25Gbit/s-SFP28&QSFP28 copper cable interconnection technology rise


Published:

2019-01-06

OFweek, March 6, 2013 - Recent technological advances in copper cable components have made them a more viable option for high-speed applications. As Bishop & Associates states, designers prefer to use familiar copper cable interconnect technologies and are developing expertise in channel design, simulation and circuit board layout to continue to expand bandwidth; A few engineers are happy to predict the ultimate performance limits of copper cable connector products.

25Gbit/s-SFP28&QSFP28 copper cable interconnection technology rise

OFweek, March 6, 2013 - Recent technological advances in copper cable components have made them a more viable option for high-speed applications. As Bishop & Associates states, designers prefer to use familiar copper cable interconnect technologies and are developing expertise in channel design, simulation and circuit board layout to continue to expand bandwidth; A few engineers are happy to predict the ultimate performance limits of copper cable connector products.

Cable integration, power and heat management are inherent challenges in today's data centers, which consist of enterprise servers and storage applications. The increasing bandwidth requirements of data centers require copper cable transmission rates to continue to increase, and the introduction of 25Gbit/s channels is a game changer. The high-speed 25Gbit/s copper cable products implemented in the prototyping phase now offer a higher bandwidth option than traditional copper cables and are cheaper in terms of cost than fiber optic connections.

Copper cables adhere to short - and medium-distance wired network applications

Although optical fiber has become a popular medium for long-distance network communication, copper cable connections are still a more cost-effective solution for short - and medium-distance applications. From a design point of view, optical media also pose challenges, including thermal and power management. Passive copper cables meet the needs of low-cost, low-power, short-distance (1 to 7 m) applications, and are often the best solution for stand-alone systems or between fiber optic and structured copper cable wiring. About 90% of wired communications are currently used at distances of three meters or less, including most data connections in highly efficient computing systems.

Network system data centers often use a mix of fiber optic modules and copper cable components. Professional system designers can easily integrate and optimize a system to take advantage of the advantages of both fiber and copper modules. For data center wiring, high-speed passive 25Gbit/s copper cables offer cost - and efficient-competitive solutions, including Top-of-rack, Middle-of-rack, and for connecting to data storage servers.

When retrieving and transferring data from memory, the high density cable must be fast enough to meet the varying peak demand. Increasing the density of the front panel I/O bandwidth allows the data center to increase capacity without requiring additional floor and rack space, and engineers can achieve higher speeds by increasing port density on the panel. For a single high-speed connection, the current passive copper cable transfer rate of 10Gbit/s would require 10 wires to reach 100Gbit/s. Increasing each wire to 25Gbit/s would reduce the number of wires needed from 10 to four, saving valuable space and developing higher density front panel I/O.

The 100Gbit/s standard specification was born

Every element of the Netcom system will be the key to the transmission rate of the high-speed copper cable. Channels must be evaluated against changes in time, process, and temperature. The challenge to interoperable high speed electrical performance increases exponentially as the speed increases. While 10Gbit/s has an error margin in the specification, interoperability cannot afford the same buffer in 25Gbit/s channels.

In July 2008, our iPass+ HSC CXP dual-switch card system supporting plug-in copper or fiber was selected as the InfiniBand CXP 12x QDR standard, which is also adopted by IEEE 802.3ba. As a 100Gbit/s Ethernet network standard, ten 10Gbit/s Ethernet cables are provided.

This final standard for high-speed copper cables differs significantly from other IEEE 802 standards. Although 802.3ba contains the 100G specification, until now there was no standard to support Ethernet on backplane media at 100Gbit/s operating rates. However, the industry community has recognized the ability of 100Gbit/s backplanes and twin-axis copper cable connections to achieve desired density, power and cost goals for computer networking systems and equipment. bit/s

Since the advent of the IEEE 802.3ba standard, the market has seen significant improvements in connectors, switching card design, Connector Launch, Conductor Termination, and Raw Cable, The 25G copper cable element incorporates these design improvements into these critical areas. The small, plug-in I/O system provides eight 25Gbit/s data rate lines (four in each direction) and uses transceivers and oscilloscopes to show the transmission performance of a 3-meter passive cable through the Eye Pattern. bit/s

At high frequencies, the next generation 5 m 25Gbit/s copper cable assembly has better differential insertion losses than the current 3 m 10Gbit/s copper cable assembly (Figure 1). In terms of Integrated Crosstalk Noise (ICN), the results obtained according to the 802.3ba standard calculation show that, compared with the 3-meter product, the noise of high-speed 5-meter cable is reduced by about 50%(FIG. 2). The improved ICN also gives the 5-meter 25Gbit/s copper cable a better Signal-to-noise Ratio (SNR). With the improvement of SNR, the interconnection signal integrity is improved.

FIG. 1 Differential insertion loss performance of the next generation 5-meter cable element is better than that of the current 3-meter cable element at high frequencies.

Figure 2 The next generation cable element provides crosstalk improvement and noise reduction of more than half compared to the current 3 m cable element.

Passive copper cable with low power characteristics

Passive copper cable components use very low power compared to fiber optic connector products. At a peak of 3.3 volts (V) and less than 30 milliamps (mA) (typical value of 3mA), significant power savings and low power consumption are equivalent to less heat, thereby reducing heat-related performance problems. Passive 25Gbit/s copper cables have a market advantage in local area networks (Lans), data centers and storage applications because of their low power consumption, which can help enterprises solve energy and heat dissipation problems and further reduce operating costs.

A valuable suggestion is that the price per passive copper cable may be reduced by a factor of less than 3 compared to optical modules and cables of 7 m or less. In terms of design flexibility, passive copper cable components contain only one electronically erasable programmable Read only memory (EEPROM) electronic component, and can therefore provide a mean time between failures (MTBF) that may be ten to fifty times longer than optical cable components.

Component level model to solve the noise problem 25Gbit/s copper cable price ratio to improve again

Trade-offs are inherent in linear selection and design, whether for fiber or copper transmission. While optical fiber is good for long distance operations, copper cables are the solution of choice for shorter cable length applications, especially in the future when high-speed 25Gbit/s copper cables become a more attractive option.

However, there are still unmet challenges between the linearity and commercial viability of 25Gbit/s copper cables. For designers looking at 25Gbit/s copper cables, the main considerations are high frequency loss and noise, and the main consideration is the SNR margin.

Component suppliers are working together to provide designers with accurate and predictable component-level models and End-to-end channel models to achieve appropriate cost performance in the new 25Gbit/s systems.

Manufacturers and industry analysts engaged in the development of high-speed copper cables have recognized the importance of copper cables and how advanced signal conditioning technology can extend the life of existing components while stimulating the development of next-generation copper cable interface products that can be mass-produced.

High frequency wide applications in full swing 25Gbit/s copper cable market accelerated to take off

The boom in Cloud Computing, the Internet of Things, high-performance computing applications, server virtualization, and converged networking will continue to drive demand for blade and rack-mounted server connectivity products with higher frequency and width, All this is conducive to the development of a cost-effective and efficient 25Gbit/s copper cable connection market.

The 25Gbit/s copper cable prototype is currently under review and testing, and is expected to be mass-produced in the next three to five years. In addition, full interoperability of 25Gbit/s copper cables will require appropriate component specifications, clear definitions and accepted compliance methods, as well as continued cooperation from all parties.
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