Long-distance connections for surveillance solutions
- Fast and long-distance connection
- Cost-effective investment with long lifetime and large capacity of data transmission
- Immune to electromagnetic interference
For surveillance solutions, fiber-optic cables are typically used in city surveillance, airports and other long-distance installations.
They also benefit areas subject to frequent lightning, because fiber-optic cable does not conduct electricity.
To meet these demands, Axis offers network video products that support fiber-optic cables through built-in SFP slots. Moreover, thanks to Axis media converter switches, network switches and SFP modules, your surveillance system can benefit from the advantages that come with fiber-optic cables.
Benefits of fiber optics
In long-distance connections, as in city surveillance, fiber cabling is more cost effective than copper cabling. As copper has a lower range limit than fiber, it is not suitable for use in long-range installations. It could be made possible using repeaters, but at a very high cost.
Fibers are more expensive per meter than copper, but considering the large capacity of data transmission and the longer lifetime, they are very cost effective and can be seen as an investment.
In addition, unlike electrical signals in copper wires, light signals from one fiber do not interfere with those in other fibers in the same cable. This means that fiber optics are immune to electromagnetic interference (EMI).
Fiber-optic communication system
1. ON THE SENDER SIDE
- Information source (Axis network camera with SFP slot). The data you want to send, for example video.
- Switch (AXIS T8516 PoE+ Network Switch).
- Optical transmitter and receiver (Axis SFP module). Produces and encodes the light signals.
2. FIBER-OPTIC CABLE
- Conducts the light signals over a distance.
3. ON THE RECEIVER SIDE
- Optical transmitter and receiver (Axis SFP module). Receives and decodes the light signals.
- Switch (Axis Network switch with SFP slot).
- Information Destination (Server, Storage Unit).
One end of the fiber-optic communication system has an optical transmitter (SFP module). The transmitter encodes the signal into a digital light signal.
At the other end, an optical receiver (another SFP module) takes the incoming digital light signals, decodes them and sends the electrical signal to the other user's device.
Axis SFP modules are transceivers, meaning that they are transmitters and receivers combined in one module. The SFP module is inserted in the SFP slot.
The SFP modules could be single or multi-mode, simplex or duplex. They carry different bandwidths, from 100 Mbit/s up to 10 Gbit/s.
Axis choice of SFP modules
Axis SFP modules support duplex transmission and support either multimode or single-mode fiber-optic cable. A duplex multimode or single-mode fiber-optic cable is often used for applications that require simultaneous, bidirectional data transfer.
The duplex transmission consists of two rays of light, each traveling in opposite directions. The transmitted signal travels through one fiber strand in one direction and the received signal travels through the same fiber strand in the opposite direction. This allows cutting the number of fibers required by half.
A multimode fiber-optic cable has a large diametric core that allows multiple modes of light to propagate. With single-mode fiber-optic cable, you can reach up to 50 times more distance compared to multimode. Consequently, single-mode is typically used in 10-/100-Mbps network connections spread out over extended areas. Therefore, multi-mode optical-fiber cable is a type of fiber used mostly for communication over short distances (up to 5 km), such as within a building or on a campus.
It is worth mentioning that the actual distance you achieve with fiber optics will vary according to the type of cable and connectors, the type of SFP modules and the type of LAN devices used with the cable.
To define the type of cable (single or multi-mode) and the type of SFP modules, one should consider:
Length of the connection.
How far away do you intend to place the device? Depending on the length of your connection, you have to decide whether to use single or multi-mode fiber cabling.
The existing equipment in perimeter locations.
Which kind of fibers do you already have in place?
How much do you want to spend?