Wider-Bandwidth Operation of IEEE 802.11 for Extremely High Throughput: Challenges and Solutions for Flexible Puncturing

This paper aims to explain the wideband operation of IEEE 802.11, illustrate the challenges for wider-bandwidth support, and propose solutions. First, we describe the wideband operation of conventional IEEE 802.11 systems and the low-efficiency problem related to their contiguous channel-bonding limitations. Next, we describe how the puncturing of IEEE 802.11ax supports noncontiguous channel bonding. After that, we discuss the challenges of the limited bandwidth patterns of puncturing as a tradeoff problem between signaling overhead and transmission bandwidth. Using wider bandwidth facilitates a larger amount, thus a longer airtime, of resource-unit allocation information. To reduce this signaling overhead, splitting and delivering the information over multiple channels can be considered, but with the increased difficulty to find all of these channels available at the same time. We investigate this tradeoff problem based on a simple mathematical analysis and numerical data. We propose adaptation of the signaling structure for resource-unit allocation in either a statistical or opportunistic manner such that signaling of full resource-unit allocation information is made with minimal overhead. Comparative evaluation results are provided and analyzed for dense deployment and traffic load scenarios, demonstrating that the proposed adaptation always outperforms the conventional and static methods in terms of both bandwidth utilization and throughput.