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>> What is Birefringence in Optical Fiber? The analysis of the guiding properties of single mode fibers leads to the propagation of one transversal mode called LP01, or, more precisely, two orthogonal degenerate modes LP01x and LP01y. The term degenerate means that both modes are characterized by the same propagation constant, i.e. the same effective refractive index (nx = ny). However, this degeneracy is theoretical: nx = ny holds only for an optical fiber with a perfect circular symmetry which can never be obtained in practice. The core is indeed always slightly elliptical rather than circular. Moreover, the dopant concentration

>> What is Synchronous Transmission? The term synchronous is used to describe a continuous and consistent timed transfer of data blocks. Synchronous data transmission is a data transfer method in which a continuous stream of data signals is accompanied by timing signals (generated by an electronic clock) to ensure that the transmitter and the receiver are in step (synchronized) with one another. The data is sent in blocks (called frames or packets) spaced by fixed time intervals. Synchronous transmission modes are used when large amounts of data must be transferred very quickly from one location to the other. The speed

>> Why Do We Need Grounding and Bonding for Telecommunication Systems? With the increasing demand for computer network installations, telecommunications grounding and bonding has become a growing opportunity for electrical contractors. Although similar grounding principles apply, understanding the telecommunications terminology and special considerations has been a challenge. As with traditional electrical grounding, telecommunications networks and equipment should be grounded to the electrical service. However, simply grounding to structural steel isn’t enough when tackling telecommunications systems. The sensitivity of the electronic equipment requires that the telecommunications cabling and power be effectively equalized to prevent loops or transients that can damage the

>> What is Radio Over Fiber (RoF)? Radio over Fiber (RoF) refers to an analog transmission over fiber technology whereby light is amplitude modulated by a radio signal and transmitted over an optical fiber link to facilitate wireless access. Although radio transmission over fiber is used for multiple purposes, such as in cable television (CATV) networks and in satellite base stations, the term RoF is usually applied when this is done for wireless access. In RoF systems, wireless signals are transported in optical form between a central station and a set of base stations before being radiated through the air.

>> What is Higher-Order Modulation Method? A range of newly developed fundamental communications technologies must be employed in order to reliably transmit signals of 40/43 Gbps and even 100 Gbps in the near future using telecommunications networks. One of these technologies involves the use of higher-level modulation methods on the optical side, similar to those which have been used for many years successfully on the electrical side in xDSL broadband access technology, for example. Until now, just one modulation method was used for transmission rates of up to 10 Gbps, namely on/off keying or OOK for short. Put simply, this