1、Definition of LPWA
lpwa - low power wide area, short for low power wide area technology, uses low power consumption to achieve long distance wireless signal transmission. Compared with the lpwa standardfamiliar low-power Bluetooth (BLE), Zigbee, Wifi technology, LPWA has a longer transmission distance, generally at the kilometer level, and its link budget can reach 160dBm, while BLE, Zigbee is generally below 100dBm. Compared with traditional cellular network technologies (2G, 3G), LPWA has lower power consumption and battery-powered devices can have a lifetime of several years. Based on these two significant features, LPWA can truly enable IoT, helping and leading the Internet of Things (IoT) revolution.
LPWAN - Low power wide area network, i.e. a wirelessly connected enterprise network built using LPWA technology. the LPWAN network system connection structure can be structured in various ways, and the typical topology is shown in Figure 1. uplink) for example, wireless intelligent terminal users send relevant data analysis signals, the base station or gateway receives and transmits these data to the cloud platform, which needs to distribute the data to the corresponding customer management server according to the teaching device ID. For a private LPWAN network, the cloud and the client provisioning server can be one and the same.
2、Characteristics of LPWA
To meet the requirements of IoT applications, LPWA has the following technical features.
Low power consumption
Generally IoT devices cannot be powered directly from the power supply, and battery life is the primary consideration. lpwa optimizes this technology so that battery-powered devices can be used for years. For example, terminals using sigfox technology can be powered by aa batteries for up to 10 years.
For indoor or short-range IoT applications, wireless technologies such as low-power Bluetooth and Zigbee can be used. lpwa targets outdoor or long-range wireless connections with low transmission rates, so the transmission distance is longer, at least at the kilometer level. sigfox uses ultra-narrowband for data transmission, choosing a low transmission rate that allows a link budget of up to 160dBm between the device and the base station, and in signal transmission distance in open areas can reach tens of kilometers.
The popular development of new technologies cannot be separated from the continuous and continuous reduction of business costs, and lower cost management can be improved to make information technology mainly used in more of our fields, especially for price-sensitive applications. The RF module used for LPWA terminals to carry out equipment, with the maturity of science and technology, the popularity of the application, the increase in the number of devices connected, its general through the price under 5 U.S. dollars is expected. And Sigfox technology very early has not been able to completely without reaching the maturity of commercialization, its terminal system module price impact even up to 2 U.S. dollars, the popularity of the technology to play a very important factor role.
The main connection object of traditional wireless cellular network is people, and the connection object of IoT is things, and the number of things must far exceed the number of people, which requires LPWA network to have a larger capacity. Avoid network congestion and interference between devices. A single base station in a Sigfox network can handle millions of device messages per day, and can receive and process nearly 300 messages at the same time with a packet loss rate of only 0.5%, ensuring high QoS.
In addition to the above remarkable technical features, Lpwa usually has low speed and high latency.
3、LPWA Application Scenario
LPWA technology can be used in many IoT application scenarios to realize the digitization and intelligence of industries, thus further improving efficiency and saving cost, and promoting the improvement of labor productivity of the whole society.
Its typical application scenarios are
Logistics enterprise positioning and tracking - real-time reporting of logistics center location and status for information
Asset management - asset positioning and inventory status reporting
Intelligent meter reading meter number and status report
Smart city-intelligent detection of lighting, traffic, infrastructure, smart parking, etc.
Smart China Agriculture-Livestock tracking enterprise management, soil environment detection, smart irrigation, etc.
Environment/utilities-disaster detection, smog, air pollution, equipment condition, elderly care, etc.
Smart home-smart home appliances, home security system, state detection report, etc.
4、Typical LPWA technology
According to the nature of wireless spectrum usage, LPWA can be divided into two types of technologies: licensed bands and public bands.
Public bands typically include Sigfox and LoRa, which use the public ISM bands without paying spectrum management fees, but there are still some governments that design and regulate the use of spectrum to ensure that different IT developments in enterprises can achieve mutual compatibility, similar to BLE and Wifi, etc.
Licensed bands for cellular IoT technology, the use of specific dedicated wireless bands authorized by the government requires payment of spectrum fees, traditional telecom operators are the main body to deploy and operate the network, technical specifications based on cellular network technology. And the distribution is dominated by 3GPP.
Founded in 2010, sigfox technology, designed and developed by the French company of the same name sigfox, is one of the oldest lpwa players with the highest level of technical maturity. By 2019, it is commercially available in more than 60 countries worldwide. sigfox uses 100 Hz ultra-narrowband spectrum to modulate and transmit data information in the common band, thus offering higher power density per unit band and better resistance to interference, making it suitable for data transmission in the common band.
Sigfox offers complete network solutions, including base stations and cloud, and seeks and relies on local partners to deploy and operate the network globally. sigfox provides network equipment and technical support services. The terminal is an open ecosystem, and any RF module or chip that supports the Sigfox protocol can access the Sigfox network, which can provide terminal equipment manufacturers with more choices and better pricing options. Relying on a strong global ecosystem, Sigfox users can get an end-to-end (terminal to cloud) total solution that enables their products to quickly access the Sigfox network and hit the market.
Because the Sigfox network is analyzed by Sigfox as the leading company for global strategic deployment, this can ensure the unity and stability of the quality of the information network technology service products to the maximum different extent, that is, one global network, users manage their devices that can enjoy the convenience of transnational, no roaming services, and can connect to the same quality of network, which is especially useful for the development of our logistics or cross-border This is particularly attractive for applications such as logistics development or cross-border economic operation in China.
LoRa is a special technology from Semtech, which is actually a wireless modem technology using a spread spectrum scheme. Semtech acquired the intellectual property of LoRa in 2012 through the acquisition of Cycleo, a French company that designs, manufactures and markets RF chips. Semtech is a pure semiconductor company with a monopoly on the supply of LoRa chips. Currently, while Semtech also licenses a small amount of LoRa IP, such as Ali in China, the IP is Semtech's proprietary IP and no company is licensed to design and manufacture LoRa chips, so customers have no choice.
Lora also transmits RF signals in the common frequency band. The upper layer protocols and specifications are defined by Lorawan and published and maintained by the Lora Association. Anyone can buy a lora chip or module to design a lora terminal or gateway device, or they can design or buy a device to build a lora network, so most of the current lora networks are small and private, with few nationwide universal iot networks, and compatibility between devices and networks is a major challenge.
LoRa achieves high sensitivity through spread spectrum technology, which enables long-distance transmission. However, network capacity is limited to efficiently achieve parallel reception and processing of information from a large number of devices, which is a great challenge for large-scale or nationwide deployment.
Currently, the mainstream Cellular-IoT (C-IoT) technologies in China refer to NB-IoT and LTE-M, both of which are based on China's traditional cellular mobile network information technology, with data tailoring and optimization to apply to low-cost and low-power design applications for IoT. The technical management specifications are defined and distributed by 3GPP, based on enterprise proprietary licensed spectrum, and can be analyzed by traditional international telecom service operators for network system deployment and operation.
Since C-IoT is based on traditional cellular network technology, its technical complexity, corresponding cost and power consumption are higher than new LPWA custom technologies such as Sigfox, similar to 3G/4G, etc. C-IoT end devices also need to connect to base stations, perform protocol handshakes, and configure network parameters. In contrast, Sigfox end devices do not have any dependency on the base station and have higher independence and controlled power consumption. In addition, due to the attachment of the base station, NB-IoT is actually only applicable to application scenarios where the device location is fixed.
From a global perspective, c-iot networks are decentralized in nature, and each operator can only deploy to operate in one regional country or area with different network parameter configurations and quality of service. For example, nb-iot networks support more than a dozen bands, allowing different countries or regions to use different bands, which is more costly and technically challenging for end devices. Quality of service cannot be unified and guaranteed across different networks, and switching between networks requires higher roaming costs. nb-iot networks do not even support roaming.
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