along the line between Pleasant Hill and Concord, to look like trees, except that in this case the many relatively new homes can be seen in a camouflage is actually planted. landscape one might describe as "generically Californian." These houses are built out of mass- produced, often inexpensive materials and are quite Walnut Creek (BART official designator: C40) RF-permeable. Wardrivers and those interested in cordless telephone communications (monitoring BART crosses over twelve freeway lanes and enters cordless telephones is prohibited by state and downtown Walnut Creek, which has become a federal law) will find these houses to be quite regional office and corporate center and nightlife forthcoming with details about the interests and hub for Contra Costa County. The downtown area activities of those inside. is filled with self-contained office "plazas", new buildings designed to look historic, and some relics of the area's agricultural past, including old farm buildings. The office buildings generate the usual radio traffic, as do the freeways, especially the busy intersection of I-680 and CA 24.

On the east and south lies Mount Diablo, one of the two high mountain transmitter sites in the area (the other being Mount Hamilton, east of San Jose). Diablo is a major site used by federal and state government agencies, and transmissions from the 3900-foot peak can be heard throughout Central and much of Northern California. From Diablo, there is a line-of-sight view to the snow-capped peaks of the Sierra Nevada, weather and smog permitting, and radio reception is equally great,

WIRELESS LANDSCAPES 15

Concord (BART official designator: C60) operations and security can be heard in the military VHF band (138-144 Mhz) and elsewhere; much of Entering Concord, we pass by BART's Concord this traffic is encrypted for security. yards, where much maintenance, repair, switching and train assembly activity takes place, with On September 1, 1987, S. Brian Wilson, who had accompanying radio chatter. By Concord station served as a U.S. Air Force officer in Vietnam and the Concord police headquarters is visible, sporting whose uncle had served as a young officer on the a tall radio tower in support of its 11-channel radio U.S. prosecution team at the Nuremberg trials, system. chose to commit nonviolent civil disobedience in protest of U.S. military actions in Central America Nearby is the Bank of America Center, a large by engaging in a 40-day water-only fast while backoffice processing complex that relies on a four- sitting on the railroad tracks outside the Weapons channel UHF system for operations, security, and Station, where the tracks crossed the public engineering. If the wireless observer hears evidence highway. He was struck by a train and lost both of of mall operations, it is likely to emanate from the his legs, among other injuries. Various unofficial nearby Sun Valley Mall. markers placed by peace activists and other traces recall this event. We are just east of Buchanan Field, a large airport serving mostly general aviation, whose air traffic Martinez, county seat of Contra Costa County, is control activities can be heard in the conventional also home to the Shell and Tosco refineries, both of airband. which operate busy trunked radio systems. Eastern Contra Costa County also is home to other Leaving Concord, we proceed along an extension of refineries and chemical companies, and residents the original BART system. have major environmental and epidemiological concerns. There are frequent alerts and shelter-in- place alarms, which can be heard audibly via sirens North Concord-Martinez (controlled via a VHF lowband network) and via (BART official designator: C70) county radio and state EDIS (Emergency Digital Information Service) bulletins. Passing through another fairly generic suburban area, the BART line proceeds at grade past houses that are walled off from the street, past the Olivera Crossing shopping mall and into the newish station. This portion of the line is unusual in that it is visually integrated with the area it passes through rather than on an elevated structure or in a subway. A wireless observer along this part of the system would experience the quotidian traffic of home life and the mall.

North Concord-Martinez is the closest station to the Naval Weapons Station (WPNSTA) Concord (also known as Naval Weapons Station Seal Beach Detachment, Concord), a 12,800-acre site. WPNSTA Concord is comprised of two geographically separate units, the Inland (5,170 acres) and Tidal (7,630 acres) Areas. The Department of Defense (DoD) announced in May that it had included the Inland Area of the Concord Naval Weapons Station (CNWS) on its list of recommended bases to be closed by the Base Realignment and Closure (BRAC) Commission. The station houses conventional explosive ammunition and munitions and is reputed, though not officially acknowledged, to house nuclear weapons as well. From BART, the typical gray and white railroad cars used for munitions transport can be seen on the numerous rail spurs within the base. Base

WIRELESS LANDSCAPES 16 Pittsburg/Bay Point These handsets are voice-activated and generally (BART official designator: C80) operate on unlicensed 49 Mhz frequencies.

BART now passes through golden hills that are We return along this line to MacArthur and then currently unbuilt but may not long remain so. This transfer to the Richmond line. "natural" gap between two heavily built-up sectors of the Bay Area is quite striking. We pass under CA Highway 4, then into its median. The Naval Weapons Station may be seen on the right (south) side, with the telltale white cars used for munitions transport and the lumps in the ground that represent underground ammunition bunkers. Mount Diablo is also visible in this direction, standing alone in the landscape. Turkey vultures and other raptors populate this area and are easily seen from the train.

North of the BART line, before arriving at Bay Point station, is the Calvary Temple, a large church. Churches frequently use wireless microphones to amplify pastors and principal singers, and these can often be heard at some range from the buildings. There have been many cases where passing vehicles, notably taxis, interfere with the mics and spurious transmissions are heard over church public address system.

South of the line, new homebuilding was in progress (as of August 2005). The traditional sounds of homebuilding, such as hammers and saws, are now augmented by Family Radio traffic and the Nextel wireless handsets favored by workers in the building trades, which emit the well-known chirping when announcing transmissions in "Direct Connect" (walkie-talkie) mode. On the South side, a hillside has been burned, the fire almost but not quite reaching a cellular transmission tower.

Also on the North (left) side of the line is San Pablo Bay. On a clear day, the view from the train encompasses a great deal of the Bay and surrounding land. Northeast of the station, wind turbine power generators can be seen.

The Bay Point area is an industrial community with a large African American and Spanish-speaking population, many of whom trace their family heritage to ancestors who worked in the US Steel- Posco finishing mill (which operates a complex radio sytstem) and shipyards. It is a current example of a post-industrial landscape that's rapidly converting to residential use, where it is safe to construct houses.

Motorcyclists along the freeway can frequently be seen wearing wireless headsets to speak with other riders or even persons riding on the same bike.

WIRELESS LANDSCAPES 17

Ashby (BART official designator: R10) Berkeley (BART official designator: R20)

The line between MacArthur and Ashby runs on an A university town that has morphed into an affluent elevated structure above Martin Luther King Jr. suburb with the issues we commonly associate with way, formerly known as Grove street. On the right large cities, Berkeley supports a remarkably high (North) side of the line, we pass by the former site volume of upscale restaurants and shops, especially of Merritt College, later Grove street College, a site on its north side and in the Fourth street area. It of significant political organizing and activism, runs from the hills down to the bay, and is especially involving peoples of color, in the late economically dominated by the University of 1960s and early 1970s. In January 1967, the first California campus. Black Panther Party office was established at 5624 Grove street. The campus is a rich generator of wireless traffic, with its own 800 Mhz trunked radio system and a Ashby station, the southernmost station within the number of Federal systems (operated by the city limits of Berkeley, is perhaps more interesting Department of Energy and possibly other agencies) for its wireless past than its present. Throughout located at the Lawrence Berkeley Laboratory uphill the 1960s and 1970s, radio communications and from campus. The Berkeley Police use a standard radio interception played a key role in radical social UHF radio repeater system on three channels, and political movements. This story is not well which can easily be heard throughout the Bay Area. known, and it is not clear whether documentation Several other low-power channels are used for survives. surveillance and narcotics squad activity, especially around Telegraph and San Pablo avenues. There Beginning in 1967, members of the Black Panther are a number of community Wi-Fi networks in the Party followed Oakland police cars to observe area, as well as many thousands of private wireless interaction between police and members of the networks. community, and confronted police officers when they witnessed incidents of police brutality. BPP For five years, Free Radio Berkeley operated from a members used tunable radios and later scanners to number of temporary sites in the city and hills, at monitor Oakland police operations. Some of these 104.1 FM. Around the city, especially at its entry encounters ended violently. Law enforcement points, are handmade signs on which are painted agents at all levels closely monitored BPP only "104.1 FM," a cryptic allusion to the station. activities, coordinating surveillance by two-way This micropower station was pulled off the air by radio. They also paid much attention to antiwar court injunction in June 1998. Berkeley Liberation activities and activists, putting many of them under Radio, another organization, has succeeded in its surveillance. After Patricia Hearst's kidnapping in place, but I don't know whether it is still February 1974, FBI agents blanketed the area in broadcasting. search of the mysterious Symbionese Liberation Army. The city of Berkeley operates its own "emergency radio station" at the top end of the AM dial on 1610 North Oakland and Berkeley together were the site Khz. It generally transmits a taped loop of city of a massive and longterm surveillance and information, but could be used to transmit live information collection effort on the part of many emergency messages if needed. Signs at the city government agencies. The traces of this effort can limits alert those entering the city to its existence. be seen in declassified documents and in accounts by activists of the era. Thousands of hours of radio conversation once occurred, most of it unmonitored by hobbyists or activists due to the lack of equipment at the the time, and it isn't easy to determine whether it was taped at the FBI dispatch console or at other control points. Since radio waves weaken but don't stop vibrating until they vanish into the RF noise floor, though, we may playfully imagine that the evidence of this massive taxpayer-funded surveillance effort is still bouncing around the cities, available for reception and reconstruction if only the means could be found to do so.

WIRELESS LANDSCAPES 18 North Berkeley (BART official designator: R30) El Cerrito del Norte (BART official designator: R50) The northernmost underground station in Berkeley lies in a residential neighborhood favored by The neighborhood continues along similar lines, families. with a similar RF signature. A big-box Target store, a hotbed of RF activity, sits by the track. Many families with young children employ baby Family Radio walkie-talkies may be obtained very monitors as a means of benevolent surveillance. A inexpensively there. transmitter in the child's bedroom relays sounds (hopefully of normal snoring and breathing) to a West of the line between del Norte and Richmond, a small portable receiver. These generally operate in large cellular tower rises into the sky. The United the unlicensed 49 Mhz range. Though FCC States has a large number of such towers, and many regulations limit the power of unlicensed devices, communities have actively opposed their baby monitors can often be monitored at quite some construction and proliferation. One reason we have distance from the baby's room, including outside the built so many towers in the US is that the major house, and can make interesting listening, especially cellular carriers (in the Bay Area Verizon, T- because they are never powered down. A drive Mobile, Cingular, Sprint/Nextel and Metro PCS) through areas in which families with children are reluctant to colocate (share towers) unless they predominate with a scanner programmed to sample are forced to. This is why, for instance, a drive common baby monitor frequencies can yield some along I-5 will reveal three or four separate interesting ambient sounds, especially if the parents proximal cell towers, and why carriers resort to sleep in the same room with the child. ever more sophisticated means to camouflage their antenna sites in cities and suburbs. BART exits the Berkeley tunnel at the city line and passes along an aerial structure in the town of Albany, adjacent to Key Route boulevard, named after the Key System interurban trains that once served Alameda County and San Francisco.

On the West (left) side of BART is the Bay, and beyond the bay in Marin county, Mount Tamalpais, at some 2,500 feet the tallest peak in Marin County and a site for state, county and federal radio transmitters. A semi-classified Air Force radar station is situated below the top of the mountain. Many of the antennas at the station are hidden within plastic or fiberglas radomes.

El Cerrito Plaza (BART official designator: R40)

The Plaza station is situated adjacent to a shopping center of the same name, which appeared to have come upon hard times in the early 2000s, but now seems to be thriving once again. The neighborhood consists of a mall on the west side and densely arranged small houses on the east, and the wireless environment is the mix of domestic and retail use that's quite typical in the Bay Area.

WIRELESS LANDSCAPES 19

Richmond (BART official designator: R60) prisoners and their activity (including incidents that result in disciplinary action) trickles out. Richmond, "The City of Pride and Purpose," is an industrial city that expanded rapidly during World We leave Richmond and proceed south on the A line War II. Its population jumped from 23,000 in towards Fremont. 1940 to over 100,000 by the end of World War II. Most migrants worked in the city's four shipyards, built from scratch by Henry J. Kaiser's company, Lake Merritt (BART official designator: A10) employing 90,000 and building 747 ships in less than four years. During World War II, some Lake Merritt, on the eastern side of downtown 46,000 African Americans moved to the Bay Area, Oakland, was once the flagship station on the BART many settling near the shipyards that employed system and the location of BART Headquarters (the them in Richmond, Vallejo, Hunters Point and original building at 800 Madison street is now elsewhere. The urban infrastructure strained with being evaluated for possible demolition, and BART this extreme migration, and many workers lived in trains are now centrally controlled from an office squalid trailers and later in industrial housing that building elsewhere in downtown Oakland). It is was rapidly and poorly built. close to the Oakland Museum and to Laney College.

World War II still affects the community of We exit the tunnel at 6th avenue and East 8th Richmond. Many working class and poor African street and proceed southeasterly with I-880 and the Americans still reside in communities built to be Oakland Estuary to our South (right). Active temporary, especially in the unincorporated North railroad tracks and yards are there as well. Radio Richmond area, where streets remained unpaved for traffic in this area is heavily transportation- over thirty years and urban amenities were oriented, with activity especially on marine and nonexistent. The legacy of World War II migration railroad VHF channels. To the right, off 22nd and displacement also troubles the city, which has avenue, is the local Ham Radio Outlet, where fine been the venue for many tragic youth-on-youth amateur radio equipment (as well as scanners, killings in recent years. The Richmond Police antennas, battery packs and frequency guides) may Department's radio frequently reveals current police be obtained. response to these and other incidents.

Richmond's industrial heritage is also a matter of Fruitvale (BART official designator: A20) pride; it is one of the last true working-class cities in the Bay Area, home to foundries and oil The Fruitvale neighborhood was known in the refineries. It is well served by a number of freight 1920s as Oakland's "second downtown," with its own and passenger railroads, many of which run along courthouse, highrise buildings, banks and BART and are very active users of railroad radio, community organizations. It later deteriorated, but stretches into the hills and northeast towards its has seen major growth and commercial suburban-style shopping center, the Hilltop Mall, revitalization in recent years. East of the station is which may one day be a further terminus for the Fruitvale Village, a mixed-use development with BART system. The present BART station is an many stores catering to the Mexican American intermodal transfer point between BART, buses, consumer, and on the west is a new mall with big- and Amtrak. box stores. Family Radios are very active here, and the listener will hear a great deal of traffic in Between Richmond and San Rafael (Marin County) Spanish, testifying to the demographic transitions runs the deteriorating and frequently-under- occurring in the once traditionally African construction Richmond-San Rafael Bridge, crossing American East Oakland flatlands. the north reaches of San Francisco Bay and meeting the Marin County mainland at San Proceeding south, we pass an AC Transit bus yard Quentin, where the famous California state prison is near 55th avenue. The AC transit buses have long situated. Like other California Department of been equipped with radios and are capable of both Corrections facilities, San Quentin operates a three- voice and data communication. The powerful data channel 800 MHz trunked system on which much bursts from AC buses have long interfered with activity can be heard. Those wishing to dissolve the other transmissions in the Bay Area. information barrier that separates prisoners from those outside the walls might well monitor prison radio systems, where some information about

WIRELESS LANDSCAPES 20 Coliseum (BART official designator: A30) San Leandro (BART official designator: A40) The Coliseum station serves both the Oakland- Alameda County Arena/McAfee Coliseum (built Southern Alameda County is one of the most 1966), spiritual home of Raider Nation, the interesting regions served by BART. The landscape Oakland A's and Golden State Warriors, and is a mix of suburban housing, neighborhoods that connects by bus to the Oakland International still appear to be semirural, traces of the county's Airport (OAK). agricultural past, heavy industry, shopping centers, and unconstructed areas full of wildlife and wild Sports arenas are fascinating places for the wireless plants. observer. The full wireless profile of each venue is different and the overall picture quite complex, but Near San Leandro station, the high-tech company the typical arena offers the following opportunities Tri-Net has constructed a new Mission-style for the careful observer: headquarters building that sits directly across from old houses with fenced-in yards. • Team operations: coaches to players via helmet- mounted radios; managers and owners to coaches Up the hill from the station at approximately 150th via walkie-talkies; Avenue sits the county services complex, with a large radio site servicing various Alameda County • Media production: wireless microphones, agencies, the county juvenile hall, an adult communication between anchors and commentators detention facility, and a maintenance yard. and production personnel, remote control of cameras and sound equipment, communications South of the station on the east (left) side of the with Goodyear and other blimps in the air above the BART line is the base of an old windmill. Several stadium; of these, occasionally next to older houses identifiable as former farmhouses, may be seen • Stadium operations: security, hospitality, food from BART trains. vending;

• Police, security and emergency medical activities; Bay Fair (BART official designator: A50) quite extensive traffic since as many as 80,000 people may be assembled for periods of time; Bay Fair station is located within the unincorporated area known as Ashland, a bit of • Federal undercover antiterrorist patrols and post-World War II-era suburbia that (aside from activity; security for elected officials and VIPs individual home remodeling) looks remarkably unaltered from its original design. It is also • Parking control adjacent to the Bay Fair mall, anchored by big-box stores including Target, Macy's, Kohl's, and Bed The nearby Oakland International Airport is a busy Bath & Beyond. The radio profile for malls is well- place and houses, among other airlines, the discount described elsewhere in this guide. carriers Southwest and JetBlue. For a wireless profile of the airport, please see above, under San Bay Fair is a transfer station for the Pleasanton Francisco International Airport. line. At the junction between the lines, a Yagi antenna points up the branch line, placed there to We proceed southwards through East Oakland, relay BART communications. entering the city of San Leandro at about 103rd avenue. Along the way, we pass by numerous We pass another old farm site with the base of a factories and warehouses on both sides of the line, windmill on the east side. some housing heavy industries such as the AB&I foundry. Those who believe that the United States is a postindustrial nation would do well to monitor incidental radio traffic in this area; they'd be surprised by what they heard and whom they heard speaking. One distinctive industrial building houses a plastics recycling company whose yard is filled with a plethora of interesting raw material.

WIRELESS LANDSCAPES 21

Hayward (BART official designator: A60) On the West side of the tracks lies a large grassy As we pull into Hayward, we pass the residence of a tract with no buildings, providing a rare example of Citizens Band aficionado on the East side of the liminal space in the central Bay Area that seems to tracks, distinguished by its very tall ground-plane have escaped development. antenna, a vertical element with four poles in a cross-like pattern at its base. CB radio, which Prior to Fremont, we pass through Quarry Lakes operates in the 27 Mhz range, was first authorized Regional Park, where lagoons border the track on in the 1950s and reached the apex of its popularity both sides. On my survey for this guide, a strong in the mid-to-late 1970s. Though CB radio is skunk smell pervaded the car for two to three restricted by law to modest power levels and local minutes, a refreshing reminder that some outside communication, many CBers employ illegal linear sensory information can permeate the somewhat amplifiers and operate on unauthorized frequencies sterile environment of the BART car. to permit communication with faraway stations. CB is also a favorite of longhaul truckers, who use Fremont (BART official designator: A90) the band to warn of hazards and police speed patrols, to chat and flirt with other truckers and Some 23 miles from Oakland, we reach BART's interested members of the public, and to avert present southern terminus. An extension of BART boredom and loneliness. southward past Fremont to the Warm Springs District in southern Fremont is in the planning and Hayward is an ethnically diverse city of 140,000 engineering stage by BART planning staff. A whose official city slogans are "Heart of the Bay" further, controversial extension towards San Jose is and "No Room for Racism." It is home of the also proposed by the transit district south of BART, California State University campus that recently the Santa Clara Valley Transportation Authority, renamed itself "Cal State EastBay," up the hill from but preliminary engineering remains to be town with the easily-seen highrise building. Many completed and funding to be acquired. small aircraft use the Hayward airport, west of the station, and can be heard with the ears (and with Fremont, a city of 203,000 people, has the largest the airband receiver) at all times. Afghan population in the United States. The area around the station is mixed residential and business, As we push further south, the hills become barer and the traveler can see many planned-unit houses, and less populated and the BART right-of-way townhouses, and a few office buildings, some of becomes bordered with flowers. The area begins to which seem to serve as transmitter sites in the resemble an old-time ruralized suburb. absence of other highrises. Fremont is also an auto production center. The NUMMI (New United South Hayward (BART official designator: A70) Motor Manufacturing Inc.) plant at I-880 and Fremont Blvd., a joint venture between General Just north of the station, the house of a radio Motors and Toyota, employs about 4,800 workers, amateur (ham) may be seen on the west side, where produces the Toyota Corolla, the Toyota Tacoma there are also some fine old houses. truck and the Pontiac Vibe, and can build almost 400,000 cars per year. Radio is used for paging, South of South Hayward station is BART's operations and manufacturing support, and several Hayward shop, a large rail storage yard. There is complex radio systems exist on the site. also a test track for BART cars. Yard operations are busy and generate a lot of traffic on the BART We take a northbound train and transfer to the communications system. Dublin/Pleasanton line at Bay Fair.

Union City (BART official designator: A80)

This station serves the historically Mexican American community known as Decoto and newer suburban-style developments in the vicinity. Real estate development is occurring in this area: a 16- acre office park just south of the station on BART's East side is announced by signs, and a walled-in development is also on the same side.

WIRELESS LANDSCAPES 22 Castro Valley (BART official designator: L10) Appendix: BART's Radio Communications System The L line proceeds down the median of I-580 for its full length, as if to convince motorists on the BART operates a ten-channel EDACS analog perennially crowded freeway of the ease and trunked radio system. It can be monitored on most convenience of mass transit. Sadly, the message trunktracking scanners. doesn't seem to have taken. Castro Valley is an unincorporated residential extension of Hayward. Frequencies: When it gives way to hills and Dublin Canyon, there is little to see but quiet countryside. As might be 01 866.07500 expected, the wireless traffic here is predominantly 02 866.72500 automobile- and freeway-related, as described 03 866.88750 elsewhere. 04 867.37500 05 867.60000 The West Dublin/Pleasanton station is planned and 06 867.80000 funding has been secured for its construction. 07 867.85000 08 867.96250 09 868.15000 Dublin/Pleasanton (BART official designator: L30) 10 868.68750

This station is located in a recognizable "edge city," 867.7500 Conventional wide area a sprawling satellite city complete with regional 868.9875 California fire mutual aid shopping centers, many large office buildings, major hotels, a sporting grounds, entertainment facilities, Talkgroups (see next page) are reprinted from and a variety of styles of relatively new housing. It Government Radio Systems: Golden Gate Region, is a congested area, with the city of Dublin on the published by Mobile Radio Resources, by north and the city of Pleasanton on the south. As permission of Robert Kelty, publisher. an edge city, it combines many of the attributes of legacy cities and newer suburbs, and has a diverse wireless profile.

If and when BART continues along this same route, it will serve the city of Livermore, home of the Lawrence Livermore Laboratory, an indispensable component of our nation's nuclear weapons program and operator of many interesting radio systems, many encrypted.

In the seven minutes that we have between trains, we will use the search feature of our scanner to make a quick survey of the wireless landscape, and see what we can do to make the invisible intelligible.

WIRELESS LANDSCAPES 23