Virtual fencing on the Arizona-Mexico border is set to start soon, despite uncertainty that the sophisticated system works as promised, reports the Associated Press [1].

A virtual fence along a 28-mile stretch of Arizona will get the government's conditional stamp of approval Friday, allowing it to move into the next testing phase.... If the 28-mile virtual fence is successful, elements of it could be used as a prototype along other parts of the southern and northern borders. The project is being tested in Arizona because over much of the last decade, more illegal immigrants have crossed from Mexico through the state than anywhere else on the border.

The AP reports that the virtual fencing system made by Boeing Co., known as SBInet's Project 28 [2], consists of 98-foot-tall unmanned towers armed with a slew of advanced technology such as radar, sensor devices, and cameras. Department of Homeland Security sources say the technology can tell apart  people from cattle from 10 miles away and can tell whether a person is carrying guns or drugs.

These claims, though, conflict with congressional criticism and flaws discovered in the virtual fencing system this summer.

On Wednesday, Representative Bennie Thompson (D-MS), the chairman of the House Committee on Homeland Security, wrote a letter [3] to DHS Secretary Michael Chertoff recommending that he delay paying Boeing the full contract amount of $20 million, saying the contract should not be paid until the project performs up to what Boeing promised. Boeing already received $15 million worth of the contract's amount before the government found glitches in the virtual fencing's software this summer.

The software glitches, reports the AP, have failed to give Border Patrol command centers and agents in the field a "common operating picture with global positioning information" to stop illegal immigrants from crossing into the United States.

Border Agents will test the virtual fencing system over the next 45 days. If it works up to their standards, DHS will accept it. If not, Boeing will be asked to fix what's wrong.