Recently, Huawei released the world's first NB-IoT commercial version eRAN13.1 based on the 3GPP R14 protocol. Compared with the previous version, eRAN 13.1 can provide four times the user rate, twice the cell capacity, twice the cell coverage, and the location service. It explores the road to comprehensive replacement of the GPRS Internet of Things.
Since the NB-IoT protocol was frozen, NB-IoT has quickly occupied the low-power and wide coverage of the IoT market with its unique features of large capacity, low power consumption and deep coverage. As of May 2018, 45 NB-IoT commercial networks have been deployed worldwide, and more than 500,000 base stations have been built. 40 use cases such as wireless meter reading, cattle network, smart manhole cover, wireless smoke, and smart door locks have been deployed in batches. More than 10 million NB-IoT connections have been widely used in urban management and personal life.
Now, NB-IoT has been recognized by 3GPP and GSMA as the Internet of Things technology in the 5G era, and will be evolving in the low-power and wide coverage of the IoT market. However, with the continuous development of the Internet of Things market, NB-IoT's first-generation R13 protocol can no longer meet the demand for NB-IoT performance in the increasingly rich IoT applications. For example, asset/pet tracking requires low power positioning to reduce equipment cost and frequency of charging. Furthermore, due to the low spectral efficiency of GPRS, an IoT technology capable of supporting high communication rates is needed to replace GPRS to accelerate the re-cultivation of the GSM spectrum.
To this end, in the R14 protocol, 3GPP defines the NB-IoT performance enhancement feature, Huawei eRAN 13.1 is the world's first commercial version based on the R14 protocol:
First, seven times the user rate: the uplink peak rate is 157 kbps, and the downlink single-user peak rate is 102 kbps, which has the ability to fully replace the GPRS application at the single-user rate.
Second, twice the cell capacity: the maximum number of users in a single cell can reach more than 80,000, close to twice the capacity of the R13 protocol cell, providing strong support for connecting all things.
Third, double cell coverage: Huawei's unique uplink channel estimation enhancement technology enhances the deep coverage capability of the cell and reduces the cost of operators investing in network construction.
Fourth, GPS-independent positioning: The terminal does not need to integrate GPS module, the positioning accuracy can be as low as 50 meters, the power consumption and positioning delay are only half of the GPS solution, which can better serve asset tracking, logistics and transportation. Application scenarios such as pet tracking.
Chen Chuanfei, vice president of Huawei's LTE product line, said: "In the next few years, the gradual construction of full-service capabilities has become the consensus of global operators. The Internet of Things will become the best practice for operators to deepen vertical industries. This NB-IoT commercial based on R14 Released to improve the performance of the NB-IoT network in terms of user rate, cell capacity, and cell coverage, and extend the application range of NB-IoT through location services. In 2018, Huawei will improve network performance based on NB- The IoT Open Lab and the Local Industry Alliance, in-depth ecological construction and business exploration, together with operators and partners to open the golden age of IoT-scale commercial use."
Semiconductor Fuse And Ferrite
Fuse refers to an electric appliance that, when the current exceeds the specified value, melts the fuse and disconnects the circuit with the heat generated by itself.When the current exceeds the specified value for a period of time, the fuse melts and disconnects the circuit with the heat generated by the fuse itself.A current protector made from this principle.The fuse is widely used in high and low voltage power distribution system and control system as well as power equipment.
Ferrite is a metal oxide with ferrous magnetism.As far as electrical properties are concerned, the resistivity of ferrite is much larger than that of single metal or alloy magnetic materials, and it has higher dielectric properties.Ferrite magnetic energy also shows high permeability at high frequencies.As a result, ferrite has become a non-metallic magnetic material widely used in the field of high frequency and weak current.Due to the low ferrite magnetic energy stored in the unit volume, saturated magnetic induction strength (Bs) and low (usually only pure iron 1/3 ~ 1/5), and thus limits its higher requirements in the low-frequency magnetic energy density in the field of high voltage and high power applications.
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