This is a technology which allows to build an efficient multi-hop network based on the sub-GHz low-power wide-area (LPWA) technology.
LoRa, a physical-layer standard that can provide several kilometer outdoor coverage, and concurrent transmission (CT), a recently proposed multi-hop protocol that can significantly improve the network efficiency. It has potential to use in variou situations.
Technology Features, Specifications and Advantages
Routing cannot build wide range network, and takes longer time for packet communication at the time of the reception. Even using concurrent transmission flooding, Re-Tx right after Rx method leads synchronized packet collisions (Fig1).
To solve this situation, we develop CT based LoRa multi-hop network (CT-LoRa) and the performance improvement brought by the proposed offset-CT method. The feature of this technology is as follows (Fig 2).
The receiver performance under CT can be further improved by introducing timing offsets between the relaying packets. In view of this, we propose a timing delay insertion method, the offset-CT method that adds random timing delay before the packets while preventing the timing offset from diverging over the multi-hop network (Fig 3).
This technology can be used for ambient environment sensing using IoT devices.
Use case examples are as follows:
- People flow analysis in wide space such as universities, research institutes, parking lots and so on.
- Temperature monitoring for vast farmland
- Monitoring snow slide of a wide snow park
In other words, this technology can be applied in various situations. More specifically, this technology can be applied to IoT devices where their use is considered to be difficult to implement, such as mountainous areas, parks, and shopping centers.
Low power wide area network (LPWA) including LoRa can be applied in logistic, asset management, smart-meter, infrastructure, ambient environment monitoring, security, smart-building, energy production and so on. The scale of LPWA applicable market is estimated to be 1 billion US dollars in 2021.
This technology suits wide area network environment. One of the biggest obstacles to build wide area networks is how to manage communication in the environment where various impediments exist. Other LoRa technology using single hopping system/routing system has not yet found a clear solution. Application of this technology however makes it possible to communicate even in those difficult environments.
In addition, the high extensibility of this technology allows us to easily expand the network coverage area without any complex operations.