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The IEEE 802.11 set of specifications, commonly referred to as Wi-Fi, is the most widely used wireless communication technology found in fog computing. Since Wi-Fi infrastructure is widely deployed in homes, offices, public spaces, and so forth, it is the natural choice for fog-thing and fog-UE communication, with the fog node hosting the Wi-Fi AP.

The standards 802.11n and 802.11ac, for instance, have a typical data rate of 200 and 400–700 Mbps respectively, the typical range of 802.11 routers in the 2.4 GHz band can be up to 50 m [37]. The next generation 802.11ax promises to enhance data rates further, but it is unlikely that significantly higher coverage range will be achieved in practice, due to the recent versions using the 2.4 and 5 GHz bands.

Interestingly, advertising capabilities of 802.11 can be improved by including additional information (e.g. fog node capability and status) in the 802.11 advertising beacons [38].

The mentioned signal coverage ranges are suitable in domains where the client device mobility speed is low; consider, for example, pedestrians in UE-fog. Additionally, the smartphones already employ the technology. Existing UE-fog research that does not include real-world technology choice and simply consider the data rate aligns with the capabilities of wi-fi. For example, even 6.9 Gbps rates [39] are theoretically supported by 802.11ac. In terms of existing research prototypes, laptop hotspots are a common choice to establish the wi-fi AP [40–42]. Since laptop hotspots generally operate with 802.11n technology, it is important to consider the newer standards in future fog prototypes.

In UAV-fog, following the mFog concept, a wi-fi AP could reside at UAV node or, alternatively, static 802.11ac APs may act as sink nodes supporting a group of UAVs [16].

IEEE 802.11p, a.k.a. wireless access in vehicular environments (WAVEs) is adapted for the wireless environment with vehicles. In addition, they are designed in such manner that they are very suitable for single hop broadcast V2V communications; however, this technology suffers from an issue related to scalability, reliability, and unbounded delays due to its contention-based distributed medium access control mechanism [23, 43].

For maritime use cases, the coverage ranges offered by Wi-Fi are generally not suitable. However, Wi-Fi is useful in vessels for onboard networks where the clients are crew and passengers, but such scenarios can be categorized rather as UE-fog.