s. Since the smaller coverage range leads to lighter loads at the small base stations [34], to relieve the macroBSs of the traffic, the users can be offloaded to the smaller base stations operating under open access. The offloading to small base stations may be biased, i.e., in a manner to have a bias towards admitting users [35], or unbiased. To address the issue of load balancing in HetNets, the contemporary cellular standards, e.g., LTE, use cell range expansion [29] using offloading. Offloading also becomes essential in internet of video things devices [36] due to high computation requirements in visual processing which the Internet of video things are unable to handle. 5.3.1 Tier Selection Probability/Offloading Probability Based on Biased Received Power The load balancing in the HetNet can be effectively managed using the concept of biasing within tiers leading to flexible association among the tiers. Assuming open access femtoBSs indicates that a user can select either macroBS or femtoBS tier. Considering selection/offloading based on maximum biased received power (BRP) at the user, the offloading probability from the macroBS tier to the femto BS tier may be expressed as [37] (5.1) where BC and B f represent bias for the macroBS tier and the femtoBS tier, respectively, and dc and af indicate path loss exponent for the macroBS tier and the femtoBS tier, respectively. The rc and rf are distance of user from the macroBS tier and the femtoBS tier, respectively. It must be noted that, since the long-term averaged value is considered, fading is averaged out and, thus, is not included. When the bias factors are equal to 1, i.e., Bm = Bf=1, = it is termed as an unbiased association and is similar to the conventional association, where the user connects to the BS that offers the strongest average power to the user. However, with Bf>1, the range/coverage of the femtoBS tier is extended. 5.3.2 NOMA-Enabled Heterogeneous Networks NOMA and HetNets have achieved immense popularity individually. However, the two technolo