Power over Ethernet (PoE) and Ethernet over Power (EOP) are two technologies that have gained popularity in recent years. PoE allows network devices to be powered through an Ethernet cable, eliminating the need for separate power cables. EOP, on the other hand, uses existing electrical wiring to create an Ethernet network. In this beginner's guide, we will explore these technologies in more detail, including how they work, their benefits and drawbacks, and when they are most useful.
What is PoE and how does it work?
Power over Ethernet or PoE is a technology that allows data cables to carry both electrical power and data across one cable to network devices. This eliminates the need for installers to run multiple cables or install a separate power source.
Power is supplied by a PoE-enabled device such as a network switch or PoE injector which adds power to the Ethernet data signal before it is sent over the cable. The PoE-enabled device at the other end (IP camera, access point etc) receives this power in order for the unit to operate without the need for a separate power supply.
This works by using two of the four twisted pairs of wires in the Ethernet cable to carry power, they are unused for data transmission. PoE-enabled devices have a special circuit that separates power from data signal which allows the device to use the power for its operation.
There are different power levels when it comes to PoE, what power level is needed will depend on each individual device. IEEE 802.3af is the most common type and will deliver up to 15.4 watts of power to a device, this is generally enough to power most standard IP cameras. However for higher spec models such as those that feature artificial intelligence or PTZ cameras, there is IEEE 802.3at, also referred to as PoE+ can deliver up to 30 watts of power.
Power over Ethernet provides installers/users with a convenient and cost-effective solution for powering network devices. Particularly in applications where it would be complicated to run extra power cables.
For an introduction to PoE and Network hardware please see our video below:
What is a PoE Midspan and a PoE Endpan?
There are two main methods of implementing PoE, PoE Midspan and PoE Endspan. If you
have heard of the terms midspan and endspan and not understood what they meant then you wouldn’t be the only one.
A device that is placed between the Ethernet Switch and the end device such as an IP camera is referred to as a PoE Midspan. This is because it is placed somewhere in the mid-point. The midspan injects power onto the Ethernet cable which allows the end device to receive both data and power over the same cable. In this method an additional device is required to be installed in the network, however, there is greater flexibility in the power supply and management of the end devices.
Midspans can deliver different levels of power depending on the device that is being powered and is available in different port configurations which allows multiple devices to be powered by a single midspan.
PoE Endspan, however, refers to a switch that has PoE capabilities built-in. This provides both power and data to the end devices without the need for an additional midspan. This method provides users with simplified installation and management of PoE devices on the network, however, can be less flexible than PoE Midspan in terms of power management.
Endspans are able to deliver different levels of power to connected devices dependant on the PoE standard it supports. However, the device will have a total power budget so users will need to ensure that it is able to deliver the required power to each connected device. There are also different port configurations so multiple devices can be powered from one switch.
To put it simply a midspan is called such as it is installed at some mid-point along the data network cable length and an endspan is placed at one end of the network cable hence its name. The main difference between PoE midspan and PoE endspan is the location where power is injected into the Ethernet cable, midspans inject power between the switch and end device whereas endspans have PoE capabilities integrated into the switch.
Do I need a PoE splitter?
A splitter is only required when the device being powered through the Ethernet cable is not PoE-compliant. In this case, a PoE splitter will separate
power from the Ethernet data signal and enable the device to receive the power through a separate power cord.
If, for example, you have a CCTV camera that you want to connect to your PoE network but it only has a 12V DC power input then you would need a PoE splitter. However, if the camera already has a PoE-compatible input then you would not need a splitter.
PoE splitters are rarely used these days as the technology has been around for a while now and so, many devices are PoE-compatible.
What is Ethernet over Power?
Not to be confused with Power over Ethernet, Ethernet over Power (EOP) can also be referred to/known as
Powerline Networking, Powerline Communication (PLC) or HomePlug. This technology uses existing mains power cabling in a building to enable an Ethernet network.
Data is transmitted over the electrical wiring using high-frequency signals and the standard power is also transmitted at the same time. Users will need at least two of these adapters, one placed adjacent to the router or switch and another placed adjacent to the device they wish to add to the network. These adapters typically take the form or a mains plug unit with a connector socket for an RJ45 plug to enable connection to the network.
EOP is a great option for situations where it is difficult to extend the network to reach a new location but where mains sockets fed from the same area as your main network already exist. An example of this would be outbuildings such as garages, or garden offices. As well as this, EOP can be used in applications where it is difficult to achieve a consistent wireless network performance (homes with thick walls etc).
The performance of these systems can however be affected by the quality of the wiring and the existence of noise or interference on the electrical network. Not only this but the data transmission speeds may be limited by the age and quality of the electrical wiring in the building.
As a whole Ethernet over Power can be a convenient solution for extending network connectivity over existing electrical wiring. However, it does need to be noted that it may not always be the most reliable or high-performing solution in all scenarios.
What is PoE and how does it work?
Power over Ethernet or PoE is a technology that allows data cables to carry both electrical power and data across one cable to network devices. This eliminates the need for installers to run multiple cables or install a separate power source.
Power is supplied by a PoE-enabled device such as a network switch or PoE injector which adds power to the Ethernet data signal before it is sent over the cable. The PoE-enabled device at the other end (IP camera, access point etc) receives this power in order for the unit to operate without the need for a separate power supply.
This works by using two of the four twisted pairs of wires in the Ethernet cable to carry power, they are unused for data transmission. PoE-enabled devices have a special circuit that separates power from data signal which allows the device to use the power for its operation.
There are different power levels when it comes to PoE, what power level is needed will depend on each individual device. IEEE 802.3af is the most common type and will deliver up to 15.4 watts of power to a device, this is generally enough to power most standard IP cameras. However for higher spec models such as those that feature artificial intelligence or PTZ cameras, there is IEEE 802.3at, also referred to as PoE+ can deliver up to 30 watts of power.
Power over Ethernet provides installers/users with a convenient and cost-effective solution for powering network devices. Particularly in applications where it would be complicated to run extra power cables.
For an introduction to PoE and Network hardware please see our video below:
What is a PoE Midspan and a PoE Endpan?
There are two main methods of implementing PoE, PoE Midspan and PoE Endspan. If you
A device that is placed between the Ethernet Switch and the end device such as an IP camera is referred to as a PoE Midspan. This is because it is placed somewhere in the mid-point. The midspan injects power onto the Ethernet cable which allows the end device to receive both data and power over the same cable. In this method an additional device is required to be installed in the network, however, there is greater flexibility in the power supply and management of the end devices.
Midspans can deliver different levels of power depending on the device that is being powered and is available in different port configurations which allows multiple devices to be powered by a single midspan.
PoE Endspan, however, refers to a switch that has PoE capabilities built-in. This provides both power and data to the end devices without the need for an additional midspan. This method provides users with simplified installation and management of PoE devices on the network, however, can be less flexible than PoE Midspan in terms of power management.
Endspans are able to deliver different levels of power to connected devices dependant on the PoE standard it supports. However, the device will have a total power budget so users will need to ensure that it is able to deliver the required power to each connected device. There are also different port configurations so multiple devices can be powered from one switch.
To put it simply a midspan is called such as it is installed at some mid-point along the data network cable length and an endspan is placed at one end of the network cable hence its name. The main difference between PoE midspan and PoE endspan is the location where power is injected into the Ethernet cable, midspans inject power between the switch and end device whereas endspans have PoE capabilities integrated into the switch.
Do I need a PoE splitter?
A splitter is only required when the device being powered through the Ethernet cable is not PoE-compliant. In this case, a PoE splitter will separate
If, for example, you have a CCTV camera that you want to connect to your PoE network but it only has a 12V DC power input then you would need a PoE splitter. However, if the camera already has a PoE-compatible input then you would not need a splitter.
PoE splitters are rarely used these days as the technology has been around for a while now and so, many devices are PoE-compatible.
What is Ethernet over Power?
Not to be confused with Power over Ethernet, Ethernet over Power (EOP) can also be referred to/known as
Data is transmitted over the electrical wiring using high-frequency signals and the standard power is also transmitted at the same time. Users will need at least two of these adapters, one placed adjacent to the router or switch and another placed adjacent to the device they wish to add to the network. These adapters typically take the form or a mains plug unit with a connector socket for an RJ45 plug to enable connection to the network.
EOP is a great option for situations where it is difficult to extend the network to reach a new location but where mains sockets fed from the same area as your main network already exist. An example of this would be outbuildings such as garages, or garden offices. As well as this, EOP can be used in applications where it is difficult to achieve a consistent wireless network performance (homes with thick walls etc).
The performance of these systems can however be affected by the quality of the wiring and the existence of noise or interference on the electrical network. Not only this but the data transmission speeds may be limited by the age and quality of the electrical wiring in the building.
As a whole Ethernet over Power can be a convenient solution for extending network connectivity over existing electrical wiring. However, it does need to be noted that it may not always be the most reliable or high-performing solution in all scenarios.
Last edited by a moderator:
