Internet Cameras Explained
Everything you need to know about viewing live video over the internet
What is an Internet Camera (Also Known as a Webcam)?
Internet cameras go by a lot of different names. You might hear them referred to as IP or "internet protocol" cams, "network cameras," or "webcams." Whatever you choose to call it, an internet cam is a camera that sends and receives data over a local area network (LAN) and/or the internet.
How Do I See What's Happening in My Home or Office When I'm Not Around?
It's become incredibly easy to check in on your young child and her nanny from your desk at work -- or to monitor your business from your laptop at home, all in real time. Internet cameras allow you to connect to the internet via a broadband network and remotely view live video from any web browser anywhere in the world. Once your system is set up, the only requirement is Internet access. You can even monitor multiple video cameras or DVRs from your tablet or smartphone.
Some internet cameras require a physical cable connection, others are wireless and transmit their data via radio frequency (RF) signals or over a local WiFi network.
Think of internet cameras as mini computers that happen to have sophisticated optics built in. They come with their own software and need to be configured to a network in order to function. The network configuration is a relatively simple process for many devices; generally set up is no more complex than configuring a Wi-Fi network. While some models require a good working knowledge of Internet technology to get them up and running, that's becoming more the exception than the rule. Many cameras now come with their own apps, which make recording and viewing video on the web even easier.
These versatile devices come in a number of "form factors." Many look like traditional security cameras, but consumers have demanded hidden cameras (also known as nanny cams) with webcam capability -- and the market has responded. Internet cams are now discreetly hidden in a wide variety of form factors, from a Bluetooth speaker, to a smoke detector, to an air freshener.
Can I Use a Dial Up Internet Connection to Host My Internet Cameras?
While it is technically possible, using dial up to host video is virtually impossible. The biggest issue is that the bandwidth provided is insufficient for streaming video.
Does My Computer Need to Be On All the Time If I Use an Internet Camera?
Generally speaking, no, but it depends on the particular camera and how you have it set up. If you are using a PC as a network access point instead of connecting directly to the network from the camera, the PC will need to remain on.
What is the Difference Between a Standard Webcam and a PTZ Internet Camera?
PTZ is an acronym for pan, tilt and zoom. A PTZ camera can be viewed and controlled by multiple users just like a standard network camera, but has the added ability to be moved remotely. Unlike a traditional fixed camera, a PTZ allows a user to adjust the camera's view as necessary.
Do I Have to Purchase Additional Software to Use My Internet Camera?
Whether outside software is necessary will vary by camera brand. Most will come with whatever software is required to configure and view your camera, and usually include recording software. Some may also include more advanced software features, like multiple camera viewing and text/email motion alerts.
If the camera you purchased does not include the features you want, there are many NVR programs available for purchase that can add these and other capabilities.
How Does an Internet Camera Work?
Instead of transmitting video over a video cable to a monitor or DVR, an internet camera transmits digital video over a data connection: ethernet, USB, WiFi, etc. Everything required to transfer images over the network is built into the unit. It is connected directly to the network, just like any other network device, like a printer or scanner. Depending on what type of camera it is, it may save video to an attached memory source, connect to another device on the network for storage, or stream captured video to the internet.
An internet camera captures images the same way any digital camera does. What makes it different is its ability to compress the files and transmit them over a network. If a building is equipped with a network, the necessary infrastructure is already in place to install network cameras. If adding one or a few cameras, a user may use a decentralized network camera, one that has its own control interface and storage medium built in. When installing multiple network cameras it can be wise to use a centralized network camera, which requires a network video recorder (NVR).
An NVR is a program that can store video from network cameras and allow for viewing of multiple cameras at once. It is similar to a DVR, but while a traditional DVR is responsible for encoding and processing video from component cameras, an NVR depends on the cameras to encode their video, simply storing it and allowing for centralized remote viewing. NVR software can be installed on a dedicated device with its own operating system or on an existing computer. There are hybrid systems available that can accept both IP and analog inputs. These will often allow analog cameras to be viewed remotely along with any network cameras.
Here's How it Works:
There are three types of networks in common use for security applications:
- Wired networks will connect to a broadband modem or router through ethernet cables (RJ45, CAT5, CAT6). These are the fastest and most secure way to connect, removing the chance of signal interception and interference.
- Wireless networks use a WiFi router to transmit data to and from a wired modem. They transmit data at a slower rate than a wired network, and are at increased vulnerability to unauthorized access, though this can be mitigated through the use of encryption. The decreased security is balanced by the ease of setup and customization of a wireless network.
- Cellular network access tends to be the slowest of the three, but is more secure than WiFi. If the cameras themselves are equipped with cellular transmitters, they don't even require a LAN to be in place, so there's virtually no installation required. These types of cameras, however, can be quite expensive, especially when transmitting high quality video.
What Do I Need in Order to Use a Webcam?
In addition to internet service and a wired or wireless router (depending on your specific camera), an internet camera requires a static IP address or a Dynamic Domain Name Server (DDNS). It also requires a personal computer to configure your camera and an internet-connected video device to act as a remote viewing station. If you plan to record and store footage, you will also need a dedicated NVR or a PC to install NVR software on, as discussed earlier.
What is a Static IP Address and Why Do I Need One?
When you have a device on a network, you can access it by entering the IP (Internet Protocol) address into a web browser. Internet service providers (ISPs) supply a dynamic IP address to most customers. A dynamic IP address is like a phone number that changes every time you hang up your phone, while a static IP address never changes.
Only your ISP can provide you with a static IP address and they will usually charge a monthly fee for that service. In order for you to gain consistent access to your network cameras you will need a static IP address. If your ISP is unable to provide you with a static IP, there are third party services that can provide a virtual static IP address. Many are free to use, and a simple web search will provide multiple options.
For more information on static and dynamic IP addresses, consult this learning article.
Compression Techniques and Image Resolution
Digital Image resolution is measured in pixels. The more detailed an image is, the more pixels it is made up of, and therefore the more data it contains. Detailed images require more space on a hard disk and more bandwidth for transmission.
To transmit images over a network, data must be compressed to avoid consuming too much bandwidth. If bandwidth is limited, lowering the frame rate or accepting a lower image quality can radically reduce the size of video files. A number of compression standards exist that deal with the trade off between frame rate and image quality in different ways, but the most common has become h.264/MPEG-4, otherwise known as AVC (Advanced Video Coding).