With the rapid progress of network technology, the data transmission rate of Ethernet, which is represented by it, has increased nearly 1,000 times in the past 10 years. In 1999, the IEEE formulated the Ethernet specification 1000BASE-T with a data transmission rate of 1G bit/s using twisted pair cables, which has now become one of the must-have standard configurations for high-end personal computers.
With the rapid popularization of 1000BASE-T, people’s attention turned to Ethernet whose data transmission rate was increased to 10G bit/s (hereinafter referred to as 10G bit Ethernet). This is because, in general, the data transfer rate of a local area network composed of network devices and servers connected to each other should be more than 10 times higher than that of a local area network composed of personal computers connected to each other.
10GBASE-T Chip Comes Out
Against the above background, the 10GBASE-T specification for 10Gbit Ethernet using twisted pair cables was quickly put on the agenda. In March 2004, the US Solar Flare Communications announced that they had successfully developed an integrated circuit chip that can be used to manufacture 10G bit/s twisted pair cable transceivers. In the same month, the IEEE802.3an working group meeting to formulate the 10GBASE-T specification was held in the United States. At the conference, nearly 10 large and innovative companies and research institutes submitted their specification proposals for 10GBASE-T. The working group decided to finalize the first draft of this specification in July 2004 and complete the final specification in the first half of 2006.
The 10G bit Ethernet that has been used at present includes 10GBASE-LR using optical fiber and 10GBASE-CX4 using 4-pair coaxial cable. Compared with 10GBASE-LR, 10GBASE-T does not have to use optical communication modulators, thus reducing the cost; compared with 10GBASECX4, the transmission distance is only 15m, the maximum transmission distance of 10GBASE-T can reach 100m.
10GBASE-T Cable
10GBASE-T cannot be achieved with ordinary cables. In order to realize the maximum transmission distance of 100m and the transmission rate of 10Gbit/s with twisted pair, a higher technical threshold must be crossed.
The IEEE802.3an working group pointed out in November 2003: According to the specification of twisted pair cables, the precondition for deciding the 10GBASE-T standard is that the currently widely used Category 5 lines and Category 5e lines cannot be used. In this way, there are only Category 6 and Category 7 cables suitable for high-speed transmission. According to the working group, it is difficult for Category 5 and Category 5e cables to achieve a data transfer rate of 10G bit/s due to their high attenuation rates for high frequency components. The maximum transmission distance using Category 6 cable is 55m to 100m; when using Category 7 cable, the maximum transmission distance is 100m.
The exclusion of Category 5 and Category 5e will inevitably have a large impact on the future of 10GBASE-T, since the popularity of the former Category 6 and 7 cables was not high at that time. Mr. Otsu Mitsuo, director of LAN systems of Japanese cable manufacturer Communications Industrial Corporation, said: “Even in the United States, which used Category 6 cables for the first time, as of the first quarter of 2004, only 50% of the cables laid use Category 6 cables. In Japan, by the end of 2004, only about 20% of the cables are expected to use Category 6 cables.” According to the forecast of the IEEE802.3an working group, by the end of December 2005, in the Ethernet laid globally, 34% of the Ethernet cables will use Category 6 cables. Category 7 cable is only 0.4%. This means: In order to access 10GBASE-T Ethernet, the rest of the users have to re-cable. For users who modify the LAN, the cost burden will be larger. However, the popularization of new technologies will inevitably go through a relatively difficult transition period. It is foreseeable that 10GBASE-T will eventually become popular.
