Why is LoRa vs Wifi positioning technology?
There are various wireless technologies applied in industrial personnel location systems, which can form local area networks or wide area networks. Today we will mainly discuss the Lora vs Wifi positioning technology difference.
Here have 7 basic positioning technology principles
Proximity detection positioning technology
Description
The proximity detection method is determining the presence of a mobile device in the vicinity of a transmitting point by the reception of some physical signals with a limited range.
Features
This method can only provide approximate positioning information, but its deployment cost is low and easy to set up, so it is suitable for some applications that do not require high positioning accuracy, such as automatic identification systems for employee check-in in companies.
Center-of-mass localization positioning technology
Description
Based on the location of all known beacons within the range of the mobile device, the center-of-mass coordinates are calculated as the coordinates of the mobile device.
Features
The method is easy to understand, the calculation is small, and the positioning accuracy depends on the density of beacons.
Multilateral localization positioning technology
Description
The position of the target to be measured is determined by measuring the distance between the target to be measured and a known reference point.
Features
High accuracy and wide application
Triangulation positioning technology
Description
This method is to determine the position of the target to be measured by obtaining the angle of the target to be measured relative to two known reference points and then combining the information of the distance between the two reference points to determine the unique triangle.
Features
High-accuracy and wide application
Pole positioning technology
Description
By measuring the distance and angle relative to a known reference point, the method only needs to determine the position of the point to be measured.
Features
The coordinates of the position of a reference point are known, so it is easy to use and has been widely used in geodesy.
Fingerprint positioning technology
Description
A database of fingerprints is created in the positioning space, and positioning is achieved by comparing the actual information with the parameters in the database.
Features
The advantage of fingerprint positioning is that there is almost no need for reference measurement points and the positioning accuracy is relatively high; however, the disadvantage is the huge workload of establishing fingerprint databases offline in the early stage and the difficulty of adapting to scenes with large environmental changes.
Aerial position projection positioning technology
Description
It is based on the known_previous position, and the current position is obtained by calculation or known movement speed and time calculation.
Features
It has stable data, no dependency, but the method has a cumulative error and the positioning accuracy deteriorates with time.
How about the LoRa vs Wifi positioning technology?
About Wi-Fi of LoRa vs Wifi positioning technology
Wi-Fi is a relatively mature and widely used technology, and many companies have invested in this field in the past few years.
There are mainly two kinds of WiFi indoor positioning technologies: proximity detection method and triangle nail violation.
WiFi positioning of LoRa vs Wifi positioning technology generally uses the proximity method to determine which hotspot or base station is closest, that is, what location it is considered to be in. If there are multiple sources nearby, cross-positioning (triangulation) can be used to improve positioning accuracy.
Since WiFi is already popular, there is no need to lay down special equipment for positioning. Users who have turned on Wi-Fi and mobile cellular networks while using smartphones may become data sources. The technology has the advantages of easy scalability, automatic data update, and low cost, so it was the first to achieve scale.
However, WiFi hotspots can be more affected by the surrounding environment and have lower accuracy. In order to do accurate positioning, some companies have done WiFi fingerprinting, recording huge amounts of signal strength of the identified location points in advance, and determining the location by comparing the database with the signal strength of newly added devices that have huge amounts of data.
Since the collection requires large numbers of personnel to carry out and regular maintenance, the technology is difficult to expand and few companies can update the fingerprint data regularly for so many shopping malls in the country.
Data collection is greatly affected by the environment, especially for personnel positioning, due to the environmental changes, the positioning drift phenomenon is particularly serious.
Disadvantages of wifi positioning technology in LoRa vs Wifi positioning technology
WiFi positioning technology can achieve complex wide range positioning, convenient networking, and easy to set up in the existing wireless wifi network.
Wifi positioning technology can be used in medical institutions, theme parks, factories, shopping malls, and other occasions that require positioning navigation.
The disadvantages of Wifi positioning are also obvious, mainly in the following aspects.
1) The wifi tags used for Wifi positioning are non-standard designs, only the data format refers to 802.11b format, which does not support the standard wifi protocol.
Wireless routers do not support the scanning wifi tag function and require secondary development of the router, i.e. loading wifi tag scanning firmware in the router.
Some wireless routers support the wifi scanning function to get the MAC address of the wifi tag, other functions defined by the wifi tag are not supported. For example, wireless sensing, button calls, low-power alarm, etc.
These are non-standard protocols, standardized routers do not support non-standard protocols.
2) Wifi tag power consumption is large, continuous emission current in more than 200ma, and battery life limits the promotion of the use of wifi positioning tags.
3) The cost of Wifi tags is relatively high, which is not conducive to significant commercial promotion.
4) Wifi positioning has a serious problem of co-channel interference, and the systems will affect each other.
LoRa of LoRa vs Wifi positioning technology
LoRa technology is one of the LPWAN communication technologies, which is an ultra-long-range wireless transmission solution based on spread spectrum technology adopted and promoted by Semtech in the United States.
This solution changes the previous compromise between transmission distance and power consumption and provides users with a simple system that can achieve long-distance, long battery life, and high capacity, thus extending the sensing network.
Currently, LoRa operates mainly in global free bands, including 433 MHz, 868 MHz, 915 MHz, etc.
The LoRa network mainly consists of four parts: Terminal (which can have a built-in LoRa module/antenna), Gateway (or Base Station), Server, and Cloud. Application data can be transmitted in both directions.
Generally speaking, transmission rate, operating frequency band, and network topology are the three main parameters that affect the characteristics of the sensing network. The choice of transmission rate will affect the transmission distance and battery life of the system.
The selection of the operating frequency band is a compromise between the frequency band and the design goals of the system; and in FSK systems, the selection of the network topology is determined by the transmission distance requirements and the number of nodes needed for the system.
LoRa incorporates digital spread spectrum, digital signal processing, and forward error correction coding technologies to deliver unprecedented performance.
Previously, only those high-level industrial radio communications would incorporate these technologies, but with the introduction of LoRa, the landscape in embedded wireless communications has changed forever.
Forward error correction coding technology is the addition of some redundant information to the sequence of data to be transmitted, so those erroneous code elements injected during the data transmission process are corrected in time at the receiving end.
This technique reduces the previous need to create self-healing packets for retransmission and performs well in resolving bursty error codes caused by multipath fading.
Once packets are built and forward error correction coding is injected to ensure reliability, the packets are sent to a digital spread spectrum modulator.
This modulator feeds each bit of the packet into a spreader, dividing each bit of time into numerous code slices.
Even with high noise levels, LoRa can handle it comfortably, and the LoRa modem can be configured to divide in the range of 64-4096 code slices/bit, using up to the highest spreading factor (12) of 4096 code slices/bit.
In contrast, ZigBee can only divide the range of 10-12 slices/bit.
By using a high spreading factor, LoRa technology can transmit small volumes of data over a wide range of radio spectrums. In fact, when you measure it through a spectrum analyzer, the data looks like noise, but the difference is that the noise is not correlated.
The data is correlated and based on this, the data can actually be extracted from the noise. The higher the spreading factor, the more data can be extracted from the noise.
In a well-functioning GFSK receiver, a minimum signal-to-noise ratio (SNR) of 8 dB is required to reliably demodulate the signal. With the AngelBlocks configuration, LoRa can demodulate a signal with an SNR of -20 dB, and the GFSK approach differs from this result by 28 dB, which corresponds to a much larger range and distance.
In an outdoor environment, a difference of 6dB can achieve 2 times the original transmission distance.
Therefore, using LoRa technology we can get a wider transmission range and distance with low transmitting power, and this low-power wide-area technology is exactly what we need.
The features of LoRa in LoRa vs wifi positioning technology
- Open transmission distance of 8000 meters
- Operating frequency: 169/315/433/470/868/915MHz optional
- Sensitivity up to -139 dBm -139 dBm
- TTL/232/485 level interface
- Up to 40 communication channels
The emergence of LoRa wireless communication technology has made a new breakthrough in wireless communication distance, bringing new development space for IoT applications and providing technical support for some applications that require long-distance.
LoRa antennas are used in remote meter reading, security systems, access control systems, real-time positioning, and other fields.
Positioning technology is blossoming, each has its own advantages and disadvantages. After compared of LoRa vs Wifi positioning technology, we find that the LoRa transmission method is the most suitable, there is no best technology, only the most suitable.
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