What are Fiber Optic Modems？
What are Fiber Optic Modems？
A fiber optic modem (FOM) acts as a connecting interface between an electronic device and an internet network. These modems are different than regular DSL modems because the signal transmission is not via copper cables. It uses a fiber optic cable network to transmit signals. It transforms electronic communication signals via a fiber-optic network. Fiber optic modems (FOM) are nowadays being used in several applications such as data communication network systems, inter-network communication systems, etc. Since these fiber optic modems are gaining popularity, it is important to have information about them before using them blindly. This post gives you insights about these fiber optic modems and their working.
How Does Fiber Optic Modem Work?
Fiber optic modems receive incoming optical signals over fiber optic cables and convert them back to their original electronic form for full-duplex transmission. Together with the tactical fiber optic cables, the FOM provides a rugged, secure, and easy deployable optical link.
The working of a fiber optic modem is quite simple. The following pointers will help you understand it better.
- The internet signal is transmitted via fiber optic cables to the fiber optic modems.
- The modem transforms the internet signals into electronic data.
- This transmission is a full-duplex transmission. That means the data can be transmitted from the internet source to the electronic device and vice versa.
What is the maximum distance that a fiber optic modem can go?
The maximum distance a modem can go is the difference between receiver sensitivity and transmit power of the fiber optic modem, divided by the transmission loss of the fiber used. For example, a basic single-mode OSD815 digital video system’s transmitter power is greater than -10dBm and its receiver sensitivity is better than -29dBm so the difference of 19dB at 1310nm allows operation over at least 45km. Note this would be a very poor design because there is no allowance for a link margin.
What Is Fiber Optic Modem Used For?
Fiber optic modems are often used in data communication systems to bridge long distances at high data rates. Fiber optic systems are particularly immune to electromagnetic interference and therefore very suitable for harsh industrial environments. They can transmit data at up to 12 Mbit/s over distances up to 80 km depending on the fiber type. They range from simple devices with just a few ports to multiplexers capable of handling large-scale communication networks. For example, fiber optic cables are used by some networks for the server to build connections, while cat 7 cable is used for the wiring within the building. To convert these two types of cables you need a fiber optic modem.
Types of Fiber Optic Modems (FOM)
There are different categories of fiber optic modems according to the data transmission protocol followed by the modem. Let us discuss the types of FOM in brief.
E1 FOM: E1 fiber optic modem is used for modulating a framing or non-framing E1 data signal directly into a single mode or multimode optical fiber for transmission via a fiber optic cable line. At another end of the optic cable, the optical signal is demodulated into a framing or non-framing E1 data signal. E1 interface may be directly connected with the E1 interfaces of image and data terminals or the WAN ports of MUX, switch, and router for a dedicated network setup or a LAN connection.
V35 FOM: V35 FOM is utilized for single or multimode transformation and transmission of electrical-optical-electrical signals. This V35 modem acts as an electrical to optical data converter and vice versa at the end of the fiber optic cable. The transmission range of these modems is up to 100km.
RS FOM: RS stands for recommended standards. The modems that act under recommended standards are called RS modems. These RS standards are established by The Electronics Industry Association. The different RS FOMs available in the market are as follows.
RS232: RS232 converter, RS485 converter, and RS422 converter (RS means “recommended standard”) are the standards introduced by The Electronics Industry Association to ensure compatibility of the data transmission between equipment made by different manufacturers. RS232 Modem is for single-ended data transmission from one transmitter to one receiver at relatively slow data rates (up to 20K bits/second) and short distances. RS232 Ethernet converter is widely used as we can see them from the common desk computer cases. An RS422 converter is a standard for longer data transmission distances and higher Baud rates compared with RS232. R485 converter standard meets the requirements for a truly multi-point communications network, and the standard specifies up to 32 drivers and 32 receivers on a single (2-wire) bus.
RS422: RS422 FOMs are designed for faster data transmission rates and longer transmission distances. They can transmit up to 20km at a 10MBPS transmission rate.
RS485: RS485 FOM is designed for multimode data transmission. For multichannel fiber optic transmission, these RS485 fiber optic modems are used. It supports over 32 channel simultaneous transmission.
Features of Fiber Optic Compatible Modems
That Make Them Popular FOMs are gaining popularity over DSL modems and cable transmission due to their beneficial features. The fiber optic modems offer the following benefits.
- This type of modem is immune to electromagnetic interference.
- This system is immune to data loss; therefore, the user gets uninterrupted data transmission.
- These modems are compatible with the single or multi-portal transmission.
- Due to uninterrupted data transmission, these modems can be used for long-distance telephone communication. As these modems can resist electromagnetic interference, thus, the audio signal transmission is clear.
- Having Fiber optic as transmission media, the speed of transmission is higher than the general cabled network. Also, in comparison to a wireless network, the function of these fiber optics modems is not affected by harsh weather fluctuations.
- They are microprocessors based and using ANSI-certified ones is highly recommended.
- These modems have a user-friendly GUI and multiple features such as fiber path protection, menu-based interface and control, end-to-end monitoring controls which allow handshaking of devices, and a smart manager.
- They can be used as a standalone device or mounted on a rack in an integrated network.
- They have self-troubleshooting features such as remote loopback as well as local capabilities.
- You can use NDT or non-intrusive testing techniques such as BERT to check the communication link of these modems. This prevents the closure of systems when testing.
- They support various encryption product lines.
- They can pass bipolar violations, and offer full modem redundancy.
- They help reduce latency of the legacy networks and offer a huge bandwidth even for VoIP calls, video conferencing, archiving of bulky files, and so on.
- Overall, fiber optics along with these modems and other network devices offer your business network enough scalability, thus leaving room for future expansions, configuration changes, and application flexibility.
Advanced Applications of Fiber Optic Modems
Fiber optic modems (FOM) are nowadays being used in several applications such as data communication network systems, inter-network communication systems, and so on. They can be used to expand networks across cities and states, and help you extend the distance by around 100km, without compromising on the speed and signal strength. This is why they are useful in networks of mission-critical applications such as defense and government. Here are some advanced applications of fiber optic modems:
- Smart homes
- IoT
- Augmented and virtual reality
- Cryptography
- High-speed device linking and syncing
- Microwave extension linking
- Satellite downlinks
- System integration of public and private networks