… We also identify several research challenges in these promising design trends that beyond-5G
… trends and associated research challenges in beyond-5G networks in Sections IV and V. …

… We discuss all the fundamental challenges related to pilot contamination, channel estimation,
… issues that direct future research in massive MIMO systems for 5G and beyond networks. …

… and aerial access networks can bring manifold benefits, [5]–[7]: i) extend 5G services in … ;
ii) improve the 5G service reliability and continuity; and iii) enable 5G networks scalability and …

… (5G) and beyond networks creates various non-conventional communication challenges
and … In this regard, the authors in [43] highlighted the current and future trends of VR systems …

… UDNs in 5G and beyond wireless networks, discuss approaches and techniques to overcome
the obstacles when accomplishing the resource allocation, and debate challenges as well …

… security challenges in wireless networks, mainly in 5G, and … 5G with regards to their
corresponding security challenges … into security in communication networks beyond 5G, named as …

… mission-critical cases, and predecessor’s limitations [38]. The future 5G networks demand
a new and stringent mobility management mechanism [39]. The rising trend for the mobility …

… , ultra-massive MIMO, and extremely dense network show this trend as well. In this survey, …
moves on to beyond-5G, we present the works on beyond-5G and 6G networks that may be …

… The current research on systems beyond 5G indicates that these applications shall be … -called
network slicing [18] and enables different services that go considerably beyond what was …

… projects beyond 4G … trends show that the future 5G-IoT network should be capable of
supporting the massive connectivity of devices by providing high and consistent QoS. A 5G network …