Questions and Answers on VaiNet (LoRa-based) Wireless Data Loggers

You probably can’t increase your link budget mechanically. If you are using a commercially available system, the transmission power and receiver sensitivity* are things that cannot really be adjusted by the end user. For example, to try to change the antenna on the AP10 would void the FCC and ETSI certifications for the AP10. The best way to decrease your link losses is by moving devices closer together.  It won’t increase the link budget, but it will allow a signal to better overcome obstacles.

*Receiver sensitivity is the lowest power at which the receiver can detect an RF signal. Sensitivity is a receiver specification and is independent of the transmitter.

The three networks used to network data loggers to viewLinc, Ethernet, Wi-Fi, and VaiNet, are technologies as they are used to connect a monitoring sensor to the existing network of servers in your LAN or Intranet. The core of that network is going to operate on Ethernet cables or fiber optics.  This is true, even for a cloud-based system.  The core will be Ethernet-based.  But how we connect to that core network is changing fast.

See the viewLinc network connectivity guide. 

Most applications that use LoRa® technology involve data being sent from your device over a public network, like a cell tower, in order to get to the server on your local network. This can involve two risks:  sending your data over the public network, and having to provide a doorway from the public network into your private secure LAN.

VaiNet uses LoRa® but in a fully private network. You can think of the AP10 access points as miniature cell towers that are completely private; this ensures a closed network and secure data.

Yes, 100 meters is the actual range we are seeing in usage.  In fact, its often as high as 200 meters, especially when we move into more open spaces like warehouses. Only one test implementation showed a real-life range of under 100 meters…  In that case it was a museum in an old stone building, the signal was slower to penetrate the 8-foot thick stone walls. Despite the walls, we still achieved better range than any of the other competing systems in that test.  What's most exciting is that this range is achieved by a device using two normal AA batteries that last for a year and a half.

The RFL100 housing is classified IP54 to protect the device from dust and cleaning. The optional HMP110 probe has a higher rating of IP65.  The AP10 Access Point has a rating of IP30.

The  RFL100 data loggers with temperature and humidity and temperature only use 2 AA alkaline batteries. Typical battery life for the AA batteries is 18 months.  There is a small lithium CR1/3N clock battery.  This battery has less than 0.3g of lithium and is safe to ship, as it is exempt from shipping restrictions due to its small size, and because it is already installed in the device.  This clock battery has an expected lifetime of 10 years. All batteries may be changed out by the customer as needed. 

The RFL200 for CO₂ data loggers use an external power supply with lithium battery backup (22 hours). Learn more in the RFL100 CO₂

Automatic failover in VaiNet occurs when a RFL series logger can’t connect with its preferred AP10 access point.  It will immediately initiate a series of 4 retries at which point it find another AP10.  If another AP10 is available and in range, the RFL will switch over automatically.  This process could take up to 10 minutes. For more details on how the loggers work together - here is an Application Note on VaiNet.  And here is a viewLinc system Connectivity Options technical note.

No.  The AP10 can only be used as a gateway in a VaiNet implementation to connect our RFL-Series loggers with a Vaisala viewLinc Monitoring System.
 

In a WiFi network, the signals are between the sensors and the WiFi gateway use TCP/IP Ethernet protocols to communicate wirelessly.  It is essentially, wireless Ethernet. The rest of the Ethernet-based LAN uses the same protocols.  The two side of the network speak the same language, and a malicious signal on the wireless side could easily continue onto the wired side. In order to build in security, you must add a firewall or take some specific action.  In a VaiNet network, the wireless network between the sensors and the AP10 uses LoRa® modulation and protocols, while the rest of the LAN uses Ethernet protocols.  Since the communication protocols are so vastly different, there is not direct connection between the wireless side and the wired side. If a LoRa® protocol message somehow did make it over to the Ethernet side, it would just be nonsense.
 

A standard VaiNet system can have up to eight access points (AP10) and up to 256 wireless dataloggers on a single site. VaiNet systems are easy to plan and deploy because every access point and data logger can be freely positioned. The signal is extremely reliable and performs well in almost any environment, including sites that are challenging for wireless connections.

Large systems that require more than eight access points can use channel sharing, which means an access point will use two channels. Field testing and laboratory measurements show that VaiNet wireless connections tolerate channel sharing well. Systems with up to 32 access points and up to 1,024 data loggers can be deployed on a single site so long as the guidelines for setting up large systems are followed.

See the guidelines for large VaiNet systems in this Technical Note.
 

The AP10 access points and the viewLinc Server are typically on the same wired Ethernet network, so no backhauling is really necessary. 
 

VaiNet doesn’t replace cables in existing equipment.  It does make cables unnecessary in new installations!
 

In our initial offering of the RFL100, it will come with a single combination probe that measures both temperature and humidity.  Future logger versions will incorporate a variety of probe types and measurements. Contact your local sales representative to learn more about upcoming RFL options.
 

You should see 12 months of battery life with alkaline batteries. If you need to operate at lower temperatures down to -20°C, then we recommend you upgrade to lithium AA batteries to get 12 months of battery life.  The best practice for cold environment is to get the RFL100 with the sensor on a cable and place the sensor only in the cold environment, while keeping the data logger in an ambient temperature environment.
 

Most of the interference or attenuation in heavy foliage will come from the water content in the vegetation itself.  You may have already noticed that a signal that does fine going through the trees in clear weather will get blocked on a rainy day when the leaves are covered with water.  Water, as a general rule, will easily absorb high frequency radio waves.  868 MHz will perform better than 2.4 GHz, because the lower frequency will lose less energy to the water.  You should see better performance (less absorption by water) as you lower the frequency.  Your best path may be to do some practical tests to see if the devices you want to use function well in your forest environment. Interestingly, we have RFL100s installed in a foliage situation. This is detailed in our release on the RFL data loggers installed at a zoo. The data loggers monitor both the enclosures, and the bamboo that is the food of the pandas. Read more...

Vaisala's Cutting-Edge Wireless Technology Monitors the Wellbeing of the Pandas in Ähtäri Zoo in Finland  

 No. The RFL100 data loggers were designed for in situ monitoring.  Theoretically, could use them to monitor the shipping of temperature-sensitive products, but they would have to be protected from direct contact with the product.
 

The RFL data loggers that are currently available are used with the HMP110 and HMP115 intelligent temperature and humidity sensors.  Future models of the loggers may incorporate other Vaisala intelligent probes, but they will likely be probes that are used for various industrial measurements, rather than weather measurement.

Note: The PWD22 is a weather sensor, the CL31 is a cloud height ceilometer, and the HMP155 is a temperature and humidity probe.
 

See our other blogs addressing commonly asked questions on VaiNet: 

• VaiNet Wireless Monitoring More Q&A
• Regulatory round-up with the latest on VaiNet