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Currently operating cellular networks target the requirements of the 4G standard (also known as IMT-Advanced), specified by the International Telecommunication Union (ITU) in 2008 [44]. For instance, the requirements suggest 100 Mbps data rates for clients moving at high speeds (e.g. in a train) and 1 Gbps for stationary situations.

Among technology standards accepted as fulfilling the 4G requirements are IEEE 802.16m (WiMAX v2) and 3 GPP Long Term Evolution-Advanced (LTE Advanced), the latter of which has seen far bigger deployment and thus is the common option for existing mobile fog.

To supersede 4G, the ITU is defining requirements for the 5G networks, also called IMT-2020. The 2017 draft of technical performance requirements [45] notes peak data rates of 20 and 10 Gbps for downlink and uplink, respectively, and specifies channel link data rates for four different mobility classes. 5G also specifically targets supporting cases where the density of devices is large, growing from 4G's 10⁵–10⁶ devices km⁻² [46].

5G networks are enablers for smart collaborative vehicular network architecture since they provide possibilities for fulfilling the requirements of reliability, handover, and throughput of future vehicular networks [47]. LTE D2D-based VANET has proven to be suitable for the safety-critical IoV applications, thanks to their effectiveness in coping with high mobility and precise geo-messaging [43].

The MEC paradigm has introduced the handover and migration of VMs to the cellular base stations for supporting the UE [48–50], however, the similar idea potentially applies to the other mobile fog domains.

In maritime fog systems, the shore-located cellular base stations can be leveraged to also act as sink nodes [4, 51], gathering sensor data from the vessels. Multiple access techniques, such as nonorthogonal multiple access (NOMA) offered by 5G, are considered useful for UAV cloudlets to maximize efficiency [52]. However, generally 4G/5G coverage is available in more urban areas, so for marine communication at sea or UAV deployments in remote areas, alternatives such as satellite communication need to be considered.