Cellular Communication for EC Stations

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Instructions for configuring an EC system for cellular communication.

Although LI-COR® provides cellular communication systems that are certified for many regions of the world, you may need to provide your own cellular modem in some situations. If you provide your own cellular modem (referred to as gateway henceforth), this technical note will help you configure the cellular gateway and instruments in your LI-COR eddy covariance (EC) system. For areas without cellular service, satellite options are also available from LI-COR.

Gateway Specifications

The basic specifications for compatible cellular gateways are given below.

  • Operating temperature and humidity range suitable for outdoor environments.
  • Ethernet socket (female RJ45 terminal).
  • TCP/IP communication and port forwarding (DNAT).
  • Input voltage range compatible with power supply at site.

To use your modem, the modem must fit in a 20.3 cm x 15.2 cm x 10.2 cm space with room to connect the antenna, power, and Ethernet cables.

Data Plan Requirements

You must arrange a data plan with a cellular service provider that has coverage at your station.

  • The cellular service provider should provide a public static IP address.
  • The data plan must support machine-to-machine (M2M) communication.
  • If a public IP address is not available, you can get data service through a mobile virtual network operator (MVNO).
  • If you get a dynamic IP address, use a Dynamic Domain Name Server (DDNS) to resolve the IP address.

Your data plan should cover the amount (GB) of data that you will transfer over the cellular network. For example, do you want to view small summary files showing the overall performance of your system, or do you want to transfer all your raw data files over the cellular network?

Table 1. Suggested data volume for LI-COR eddy covariance systems.
Sensors Files to Transfer Data Plan
Basic EC System Status Reports and Final Flux Results <1GB per month
Basic EC System Raw Data <2GB per month
EC System with LI-7700 or Biomet System Raw Data <3GB per month

Cellular Communication Components

For a station that includes a LI-COR Biomet Enclosure or Systems Enclosure, we recommend the components indicated in Table 2. Some will be included with your communication system, if acquired from LI-COR.

Figure 1. Cellular communication setup for an EC station with a biomet system.
Table 2. Recommended communication system components.
Description Part Number
Weatherized communication enclosure with mounting hardware na
High-gain Cellular Antenna 609-13832
Antenna Cable (4.6 m; 16.4 ft) 380-13839
Antenna Mounting Post (1.5 m; 4.9 ft) 9879-064
Network Switch 616-16771
Gateway Mounting Bracket na

The bracket is used to mount the modem and Ethernet switch inside the biomet system enclosure. It is specific for AirLink® LS300, but you can mount any modem with zip ties, adhesive mounting tape, or adhesive hook-and-loop; or install a DIN-mountable modem and switch to a segment of DIN rail (part number 6579-023).

EC System Network Configuration

Set unique IP address for each instrument in your system so it is compatible with your gateway (similar to the addresses given in Table 3)1. Port numbers for EC instruments are pre-configured as shown.

Gateway Configuration

Use the software provided with the gateway to configure the gateway. Typically, the software is accessed through a web browser. The gateway must have Port Forwarding enabled for each instrument that is in the system2. The port should be forwarded to the IP address that you set for each instrument in your system and the port given in Table 3.

Table 3. Example IP addresses and ports for instruments.
Sensor Example IP Address Ports
Personal Computer: (optional) 192.168.1.200 na
LI-7500DS or LI-7200RS: 192.168.1.201 7200, 22
LI-7700: 192.168.1.202 7700
Biomet System 192.168.1.203  
LI-8100A: 192.168.1.204 1526