There are a lot of wireless communication technology for Internet of things, mainly divided into two categories: one is short-range communication technology, such as Zigbee, WiFi, Bluetooth, Z-wave and so on; the other is LPWAN (low-powerWide-AreaNetwork, low-power wide area network), that is, wide area network communication technology.

The rapid development of Internet of Things puts forward higher requirements for wireless communication technology. LPWAN, which is designed for low-bandwidth, low-power, long-distance and large-scale connected Internet of things, is also rising rapidly.

Internet application costs need to consider a number of factors such as node cost, network cost, battery life, data transfer rate (throughput), latency, mobility, network coverage, and deployment type. The two technologies, NB-IoT and LoRa, having different technical and commercial characteristics, but also having the most promising two low-power WAN communication technology. These two LPWAN technologies having the characteristic of widely covered, more connection, low speed, low cost, low power consumption and so on, which are suitable for low power consumption networking applications and are actively expanding their own ecosystem.

Brief for NB-IoT, LoRa

NB-IOT (NarrowBandInternetofThings, NB-IoT, also known as narrowband Internet of things), is a technical standard defined by the 3GPP standardization organization and one kind of narrowband RF technology designed for the Internet of things; LoRa (LongRange) is a ultra-long distance wireless transmission program based on a spread spectrum technology and adopted and promoted by the United States Semtech company. LoRa network mainly composed of the terminal (built-in LoRa module), gateway (or base station), Server and cloud four parts, and the application data can be two-way transmission.

NB-IoT, LoRa using band

NB-IoT uses the authorized band, there are three deployment methods: independent deployment, protection zone deployment, inband deployment. The world's mainstream bands are 800MHz and 900MHz. China Telecom will deploy NB-IoT in the 800MHz band, while China Unicom will choose 900MHz, and China Mobile may be re-existing 900MHz band.

LoRa uses a license-free ISM band, but the ISM band usage varies from country to country. In the Chinese market,China’s LoRa Application Alliance (CLAA) leading by the ZTE recommended the use of 470-518MHz. However the radio meter uses a band of 470-510MHz. As LoRa is working in the license-free band, without the need to apply for network construction, and the network architecture is simple with low operating costs.

Communication distance for NB-IoT, LORA

NB-IoT communication distance

The coverage of the mobile network depends on the base station density and link budget. NB-IoT having a 164dB link budget, link budget of GPRS is 144dB, LTE is 142.7dB. Compared with GPRS and LTE, NB-IoT link budget has a 20dB increase, with the open environmental signal coverage can be increased by seven times. 20dB is equivalent to the loss of the signal passing through the building wall, and the signal coverage is relatively better for NB-IoT indoor environment. In general, the communication distance of the NB-IoT is 15 km.

Communication distance for LoRa:

LoRa offers a maximum 168dB link budget with its proprietary patented technology. In general, the wireless distance in the city is 1-2 km, the wireless distance in the suburbs can be up to 20km.

Cost comparison between NB-IoT and LoRa

No matter how strong for LPWAN agreement, it also needs to consider its low cost, otherwise they could not be viable for the solution program of Internet of Things. LoRa has an advantage in this area. The overall cost of the LoRaWAN module is around $ 8-10, which is about half the price of a cellular LTE module such as NB-IoT. The higher the complexity of the NB-IoT network, the higher the cost of intellectual property-related (authorized bands) and the overall cost of NB-IoT. NB-IoT upgrades to advanced 4G / LTE base stations are more expensive than LoRa passing through industrial gateways or overhead gateway deployments. As the market being more and more mature, the cost of LoRa technology is expected to decline in the further.

NB-IoT and LoRa are still in the initial stages of development, with the need for all inputs and common development. When large-scale deployment becomes possible, the module costs for NB-IoT and LoRa will be further reduced. In terms of technical solutions, in a short period of time, NB-IoT and LoRa will certainly be parallel, have their own advantages and shortcomings, it is difficult to say who overriding who; however, if you are affected by factors other than technical solutions, such as profit model innovation, and which should be close intergrated with the application of the industry, relying on the influence of the industry, then everything would be possible. In the new wave of the development of the market for Internet of things, firstly landing the project, and then it can win the opportunity to step forward. NB-IoT and LoRa not only need product innovation, but also need the application of project innovation.

CLEARED UP BY LI GANG