## 5 Further Challenges and Solutions in 5G and LPWAN-IoT
### Cell Edge Interference Challenges and Solutions in 5G and LPWAN-IoT  
There is cell edge interference in 5G networks and its impact on the end-user devices as the demand for public resources such as IoT, real-time video/virtual reality (VR) applications, and so on increases. Cell edge interference is the overlapping of signals with signals from other cell edge towers. This is bound to occur due to massive MTC in the 5G network. However, the problem of cell edge interference can be mitigated by implementing 5G jointly with a very long-range LPWAN such as LoRaWAN, Sigfox, Weightless-N, etc. Weightless-N is based on a television (TV) white space (WS) or TVWS standard, which operates in a Sub-GHz TV frequency band. It has up to 10 Mbps throughput with a range of over 20 km. Unused TV channels by the Primary Users (PU) are called White Space, which can be exploited by Cognitive Radio (CR) or TVWS technology to serve other devices or Secondary Users (SU). TVWS has a long propagation range with high penetration power rate properties and a high appreciable data rate. Hence, lightweight/low complexity TVWS like Weightless-N can be implemented with a novel strategy in the backhaul/last mile connectivity of a 5G network to overcome interference at the edge and IoT endpoint user. This will create room for wider dispersed cell edge towers deployment, thus, eliminating the closeness of towers that may lead to interference. Detailed research on TVWS is found in [98; 99].  
Furthermore, the problem of cell edge interference and its impact on the end-user in 5G has been investigated in literature from different perspectives. This problem occurs where adjacent cell towers direct radio frequencies (RF) across their target areas [20]. Some of the works involving cell edge interference include [PERSON] et al. [100], who opinedthat overlaying of small cells on macro-cells causes interference which affects small-cell edge users and NB-IoT UEs towards obtaining satisfactory QoS in the NB-IoT network. [PERSON] et al. [101] provided measures based on spectral efficiency, coverage, and capacity over heterogeneous infrastructures such as macro cells and small cells to reduce cell edge interference in NB-IoT.  
Some mechanisms have also been proposed to address this problem. For instance, [PERSON] et al. in [102] proposed advanced interference management for a 5G cellular network based on an elaborated joint scheduling mechanism. In [103], the authors developed a new scheduling technique to increase the probability of assigning the available resource blocks (RBs) to the cell-edge users so that their achieved throughput would increase. NOKIA in [104] developed a smart scheduler to mitigate cell-edge interference by employing the method of Frequency Selective Scheduling (FSS). FSS uses Channel Aware Scheduling (CAS) and Interference Aware Scheduling (IAS) to select non-faded RBs for each user. [PERSON] et al. [105] proposed a practical interference coordination scheme for 5G Cellular Networks based on beamforming and user scheduling. Also, citizen broadband radio service (CBRS) for 5G-IoT uses a strategy called spectrum access services (SAS) to mitigate interference from C-band (3.5-4.2 GHz) [106], though CBRS use cases are predominant in the United States (US).