Effective transmission distance of network cables and optical fibers.

Author: Hosecom Release time: 2024-04-26 06:26:00 View number: 2504

There are obvious differences in the effective transmission distance between network cables (also known as copper cables) and optical fibers, which mainly depend on their physical characteristics and application environment. Optical fiber has longer effective transmission distance and lower signal attenuation, and is suitable for scenarios with long-distance communication and high bandwidth requirements. The transmission distance of network cables is relatively short and is suitable for local area networks and short-distance communications. The following are their typical effective transmission distances:

1. Network cable (copper cable):

The effective transmission distance of Ethernet cables (such as Cat 5, Cat 6, Cat 7, etc.) is usually limited to within 100 meters. This is because the signal attenuation of the network cable will increase as the transmission distance increases. After it exceeds 100 meters, the signal attenuation will cause data loss or an increase in the bit error rate, thus affecting network performance and reliability. If you want to increase the transmission distance, a repeater can be installed between two sections of network cable, and up to 4 repeaters can be installed. If 4 repeaters are installed to connect 5 network cables, the maximum transmission distance can reach 500m.

The network cable transmission distance is limited to 100 meters mainly due to the following factors:

Signal attenuation: Signal attenuation occurs when network cables transmit data, that is, the strength of the signal weakens as the transmission distance increases. The 100-meter distance is a typical length considered under the premise of ensuring signal quality. Signal attenuation beyond this distance will lead to data loss or increased bit error rate.
Signal distortion: As the distance increases, the signal will be affected by electromagnetic interference, noise and other factors, resulting in signal distortion. Distances within 100 meters can reduce these effects and ensure the stability and reliability of data transmission.
Standard limitations: Ethernet standards usually specify the maximum transmission distance of network cables. In Ethernet, common network cable types include Cat 5, Cat 5e, Cat 6, etc., and their maximum transmission distance is about 100 meters.
Cost and performance balance: There is a balance between transmission distance and cost. Extending the transmission distance may require the use of more expensive materials and equipment, and may increase the complexity of the network.

Although the network cable transmission distance is limited to 100 meters, other technical means can be used to expand network coverage, such as using repeaters, fiber optic converters, fiber optic connectors and other equipment to extend the transmission distance to meet the needs of specific application scenarios.

2. optical fiber:

The transmission distance of optical fiber depends on many factors, including the quality of the optical fiber itself, the frequency of the optical signal, the use of optical amplifiers, and losses during transmission. Generally speaking, the transmission distance of optical fiber can reach tens of kilometers or even hundreds of kilometers. Here are some common fiber optic transmission distances:

Multimode fiber (MMF): Multimode fiber is suitable for short-distance communications, with transmission distances usually ranging from a few hundred meters to several kilometers.
Single-mode optical fiber (SMF): Single-mode optical fiber is suitable for long-distance communication, and its transmission distance can reach tens of kilometers or even hundreds of kilometers. Generally, single-mode fiber transmission distances between 10 km and 100 km are common.
Enhanced single-mode fiber (E-SMF): E-SMF generally has lower transmission loss and can achieve longer transmission distances, some even exceeding hundreds of kilometers.
Use of optical amplifiers: When longer transmission distances are required, optical amplifiers can be used to amplify optical signals to compensate for losses in transmission, thereby achieving longer transmission distances. The transmission distance of single-mode fiber can be extended to hundreds of kilometers using optical amplifiers.

It should be noted that the transmission distance of optical fiber will also be affected by the frequency of the optical signal, the quality of the optical fiber connection, environmental factors, etc. Therefore, in practical applications, comprehensive consideration and evaluation need to be carried out according to the specific situation.

Comparison of effective transmission distances of different standards of network cables and optical fibers:

standard	type	Maximum transmission distance
1000BASE-CX	Twinaxial shielded copper cable[3]	25 meters
1000BASE-KX	Backplane copper cable	1 meter
1000BASE-SX	multimode optical fiber	220 meters - 550 meters (determined by the diameter and bandwidth of the fiber)
1000BASE-LX	multimode optical fiber	550 meters
1000BASE-LX	single mode fiber	5 kilometers
1000BASE-LX10	Single mode fiber (using laser with wavelength 1310nm)	10 kilometers
1000BASE-EX	Single mode fiber (using laser with wavelength 1310nm)	More than 40 kilometers
1000BASE-ZX	Single mode fiber (using laser with wavelength 1550nm)	More than 70 kilometers
1000BASE-BX10	Single-channel single-mode fiber (downstream uses a laser with a wavelength of 1490nm, and upstream uses a laser with a wavelength of 1310nm)	10 kilometers
1000BASE-T	Twisted pair (CAT-5/CAT-5e/CAT-6/CAT-7)	100 metres
1000BASE-TX	Twisted pair (CAT-6/CAT-7)	100 metres

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