By David John Urban, Comcast
It is a thing of beauty when two interdependent technologies arrive at the same time wherein each needs the other to deliver service to customers. Such is the case with the newest cable modem standard for Data-over-Cable Service Interface Specification DOCSIS 4.0 and Institute for Electrical and Electronic Engineers (IEEE) 802.11be standard Wi-Fi 7. Two technologies under development for many years coming out of the lab and into customer homes. Wi-Fi 6 and 6E wireless adapters in many phones, computers and tablets have a maximum physical symbol, PHY rate of 2400 Mbps, (million bits per second). With a 2400 Mbps PHY rate throughput of file downloads, speed tests can reach 1.2 gigabits per second (Gbps). Wi-Fi 7 increases the modulation to 4096-QAM, quadrature amplitude modulation, and the channel width to 320 MHz, million cycles per second, resulting in a 2x2 client wireless adapter with a maximum PHY rate of 5764 Mbps, enough PHY rate for a throughput of 4.6 Gbps. About one and a half years ago, the first laboratory trials of DOCSIS 4.0 demonstrated speeds faster than 4 Gbps upload and download. This paper will describe the underlining technology propelling Wi-Fi 7 based on the IEEE 802.11be standard that will allow the speeds delivered by the DOCSIS 4.0 cable modem and the DOCSIS 4.0 infrastructure sending the signal to the cable modem to be delivered all the way to customer phones, tablets, and computers. In addition to higher order modulation and wider channel width, Wi-Fi 7 adds key technology to improve the range in the 6 GHz, billion cycles per second, band. Improving the range in the 6 GHz band is just as important as improving the speed. After all, high speed in the 6 GHz band is not much good to customers if they need to use another band to maintain coverage. Dual carrier modulation, duplication of dual carrier modulation, increased transmit power at 320 MHz channel width, and improved receiver sensitivity are key aspects of Wi-Fi 7 to improve the 6 GHz band range. This paper explains how modulating two carriers within a 20 MHz block of spectrum and duplicating these 20 MHz blocks results in improved dynamic range and better coverage. The paper provides measured results in both the lab and customer homes showing DOCSIS 4.0 and Wi-Fi 7 are perfect together.