Which DOCSIS version was the first to allow an increase in the top frequency of the upstream spectrum to 85 MHz?

DOCSIS 3.0 was significant in the evolution of data over cable systems as it enhanced the upstream and downstream capacity significantly. One of its key features was the expansion of the upstream frequency spectrum, which was increased to accommodate frequencies up to 85 MHz. This enhancement allowed for greater data bandwidth in upstream communications, which is useful for applications like video conferencing, online gaming, and other interactive services that require significant upload speeds. The increase in upstream capacity marked a notable improvement in the performance of cable modem systems, enabling providers to offer better overall service to customers. This change in DOCSIS 3.0 set a strong foundation for subsequent versions, which continued to enhance both upstream and downstream capabilities.