What You Should Consider When Choosing Switches for Your Surveillance System?

To date, surveillance systems are widely used in hospitality, catering, retail, education, transportation, and more. IP cameras are an essential component of a business surveillance system to gain visibility and insight of the business, creating a safe environment for staff and customers. Maintaining your video surveillance system properly is as critical as the system itself to your business’s security. When you plan to add a video surveillance system, the essential question always comes: What infrastructure to choose as your supporting equipment? In today's typical business, using PoE (Power over Ethernet) switches for IP camera is very common and popular and should be your first choice.

What is PoE?

Power over Ethernet, or PoE, describes any of the several standard or ad hoc systems that pass both electric power and data on the same twisted pair Ethernet cabling. This allows a single cable to provide both a data connection and electric power to devices such as wireless access points, IP cameras, and VoIP phones. PoE has the advantage of allowing connected devices to be used without the need for additional power outlets, saving time and money in power cord configuration and reducing system layout costs.

PoE standards provide signaling between the power sourcing equipment (PSE) and powered device (PD). Its protocols are divided into 802.3af, 802.3at, and 802.3bt. The maximum output power of 802.3af and 802.3at are 15.4 W and 30 W, respectively. 802.3bt is divided into two power types (Type 3 and Type 4), and the maximum output powers of the two bt types are 60 W and 90 W, respectively.

Power Requirements of IP Cameras

In general, 802.3af PoE with a maximum of 15.4 W power output is enough to power most security cameras. For a camera with high power consumption, like PTZ cameras, 802.3at PoE with maximum 30 W power output is usually adequate.

Simultaneously, cameras come with a variety of different wattage demands and the sum power must be less than the switches’ total PoE Budget. Power consumption and a number of powered devices, line loss, and an additional reserved power budget should be considered. Line loss is affected by PSE power, transmission distance, and cable quality. For line loss, comparing the test results of PSE output of 30 W, 15 W, and 10 W (CAT5E cable) at 100 m, the loss of the three kinds of output power is around 1.1 W, 0.8 W, and 0.3 W, respectively.^† For example, when you have four cameras with 12 W power consumption individually connected to a switch, the PoE power budget of the switch should exceed 4 × (9 W + 0.8 W) = 39.2 W. When considering the additional reserved power budget, a PoE switch with more than 40 W would be an ideal choice.

Network Requirements of IP Cameras

There are four main elements that affect IP cameras’ bandwidth and internet speed—Resolution, FPS (Frame Rate per Second), Video compression codec, and the number of cameras.

In order to ensure stable video transmission, the peak bandwidth of monitoring is generally 120% of the stream’s bitrate. As a result, the recommended bandwidth of every camera is calculated as follows. The mainstream is generally a high-definition picture, used for recording and single-screen display; the sub-stream is generally a standard-definition picture, used for network transmission or a multi-screen display, usually at 0.5 Mbps

Bandwidth = 1.2× (Bitrate (main stream) + Bitrate (sub stream)).

Additionally, the actual bandwidth of the switch is typically 50%~70% of the theoretical speed. Hence, the calculated bandwidth needs to divide by 0.7 to get the recommended theoretical bandwidth of the switch. Here you can find the common camera resolution and the corresponding recommended switches.^‡ It could be seen that 10/100 Mbps switches are enough to transmit the video data for almost all scenarios.

Switch Recommendations

According to the analysis above, PoE switches with 10/100 Mbps ports are sufficient to meet the requirements of common IPC. TP-Link’s 100 Mbps PoE switches are specially designed to address specific SMB surveillance needs and satisfy the demands of most IP cameras. Many robust features like Extend Mode, Priority Mode, and Isolation Mode provide value well beyond basic networking needs, creating a versatile and reliable surveillance network to grow your business.

• 250 m PoE Transmission. With Extend Mode, PoE supports data and power transmissions up to 250 m away—perfect for surveillance camera deployment in large areas.

• One-Click Priority Mode. Guarantees the quality of sensitive applications like video monitoring in critical business areas by prioritizing the data of certain ports.

• One-Click Traffic Separation. Isolation Mode easily divides traffic for downlink ports to avoid snooping and tampering and isolates broadcast storm for higher security and performance.

• Silent Operation. Desktop switches’ fanless design delivers zero added noise in their locations. Rackmount switches automatically adjust their built-in fans to balance power consumption with sound reduction in noise-sensitive locations.

Demands for PoE switches are expected to significantly expand over the coming years. TP-Link has been developing different kinds of PoE switches to meet the needs of different scenarios. A wide range of 100 Mbps, gigabit, and multi-gig PoE products provide more flexible deployment and cost-effective options for fixed devices like IP cameras, access points, and IP phones. TP-Link has been dedicated to developing products that people need, and the PoE switches are always ready to give you a more convenient experience. Tell us your needs and leave the rest to us.

Find more information on the TP-Link PoE switches page.

^†PoE budget calculations and line loss are based on laboratory testing. The actual PoE power budget is not guaranteed and will vary as a result of client limitations and environmental factors.

^‡ Actual bandwidth may vary due to different types of cameras.

*Zero-Touch Provisioning requires the use of the Omada Cloud-Based Controller.

**Not all PoE Switches support this feature. Please refer to the product pages for details.

More information: https://www.tp-link.com/solution/poe/

Contact: pr@tp-link.com