There are three types cable connectors in a basic cabling installation techniques: twisted-pair connectors,coaxial cable connectors and fiber-optic connectors. Generally cable connectors have a male component and a female component, except in the case of hermaphroditic connectors such as the IBM data connector. Usually jacks and plugs are symmetrically shaped, but sometimes they are keyed. This means that they have a unique,

asymmetric shape or some system of pins, tabs, and slots that ensure that the plug can be inserted only one way in the jack.
Twisted-Pair Cable Connectors

Many people in the cabling business use twisted-pair connectors more than any other type of connector. The connectors include the modular RJ types of jacks and plugs and the hermaphroditic connector employed by IBM that is used with shielded twisted-pair cabling. Twisted-Pair Cable Connectors are used with patch panels, punchdown blocks, and wall plates. Twisted-Pair Cable connector is called an IDC, or insulation displacement connector.
Most unshielded twisted-pair (UTP) and screened twisted-pair (ScTP) cable installations use patch panels and, consequently, 110-style termination blocks. The 110 Block Wiring (shown in Figure1) contains rows of specially designed slots in which the cables are terminated using a punch-down tool. When terminating 66-blocks, 110-blocks, and often, wall plates, both UTP and ScTP connectors use IDC technology to establish contact with the copper conductors. You don’t strip the wire insulation off the conductor as you would with a screw-down connection. Instead, you force the conductor either between facing blades or onto points that pierce the plastic insulation and make contact with the conductor.

Both UTP and ScTP cables use modular jacks and plugs. For decades, modular jacks have been commonplace in the home for telephone wiring.
Modular connectors come in four-, six-, and eight-position configurations. The number of positions defines the width of the connector. However, often only some of the positions have metal contacts installed. Make sure that the connectors you purchase are properly populated with contacts for your application.
Common Modular-Jack Designations and Their Configuration

Coaxial Cable Connectors
Unless you have operated a 10Base-2 or 10Base-5 Ethernet network, you are probably familiar only with the coaxial connectors you have in your home for use with televisions and video equipment. Actually, a number of different types of coaxial connectors exist.
>>F-Series Coaxial Connectors
The coax connectors used with video equipment are referred to as F-series connectors.The F-connector consists of a ferrule that fits over the outer jacket of the cable and is crimped in place. The center conductor is allowed to project from the connector and forms the business end of the plug. A threaded collar on the plug screws down on the jack, forming a solid connection. F-connectors are used primarily in residential installations for RG-58, RG-59, and RG-6 coaxial cables to provide CATV, security-camera, and other video services.

F-connectors are commonly available in one-piece and two-piece designs. In the two-piece design, the ferrule that fits over the cable jacket is a separate sleeve that you slide on before you insert the collar portion on the cable. Experience has shown us that the single-piece design is
superior. Fewer parts usually means less fumbling, and the final crimped connection is both more aesthetically pleasing and more durable. However, the usability and aesthetics are largely a function of the design and brand of the two-piece product. Some two-piece designs are very
well received by the CATV industry.
>>N-Series Coaxial Connectors
The N-connector is very similar to the F-connector but has the addition of a pin that fits over the center conductor; The pin is suitable for insertion in
the jack and must be used if the center conductor is stranded instead of solid. The assembly is attached to the cable by crimping it in place. A screw-on collar ensures a reliable connection with the jack. The N-type connector is used with RG-8, RJ-11U, and thicknet cables for data and
video backbone applications.

>>The BNC Connector
When coaxial cable distributes data in commercial environments, the BNC connector is often used. BNC stands for Bayonet Neill-Concelman, which describes both the method of securing the connection and its inventors. Many other expansions of this acronym exist, including
British Naval Connector, Bayonet Nut Coupling, Bayonet Navy Connector, and so forth. Used with RG-6, RG-58A/U thinnet, RG-59, and RG-62 coax, the BNC utilizes a center pin, as in the N-connector, to accommodate the stranded center conductors usually found in data coax.
The BNC connector comes as a crimp-on or a design that screws onto the coax jacket. As with the F-connector, the screw-on type is not considered reliable and should not be used. The rigid pin that goes over the center conductor may require crimping or soldering in place. The rest of the connector assembly is applied much like an F-connector, using a crimping die made specifically for a BNC connector.

Fiber-Optic Cable Connectors

Fiber-optic connections use different terminology than copper based connectors. The male end of the connection in a fiber-optic system is termed the connector, in contrast to the plug in a copperbased system. The female end of the connection is termed the receptacle or adapter, in contrast to the jack in a copper-based system.
To transmit data up to 10Gbps, two fibers are typically required: one to send and the other to receive. For 40Gbps and 100Gbps over multimode, as many as 24 fibers will be required. Fiber optic connectors fall into one of three categories based on how the fiber is terminated:
•Simplex connectors terminate only a single fiber in the connector assembly.
•Duplex connectors terminate two fibers in the connector assembly.
•Array connectors terminate more than two fibers (typically 12 or 24 fibers) in the connector assembly.

The disadvantage of simplex connectors is that you have to keep careful track of polarity. In other words, you must always make sure that the connector on the “send” fiber is always connected to the “send” receptacle (or adapter) and that the “receive” connector is always connected to the “receive” receptacle (or adapter). The real issue is when normal working folk need to move furniture around and disconnect from the receptacle in their work area and then get their connectors mixed up. Experience has shown us that the connectors are not always color coded or labeled properly. Getting them reversed means, at the least, that link of the network won’t work.

Array and duplex connectors and adapters take care of this issue. Once terminated, color coding and keying ensures that the connector can be inserted only one way in the adapter and will always achieve correct polarity.

Figure2: Some common Fiber Connectors

>>The SFF Connector
As transmission rates increase and networks require the cramming in of a greater number of connections, the industry has developed small-form-factor (SFF) connectors and adapter systems for fiber-optic cables. The SC, ST, and FC Connector shown in Table 10.5 all take up more physical space than their RJ-45 counterparts on the copper side. This makes multimedia receptacle faceplates a little crowded and means that you get fewer terminations (lower density) in closets and equipment rooms than you can get with copper in the same space. The goal for the designers of the SFF connector was to create an optical-fiber connector with the same or lower crosssectional footprint as an RJ-45-style connector in order to increase the number of connections per area (higher density). The LC, the VF-45, and the MT-RJ SFF fiber-optic connectors were initially developed to support the increase in density of fiber connections. The LC Connectorsis gaining greater use and is regarded by many optical-fiber professionals.

Introduction

As all we known: cabling of building local area network (LAN) at the end of the 100m cabling, community area last 2km integrated network cabling computer data center room, such as several internal cabling. Cabling in different locations, in accordance with their purpose and corresponding transmission index calculating the length of the cabling to allow laying. No matter what position cabling used, all belong to the city telecommunications network extension and an important part. Only in depth understanding of urban development trends of telecommunication networks, in order to accurately grasp how to design integrated cabling; also only be taken with the city development strategy telecommunication network synchronization and with suitable, cabling can really play the overall effectiveness of the network and obtain win-win enconomic effects. Here only to the development of telecommunication networks, cabling should be synchronized with the development, as well as the latest developments in cabling issues such as study and discussion.

The development trend of telecommunication network

In traditional telecommunications networks based voice communication, a small amount of digital data network (DDN), Frame Relay (FR) point to point, such as low rate of data communication, a voice path begins only within the bandwidth of 64kbps. In the early 1990s, China's foreign experience with the introduction of Copper Network and network communication technology, and accordingly developed our standards, and actively promote the application of the telecommunications network to get great propress. In just 10 years time, network communication technology from 10 megabytes, 100 megabytes, Gigabit to 10 Gigabit-class development, or even 10 Gigabit-class network will soon put into large-scale application.

The development of the telecommunication network is omni-directional, methods of communication include: wired, wireless, satellite, etc.; Communication contents include: telephone, television, data, etc..

a. The rapid development of the passive optical network (PON)

Currently, the passive optical network (PON) is rapidly developing country, for example: EPON (Ethernet Passive Optical Network), GPON (Gigabit Passive Optical Network), GEPON (Gigabit Ethernet Passive Optical Network), APON (ATM Passive Optical Network), BPON (Broadband Passive Optical Network) and other network applications, structured cabling will have a direct impact. Now illustrate EPON/GPON networking mode:

EPON/GPON is mainly composed of OLT (Optical Line Terminal), ODN (Optical Distribution Network) and ONU (Optical Network Unit) and other components. EPON / GPON networking shown in Figure 1:

Figure 1 shows EPON/GPON networking model

Figure 2 shows ODN optical channel model

The network characteristics of EPON/GPON:

* On the OLT and ONU in addition to optical interface, combined with GE (Gigabit Ethernet), FE (Fiber optic Ethernet), RF (Radio Frequency), E1 (2.048Mbps) interfaces, can be applied to various network applications.

* EPON can provide uplink and downlink symmetrical rate 1.25Gbps.

* GPON can provides uplink 155Mbps, 622Mbps, 1.24Gbps or 2.48Gbps; Downlink 1.24Gbps or 2.48Gbps.

* Public IP network signal WDM Mux Demux, the uplink of 1490nm and downlink of 1310nm signal through the central office OLT integrated transceivers were injected into the same optical fiber, through the optical distribution network ODN spending 32.64 points or 128 optical link to the corresponding ONU. If necessary, can also be injected CATV signals using the third wavelength of 1550nm central office OLT transceiver integrated in the corresponding ONU than the client integrated transceivers separated by the RF interface of the user received a cable distribution network.

* EPON/GPON network support tree, star, bus, hybird and redundant topology etc..

* EPON is based on the standard Ethernet technology and IEEEP802.3ah, in the case of transport 1.25Gbps data stream, the optical line terminal (OLT) and the optical network terminal (ONU) between a transmission distance up to about 20km.

* GPON is based on the ITU-T standard G984.1-G984.5 version, is preferred in Europe and North America, FTTH technology, is being used worldwide. GPON generic framing protocol that provides a multi-protocol transmission efficiency can provide an open interface, with 2.48Gbps rate symmetric and asymmetric transmission capacity, OLT/ONU transmission distance up between 37km.

b. FTTH or FTTB/N

As EPON/GPON technology matures, the price of Fibre Optics Cable are more and more cheap. Fiber optic cable extends to the floor, community nodes, and even to the family increasingly likely. As telecom companies certainly want to consider the relationship between input and output in the short term cost recovery and profit is the ultimate goal.

The advantages of FTTH solutions:

1. Provide greater bandwidth capacity, suitable for high speed network applications.

2. Is not affected by the outside electromagnetic interference, anti-interference performance is good, high quality communications.

3. Silica fiber material production inexhaustible.

4. The price of fiber optic cable has lower than copper (but photoelectric conversion equipment price is still relatively high, therefore, the overall cost is higher).

The disadvantages of FTTH solutions:

1. Same scale projects, the initial investment is higher.

2. New fiber optic cable and more, longer construction period (relative to the FTTB/N solution).

3. Slow return on investment.

About Fiber Optic Modem

Fiber Optic Modem, also known single-port optic multiplexer, is a point-to-point type terminal equipment which uses a pair of optic fibers to achieve the transmission of E1 or V.35 or 10base-T. Fiber modem has the function of modulation and demodulation. Fiber modem is a local network relay transmission equipment, suitable for base station transmission fiber terminal equipment and leased-line equipment.

Fiber modem is similar to the baseband MODEM (digital modem). The only difference from baseband MODEM is that it access fiber line, the optical signal. The multi-ports optic transceiver generally called multiplexer. For multi-port Optical Fiber Multiplexer is normally be directly called “multiplexer”, single-port multiplexer is generally used on the client, similar to commonly used WAN line (circuit) networking with the baseband MODEM, and also named for “fiber modem”, “optical modem”.

About Fiber Media Converter

Optical Fiber Media Converter is a simple networking device making the connection between two dissimilar media types become possible. Media converter types range from small standalone devices and PC card converters to high port-density chassis systems that offer many advanced features for network management.

Fiber media converters can connect different local area network (LAN) media, modifying duplex and speed settings. Switching media converters can connect legacy 10BASE-T network segments to more recent 100BASE-TX or 100BASE-FX Fast Ethernet infrastructure. For example, existing half-duplex hubs can be connected to 100BASE-TX Fast Ethernet network segments over 100BASE-FX fiber.

When expanding the reach of the LAN to span multiple locations, media converters are useful in connecting multiple LANs to form one large campus area network that spans over a limited geographic area. As premises networks are primarily copper-based, media converters can extend the reach of the LAN over single-mode fiber up to 160 kilometers with 1550 nm optics.

Wavelength-division multiplexing (WDM) technology in the LAN is especially beneficial in situations where fiber is in limited supply or expensive to provision. As well as conventional dual strand fiber converters, with separate receive and transmit ports, there are also single strand fiber converters, which can extend full-duplex data transmission up to 120 kilometers over one optical fiber.

Other benefits of media conversion include providing a gradual migration path from copper to fiber. Fiber connections can reduce electromagnetic interference. Also fiber media converters pose as a cheap solution for those who want to buy switches for use with fiber but do not have the funds to afford them, they can buy ordinary switches and use fiber media converters to use with their fiber network.

The Difference Between Media Converter And Optical Modem

The difference between the media converter and optical modem is that the media converter is to convert the optical signal in the LAN, simply a signal conversion, no interface protocol conversion. While, fiber modem for WAN is the optical signal conversion and interface protocol conversion, protocol converter has two types of E1 to V.35 and E1 to Ethernet.

In fact, as the developing of network technology, the concept of media converter and fiber modem has become increasingly blurred, which are basically can be unified for the same equipment. Media converter becomes the scientific name of fiber modem.

10G PON technology to meet future access networks, "large-capacity, fewer offices," the direction of development, while improving access speed, supports larger branching ratio, covering more users. Therefore, 10G PON technology will become the future telecom operators to achieve "broadband speed", "Light of Copper" and other broadband network construction hot technology for sustainable development.