Wireless spy cameras operate at different frequencies.
As of 2010, wireless spy cameras operate within a range of frequencies: 434mhz, 900mhz, 1.2ghz, 2.4ghz and 5.8ghz. Though other wireless surveillance methods are quickly coming to market, like the remote workstation spying conducted by a Pennsylvania School District, the wireless spy camera remains the backbone of most covert surveillance installations.
Wireless spy cameras constructed in the future will likely operate at even higher frequencies, enhancing range and video resolution, due to continuing improvements made to wireless technologies.
How it Works
In order to conduct and capture wireless video surveillance more than just a pinhole camera is required. Wireless spy camera installations always include a minimum of four components:
1) B/W or color pinhole camera.
3) Transmitter with a power source.
4) Receiver.
4) Storage device (for video received from the transmitter).
In many newer spy camera kits a micro-transmitter and antenna are built-in to the pinhole camera. A dongle from the transmitter connects to a nine-volt battery clip to power the broadcast signal.
Frequencies
Wireless spy cameras in the 900mhz-1.2ghz range are still on the market, but as of 2010 receive little use. There are 2.4ghz or 5.8ghz cameras that provide good value, and are popular choices for wireless surveillance setups.
Cameras that use 2.4ghz are widely used in many covert surveillance applications. 5.8ghz cameras are becoming more prevalent due to growing consumer awareness of the greater range and reduced signal corruption provided by the 5.8ghz band.
Limitations
Wireless camera range varies greatly in real-world applications. Most range information published by manufacturers assumes a clear line-of-sight (LOS). Real-world camera installations, though, generally occur in environments that include walls, doors, overhangs and many other obstructions that impact wireless video signal reception.
Radio frequency interference also becomes an issue. Signal corruption or "noise" increases as more devices "share" the same band (cordless phones, microwaves, garage door openers). The 2.4ghz band is particularly sensitive to signal corruption.
Detection
All electronic devices give off some level of radio waves. "Bug-sweeping," or Technical Surveillance Countermeasures (TSCM), is the professional activity of using various scanning devices to detect existing Radio Frequency (RF) transmissions.
In a situation where a wireless hidden camera installation is suspected a technician might, for example, scan for RF activity on the 1.2ghz and 2.4ghz bands. While this sounds simple, in reality TSCM is a highly technical field of surveillance countermeasures.
Hidden cameras, by comparison, may be entirely self-contained. Hidden cameras include a power source and storage medium (typically a micro-SD card) within the main device, circumventing many of the limitations of wireless setups. Non-wireless "Teddy-Bear" and "nanny cams" are examples of hidden cameras. (See Resources)
A hidden camera also gives off lower RF activity, as it is not actively broadcasting. This makes non-wireless hidden cameras much less susceptible to "bug sweeps."
Legal Considerations
Are wireless spy cameras legal? Is covert video surveillance acceptable as evidence in court? The jury is still out on this question, literally.
States have many different laws regarding the legality of taping people without their permission. (See Resources) Most laws take one or all of the following criteria in to consideration:
1) Location. (Home, Workplace) A question of ownership may come in to play here. Is it your business? Your home?
2) Expectation. Is there an "expectation of privacy?" Hidden cameras in bathrooms or changing rooms are illegal for this reason.
3) Intent. Is it the intent of the surveillance to capture illegal activity? Nanny-cams and home security cameras meet this criteria.
Note that in some states it is illegal to videotape people covertly unless you're duly licensed to conduct surveillance activities (as a Private Investigator). It is also illegal in most states to capture audio simultaneously with video (the reason that most spy cameras sold in the U.S. have their original microphones removed).
Tags: Hidden cameras, pinhole camera, 2ghz 4ghz, 4ghz 8ghz, 8ghz cameras, camera installations, cameras operate