Comparative analysis of LoRa and NB-IoT, who is better
LPWAN technologies such as LoRa provide communication-level support for the development of the Internet of Things. At present, China's domestic LPWAN industry is mainly divided into two camps. NB-IOT is getting closer and closer to large-scale business, while LoRa has blossomed everywhere. There are many factors to consider for applications, such as node cost, network cost, battery life, data transfer rate (throughput rate), latency, mobility, network coverage, and type of deployment. It can be said that no single technology can meet all the needs of IoT. The NB-IoT and LoRa technologies have different technical and commercial characteristics, so there will be different application scenarios. The difference between the two will be explained here, and the suitable application scenarios of each will be explained.
At present, from the perspective of industrial development, a complete industrial chain has been formed consisting of seven links: chips, modules, terminals, communication equipment, platforms, operators and applications. The editor has collected a piece of NB-IoT and LoRa in The comparison chart of the market concentration of each link, let us take a look at the difference between the two from this perspective.
Frequency bands, quality of service and cost
LoRa works in the unlicensed frequency band below 1GHz, so there is no additional charge for application. NB-IoT and cellular communications use licensed frequency bands below 1GHz. The frequency band between 500MHz and 1GHz is the optimal choice for long-distance communication, because the actual size and efficiency of the antenna are quite advantageous.
LoRaWAN uses free unlicensed frequency bands and is an asynchronous communication protocol, which is the best choice for battery power and low cost. LoRa and LoRaWAN protocols have unique characteristics in handling interference, network overlap, scalability, etc., but do not provide the same quality of service (QoS) as cellular protocols. It is reported that the auction of the authorized Sub-GHz frequency band is more than 500 million US dollars per MHz. Cellular networks and NB-IoT do not offer the same battery life as LoRa due to quality of service (QoS) concerns. Due to QoS and high frequency band usage fees, cellular networks and NB-IoT are recommended for application scenarios that need to ensure QoS. LoRa is a good choice if low cost and a large number of connections are preferred, as shown in the figure below.
Battery Life and Downlink Latency
The concept of cellular network design is optimal frequency band utilization, which sacrifices node cost and battery life accordingly. On the contrary, LoRaWAN nodes are born for low cost and long battery life, and there are certain deficiencies in frequency band utilization.
There are two important factors to consider in terms of battery life, the current consumption of the node (peak and average current) and the protocol content. LoRaWAN is an asynchronous ALOHA-based protocol, which means that nodes can sleep long or short according to the needs of specific application scenarios, while nodes of synchronous protocols such as cellular must be regularly networked. For example, mobile phones on the market now have to synchronize with the network every 1.5s when working. In NB-IoT, this synchronization becomes less frequent but still occurs regularly, which consumes additional battery power.
Modulation in cellular networks is an effective means of making full use of frequency bands, but it is not efficient from a node perspective. Cellular modulation (OFDM or FDMA) requires a linear transmitter to generate the modulated signal, and a linear transmitter requires orders of magnitude more peak current than nonlinear modulation, and higher peak currents consume more power from the battery .
But the synchronous communication protocol has advantages in terms of shorter downlink delays, while NB-IoT can provide fast data transfer rates for applications that require large data throughput. And Class B of LoRaWAN shortens the delay of downlink communication by periodically (programmed) waking up the terminal to receive downlink messages.
Therefore, NB-IoT may be a better choice for applications that require frequent communication, short delay or large data volume, and for scenarios that require lower cost, higher battery life and infrequent communication Say LoRa is better.
Network Coverage and Deployment Timeline
The essential requirement of node operation is network coverage. An obvious advantage for NB-IoT is that network deployment can be provided by upgrading existing network facilities, but this upgrade is limited to certain specific 4G/LTE base stations, and Higher cost. And this upgrade is only suitable for urban areas that already have 4G/LTE coverage, and is not suitable for remote or suburban areas without 4G coverage.
The entire industry chain of LoRa is relatively mature, and the products are also in a state of "ready to go". At the same time, many countries around the world are in the process of or have completed nationwide network deployment. A prominent advantage of the LoRa industry chain is that members of each link have autonomy, and some large companies are planning to create a hybrid business model to deploy networks and applications. However, the NB-IoT industry chain will be limited by frequency bands and operators.
Equipment Costs, Network Costs and Hybrid Models
For end nodes, the LoRaWAN protocol is simpler than NB-IoT, easier to develop and more suitable and compatible with microprocessors. The modulation mechanism and protocol of NB-IoT are more complex, which requires more complex circuits and more costs. At the same time, NB-IoT is taxed like 3GPP. At this stage, the tax for a mobile phone is about $5, but this is too expensive for IoT devices, and if the tax is rashly reduced, it will cause price confusion in the mobile communication market such as mobile phones. Therefore, how the 3GPP organization weighs the tax issues of IoT and mobile communication is also a big problem.
Low-cost, relatively mature LoRa modules can already be found in the market, and upgraded versions will follow. The LoRa Alliance does not have too many restrictions on copyrights and taxes, making the module less than $4 in the LoRa industry chain very impressive. The price of LoRa modules on the market today is generally 7-10 US dollars, but as the technology matures, 4-5 US dollars is not a big problem. And now an LTE module is hard to come by for less than $20.
Compared with the traditional "iron tower" network, the deployment of IoT and LPWAN requires the use of different models to reduce expenditure and operating costs. LoRaWAN deployment is less expensive as it can be done using traditional cell towers, industrial base stations or even portable home gateways. At this stage, the price of a tower base station is about US$1,000, the price of an industrial base station is less than US$500, and the price of a home gateway is only about US$100. But for NB-IoT, the price of upgrading existing 4G LTE base stations is conservatively estimated to be no less than $15,000 each.