Other Communication Protocols

Many other communication protocol options are available beyond the common and standard Ethernet and wireless solutions. This section includes several you should consider and evaluate for use.

LiFi (light fidelity) is a technology for wireless communications using light. It is used to transmit both data and position information between devices. It uses visible light, infrared, and the ultraviolet light spectrums to support digital transmissions. It has a theoretical transmission rate of 100 Gbps. LiFi has the potential to be used in areas where interference to electromagnetic radiation would be a problem for radio wave–based solutions. Although direct line of sight between devices provides optimum throughput, signals can be transmitted off reflective surfaces in order to maintain at least some level of data transmission (typically around 70 Mbps). However, even with all of this potential, LiFi has yet to gain a foothold in the marketplace. LiFi is limited to shorter ranges than radio signals, is not considered a reliable means of transmission, and is still considerably more expensive than Wi-Fi solutions.

Satellite communications are primarily based on transmitting radio waves between terrestrial locations and an orbiting artificial satellite. Satellites are used to support telephone, television, radio, internet, and military communications. Satellites can be positioned in three primary orbits: low Earth orbit (LEO), 160–2,000 km, medium Earth orbit (MEO), 2,000– 35,786 km, and geostationary orbit (GEO), 35,786 km. LEO satellites often have stronger signals than other orbits, but they do not remain in the same position over the earth, so multiple devices must be used to maintain coverage. Starlink (from SpaceX) is an example of a LEO satellite-based internet service. Starlink has plans to deploy a constellation of over 40,000 satellites to provide global coverage of their internet from space service. MEO satellites are in the sky above a terrestrial location for longer than a LEO satellite. Individual MEO satellites also usually have a larger transmission footprint (area of the earth covered by its transmitter/receiver) than that of LEO satellites. However, due to the higher orbit, there is additional delay and a weaker signal from MEO satellites. GEO satellites appear motionless in the sky, as they are rotating around the earth at the same angular velocity as the earth rotates. Thus, GEO satellites maintain a fixed position above a terrestrial location. GEO satellites have a larger transmission footprint than MEO satellites but also a higher latency. But GEO satellites do not require that a ground station track the movement of the satellite across the sky as is necessary with LEO and MEO satellites, so GEO ground stations can use fixed antennas.

Narrow-band wireless is widely used by SCADA systems to communicate over a distance or geographic space where cables or traditional wireless are ineffective or inappropriate. Use of narrow-band wireless should be monitored and encrypted.

Zigbee is an IoT equipment communications concept that is based on Bluetooth. Zigbee has low power consumption and a low throughput rate, and requires close proximity of devices. Zigbee communications are encrypted using a 128-bit symmetric algorithm.

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Baseband radio is the use of radio waves as a carrier of a single communication. Wi-Fi and Bluetooth are examples of baseband radio. All uses of baseband radio should be identified, monitored, and encrypted.

Cellular Networks

A cellular network or a wireless network is the primary communications technology that is used by many mobile devices, especially cell phones and smartphones. The network is organized around areas of access called cells, which are centered around a primary transceiver, known as a cell site, cell tower, or base station. The services provided over cellular networks are often referred to by a generational code, such as 2G, 3G, 4G, and 5G.

Generally, cellular service is encrypted, but only while the communication is being transmitted from the mobile device to a transmission tower. Communications are effectively plaintext once they are being transmitted over wires. So, avoid performing any task over cellular that is sensitive or confidential in nature. Use an encrypted communications application to pre-encrypt communications before transmitting them over a cellular connection, such as TLS or a VPN.

4G has been in use since the early 2000s and most cellular devices support 4G communications. The 4G standard allows for mobile devices to achieve 100 Mbps, whereas stationary devices can reach 1 Gbps. 4G is primarily using IP-based communications for both voice and data, rather than the traditional circuit-switching telephony services of the past. 4G is provided by various transmission systems, the most common being LTE, followed by WiMAX.

5G is the latest mobile service technology that is available for use on some mobile phones, tablets, and other equipment. Many ICS, IoT, and specialty devices may have embedded

5G capabilities. 5G uses higher frequencies than previous cellular technologies, which has allowed for higher transmission speeds (up to 10 Gbps) but at a reduced distance. Organizations need to be aware of when and where 5G is available for use and enforce security requirements on such communications.

There are a few key issues to keep in mind with regard to cell phone wireless transmissions. First, communications over a cell phone provider’s network, whether voice, text, or data, are not necessarily secure. Second, with specific wireless-sniffing equipment, your cell phone transmissions can be intercepted. In fact, your provider’s towers can be simulated to conduct man-in-the-middle/on-path attacks. Third, using your cell phone connectivity to access the internet or your office network provides attackers with yet another potential avenue of attack, access, and compromise. Many of these devices can potentially act as bridges, creating unsecured access into a company network.