Mobile data continues to eat up 3G network capacity as smartphones have driven a massive uptake in apps and Web use. There are many ways an operator can combat the crunch, from building new cell sites to policy control and optimization. But with the proper OSS requirements in place, offloading traffic to a Wi-Fi or femtocell network emerges as the best solution from an efficiency standpoint.
Solving this requires an understanding of certain mobile data realities. For one, the 3G infrastructure required to deliver data services to smartphones is creaking at two main points: radio and backhaul. Wireless spectrum is a limited resource. Radio technology continues to improve the efficiency of transmission and reception, but there are limits to how many bits can be packed into a radio stream.
Further, network congestion is caused disproportionately by users. AT&T, for instance, has acknowledged a 5000 percent growth in data in the last three years. More importantly, the top 3 percent of smartphone users are consuming 40 percent of network capacity. They are consuming 13 times the data of an average smartphone user.
The Case for Offload
Scaling network capacity is only masking the problem. While providing a broader delivery pipe, most users realize a fractional benefit as a few consumers will continue to hog the increased bandwidth. Optimization is a promising solution as it helps in flow-control, but it is costly and raises privacy issues.
Offload on the other hand provides an alternate path with a best performance capability. If traffic for a bandwidth-hogging user is offloaded to an alternate overlay network, it will relinquish bandwidth for other consumers on the macro network. Alternately, a user competing for bandwidth from a loaded macro site can be offloaded to an alternate network. These networks can function with the macro-cellular network as an adjunct network either operating independently or as an overlay network. Both femtocells and Wi-Fi networks have their merits as candidates for offloading networks.
Femtocells leverage the licensed spectrum, offer better indoor coverage at lower power and work with common single-radio handsets. The challenge is that they have yet not reached widespread availability. This will take a few more years to reach pervasiveness. Wi-Fi offers the advantage of using the unlicensed spectrum, which means there are fewer spectrum planning and refactoring issues. Access points and hotspots are ubiquitous, with MNOs such as AT&T, T-Mobile, Orange and Vodafone owning a large footprint. Smartphones have made Wi-Fi availability and ease-of-use an attractive feature to consumers.
Wi-Fi Data Offload
A growing number of smartphone users are already using the Wi-Fi path to access Internet services. Is that not data offload? On the contrary, it is a network bypass from the mobile network. Service providers need to use this to their advantage or risk losing all. The important point to understand is that Wi-Fi simply provides an access transport. The alternate path the service provider uses to deliver data must conform closely to existing service standards.