With the successful application of DSL technology, the gradual popularization of FTTH technology, and the evolution
from traditional network to NGN, the trend of IP business bearing has been formed. In the future, the optical
transmission network of the entire business operations will be primarily responsible for the IP / Ethernet traffic
transmission, the optimization of the characteristics of data flow in groups, and will develop in a direction of smart,
integrated, broadband, efficient and reliable packet transmission technology (PTN). The PTN based on T-MPLS
technology, supporting all types of business (Ethernet, IP / MPLS, FR, ATM, TDM,...), simultaneously supporting
general users (wired / wireless) and commercial users in various types of business development, would become a new
generation of converged networks of PTN platform. This article analyzes the crucial technologies of PTN in respects of
the T-MPLS system of the framework agreement, the hierarchical structure, the network model, operational capacity,
protection switching mechanism, etc, and puts forward a PTN-building program facing the entire business operations.
It is because the MSTP based on SDH has developed to be regional multi-service communication network come from the
need of LAN-interlink and the new data traffic that the study of encapsulation protocol of MSTP data service over SDH
has become especially important. This paper firstly analyzes three kinds of encapsulation protocols which are based on
SDH to transport data. The three protocols are GFP, LAPS and PPP, and the study emphases on the encapsulation mode,
frame structure, function mode and currency disposal process of the GFP. At last it introduces the GFP's applications in
On propagation characteristic of material surface wave in laser ultrasonic, researching Fizeau fiber
interferometer system which implements measure of SAW on YAG laser. Based on interference principle in
common laser path, it eliminates a good many shortcomings in measurement means of other SAW, possess low
environment demand, simple configuration, easy adjustment, high frequency response and no contacted
measurement, highly adapts to laser ultrasonic measure.
This paper introduced fiber interferometer from the characteristic and theory of laser ultrasonic to improve the detect
efficiency of laser ultrasonic. It designed laser ultrasonic inspection system. This system provides high sensitivity of
laser ultrasonic and has general character of acoustic surface wave. It also has the merits of non-contact, broadband and
high space resolution of laser ultrasonic.
FTTH supports present and future all services and becomes the finally solution of connecting the first kilometer wide band by its giant bandwidth ability. Through analyzing each kind of FTTH network plan, this article proposes four constitute ways of the FTTH: two waves single stages P-P, two waves two stages P-P, two waves PON and three waves PON. Then, we analyze transmission protocol of FTTH system. Finally we introduced FTTH overall request for FTTH system.