What distinguishes wireless from wired surveillance systems?

Wired surveillance cameras

Wired surveillance cameras are cameras that are physically connected to the network or a recording device via cables. They typically use Ethernet cables to transmit the video and audio signals to a central recording device or a surveillance monitor. Wired surveillance cameras can take advantage of Power over Ethernet (PoE) for both power supply and data transmission, eliminating the need for separate power cables. They can offer more stable and reliable data transmission compared to wireless cameras and are therefore often preferred in areas with higher security requirements or where continuous monitoring is essential.

Wireless surveillance cameras

Wireless surveillance cameras are cameras that use wireless technology to transmit video and audio signals to a receiving device or cloud server. They are stand-alone devices that do not require physical connection to the network. Wireless surveillance cameras typically use Wi-Fi or other wireless protocols to send data over short or medium distances. They are flexible in installation and can be placed in different locations without the need to run cables. Wireless surveillance cameras can be a practical solution for both home and business owners who want flexibility and ease of installation in their surveillance system.

Why not choose a wireless surveillance system?

The frequency bands

In today's wireless world, two different legal frequency bands are generally used: 2.4 GHz and 5 GHz. The former is a well-used network and can easily be disrupted by wireless phones and microwave ovens, among others. But the problems do not end there. Virtually all wireless traffic is carried on these frequency bands:

- Cordless phones (DECT)
- WiFi (IEEE 802.11)
- Bluetooth
- ZigBee car alarms
- Microwave ovens

Output limitation

The 2.4 GHz band has a low power limit of 100 mW, the reason for this is that the band was initially intended only for short-range communications with relatively low speed and little data transfer. The technology was developed in 1991 by Nokia and was to be used for simple wireless POS systems.

Data transfer

When we use phones or computers and connect to the internet with Wi-Fi and search for a website, say www.google.se, your phone/computer retrieves information and then presents the website on your phone/computer. A website is about 1 megabyte in size, and how fast you get to the website depends on how fast your computer can receive traffic.

This means that downloading this website does not require particularly fast or stable traffic transfer. You probably won't notice much difference if you have a 100Mbit/s or 1Mbit/s transfer speed because the website you are going to view is only 1 megabyte in size. The speed doesn't affect you much either, if it takes 0.5 seconds or 1 second to download the website, it doesn't affect you much.This is where it becomes a problem for surveillance cameras that transmit their traffic wirelessly. Now let's say a camera sends its video to your computer instead. A normal camera sends a constant data stream of about 3-4 Mbit/s, that's about 30 frames per second. As long as it is possible to send 3 - 4 Mbit/s stably via wireless, there is no problem.

But let's say a drop occurs for a few microseconds and it goes down to 0 Mbit/s (i.e. no data goes through) you browsing websites on your computer wouldn't notice this, nor would you if you were watching flm as your computer buffers video. But what happens if the camera loses contact and 12 images do not arrive at your computer, what does the camera and computer do then?

Should the computer wait for these images before moving on? Or should it simply ignore them? But then the data will not be complete.

Most traffic sent on a local network is TCP-based. This means that the sender waits for a delivery message from the receiver before continuing to send the next data packet, if the sender does not receive a delivery message from the receiver, it simply does not send more data until the sender has received the previously sent packet and replied that it has received the data. So in this case, the receiver must ask the sender to send the data packet again until it arrives in full at the receiver.

A bottleneck occurs and the camera has absolutely not much choice in this case, it simply has to stop transmitting images until a stable connection can again

Disruptive products

As we've said before, wireless traffic on the 2.4Ghz band can be easily jammed by other electronic equipment. Today, burglars and perpetrators have begun to take advantage of this by simply using a so-called WiFi jammer when breaking in, since all wireless traffic is only allowed to transmit on these frequency bands, the perpetrators know that if they interfere with these frequencies, the customer's security devices will lose contact with each other.

A WiFi jammer is a nifty, inexpensive, handheld product that deliberately sends out strong interference on the 2.4Ghz and 5Ghz bands with the aim of disrupting all traffic between products.

So when using wireless transmission technology, we think you're playing right into the hands of perpetrators. Therefore, we always recommend wired traffic, even though it is more work to pull cable during installation, this often pays off afterwards in the event of a burglary.

In conclusion - "A chain is only as strong as its weakest link"

As a surveillance expert, the Surveillance Store always favours wired systems because of their security and reliability. But of course, there are also situations where wireless surveillance systems may be more suitable. Wireless systems can be more flexible when it comes to installation, especially in existing buildings where it may be difficult to run cables or areas where cables are impractical or costly to use. For example, rural areas without access to electricity or similar. They may also be more suitable for temporary monitoring needs or locations where there is no need for continuous monitoring.

We recommend carefully evaluating your surveillance needs and considering factors such as location, installation and desired level of privacy and security before deciding. Regardless of the option chosen, we always strive to provide our customers with high-quality surveillance solutions that meet their unique needs and expectations.