Gigabit Ethernet standards compared

In fiber optic network environments one of the mostly used technologies is the Gigabit Ethernet. Gigabit Ethernet is also known as 1000BASE, GbE or 1 GigE. Gigabit Ethernet has been defined by the IEEE 802.3-2008 standard and is 10 times faster than the previous standard, 100BASE Ethernet. Gigabit Ethernet is mostly used in the access layer for providing faster connection for end customers. There are various Gigabit Standards with different capabilities.

1. 1000BASE-T is the Gigabit standard for copper connections. It has a reach capability of 100 meters over Cat. 5E, 6 and 7 cables. With this standard the connection runs on all four pairs of the cable for simultaneous transmission, however only two pairs are used for the link negotiation. This could eventually cause a problem because if two devices are connected with each other with a cable with only two pairs, the devices will successfully choose “gigabit” speed but the link won’t come up. With this standard Autonegotiation must be enabled.
2. 1000BASE-CX is a standard used for connection with maximum distance of 25 meters. With this standard a shielded twisted pair cables must be used. Even though this is one of the oldest 1000BASE standards it is still used around the globe.
3. 1000BASE-KX is a standard used for connectivity over Electrical Backplanes. This variant uses electrical signaling speed. It has a distance capability of 1 meter.
4. 1000BASE-SX is a standard used for near infrared optical connectivity over Multi-mode fibers. It has a distance capability of up to 550 meters, however there are many cases where this standard is used for longer distances.
5. 1000BASE-LX is a standard which uses a 1,270–1,355 nm laser for longer wavelength. It has a distance capability of up to 5 kilometers over a Single-mode fiber. Optional there is 1000BASE-LX10 version with longer distance capability of up to 10 kilometers.
6. 1000BASE-EX is very similar to 1000BASE-LX10 however it can reach up to 40 kilometers in distance over a Single-mode fiber. This is mainly because of the higher quality of the optics it’s using with 1310 nm lasers.
7. 1000BASE-BX10 is a standard that could reach 10 kilometers in distance over a Single-mode fiber. What is interesting about this standard it’s the fact that it supports different wavelength going in each direction. This is possible with the help of the passive splitter prism. Generally the downstream uses a 1490nm wavelength and the upstream uses 1310nm wavelength.
8. 1000BASE-ZX is a multi-vendor accepted term to refer to a 1550 nm wavelength Ethernet transmission. This have been developed to reach up to 70 kilometers in distance over a Single-mode fiber. Optional there is a 1000BASE-EZX standard with extended distance capability of up to 120 kilometers, however a high quality fiber optic components must be used.
9. 1000BASE-T1 is a standard for automotive and industrial applications. It has a reach capability of up to 40 meters.

The properties of these standards are shown in the table below:

In the past couple of years Gigabit Ethernet has emerged as the main choice for LAN architectures. This is mainly because the Ethernet technology has been the mostly used technology in Local Area Networks. Since its beginning in 1970s with speeds of up to 10 Mbps, the Ethernet technology gained power and have been upgraded from day to day. Today the main reasons for the use of Gigabit Ethernet are its cost and the fact that the 10 times increase in speed will eventually improve productivity and the business will grow. With the revolution that the Gigabit Ethernet brought in the networking world, the doors for 100 GB Ethernet were officially opened.