5G Wi-Fi offloading is all about relieving the congested mobile data networks with additional capacity from unlicensed Wi-Fi spectrum.
Analysts agree that as the industry moves toward 5G, Wi-Fi becomes more important, not less important. Wi-Fi already provides near ubiquitous coverage, 5G performance for both speed and capacity densities, at a fraction of the cost of 5G deployments.
Consequently, the popular opinion is that operators must incorporate Wi-Fi offloading as part of their 5G strategy.
Several technologies have emerged recently that involve cellular data traffic offloading to Wi-Fi, however, LTE-Unlicensed (LTE-U) and License-Assisted Access (LAA) are the most notable.
LTE-U performs adaptive duty cycling with Carrier Sense Adaptive Transmission (CSAT), and adapts according to the Wi-Fi traffic load. But it does not perform Listen Before Talk (LBT).
LAA on the other hand does perform LBT, hence, it is considered to be better in maintaining fairness with Wi-Fi devices. Both LTE-U and LAA operate in 5GHz band and have been standardized in 3GPP Rel-12 and Rel-14 respectively.
Several studies have tried to analyze the fairness between LTE-U/LAA and Wi-Fi. The FCC report on the coexistence of LAA and Wi-Fi indicated that LAA could adversely affect throughput of Wi-Fi in an unfair manner. The fairness between Wi-Fi and LTE-U/LAA was investigated and it was concluded that when configured optimally, LTE-U and LAA could provide the same level of fairness as other Wi-Fi devices.
In the 3GPP Release 16, the standardization body has specified a function of the 5G core called ATSSS which manages the convergence between 3GPP-networks (such as 5G) and unlicensed 3GPP networks (i.e., Wi-Fi), turning heterogeneous networks into one converged network.
ATSSS (Access Traffic Steering, Switching & Splitting) (fig. 3) offers new capabilities to deliver an improved user experience for the Seamless Handover use case. In support of such Wi-Fi offload our focus is on Steering & Switching.
In some situations, neither Wi-Fi nor cellular networks deliver a stable connectivity. Therefore, the Splitting feature can be useful as it improves reliability of the connection by combining available wireless access.
Want to learn more? Tonex offers 5G Wi-Fi Offload Training, a 2-day course that provides an in-depth technical overview of emerging Wi-Fi offload solutions applicable to 5G macro cells and HetNets applications. Wi-Fi is considered as a key alternative access network technology in 5G deployment.
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