What is an IP Network Video Camera (also Known as an IP Camera)?
An internet protocol camera, or IP camera, is a camera that sends and receives data over a local area network (LAN) and/or the internet. This gives the camera the potential to be viewed from anywhere in the world a user has internet access. Though many webcams are technically IP cameras the term most often refers to security cameras.
How Does a Network Camera work?
Instead of transmitting video over a video cable to a monitor or DVR a network 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.
How Does a Network Camera Collect and Compress Images and Transfer Them Over a Network for Remote Viewing?
An IP 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 IP 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, and 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.
Connecting to Networks
There are 3 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.
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).
Why Use a Network Camera and Where?
Network cameras can perform all of the tasks a traditional analog video system is capable of, from security surveillance to quality assurance, but with the added feature of remote viewing. Even if you don’t need to be able to access your cameras from offsite, there are other benefits to installing IP cameras.
IP cameras can use existing internet access, so they don’t require installation of coaxial cable throughout a building. Since they transmit over the internet, anyone with a PC has no need to purchase and install additional monitoring equipment. There is also no limit to the number of cameras that can be installed for use in monitoring so long as there is sufficient bandwidth to support them.
What Do I Need in Order to Use a Network Camera?
In addition to internet service and a wired or wireless router (depending on your specific camera)a network cam 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.
Can I Use a Dial Up Internet Connection to Host My 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 a Network 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 Network Camera and a (PTZ) Network 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 Network Camera?
This can vary by camera. 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.