Since the customers have demanded for a more intensive bandwidth, the telecommunication carriers must seek to offer a matured network convergence and enable the revolution of consumer media device interaction. Hence, the emergence of FTTx technology is significant for people all over the world.
FTTx, also called as fiber to the x, is a collective term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications.
With different network destinations, FTTx can be categorized into several terminologies, such as FTTH, FTTB, FTTC, FTTN, etc. as shown in figure 1.
- FTTH (Fiber to the Home)
FTTx is commonly associated with residential FTTH (fiber to the home) services, and FTTH is certainly one of the fastest growing applications worldwide. In an FTTH deployment, optical cabling terminates at the boundary of the living space so as to reach the individual home and business office where families and officers can both utilize the network in an easier way.
FTTH can provide higher bandwidth for users to meet different demands of services of voice, video and data with fiber as transmission medium, which will gradually replace the technology of copper accessing.
There are two common systems available in FTTH networks:
- AON (active optical network)
- PON (passive optical network)
- AON (active optical network)
The AON arrangement is a point-to-point structure (PTP), meaning that each user has his own dedicated fiber optical line terminated on an optical concentrator. In an active optical system, environmentally electrical switching equipment are deployed, such as a router or a switch aggregator, to manage signal distribution and route data to proper places as shown in figure 2.
- Passive Optical Network
Passive optical network, just as its name shows, it only uses fiber and passive components like optical splitters rather than active components like amplifiers, repeaters, or shaping circuits. Its arrangement is a point to multi-point (PMP) network. That is to say a passive optical network shares fiber optic strands for portions of the network. In passive optical system, a single fiber from a central office optical line terminal (OLT) is connected to optical network terminals (ONTs) or optical network units (ONUs) at customer premises. Figure 3 is a PON system.
An OLT terminates the optical signals and distributes IT and Internet services to as many as 16 to 128 customers per fiber line. An optical splitter, also called PON splitter, is either fitted in or outside the subscriber’s premise to divide a single optical signal into multiple equal but lower-power signals and distribute the signals to users. An Optical Network Unit (ONU) terminates the PON at the customer’s home. The ONU usually communicates with an Optical Network Terminal (ONT), which may be a separate box that connects the PON to TV sets, telephones, computers, or a wireless router. ONU and ONT are basically the same device.
Moreover, PON network implements that optical signal of upstream and downstream can be transmitted in the same fiber by adopting WDM (Wavelength Division Multiplex) technology with the wavelength of downstream optical signal as 1490nm and the wavelength of upstream optical signal as 1310nm. Data is transmitted by broadcasting for downstream and by TDM (Time Division Multiplex) for upstream, so as to realize the communication of P2MP (Point to Multiple Point).
There are two main solutions for a PON access network:
- GPON (Gigabit-Capable PON)
- EPON (Ethernet Passive Optical Network).
PON standardization organization IEEE, ITU-T/FSAN made researches on EPON and GPON technology and released relative standards respectively.
Figure 4 is showing both EPON and GPON access network solutions.
AON vs. PON
Each system has its own virtual points and shortcomings. As for AON subscribers, the bandwidth in each port is dedicated to each individual without sharing of it. Thus, higher bandwidth per port is possible through AON compared with PON. In addition, because of its dedication to specific individual, it is easier to detect fiber faults or problems in AON. However, an AON system requires active equipment to manage signal transmission, which means power supply and potentially higher costs.
- FTTB (Fiber to the Building)
In a FTTB (fiber to the building) deployment, optical cabling terminates at the buildings. Unlike FTTH which runs the fiber inside the subscriber’s apartment unit, FTTB only reaches the apartment building’s electrical room. The signal is conveyed to the final distance using any non-optical means, including twisted pair, coaxial cable, wireless, or power line communication. FTTB applies the dedicated access, thus the client can conveniently enjoy the 24-hour high speed Internet by installing a network card on the computer.
- FTTC (Fiber to the Curb)
In a FTTC (fiber to the curb) deployment, optical cabling usually terminates within 300 yards of the customer premises. Fiber cables are installed or utilized along the roadside from the central office to home or office. Using the FTTC technique, the last connection between the curb and home or office can use the coaxial cable. It replaces the old telephone service and enables the different communication services through a single line.
- FTTN (Fiber to the Node)
In a FTTN (fiber to the node) deployment, the optical fiber terminates in a cabinet which may be as much as a few miles from the customer premises. And the final connection from street cabinet to customer premises usually uses copper. FTTN is often an interim step toward full FTTH and is typically used to deliver advanced triple-play telecommunications services.
FTTx Technologies Summarization
With its high bandwidth potential, FTTx has been closely coupled with triple play of voice, video and data services. And the world has now evolved beyond triple play to a converged multi-play services environment with a high bandwidth requirement. Applications like IPTV, VOIP, RF video, interactive online gaming, security, Internet web hosting, traditional Internet and even smart grid or smart home are widely used in FTTx network.
FTTx Hybrid Solutions
ALTADBIR provides FTTx hybrid solutions, which are new generations of active and passive fiber network product based on AON and PON system networks and meets relative national and international standards of GPON and EPON, and also meets the transmission requirement of high speed internet, voice and video services. The solutions not only can provide the last kilometer access with fiber for all kinds of network operators, but also can be applied on customer professional network for various industries like broadcast and television access network, video monitoring network, enterprise local area network, and servers in customer private network of different industries such as radio and television, transportation, energy sources, electric power, finance and government. Based on customer request, one or more FTTx technology can be deployed in the customers’ networks by ALTADBIR.