Creation of a broadband network based on gpon technology qualification work of bachelor

2. TYPES OF PON TECHNOLOGY
2.1 GPON technology
The most promising technology in the passive optical network family is GPON technology. Based on the standards adopted in recent years, GPON provides the operator with an efficient "last mile" high-speed solution, provides significant savings in optical fibers due to the tree network architecture and high reliability due to the passivity of branching elements. Support for modern wave multiplexing technologies allows you to significantly increase the overall network capacity without upgrading the cable infrastructure. At the same time, the point - to-multipoint network tree structureenables flexible bandwidth management for client services.
Support for ring and tree topologies with the possibility of full redundancy of network interfaces and communication channels with a short time to switch to backup provides a high level of reliability and availability of network services.
With a sufficiently high transfer rate of up to 2.5 Gbit/s in both directions, GPON provides transparent transport for all services (ATM, SDH, TDM, Ethernet). Due to the complete isolation of each service and support for built-in content encryption tools, a high level of network security is achieved.
Thus, the advantages of passive optical networks and a number of unique features determine the advantages of GPON technology over SDH and Ethernet technologies in optical "last mile" solutions and its further distribution for organizing high-speed optical access networks in urban multiservice communication networks.
The ITU-T GPON Rec. G. 984.3 GPON standard was adopted in October 2003. пIt provides a scalable frame structure at transfer rates from 622 Mbit / s to 2.5 Gbit / s, and allows systems with the same forward and reverse stream transfer rates in the PON tree, or with different ones. GPON is based on the ITU-T G. 704.1 GFP (generic framing protocol) standard, providing encapsulation in a synchronous transport protocol of any type of service, including TDM. Studies show that even in the worst-case scenario of traffic distribution and flow fluctuations, lane utilization is 93%, compared to 71% in APON, not to mention EPON.
If in SDH the bandwidth division is static, then GFP (generic framing protocol), preserving the structure of the SDH frame, allows you to dynamically allocate the bandwidth.
2.2 GEPON Technology
Ethernet Passive Optical Network (GEPON) is a passive optical network based on the Gigabit Ethernet protocol. The technology is standardized by the IEEE 802.3 Sub-committee for the Development of EFM Standards (Ethernet in the First Mile).
GEPON technology is one of the most advanced options for building communication networks, providing high-speed information transfer (up to 1.2 Gbit / s). The main advantage of GEPON technology is that it allows optimal use of the fiber-optic cable resource. For example, to connect 64 subscribers within a radius of 20 km, it is enough to use only one fiber-optic segment.
EFM standards cover all technical elements of a broadband Ethernetnetwork , including specifications for the physical layer of copper transmission, point-to - point and point-to-multipointtransmission, and a common network administration and management mechanism.
Today, GEPON technology is the most successful PON technology, with more than 20 million subscribers connected worldwide. Despite the reduction in the cost of GPON technology, GEPON equipment supplies still significantly exceed GPON sales.
On the one hand, this is due to the ease of implementation, easy scalability of GEPON networks, low cost of operation, and easy integration with Metro Ethernet networks. On the other hand - the advantages of the DBA algorithm.
-The main advantages of GEPON are:
-Using standard 802.3 ah mechanisms, which will significantly reduce the cost of equipment in the future;
-Faster round-trip transmission speeds of up to 1 Gbit / s and more broadband services;
-Providing QoS using 802.1 p/TOS mechanisms. It is possible to use strict приоритезацииtraffic prioritization mechanisms with eight dedicated queues for each type of traffic. These mechanisms allow you to provide services such as VoIP or VoD with a quality guarantee;
-Ability to connect 64 subscriber devices per PON branch and efficient use of optical fiber;
Full support for DBA (Dynamic Bandwidth Allocation), a mechanism for dynamically allocating bandwidth in accordance with subscriber requests and the availability of free bandwidth in the PON tree. So subscribers who are provided with guaranteed bandwidth for data transmission, for example, 1 MB / s can get real speed up to 1 GB /s, if полосаthe PON tree bandwidth remains partially unused (similar to UBR traffic in ATM);
-Support for video streaming (IGMP Snooping);
-Easy to install and maintain.

2.3 Metro Ethernet And PON Technologies

Let's see what preference is given to operators. Over the past couple of years, ADSL has become the main broadband access technology in terms of subscriber base. Even now, operators are aware of its significant limitations: speed, dependence on the quality of copper lines, high costs for technical support of users, etc. All this complicates the introduction of new services such as IP-TV, gaming services, etc. There is an increased interest in FTTx from operators who have already deployed ADSL on their networks. Among the reasons can be mentioned: the expansion of the range of services, the widespread use of Metro Ethernet and PON technologies, falling prices for fiber-optic products, and the success of individual operators in building FTTxnetworks. More and more often you can hear that "the houses of this microdistrict will be connected using the latest technologies," and this means just FTTx.- just an architecture, but the main technologies now are Metro Ethernet and PON. Which of them is better is a matter of preference, and there is no clear answer to it. The table shows the key features of these technologies.