Did I mention that the Democratic People's Republic of Korea has no
drug or crime problem?

MEXICO CITY (AP) — When convoys of soldiers or federal police move
through the scrubland of northern Mexico, the Zetas drug cartel knows
they are coming.

The alert goes out from a taxi driver or a street vendor, equipped
with a high-end handheld radio and paid to work as a lookout known as
a "halcon," or hawk.

The radio signal travels deep into the arid countryside, hours by foot
from the nearest road. There, the 8-foot-tall (2-meter-tall) dark-
green branches of the rockrose bush conceal a radio tower painted to
match. A cable buried in the dirt draws power from a solar panel. A
signal-boosting repeater relays the message along a network of
powerful antennas and other repeaters that stretch hundreds of miles
(kilometers) across Mexico, a shadow communications system allowing
the cartel to coordinate drug deliveries, kidnapping, extortion and
other crimes with the immediacy and precision of a modern military or
law-enforcement agency.

The Mexican army and marines have begun attacking the system, seizing
hundreds of pieces of communications equipment in at least three
operations since September that offer a firsthand look at a
surprisingly far-ranging and sophisticated infrastructure.
Current and former U.S. law-enforcement officials say the equipment,
ranging from professional-grade towers to handheld radios, was part of
a single network that until recently extended from the U.S. border
down eastern Mexico's Gulf coast and into Guatemala.

The network allowed Zetas operatives to conduct encrypted
conversations without depending on the official cellphone network,
which is relatively easy for authorities to tap into, and in many
cases does not reach deep into the Mexican countryside.
"They're doing what any sensible military unit would do," said Robert
Killebrew, a retired U.S. Army colonel who has studied the Mexican
drug cartels for the Center for a New American Security, a Washington
think tank. "They're branching out into as many forms of
communications as possible."

The Mexican army said on Dec. 4 that it had seized a total of at least
167 antennas, 155 repeaters, 166 power sources, 71 pieces of computer
equipment and 1,446 radios. The equipment has been taken down in
several cities in the Gulf coast state of Veracruz and the northern
states of Nuevo Leon, Coahuila, San Luis Potosi and Tamaulipas.

The network was built around 2006 by the Gulf cartel, a narcotics-
trafficking gang that employed a group of enforcers known as the
Zetas, who had defected from Mexican army special forces. The Zetas
split from the Gulf cartel in 2010 and have since become one of the
nation's most dominant drug cartels, with profitable sidelines in
kidnapping, extortion and human trafficking.

The network's mastermind was Jose Luis Del Toro Estrada, a
communications expert known as Tecnico who pleaded guilty to
conspiracy to distribute cocaine in federal court in Houston, Texas,
two years ago.

Using millions of dollars worth of legally available equipment, Del
Toro established the system in most of Mexico's 31 states and parts of
northern Guatemala under the orders of the top leaders in the Gulf
cartel and the Zetas. The Gulf cartel boss in each drug-smuggling
territory, or plaza, was responsible for buying towers and repeaters
as well as equipping his underlings with radios, according to Del
Toro's plea agreement.

Del Toro employed communications specialists to maintain and run the
system and research new technology, according to the agreement.

Mexican authorities, however, presented a different picture of the
cartel radio infrastructure, saying it was less monolithic than the
one described by U.S. authorities. A Mexican military official denied
that the army and navy have been targeting one network that covered
the entire Gulf coast. The operations had been focused on a series of
smaller, local systems that were not connected to each other due to
technical limitations, he said.
"It's not a single network," the official told The Associated Press on
condition of anonymity due to the sensitivity of the topic. "They use
it to act locally."

In recent years, reporters traveling with the Mexican military have
heard cartels using radio equipment to broadcast threats on soldiers'
frequencies. The military official told the AP that the signals are
now encrypted, but cartels are still trying to break in.
At least until recently, the cartel's system was controlled by
computers that enabled complex control of the radio signals, allowing
the cartel to direct its communications to specific radios while
bypassing others, according to Grupo Savant, an intelligence and
security consulting firm in Washington that has firsthand knowledge of
Mexico's cartel operations.

The radio system appears to be a "low-cost, highly extendable and
maintainable network" that shows the Zetas' sophistication, said
Gordon Housworth, managing director of Intellectual Capital Group,
LLC, a risk- and technology-consulting firm that has studied the
structure and operations of Mexican cartels and criminal groups.

Other Mexican criminal organizations maintain similar radio networks,
including the Sinaloa cartel, based in the Pacific coast state of the
same name, and the Barrios Azteca street gang, which operates in
Ciudad Juarez, across from El Paso, Texas, a U.S. law-enforcement
official said. The Zetas' system is the largest, however, the official
said, speaking on condition of anonymity because of the sensitivity of
the topic.

The Mexican raids are "a deliberate attempt to disrupt the business
cycle of the cartels," said one former law-enforcement official with
direct knowledge of the network. "By going after command and
communications you disrupt control."

Law-enforcement officials and independent analysts described the
operations against the Zetas' communications system as significant
short-term victories in the fight against the cartel.
"The seizures show that the organization is scrambling," said Steven
Dudley, co-director of InSight, a group that analyzes and investigates
organized crime in Latin America.

The longer-term impact is unclear. The cartel has had little
difficulty in replacing radio gear and other equipment seized in
smaller operations in recent years. And contacts among the highest-
ranking Zetas operatives tend to take place in highly encrypted
communications over the Internet, according to Grupo Savant.

Certainly, cartel radio equipment is a near-ubiquitous presence for
Mexicans living along the front lines of the drug war.
In the state of Tamaulipas, across the border from eastern Texas, many
antennas are concealed in the foliage of the rockrose, an invasive
shrub that has spread across much of the state's open land.

Even from a few feet (meters) away it's nearly impossible to see the
towers or their power cables.
In Nuevo Laredo, the Zetas' first stronghold, antennas sprout from
rooftops and empty lots. One soldier told the AP that even when
authorities took down an antenna there, it was swiftly replaced.
___
Associated Press writers E. Eduardo Castillo in Mexico City and Efrain
Klerigan in Victoria, Tamaulipas, contributed to this report.