How to power up an IP Camera using PoE over a distance of 2600ft?

saki shao

Power Over Ethernet (PoE) is a game-changer in the world of networking, seamlessly delivering power and data over a single cable. This not only simplifies installations but also enhances flexibility in deploying devices such as IP cameras, access points, and more. However, one of the notable limitations of traditional PoE is its restricted transmission distance. Standard PoE is typically effective up to 100 meters, posing challenges in scenarios where devices need to be deployed at longer distances from the power source. This limitation has hindered the full realization of PoE's potential in large-scale installations.

LINOVISION Ultra Long Range PoE solution:

Ultra Long Range PoE Transmission is a groundbreaking solution designed to extend the reach of PoE beyond the traditional limits. This technology enables power and data transmission over distances far beyond the standard 100 meters, facilitating deployments in outdoor areas, and remote locations.We will demonstrate how to achieve ultra-long-distance PoE transmission, powering and providing network connectivity to the end security camera by PoE switch, through total length of 800 meters of Ethernet cable. and provide a step-by-step installation guide along with the final result showcase.

Linovision Long-Range Outdoor PoE Extender (POE-EXT3001LP)

POE-EXT3001LP is a 100M waterproof single-port extender. This device provides 2 10/100Mbps RJ45 ports, the input port is connected to the PoE switch, and the output port is connected to the IP terminal device. Two extenders can be used with a PoE switch to extend 10Mbps network data up to 800 meters. No configuration is required, just plug and play.

Professional outdoor housing design, adaptable to various harsh environments, with high stability, reliability, industrial grade level, and wide temperature range. The whole machine does not require a power adapter, making it convenient for harsh outdoor environments and indoor monitoring equipment where power is not easily accessible.

In specific fields such as city surveillance or extensive camera deployment for security purposes, the demand often exceeds the standard PoE limitation, requiring solutions for distances beyond 100 meters, for extending PoE connectivity beyond the 100-meter mark within the limitations of copper cabling, PoE extenders are commonly employed. These devices can boost the signal and power to reach further distances, albeit typically up to an additional 100 meters per extender, necessitating multiple units for distances significantly beyond the standard limit.

To address the challenge of ultra-long-distance PoE transmission, as we mean that far more than 500 or even 1000 meters PoE Transmission, LINOVISION's EOC (Ethernet over Coax) converters provide a groundbreaking approach. These devices enable PoE power and data transmission over coaxial cable, offering a practical solution for extending the reach of PoE beyond traditional limitations, catering specifically to applications requiring extended distances for device deployment. By leveraging existing coaxial infrastructure, such solutions offer a cost-effective and efficient means to significantly extend the reach of PoE networks, making them ideal for applications in city safety, surveillance, and extensive camera deployment across vast distances.

Read more →

Why Choose Cloud Managed PoE Switch

saki shao


As a power supply device, users have an increasing need for remote control of powered devices, specifically remote PoE port control. This includes turning ports on and off, scheduling automatic on/off times, and triggering port actions based on specific events. Additionally, considering the different power requirements of various devices, users need to remotely adjust the output power to meet the device’s needs.


LINOVISION's Approach: Industrial, PoE Port Control, Outdoor, Affordable

To address this user pain point and considering the user scenarios, especially for outdoor use, LINOVISION has launched our new series of PoE switches: Remote Cloud Managed PoE Switches. These advanced switches, integrated with the LINOVISION Remote Monit Cloud platform, offer comprehensive remote management capabilities. You can easily control PoE ports by toggling them on and off, adjusting port speeds, managing PoE power, and setting port priorities. Additionally, the web interface allows for seamless management of VLAN, QoS, and ONVIF device discovery. (These features will be demonstrated in the testing section in the video.)

To help users save unnecessary expenses, some common local managed PoE switches often offer features, such as SNMP, that typical users do not frequently use, leading to increased costs. As a lightweight managed PoE switch, we have focused on features that users truly need. Therefore, our Remote Cloud Managed PoE Switches are more cost-effective and user-friendly in terms of price. Of course, if you need more complex functionalities, you can find corresponding products in our Managed PoE Switch category.

Why Choose Cloud Managed PoE Switches?

Compared to local managed PoE switches, cloud managed PoE switches are managed through a cloud-based platform, allowing for remote access and control from anywhere with an internet connection. Management is centralized via a web portal, offering continuous monitoring and real-time alerts through the cloud platform. This provides comprehensive visibility into network performance, device status, and PoE power consumption.



LINOVISION RemoteMonit Cloud is an integrated platform crafted to seamlessly oversee and manage complete solar-powered video and IoT systems. This solution ensures comprehensive oversight of camera video, solar charging status, IoT sensors, and cellular traffic usage, enhancing the efficiency and performance of your entire system. Certainly, this also includes remotely controlling the PoE ports of the Cloud Managed PoE Switch through the LINOVISION RemoteMonit Cloud platform. This covers functionalities such as PoE port on/off, power limit settings, port speed adjustments, and port priority configurations. The platform offers complete remote management and control, with a robust set of features for monitoring remote devices.

LINOVISION Cloud Managed POE Switch Selection Guide

Learn more >
Learn more >
Learn more >
Input 48-57V DC 55V DC 100-240V AC
Output 48V POE Standard 48V POE Standard 48V POE Standard
Uplink Ports 4*Gigabit SFP 1*10G SFP 2*Gigabit SFP
POE Ports 8*Gigabit PoE ports 8*2.5G PoE Ports 8*Gigabit PoE Ports
POE++ Ports / / /
POE budget 180W 130W 120W
L2/L3 Management VLAN, QoS, Fast-Ring VLAN, QoS, Fast-Ring VLAN, QoS, Fast-Ring
PoE Port Control Turn On/Off PoE Turn On/Off PoE Turn On/Off PoE

Read more →

How to Integrate LoRaWAN Sensor to BACnet BMS System via Linovision Gateway

saki shao


Linovision gateway is able to decode the data of LoRaWAN sensors and map the sensor data into BACnet objects used by BMS system or BACnet devices, which can quickly and easily integrate LoRaWAN devices to Building Management System.



  • Linovision Gateway: IOT-G65/G67 with firmware version and later
  • Any LoRaWAN sensor
  • BACnet Client tool: take Yabe as example



  1. Go to Network Server > Payload Codec to check if there is decoder of your LoRaWAN node, if not please add and custom the decoder referring to article How to Use Payload Codec on Linovision Gateway.

  2. Connect LoRaWAN node to Linovision gateway referring to article How to Connect LoRaWAN Nodes to Linovision Gateway. Note that ensure the correct payload codec is selected when adding this device.

  3. Go to Network Server > Packets to check if there is uplink packet and click Details to check if the decoder works. If works, the JSON item will show the decoded result.




  1. Select the Application you use and add a BACnet/IP transmission.





  1. Go to Protocol Integration > BACnet Server > Server to enable BACnet server and configure the settings. Note that the Device ID should be changed to an unique value to avoid conflict with other BACnet server devices, or the BACnet client may not find this device.


  1. Go to Protocol Integration > BACnet Server > BACnet Object page, click Add to add an object.
  • Device Name: select the device added on Network Server > Device page
  • LoRa Object: select or customize a sensor variable decoded on JSON item of Network Server > Packets page
  • Object Name: customize an unique object name
  • Object Type: select Analog Input or Binary Input for non-editable sensor data

Example 1: temperature data

  • COV: when the change of analog type object value exceeds the COV Increment, the gateway will send notification to BACnet client actively. This should ensure the BACnet client supports COV feature.




Example 2: button status

  • Active/Inactive Text: display the real status when button is pressed or unpressed
  • Polarity: Define the binary status as Normal or Reverse.



Note: for LInovision buttons (IOT-S500BT and IOT-S500SP), it's suggested to add msgid value (update a random value if the press is triggered) to an object and know if the button is pressed by the change of this value.



  1. After adding, you can check if object values are updated regularly.



  1. Open Yabe BACnet client tool, click Add device to scan the devices, then you can find the BACnet server device according to the Device ID and check the object list.




  1. Click the object to check all the properties of this object.






Read more →

How to Use Payload Codec on Linovision Gateway

saki shao


When Linovision gateway work as embedded network server, it supports to send data to third party server via MQTT/HTTPS and it will send every data as below JSON format:

{"applicationID":"1","applicationName":"cloud","data":"A2fqAARoTwUAAA==","devEUI":"24e124136b502217","deviceName":"EM300-TH","fCnt":128,"fPort":85,"rxInfo":[{"altitude":0,"latitude":0,"loRaSNR":13.8,"longitude":0,"mac":"24e124fffef54092","name":"Local Gateway","rssi":-51,"time":"2022-12-27T07:21:27.078763Z"}],"time":"2022-12-27T07:21:27.078763Z","txInfo":{"adr":true,"codeRate":"4/5","dataRate":{"bandwidth":125,"modulation":"LORA","spreadFactor":7},"frequency":868100000},"metadata":{"mqtt_topic":"/mqtttest"}}


This article will guide you how to custom uplink and downlink contents via Payload Codec feature.


  • Linovision LoRaWAN Gateway: IOT-G65/G67 with firmware version and later

For other models or versions, please refer to How to Use Payload Codec on Linovision Gateway(old).



Inbuilt Payload Codec

Linovision gateway has supported the inbuilt payload codec library to add Linovision decoders and encoders easily. It supports two obtaining types:

Online: when gateway is able to access the Internet, it will check the update and update the library automatically. You can also click Obtain to check the update.

Local Upload: upload decoder package locally.



When you add any device on Network Server > Device page, you can select the decoder and the decoded data will be shown on the packet details of Network > Packets page.


Custom Payload Codec

If you use other brand devices or the default decoder does not work with your application, please add a custom payload codec:





Uplink Content Customization

Take IOT-S500TH as example, here are 3 situations for uplink content customization.

1. Only upload decoded sensor data.

Copy IOT-S500TH decoder and paste it to Payload decoder function box.

Note: If you configure the sensor from other company, please contact their support to get the Decoder Script (Java Script), then ensure the script header is function Decode(fPort, bytes) when paste.



You can use Payload Codec Test feature to test the uplink result.



Uplink Result:

{ "battery": 92, "temperature": 30.8, "humidity": 50.5,}

2. Upload specific attribute items and raw data.

Click here to know all attribute items in one package. Linovision gateways provide function LoRaOject to call every item you require. If you need to send dev EUI, RSSI, SNR and raw data, edit this example coder:

function Decode(fPort, bytes) {var decoded = {};decoded.devEUI = LoRaObject.devEUI;decoded.rssi = LoRaObject.rxInfo[0].rssi;decoded.snr = LoRaObject.rxInfo[0].loRaSNR; =;return decoded;}


Uplink Result:

{"devEUI":24e1611234567890"rssi": -5,"snr": 11,"data": AXVkA2cgAQRoeg==}


After adding, you can add this payload codec to a device and go to Network Server > Packets to check the uplink result on Packet Details.


3. Upload specific attribute items and decoded data.

Copy IOT-S500-TH decoder and paste it to Payload decoder function box, then add attribute items before return decoded statement:

function Decode(fPort, bytes) { var decoded = {}; //Data decoder for (var i = 0; i < bytes.length;) { var channel_id = bytes[i++]; var channel_type = bytes[i++]; // BATTERY if (channel_id === 0x01 && channel_type === 0x75) { decoded.battery = bytes[i]; i += 1; } // TEMPERATURE else if (channel_id === 0x03 && channel_type === 0x67) { decoded.temperature = readInt16LE(bytes.slice(i, i + 2)) / 10; i += 2; } // HUMIDITY else if (channel_id === 0x04 && channel_type === 0x68) { decoded.humidity = bytes[i] / 2; i += 1; } else { break; } } decoded.devEUI = LoRaObject.devEUI; return decoded;}/* ****************************************** * bytes to number ********************************************/function readUInt16LE(bytes) { var value = (bytes[1] << 8) + bytes[0]; return value & 0xffff;}function readInt16LE(bytes) { var ref = readUInt16LE(bytes); return ref > 0x7fff ? ref - 0x10000 : ref;}

Uplink Result:

{ "battery": 92, "temperature": 30.8, "humidity": 50.5,"devEUI":24e1611234567890}

Note: If you need to add all attribute items, add decoded.obj= LoRaObject; before return decoded statement.

After adding, you can add this payload codec to a device and go to Network Server > Packets to check the uplink result on Packet Details.






Read more →

Layer 2 vs Layer 3 Switch: Which One Do You Need?

saki shao

Network switch can connect to various terminal devices, set up LANs, and enable direct communication among all equipment. With the evolution of networks, different types of switches have been introduced. According to the OSI model, a Layer 2 switch operates at the data link layer, while a Layer 3 switch functions at the network layer. This raises the question: Should I use a Layer 2 or Layer 3 switch?

Before addressing this, it’s important to understand the OSI model and the role of network switches.

OSI Model and Network Switch: What Are They?

OSI Model

The Open Systems Interconnection (OSI) model is a conceptual framework that divides network communication functions into seven layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

Transmitting data over a network is a complex process requiring the collaboration of various hardware and software technologies, crossing geographical and political boundaries. The OSI model provides a universal language for computer networks, enabling different technologies to communicate using standard protocols or communication rules. Each layer within the OSI model has specific functions and tasks that ensure the network operates smoothly. Higher-level technologies benefit from this abstraction, as they can utilize lower-level technologies without needing to understand the underlying implementation details.

Advantages of OSI Model:

  • Clear distinction between hardware and software
  • Improved understanding and communication of processes
  • Efficient troubleshooting
  • Open interoperability between different systems
  • Clear communication of product functionality

OSI Model

Figure 1: OSI Model

Network Switch

A network switch (also known as a switching hub, bridging hub, or MAC bridge by the IEEE) is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device.

A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer (Layer 2) of the OSI model. Some switches can also forward data at the network layer (Layer 3) by incorporating routing functionality, known as Layer 3 or multilayer switches.

What Is a Layer 2 Switch?

A Layer 2 switch operates at the data link layer of the OSI model, efficiently forwarding data packets based on MAC addresses. It works within the hardware layer, eliminating the need for frame modification. Layer 2 switches are commonly used for workgroup connectivity and network segmentation, enhancing performance and reducing collision domains.

Key functionalities of a Layer 2 switch include:

  1. High-speed forwarding: These switches achieve fast data frame forwarding by referencing an address table to find the port associated with the destination MAC address, eliminating the need for decapsulation and encapsulation of data frames.

  2. Collision domain isolation: Each port on a Layer 2 switch is treated as an independent collision domain, reducing collisions and retransmissions of data frames, thus improving network performance.

  3. VLAN support: Layer 2 switches enable the creation and management of virtual LANs (VLANs). By adding VLAN identifiers to data frames, different logical networks can be divided and controlled effectively.

What Is a Layer 3 Switch?

Layer 2 and Layer 3 switches differ primarily in their routing capabilities. A Layer 2 switch operates solely based on MAC addresses, disregarding IP addresses and higher layer elements. In contrast, a Layer 3 switch, or multilayer switch, performs the functions of a Layer 2 switch while adding static and dynamic routing capabilities. This means a Layer 3 switch maintains both MAC address and IP routing tables, facilitating intra-VLAN communication and packet routing across different VLANs. Additionally, there are Layer 2+ (Layer 3 Lite) switches that offer static routing exclusively. Layer 3 switches not only route packets but also provide advanced features like VLAN traffic tagging based on IP addresses, enhancing power, security, and network management capabilities.

Key functionalities of a Layer 3 switch include:

  1. Isolated broadcast domains: Each port on a Layer 3 switch functions as an independent broadcast domain, minimizing the impact of broadcast storms on network performance and bolstering network security.

  2. Routing protocol support: Layer 3 switches can accommodate various routing protocols (such as RIP, OSPF, BGP, etc.), enabling dynamic routing updates and exchanges with other routers or Layer 3 switches. This enhances network reliability and flexibility.

  3. Policy routing support: Layer 3 switches offer policy routing capabilities based on source IP addresses, destination IP addresses, protocol types, and other conditions. This allows for differentiated processing or forwarding of data packets based on their types or priorities, optimizing network efficiency and quality.

For superior processing performance and network reliability, Linovision offers different types of managed poe switch. Visit for more information.



What Are the Differences Between Layer 2 and Layer 3 Switches?

Below is a comparison of the key differences between Layer 2 and Layer 3 switches:

How to Choose the Suitable Switches for Your Network Need

When deciding between a Layer 2 switch and a Layer 3 switch, consider the following factors:

For Layer 2 Switch:

Network Size: Suitable for small to medium-sized networks that require high-speed connectivity within the same network segment.

Network Segmentation: Helps reduce congestion and improve performance by dividing the network into smaller domains within a LAN setting.

Cost-Effectiveness: Generally less expensive due to its limited functionality.

Simple Subnet Networks: Adequate for single subnet networks with low traffic volumes.


For Layer 3 Switch:

Advanced Routing: Necessary for networks that require inter-VLAN routing, Quality of Service (QoS), and enhanced security features.

Multiple VLANs: Enables routing between VLANs, making it ideal for large organizations with complex network setups.

Network Scalability: Offers greater scalability by managing routing between multiple segments, preventing congestion and accommodating complex traffic patterns.

Future Expansion: Recommended for networks with anticipated growth, providing advanced routing capabilities to support future needs.


When to use the Layer 2 switch, Layer 3 switch and router?

Figure 2: When to use the Layer 2 switch, Layer 3 switch and router?


This post has explained the differences between Layer 2 and Layer 3 Switch. The comparison of their functions is also made, in the hope of solving the problem of deciding between these devices. In network systems, Layer 2 and Layer 3 switches can be selected and combined according to different needs and scenarios to achieve high efficiency and reliability of network communication.

Read more →

What is Inside an SFP Module? – Understanding TOSA, ROSA, BOSA

saki shao

Networking technology is crucial in today's world, serving as the backbone that interconnects countless devices and systems globally. One vital element in the data communication sector is the Small Form-factor Pluggable (SFP) module. In this blog, we will explore the inner workings of these modules, with a particular focus on three essential optical components: TOSA, ROSA, and BOSA.

Introduction to SFP Modules and Optical Components SFP

Definition of SFP Modules and Their Role in Networking

SFP modules are small, hot-swappable devices used in both telecommunications and data communications. These modules connect a network device's motherboard to a fiber optic or copper networking cable. Standardized by the Multi-Source Agreement (MSA), SFPs are interoperable across different brands and devices, making them highly versatile for enhancing network flexibility and scalability.

Fiber optic transceivers are essential components of fiber optic transmission networks. These compact devices feature advanced integrated optical sub-assemblies, making them perfectly suited to meet the high-density networking requirements of today. The market offers a variety of SFPs, including standard SFPs and the enhanced SFP+ variants, each with unique features and specifications. Understanding their core functions is crucial. So, what are the primary functions of SFP transceiver modules?

  • SFPs are responsible for both transmitting and receiving data, essential processes for effective communication.

  • These transceivers enable the vital conversion between electrical signals and optical signals, ensuring smooth data transmission in both directions.

Importance of Understanding SFP Internal Mechanics

To fully comprehend the capabilities and reliability of SFP modules, it's essential to delve into their internal structure and operational principles. Understanding the inner workings of SFP modules is not only valuable for troubleshooting but also for making informed decisions when selecting and deploying the appropriate modules to meet specific networking requirements.

Given their compact size and complex functionality, have you considered the mechanisms at work within an SFP transceiver? These components are more than just parts of a network – they are the heart of connectivity. Nestled within the sturdy metal housing of a transceiver lie several intricate components and sub-assemblies. These work in unison to achieve the impressive capabilities of the SFP module. Amongst the most significant components housed within transceivers, we find:

  • The Transmitter Optical Sub-Assembly (TOSA), which plays a pivotal role in signal transmission.

  • The Receiver Optical Sub-Assembly (ROSA), essential for signal reception.

  • The Bi-Directional Optical Sub-Assembly (BOSA), which enables two-way communication over a single fiber path.

Every component within SFP modules is meticulously engineered to exacting standards, ensuring seamless data transmission across expansive networks, linking users and devices worldwide. This categorization is rooted in the specific functions that SFPs will perform.


It's commonly understood that a standard SFP module comprises two ports: Transmit (TX) and Receive (RX). The components housed within the Transmitter Optical Sub-Assembly (TOSA) facilitate the transmitting function, while those within the Receiver Optical Sub-Assembly (ROSA) handle reception.

Detailed Examination of SFP Module Components

A thorough inspection of the SFP module reveals several intricate components that collaborate to manage fiber optic signals. These include the Transmitter Optical Sub-Assembly (TOSA), the Receiver Optical Sub-Assembly (ROSA), and in certain SFP variants, the Bidirectional Optical Sub-Assembly (BOSA).

Transmitter Optical Sub-Assembly (TOSA) Overview

The Transmitting Optical Sub-Assembly (TOSA) is a pivotal component situated within the transmit section of SFP ports. Its principal role is to convert electrical signals into optical signals before propelling them through the connected optical fiber strand. The TOSA comprises several vital elements, notably a laser diode responsible for generating the light signal and an optical interface that guides this signal into the fiber. Additionally, it incorporates a monitor photodiode tasked with regulating the laser output. Encased within a robust housing crafted from metal and/or plastic, the TOSA also features an electrical interface facilitating signal conversion.

As an essential building block of fiber optic transceivers, the TOSA's design may vary to accommodate diverse requirements and applications. It may integrate supplementary components like filter elements and isolators to enhance its performance, underscoring its adaptability and significance in the field of fiber optics.


Exploring ROSA (Receiver Optical Sub-Assembly)

The Receiver Optical Sub-Assembly (ROSA) holds significant importance within the receiving segment of the SFP port. Its primary role is to capture the optical signal transmitted from the Transmitting Optical Sub-Assembly (TOSA) of a transceiver at the opposite end and convert it back into an electrical signal. This conversion is essential for making the signal intelligible to communication devices.

Comprising three primary components, the ROSA includes a photodiode responsible for detecting incoming light signals, a protective housing typically crafted from metal or plastic, and an electrical interface facilitating connection to communication equipment. This trio is fundamental for the operation of any fiber optic transceiver.

Collaborating harmoniously, a ROSA and a TOSA constitute the core of an optical transceiver module, enabling bi-directional communication. Additionally, the ROSA may integrate an amplifier to enhance the strength of the received signal, ensuring its preservation and quality for subsequent processing.


The Role of BOSA (Bidirectional Optical Sub-Assembly) in SFP Modules

TOSA (Transmitter Optical Sub-Assembly) and ROSA (Receiver Optical Sub-Assembly) are pivotal components responsible for signal transmission and reception in conventional unidirectional transceivers. Typically, they are each linked to an optical fiber to enable unidirectional signal transmission and reception.

However, the emergence of BOSA components has revolutionized the communication field by enabling their integration into bidirectional SFP modules. This integration facilitates bidirectional (full-duplex) communication over a single optical fiber, consolidating the functions of laser emitters and photodetectors. Leveraging wavelength division multiplexing (WDM) technology, BOSA transmits and receives optical signals of varying wavelengths within the same fiber channel, streamlining network architecture, lowering deployment expenses, and enhancing system transmission efficiency.

The adoption of BOSA in bidirectional SFP modules not only streamlines design and reduces equipment footprint but also ensures minimal signal crosstalk and attenuation between wavelengths, thereby enhancing communication reliability. With its precision engineering design aligning with diverse fiber optic communication standards, BOSA technology augments network flexibility and maintainability while curbing infrastructure costs, simplifying network upgrades.

Consequently, BOSA technology stands as a vital catalyst for constructing efficient, cost-effective, and sustainable network infrastructure.



The intricate components within an SFP module, including TOSA, ROSA, and BOSA, epitomize the remarkable technological strides in fiber optic communication. Delving into the inner workings of an SFP module enables network professionals to grasp the intricacy and precision required to facilitate our daily digital communications. From the generation and reception of light signals to the transmission of data across extensive distances with minimal loss, the mechanisms housed within these modules are indispensable to the networks that keep us interconnected in the digital era. As technology advances, the design and functionalities of these optical components will continue to evolve, fostering enhanced communication speeds, reliability, and overall network efficiency.

Read more →

What is Wide Dynamic Range (WDR) in IP Cameras?

saki shao

Have you ever wondered why some security camera footage appears washed out or too dark to distinguish details? This issue can be attributed to the concept of dynamic range, which refers to the balance between light and dark areas within an image. Understanding the concept of wide dynamic range (WDR) is crucial when discussing camera performance, as it plays a significant role in revolutionizing security surveillance.

What Is Wide Dynamic Range?

Wide dynamic range is a term used to describe the contrast ratio between the darkest and brightest color tones that a camera can capture in a single exposure. In video surveillance, WDR technology aims to effectively manage high-contrast environments by skillfully balancing the extremes. Its purpose is to prevent overexposure in bright areas and retain detail in dark areas, thereby avoiding under- or overexposed footage.

The measurement of a camera's dynamic range is expressed in decibels (dB), with the industry standard defined by IHS Markit stating that WDR should have a range of 60 dB or higher. However, it is not uncommon to find WDR cameras that offer dynamic ranges of 120 dB or even greater.

To illustrate the effectiveness of WDR technology in surveillance cameras, let's compare two images. In the first image without WDR, the camera's exposure is affected by the intense light coming from the window. As a result, the exterior view is overexposed, obscuring the details, while the room's interior appears too dark. However, in the second image with WDR enabled, the camera achieves balanced exposure. Both the bright outdoor scenery and the interior details of the conference room are captured clearly, ensuring visibility of both areas within the same frame.

WDR Off vs. WDR On

How Does WDR Work?

WDR technology utilizes two processors, namely a light image processor and a dark image processor, to enhance the overall image quality and clarity.

When employing WDR technology in a PoE IP camera, the camera lens allows different amounts of light to enter specific areas of the image by utilizing varying shutter speeds. This control of light exposure helps achieve a well-balanced WDR image.

In areas with brighter lighting conditions, the camera lens employs a higher shutter speed, resulting in a shorter duration of light exposure for the camera sensor.

Conversely, in darker areas, the camera lens adopts a relatively slower shutter speed, allowing the sensor to capture more light over an extended period.

By combining the information from both images captured at different exposure settings, a final image is generated, which exhibits improved quality and clarity compared to a single-exposure image.

True WDR vs DWDR

True WDR (Wide Dynamic Range) and DWDR (Digital Wide Dynamic Range) are two technologies utilized in cameras to handle high-contrast lighting conditions.

True WDR employs a combination of hardware and software to capture multiple frames simultaneously at different exposure levels. These frames are then merged to create a single image with well-balanced exposure, ensuring that both the brightest highlights and darkest shadows retain their detail.

In contrast, DWDR operates solely through software manipulation on a single image. It adjusts the brightness of shadows and reduces the intensity of highlights. While DWDR is a cost-effective solution, it is generally less effective than True WDR and more suitable for lighting situations that are less challenging.


WDR (Wide Dynamic Range) and HDR (High Dynamic Range) are two distinct image processing techniques that aim to improve image capture performance in high-contrast scenes. It is important to understand the differences between WDR and HDR to choose the appropriate surveillance technology that meets the requirements of various environments and image quality needs.

When comparing HDR and WDR, we recommend using WDR technology for security cameras due to the following advantages:

  1. High-Speed Processing: WDR technology is supported by high-speed digital signal processing (DSP), enabling it to effectively handle dynamic images and videos.

  2. Adjustable Exposure: WDR allows for the output of multiple frames with different exposure times, and each frame's gain can be individually set. This flexibility allows for precise control over the exposure settings.

  3. Backlight Compensation: WDR enables imaging systems to compensate for intense backlighting surrounding subjects. This feature enhances the ability to distinguish features and shapes on the subject, ensuring clearer and more detailed images.

  4. Better Low-Light Imaging: WDR technology excels at capturing images in low-light environments. It can effectively illuminate dark areas, ensuring security even in situations with low or no power supply.

  5. Sharp Details: Compared to HDR, WDR technology produces images with exceptional sharpness and more pronounced details. This results in improved image quality and enhanced visibility of important information.

  6. Cost-Effective: WDR cameras are more cost-effective in terms of installation and purchase price compared to HDR cameras. This makes WDR technology a practical choice for various surveillance applications, providing high-quality imaging at a more affordable cost.

Where to Use WDR Cameras?

WDR cameras find extensive use in environments characterized by demanding lighting conditions, particularly in areas where there is a significant contrast between bright and dark areas. Here are some common applications where WDR cameras are employed:

Where to Use WDR Cameras


The primary application for WDR cameras is monitoring the entrances of buildings. Whether it's a store, bank, ATM, transportation facility, restaurant, or hospital, every establishment has entrance doors that introduce bright light compared to the interior space. WDR cameras excel at compensating for areas that are excessively bright or dark and provide clear snapshots or videos.


In high-contrast scenarios where vehicles frequently enter parking lots, darkened garages, or cars with bright headlights approach surveillance cameras, WDR cameras can capture license plates with enhanced clarity.

Window Side

In areas where sunlight streams through glass panes, creating sharp contrasts of light and shadow within interior spaces, WDR cameras meticulously balance the intense glare from the outdoors with the softer indoor lighting. This ensures that every detail, from people's expressions near the window to the movement of curtains in the sunlight, is captured accurately.


Outdoor surveillance cameras often face the challenge of strong sunlight, which contrasts with the shadows of buildings or areas without direct sunlight. WDR cameras effectively compensate for these differences, providing clear and balanced images.

To further enhance security with high-quality video capture in challenging lighting conditions, Linovision offers a range of security cameras equipped with WDR technology. These options include the 4K bullet PoE IP camera, the 4MP dome network camera, the 4MP turret network camera. Linovision not only provides security cameras but also offers comprehensive video surveillance solutions tailored for enterprises, retail supermarkets, campuses, and other specific needs.

Read more →

Dome vs Bullet Camera vs Turret Camera: How to Choose?

saki shao

Video surveillance systems are essential for ensuring safety and protecting property in industries, businesses, and communities. IP cameras have become a crucial component of such systems. However, there are various types of IP cameras, each suited for different applications. Many people may question the differences between dome cameras and bullet cameras, or between turret cameras and fisheye cameras. In this article, we will provide a comprehensive explanation of the distinctions among these four commonly used security cameras: dome camera, bullet camera and turret camera. We will offer brief introductions and analyze their functions, aiming to provide you with valuable insights to make an informed decision when choosing the cameras that best meet your requirements.

Dome Camera vs Bullet Camera vs Turret Camera

What Is a Dome Camera?

Dome cameras, aptly named for their dome-shaped design, are widely employed in surveillance systems for residential properties, entertainment venues, and commercial establishments. The rounded structure of dome cameras effectively conceals the direction in which the camera is pointing, providing a level of ambiguity to outside observers. This design also allows for significant flexibility in adjusting the camera's focus distance, enabling precise positioning for optimal surveillance coverage.

Most dome cameras are equipped with built-in infrared LED lights, facilitating exceptional night vision capabilities and ensuring high-quality video surveillance even in low-light conditions. Furthermore, dome cameras are typically encased in durable covers, offering protection against vandalism and physical damage. This feature makes them an ideal choice for deployment in exposed areas where the risk of tampering or intentional harm is present.


What Is a Bullet Camera?

Bullet cameras, characterized by their cylindrical shape resembling bullet shells, are commonly utilized in video surveillance systems. They serve various purposes, including indoor security concealment and outdoor surveillance where durability is essential. A distinguishing feature of bullet cameras is their typically large motorized variable-focus or fixed lens, enabling them to monitor a wide area effectively.

Bullet cameras are equipped with powerful built-in infrared LEDs, ensuring precise imaging in different lighting conditions, whether it's day or night. This feature allows for clear and accurate video capture. Typically, bullet cameras are relatively large and easily noticeable. However, there is also the option of mini bullet cameras. Mini bullet cameras can be discreetly concealed, such as being hidden within objects like stuffed animals, or they can be larger in size to serve as a visible deterrent for external security purposes.


What Is a Turret Camera?

Turret cameras, as their name suggests, feature a turret-style 3-axis construction that enables flexible positioning of the lens in any direction. This design allows installers to easily adjust the camera's angle for optimal coverage.

Most turret cameras are equipped with built-in infrared (IR) night vision capabilities, enabling them to capture clear video even in complete darkness. Unlike dome cameras that may be susceptible to glare effects due to their glass housing, turret cameras do not have a dome shell, minimizing such issues.

The unique structure of turret cameras makes them easier to adjust compared to other camera types. These cameras find widespread usage in video surveillance systems for residential properties, businesses, and government installations.


Dome vs Bullet vs Turret Camera Comparison: Pros & Cons

Dome Camera Bullet Camera Turret Camera
Dome shape

Small size
Bullet shell shape

Highly visible and can easily be damaged

Sliced sphere shape

Small size
Visual range Small lens and range Bigger lens with a wider range Small lens and range
Night vision
Night vision

Built-in infrared LED

Night vision

High zoom capabilities

Extended IR

Night vision

Built-in infrared LED
Indoor use More discreet and less distracting More visible and easier to vandalize More discreet and less distracting
Outdoor use
High concealment

Condensation and IR Bounce back

Wider range

Visible deterrent

Prone to wildlife nesting

Clear image

No IR Bounce

Easy to be damaged
Installation Professional installation Easy installation Easy installation and adjustment

Bullet vs Dome Camera vs Turret Camera: How to Choose?

The above three types of camera are all good video surveillance options, but it's important to choose the right one for your own needs. Therefore, we have summarized the following content for your consideration.

Dome camera is a popular choice for more vulnerable external systems and places such as schools, offices, homes, small shops and shopping centers. Dome cameras can be installed directly on the wall or under the eaves. They also have optional junction boxes and wall supports. This type of camera has an amazing anti-damage capability as the lens is completely covered in a destruction-proof glass dome, which makes it easy to hide.

A bullet camera is ideal for large, dark locations such as warehouses, factories, and parking lots as it can be a great deterrent. Normally, it is equipped with full-color night vision by adopting different sensors.

Turret cameras are becoming more popular amongst professionals and are very suitable for indoor use. Same as dome cameras, turret cameras provide high-quality video surveillance as well, but unlike dome security cameras with glass housing, the lack of dome shell makes turret cameras free from glare effects. In addition, the easy angle adjustment also makes turret security cameras overshadow bullet and dome cameras.

Being familiar with the difference between Dome, Bullet camera and Turret  is very crucial. Another important thing is to find out the ideal video surveillance solution for your home or business which involves couple of different types of IP cameras for different areas. 




Read more →

Technical Guide to IP Cameras- Overview, Types, Applications

saki shao

IP cameras, also known as Internet Protocol cameras or network cameras, are a type of security camera that utilizes an IP network to receive and transmit video data. Their primary function is to capture video footage and send it over the network. These cameras are commonly used in various sectors and environments as remote monitoring and management tools to enhance security and protect property.

How Does An IP Camera Work?

IP cameras function similarly to digital cameras in capturing high-quality images. However, what distinguishes them is their ability to compress image files and transmit them automatically to a network video recorder (NVR) through a network connection. Typically, IP cameras can be linked to the network either via an Ethernet cable connected to a broadband modem or router, or wirelessly through a Wi-Fi router.

In the case of a building already equipped with a network infrastructure, setting up IP surveillance cameras is a straightforward process. Similar to connecting your laptop or cell phone to a Wi-Fi network, you simply need to integrate the IP cameras and other devices into your existing network system. This involves establishing connections and configuring the cameras to communicate within the network.

By seamlessly integrating IP cameras into the network, you can take advantage of their features for remote monitoring and enhanced security. These cameras enable you to conveniently access and manage them from any location with network access, providing effective surveillance and peace of mind.


Once all the connections have been properly established, the cameras can begin their operation by capturing video footage and transmitting it to the network video recorder.

Four Common Types of IP Camera

There are various video surveillance solutions, in which many different types of security cameras are adopted. Among those surveillance cameras, there are four most commonly used ones, dome cameras, bullet cameras, and turret cameras.  


Four Important Specifications of IP Cameras

When selecting a security camera, it is important to consider not only the type of camera but also its specifications, as they can significantly impact performance. Here are four crucial specifications to keep in mind:


The resolution of an IP camera refers to the total number of pixels that compose an image, typically measured by its width and height. Common resolutions include 720p, 1080p, 5MP, 4K, and 8MP. Higher resolutions generally translate to a greater number of pixels per inch (PPI), resulting in sharper, high-quality images.

Field of View

The field of view (FOV) of an IP camera is determined by its lens and represents the coverage area that can be observed. Different lenses offer varying FOVs, influencing how wide an area the camera can capture. A wider FOV enables monitoring of larger areas. For instance, a large parking lot may require a different lens with a broader viewing angle compared to a small room.

Focal Length

The focal length of a camera lens, measured in millimeters (mm), determines the angle of view and the distance at which the camera can effectively capture images. There are two types of lenses commonly used: fixed focal length and varifocal lenses. Fixed focal lengths, such as 3.6mm or 8mm, provide specific viewing angles and identification distances. Varifocal lenses, like 2.8-12mm, offer adjustable focal lengths, allowing for flexibility in field of view and identification range.

Low Light Sensitivity

Low light sensitivity, often measured in Lux (lx), indicates a camera's ability to produce high-quality images in low-light environments, minimizing noise and preserving details. Factors such as pixel size, signal-to-noise ratio, and lens aperture contribute to a camera's low-light performance. Lower Lux values indicate superior performance in darker areas. For example, cameras with a range of 100-1,000lx are suitable for well-lit workspaces, while cameras with 0.0001lx are designed for moonless or overcast nights.

Most Popular IP Camera Applications


Home Use

For individuals seeking tools to enhance family connections, monitor home security, or safeguard their property, IP cameras are a must-have item. Many homeowners opt to install video surveillance systems to provide a sense of safety for themselves and their families.

IP cameras utilized in home security systems serve a multitude of purposes. They can be positioned near the front door to capture images of anyone entering or lurking around the house. They can also be installed in the backyard to preserve cherished moments with family members. Additionally, they can be placed inside rooms to ensure the well-being of babies or monitor specific areas of the house.

Business Use

Commercial security cameras are commonly employed in business premises, supermarkets, shops, restaurants, and other commercial establishments. For business owners, security cameras not only protect their property, ensuring uninterrupted operations and deterring criminal activities through real-time monitoring, but they also keep them connected to daily operations and employee safety.

Video surveillance solutions can be utilized to maintain outdoor perimeter security and monitor the surrounding areas. Compared to traditional systems, commercial IP video surveillance systems offer enhanced reliability and security with built-in encryption, data compression, network connectivity, and cybersecurity measures.

Public Safety

Surveillance cameras play a vital role in managing public order, safeguarding public safety, and protecting public property. It is common to find monitoring cameras positioned along traffic roads, parking lots, government buildings, and hospitals. Moreover, security cameras are prevalent in public areas such as schools, parks, communities, and neighborhoods.


IP cameras have become an integral part of home, business, and public surveillance systems. With the appropriate video management software, footage captured by IP cameras can be accessed from anywhere worldwide through network connectivity, be it through a laptop or a mobile phone. In many cases, IP cameras can also be remotely controlled, bringing significant convenience to our lives.

There are various types of security cameras designed for specific applications, which is why it is important to consider multiple factors when purchasing IP cameras for your security system. Before proceeding, it is advisable to determine your budget and specific requirements.

Read more →

IP Cameras vs Analog Cameras, What Are the Differences?

saki shao

In the realm of security and surveillance, the ongoing discussion surrounding IP cameras versus analog cameras holds significant importance for both businesses and homeowners. The choice between an IP camera system and a traditional analog setup can have a profound impact on the effectiveness and scalability of your security measures. This article aims to explore the distinctions between these two prevalent camera types, empowering you to make an informed decision that aligns with your specific surveillance requirements.

Understanding IP Cameras and Analog Cameras

Internet Protocol (IP) cameras refer to all the digital video cameras that can send and receive data via an IP network. They are widely used as video surveillance cameras, and they come in varying designs and capabilities. Some IP cameras need the support of a network video recorder (NVR) for recording and video/alarm management. However, others operate without an NVR, meaning they can record directly to a remote or local storage media. To read more: Technical Guide to IP Cameras - Overview, Types, Applications.

IP cameras encompass all digital video cameras capable of transmitting and receiving data through an IP network. They are widely employed as video surveillance cameras, available in various designs and functionalities. Some IP cameras necessitate the support of a network video recorder (NVR) for recording and managing video and alarms. However, others can operate independently without an NVR, enabling direct recording to local or remote storage media. For further information, please refer to the "Technical Guide to IP Cameras - Overview, Types, Applications."

On the contrary, analog cameras capture images, convert them into analog signals, and transmit them over a coaxial cable to a digital video recorder (DVR). The DVR then converts the analog signals into digital format, compresses the files, and stores them on a hard drive. Below, you will find a comprehensive comparison between an IP camera and an analog camera.

Advantages of IP Cameras

IP cameras provide superior resolutions and scalability, making them ideal for environments that demand comprehensive surveillance coverage over large areas. The transition towards IP-based surveillance has been predominantly influenced by the following factors:

1.Enhanced Resolution and Image Quality: IP cameras generally offer resolutions that surpass those of analog cameras by several magnitudes, resulting in sharper and more detailed images. With the availability of resolutions surpassing 4K, IP cameras deliver the level of clarity necessary for meeting stringent security requirements.

Analog Cameras VS IP Cameras

2. Seamless Integration and Advanced Functionality: By leveraging digital networks, IP cameras have the ability to seamlessly integrate with existing IT infrastructure and services, including cloud storage and sophisticated surveillance software. They offer a wide range of analytical capabilities, such as object recognition, perimeter breach alerts, and other intelligent analytics that leverage video data more efficiently. On the other hand, analog cameras generally lack support for advanced analytics but fulfill basic surveillance functions, such as video recording and live monitoring.

Human Detection
3. Scalability and Flexibility: Thanks to their network-based infrastructure, IP cameras offer effortless integration into existing systems. They support expansive and adaptable surveillance ecosystems that can expand and evolve over time without being constrained by physical connections.
4. PoE Support: IP cameras often have the capability to receive power through the same cable used for data transmission (Power over Ethernet), simplifying installation and reducing the complexity of wiring. This feature eliminates the need for additional power supply units and enables more straightforward and neater setups. In contrast, analog cameras typically require separate power connections.
5. Remote Access: One of the most desirable attributes of IP cameras is the ability to remotely view and manage surveillance footage. Users can access live and recorded videos via internet-connected devices from anywhere in the world, ensuring continuous monitoring and oversight.
6. Advanced Data Protection: IP cameras offer enhanced data protection through encryption and secure network transmission. This ensures that the crucial footage they capture is less susceptible to interception or unauthorized access, addressing a significant concern associated with the more vulnerable transmission methods of analog systems.

Advantages of Analog Cameras

  1. Cost-Effectiveness: One of the primary advantages of analog cameras is their affordability. The initial investment for analog surveillance equipment is typically lower compared to IP-based systems, making them an attractive option for budget-conscious users or smaller-scale operations.

  2. Simplicity and Ease of Use: Analog systems are often considered less complex to install and operate. With a straightforward setup that doesn't require in-depth knowledge of IT infrastructures, analog cameras can be an excellent choice for those seeking a basic yet effective surveillance system. In contrast, IP cameras may have a steeper learning curve for users who are unfamiliar with network technology.

  3. Wide Compatibility: Analog cameras have been in use for decades, leading to a widespread standard of system compatibility. This advantage is particularly valuable when upgrading existing systems, as existing wiring can be reused for new analog cameras.

  4. Low Bandwidth Requirements: Unlike IP cameras, which transmit large amounts of data over a network, analog cameras do not consume significant bandwidth. This results in a lighter load on your network infrastructure and potentially reduced ongoing operational costs.

IP Cameras vs. Analog Cameras: Which is ideal for your business?

Deciding between IP cameras and analog cameras for your business depends on finding the right balance between quality, cost, and ease of use. IP cameras may be the preferred choice if you require high-resolution footage, scalability, and integration with cutting-edge technology. However, if budget constraints are a significant factor and your current infrastructure supports it, analog cameras offer reliability without the need for an extensive overhaul. Ultimately, aligning your selection with your operational needs and financial capacity will ensure a secure and efficient surveillance environment for your business.

Read more →