Dat verhaal klopt niet. Docsis 3.0 is namelijk nog altijd gebaseerd op een bepaald frequentie bereik. Er is iets van 37 Mhz beschikbaar voor upstream en 70 Mhz voor downstream. Dit is ooit zo gekozen omdat het het internet gewoon anders werd gebruikt en de beschikbare frequenties beperkt zijn.
De enige manier dat Ziggo 1:1 verbindingen met Docsis 3.0 kan leveren is door je simpelweg minder download te geven voor hetzelfde geld. Daar wordt dus niemand beter van en dat is zeker niet iets om aan te moedigen. Je moet het zo zien dat je nu 'gratis' 400 Mbit download krijgt bij je 40 Mbit upload.
Met Docsis 3.1 gaat in eerste instantie uit van 10 Gbps down met 1-2 Gbps up. Echter cablelabs heeft in 2017 al full duplex docsis 3.1 aangekondigd waarmee 10 Gbps bij 10 Gbps mogelijk wordt. Tevens zitten er standaard meer mogelijkheden voor subcarriers in.
Full Duplex DOCSIS 3.1, this technology can, if proven to be successful, enable a new range of use cases that may require significantly more upstream traffic than is typical today.
Cable networks are today architected using frequency division duplex, meaning that bandwidth is divided on the network between upstream and downstream to prevent interference between traffic flowing in opposite directions. In general, much more bandwidth is allocated to the downstream usage, in the direction of the end user. That approach is consistent with current consumer broadband usage patterns. Video streaming, for instance, is largely a one-way application with most data traffic flowing downstream to the viewer. According to Sandvine, downstream traffic today makes up between 90 to 95 percent of all broadband data – on fixed networks of any type, including FTTP – during the busiest peak periods.
As the Internet continues to evolve, applications may take hold that require greater upstream bandwidth, including augmented reality, fully immersive video conferencing, and other interactive gigabit services. With Full Duplex DOCSIS 3.1 technology, CableLabs and its cable operator members are advancing capabilities to accommodate the continued evolution of broadband Internet access.
The global cable industry is researching and encouraging application innovations as gigabit networks continue to evolve. The Internet has fundamentally transformed communications and many aspects of society, and cable has played a significant role in facilitating its growth. Innovation in cable broadband technology will continue to enable the numerous benefits of Internet access.
Appendix A: DOCSIS 3.1 Technology Highlights
DOCSIS 3.1 is the latest cable broadband network technology. Specified by CableLabs in 2014, technology vendors are now producing compliant equipment and operators have begun to deploy the technology. DOCSIS 3.1 technology is backward-compatible with prior generations, enabling the flexibility for operators to deploy it over their footprint consistent with demand and other market factors.
DOCSIS 3.1 technology offers top-line potential capacity of 10 Gbps downstream and 1-2 Gbps upstream through a variety of mechanisms that make cable broadband more efficient and higher performing.
DOCSIS 3.1 architecture is designed to enable the provision of broadband over hybrid fiber/coaxial cable networks. The frequency range enabled spans from 5 MHz to 1218 MHz. This provides 1.2 GHz of network bandwidth to offer 11 Gbps of total network capacity (combined downstream and upstream). In addition, DOCSIS 3.1 technology enables the flexibility to use up to 600 megahertz of additional bandwidth to drive total capacity even higher.
Upstream traffic uses the lower portion of the frequency duplex cable system, with an upper band edge configurable to between 42 and 204 MHz. Many North American cable systems today have an upper band edge of 42 MHz, while European systems use a 65 MHz upper band edge. Configuring the upstream band edge to 204 MHz fully enables the upstream gigabit capacity of DOCSIS 3.1 networks. Downstream traffic uses the upper portion of the duplex system, and a guard band is enabled to prevent interference between upstream and downstream traffic.
DOCSIS 3.1 channels span 192 MHz on the downstream and up to 96 MHz on the upstream. Orthogonal frequency division multiplexing (OFDM) is used with subcarriers as small as 25 kHz, which aids flexibility and resiliency of the network.
To increase capacity, channels can be aggregated across the full range of network bandwidth. However, services other than broadband, including television and voice, also utilize segmented capacity on cable networks today.
OFDM techniques of DOCSIS 3.1 technology enable more efficient operation of cable broadband by ensuring that small subcarriers on the network can independently make adjustments to their operation depending on the state of the channels in operation. Without OFDM, larger portions of bandwidth would be limited to the ‘lowest common denominator’ of what can be achieved in operational circumstances.
In addition, the technology utilizes low density parity check (LDPC) forward error correction as well as quadrature amplitude modulation (QAM) up to 16384 bits per symbol (with a minimum of 4096 QAM required by the specification) to enhance efficiency. Both represent significant advances in broadband communications technology, enabling the reliable provision of more data per unit of bandwidth. By comparison, 4096 QAM makes broadband networks two times more efficient on a bits per hertz basis relative to 64 QAM. LDPC enables higher performance to be realized more consistently than previous error correction techniques.
The DOCSIS 3.1 specification also enables increased energy efficiency, with cable modems entering ‘light sleep’ mode during periods of low utilization.
The DOCSIS 3.1 specification requires that packets carrying subscriber traffic are capable of encryption using asymmetric and symmetric keying algorithms between the cable modem and the cable modem termination system. In addition, cable modems are authenticated using a public key infrastructure (PKI) digital signature. The cable PKI ecosystem is operated by CableLabs using a single root certificate. Security is reinforced with certification by CableLabs, which ensures that the security features of the specification are present. This approach to security has been a foundation of DOCSIS technology since its initial release, and encryption algorithms have continued to get stronger with reach new generation.
The specification also supports authenticating software image downloads used for updating the device. The technology does this through a digital signature process known as public key cryptography, which authenticates that software originates from trusted sources. This architecture applies to all DOCSIS 3.1 deployments, enabling secure broadband infrastructure on a global scale.
Though network capacity is often the first metric used to characterize broadband performance, latency, or the time between transmission and reception, also has bearing on user experiences. DOCSIS 3.1 technology uses advanced techniques to reduce latency on cable broadband networks.
The latency that a user experiences is influenced by a range of factors in the transmission of data across the Internet, many of which may be upstream of cable access networks. At every intermediate network node between packet origination and destination, routers, switches, and other network devices play a role in delivering data. Each node must assess data packets and make decisions about how they are to be forwarded. As data traffic bursts, network equipment may create a brief queue or ‘buffer’ before traffic is routed.
To enable network responsiveness and low latency even during periods of heavy traffic, DOCSIS 3.1 broadband employs an active queue management (AQM) technique that monitors the ‘buffer’ of traffic at cable modem termination systems and cable modems. This technique reduces latency by influencing the behavior of the Transmission Control Protocol (TCP) that underlies the Internet. By intelligently dropping data packets, AQM invokes TCP’s ability to balance throughput, latency, and packet loss based on the conditions of the links and networking devices along the path of data transmission. This approach improves user experiences by helping to significantly reduce latency during busy periods on the cable broadband segment of the network of networks that comprise the Internet. AQM was made available to DOCSIS 3.0 broadband systems, and is mandatory in the DOCSIS 3.1 specification.
Full Duplex DOCSIS 3.1
CableLabs and its members are currently developing an enhancement to DOCSIS 3.1 technology that will enable symmetric 10 Gbps capacity. Known as Full Duplex DOCSIS 3.1, this development offers the ability to move beyond current frequency division architecture, instead using the full bandwidth available on cable networks for both upstream and downstream transmissions, simultaneously.
In the frequency division approach used today, a smaller proportion of bandwidth is allocated to upstream transmissions, constraining upstream performance relative to downstream. Full Duplex would eliminate this limitation through simultaneous transmission of downstream and upstream traffic on the same frequencies at the same time. This is accomplished through intelligent transceiver design that enables interference cancellation by utilizing knowledge about transmission to subtract noise from signal. Since the transceiver knows what it is transmitting, Full Duplex will use that information to process out noise and recover the intended received signal. Full Duplex will provide substantial increases in total capacity over either time division duplex, which is used in DSL, or frequency division duplex, which is currently used in cable networks.