Communications in Complex Environments
Communication networks are the enabler for Industrial M2M technology
M2M devices must be able to transmit data to an open architecture across different physical media depending on their availability.
For the dialogue between machines, industrial devices have standardized industrial protocols to ensure the correct transmission of information. These protocols require physical media to carry information.
Physical media. Network selection
Factors for network selection
- Network availability
- Process criticality (high network availability and/or communication redundancy)
- Reliability
- Usage cost
- Maintenance cost
- Bandwidth
- Energy consumption
- Standardization
- Security
Unlicensed band ISM digital radio networks
What are they: ISM (Instrumental, Scientific and Medical) networks are radio communication networks operating on unlicensed bands. They are used by well-known technologies such as Wi-Fi and Bluetooth.
Advantages:
- Links up to 10 km long are feasible in the unlicensed band of 868 MHz 500 mW
- No license required
- Los usage and maintenance cost
- Limited energy consumption
- Good availability
- Allows a high node density in delimited areas
- Scalable system
Disadvantages:
- Requires repeaters to cover some areas
- Requires installation of infrastructure (antennas, masts, cables, etc.)
- Low bandwidth and speed
- Emission power levels are limited, depending on national regulations
Long range digital radio networks
What are they: They are communication networks operating in frequencies assigned by the government. Power levels for base stations and mobile stations are high and allow communications at distances of tens of kilometres.
Advantages:
- The average range of a radio modem is up to 50 km approx.
- They allow big areas to be covered
- Good availability
- Low usage cost
- Scalable system
Disadvantages:
- A license is required to operate these frequencies
- They require investment in infrastructure
- Low bandwidth and speed
GSM/GPRS/3G networks
What are they: GSM/GPRS/EGPRS and 3G networks allow voice and data communications up to 2Mbps. They are operator solutions. The latest version of 4G or LTE technology enables speeds up to 150 Mbps.
Advantages:
- Easy installation
- Wide bandwidth and speed
- IP-based
- Proven technology
- Scalable system
- Standard system and interoperable between terminals
Disadvantages:
- High power consumption
- Availability depends on operator
- Cost for connection usage
- GPRS coverage reduced and unstable, especially in rural areas
SigFox network
What is it: SigFox is an independent, ultra-narrowband, low speed cellular network for short messages. It features a low consumption and has the capacity to connect millions of devices.
Advantages:
- Very low power consumption
- Easy installation
- Does not require gateways (direct from sensor to cloud)
- It accepts unlimited points
- Does not require a private infrastructure to be developed
- Cloud-based
- Very low usage cost
- Suitable to extract information from isolated points
- Long range
- Scalable system
Disadvantages:
- Very low bandwidth and speed
- Unsuitable to transmit big data volumes
- Proprietary protocol
- Expanding network (low coverage September 2014)
Cybersecurity
Devices connected to Internet can be vulnerable. We must have systems that guarantee availability, integrity and confidentiality.
The equipment must include Security features such as access protection to COM ports, HTTP access protection, HTTPS and SFTP access, integrated firewall, IEEE802-1X protection, Open VPN Server/Client and APN Support.
The system must guarantee that data entering the Centralized Management System are real, both its value and the time when they occurred.
