Analog wireless technology has been around for over a decade. Analog wireless devices are inexpensive and easy to use. Overall, analog wireless devices have the smoothest and most crisp video signal of the various types of wireless security devices, yet are limited by number of video channels and are vulnerable to signal interference—particularly Wi-Fi.
Digital wireless is an up and coming technology. Similar in form factor to analog wireless, digital wireless devices accept an analog video input, convert the signal into a digital wireless RF signal (radio frequency is a rate of oscillation, which corresponds to the frequency of radio waves), and then convert it back to an analog video output.
Therefore, they are compatible with virtually any analog security system. The difference is, like a cell phone, the RF signal is much less vulnerable to outside interference such as Wi-Fi or Bluetooth. Digital wireless signals are also almost impossible to locate with a wireless video detector, adding to system security.
Digital wireless devices generally have many more channels so you can use more of them in close proximity to each other. However, with digital wireless devices you may occasionally see video hiccups and freezing in the motion, much like satellite TV during a storm, or digital cable.
The IP video market has exploded in recent years and shows no sign of slowing down. Much like a computer network, IP cameras send their video in a pure digital stream, accessed by a network IP address. However, network cables have a theoretical limit to their length (328 ft) and though there are ways to extend that, there are still situations where you need more distance.
A wireless IP device, also sometimes known as an access point, takes the digital IP signal out of the camera by way of a cat-5 cable, and sends it wirelessly to another access point, which in turn is connected to a network video recorder. The advantage is the signal remains in digital form throughout the entire process, maintaining extremely high video signal quality and ensuring data integrity.
Wireless access points allow you to send multiple camera signals back to a single receiver, which helps reduce overall system cost. And since wireless access points have higher power limits than analog or digital wireless devices, they can transmit over much longer distances. There are also several layers of passwords and encryption, giving you some of the best in system security.
A wireless sensor allows you to send an on/off signal back to a DVR with alarm contact inputs. There is no video transmission, just a signal that an event has taken place. The transmission is analog, but the signal only lasts for a split second. It is higher powered, so the signal can travel over great distances.
The application is typically a motion sensor at a front gate that triggers a DVR back at the house to begin recording, or to expand a specific camera up to full screen. They are useful for notifications of specific physical events and are helpful in situations where video motion detection might not be accurate enough.