Analysis on the allocation of optical fiber resources in man

1 Overview

At present, after completing the network transmission infrastructure construction, China's major communication operators have made full use of the bandwidth of the existing transmission link and sought new value-added communication services to increase business profits.

The implementation of e-commerce and e-government, as well as the development of telephone bars, Internet cafes, and other small-and medium-sized Telecom customers have seen the recent boom in Man and the increase in the proportion of market profits, it has become a hot spot in a new round of competition.

In the main city of Chongqing, Chongqing Netcom plans to set up 400 IP address phones; mobile companies are expected to set up 300 IP Phone supermarkets; China Telecom and China Unicom have their own plans to set up Internet cafes; in addition, more than 200 units in the main city have the intention to build a private network, which leads to a new problem for local operators while vigorously expanding their new customers: how to complete the configuration of optical fiber in the network when the existing optical fiber resources in the man are getting increasingly tight, so as to meet the customer's activation requirements as soon as possible and seize market share.

Now, based on the geographical location of new customers and the features of activated services, a communication company is building a man in the sandarea area of Chongqing, in light of the shortage of optical fiber resources in the local network, the corresponding emergency solutions for optical fiber configuration are used as examples.

2. Construction framework of man in Sha area

The geographic structure of man in Sha area is divided into core layer, aggregation layer, access layer, and end-user-oriented optical fiber access link. The network uses MSTP Technology in the core layer and convergence layer to facilitate seamless integration of SDH, IP, ATM and TDM. This not only improves the utilization of transmission links, but also provides powerful service management capabilities to meet Personalized Requirements of different users. However, in view of the fact that the network is oriented to end users using FTTX + VDSL technology, therefore, in order to make up for the insufficient optical fiber resources at the aggregation layer and ease the bandwidth pressure on the aggregation layer, the access layer and end user links are specially configured.

In the construction of the core layer of the Area Network, the 144-core optical fiber cable is used as the transmission line, and two backbone IP data node routers are deployed ). At present, there are still surplus optical fiber resources at this layer, and access ports can be added based on future development needs; the aggregation layer uses a 24-core optical fiber cable as the transmission line and sets 622 Mbit/s and 155 Mbit/s interfaces. At present, the optical fiber resources at this layer have become increasingly tight and become a "bottleneck" affecting network upgrades. The access layer selects 12-core optical fiber cables and is equipped with SDH optical terminals. From the perspective of the entire network, the edge of the access layer is not very clear, and it is not conducive to signal passthrough and management. To reduce the transmission cost of small-scale end users, the network uses a 4-core optical fiber cable on the end user's optical fiber link.

The core layer and convergence layer are the topology of the ring network, while the access layer is the topology of the star and tree. End users usually use the traditional direct connection of bare IP fiber. The advantage of this networking mode is that it saves the investment in transmission equipment at the core and aggregation layers, and reduces the network construction cost. However, the network architecture is complex, nodes are widely distributed, and access server bandwidth is insufficient. Therefore, smooth upgrade is urgently needed.

3. configuration scheme of insufficient optical fiber resources at different layers in man

3.1 core layer optical fiber configuration

Throughout the man, the core layer is mainly responsible for large-capacity business scheduling and transmission of various services, to achieve interconnection with ATM, PSN, FR/DDN and CHINANET backbone networks. 144-core optical fiber cables can be smoothly upgraded in the future. However, in order to enhance the multiplexing rate of transmission links, we can also consider applying WDM Technology at this level in the future. The core layers of the separately established IP Broadband Network and the Metro Transport Network are unified to the same wavelength division platform to carry SDH, MSTP, and IP Broadband Services. In this way, the wavelength resources can be flexibly scheduled to meet the bandwidth requirements of the IP network. It can also solve the problem of bare fiber direct connection's consumption of optical fiber resources and improve the utilization of network resources.

3.2 optical fiber configuration of the aggregation Layer

In the metropolitan area network, the aggregation layer is mainly responsible for gathering and directing services in the network, providing local service scheduling and multi-service aggregation and distribution. From the perspective of transmission links, a large man must apply at least 36 ~ The 48-core optical cable is used to load the current traffic mainly carried by the access layer. This simplifies the topological structure of the access layer of the Metropolitan Area Network and reduces the network construction and operation costs, and better meet the business distribution needs of a large number of users.

3.3 optical fiber configuration of access layer

The access layer is mainly used to connect businesses to nearby aggregation points to achieve coverage at the user's geographical level. Compared with the entire man, this layer is the richest and most cost-sensitive technology, generally, 12-core optical fiber cables should be set. However, in order to address the shortage of optical fiber resources in some regions, MSTP technology can also be considered for networking. This makes the entire man more compact, more flexible configuration, and richer service interfaces.

3.4 optical fiber configuration of the optical fiber access link for end users

For Terminal-oriented Optical Fiber Links, a 4-or 6-core optical fiber cable is generally used to complete the physical connection of the network. However, to improve the optical fiber utilization rate of end users, it is usually solved by cascade communication devices. Now, let's take the IAD as an example. IAD uses Ping its IP address code to implement logical connections in the network. After multiple IAD cascade operations, different IP address codes can be used to avoid mutual interference.

After cascade communication equipment and the established fiber optic network connection, it is through the new laying of the optical fiber into an end, and then the adjacent two T-BOX) fiber optic cable trunk box, the use of jumpers constitute a loop.

However, in the real Metropolitan Area Network, optical fiber cables cover a wide range of areas, and users are scattered across each other. In more cases, the geographical locations of the two users are far apart. This requires from the original user's optical fiber into end ODF, T-BOX), and then lay a new cable to the new user end, which may lead to different users of optical cable, repeated Construction of overlapping routes appears in the geographical distribution. To solve this problem, the new and old optical cables can be directly connected using the "open Skylight" method in the proper position of the original optical fiber cables during the project construction, this eliminates the need to invest in new user transmission. At the same time, it facilitates the optimization and management of the entire network.

4 optical fiber connection scheme after device Cascade

In order to clearly describe the connection method for the implementation of "opening the skylight" on the optical cable, a communication company in Chongqing is taking the case that a user needs to activate the telephone business immediately, this article describes the New Interventional Optical Fiber bridging method without affecting the important services activated on the first and second-core optical fiber cables.

Description of conditions for new users to activate: The existing optical cable lines are 120 m from the nearest point of the user. However, because there are no customers nearby, it is the trunk cable without opening; the customer who activated the service is 1800 m closest to the user. If the customer follows the original connection method, a new optical cable with a length of about m needs to be laid from the original client, and in the original client into the end of the T-BOX Using Fiber jumpers to connect the two optical cables. This not only consumes more optical cables and increases the construction workload, but it is particularly important that the routes are the main roads of the city. It is quite difficult to add new optical cables for both overhead and pipeline laying; in addition, in view of the urgent requirements of new customers, re-laying of optical cables is not allowed.

To this end, the project uses the existing optical fiber cables open at the point closest to new customers, and uses the "Limit 2" cutover method to ensure that the communication between 1 and 2 core important customers is not interrupted, connect the new M optical fiber cable to the existing 3 and 4 optical fiber cables. The procedure is as follows.

1) First, find the original used optical fiber completion data, and to the activation of business 1, 2 Core Optical Fiber customers of optical fiber cable packing box T-BOX to check the optical fiber serial number, confirm the number and color of the bundle of the first and second cores in the original optical cable. Then, contact the customers who have activated the NBA service on the 3 and 4 cores, ask about the suspension time, and set the optical cable cutover time ~ 03: 00 h no business period.

2, then, cut out the plastic reinforced cables in the optical cable to leave room for the next step of longitudinal strip of the beam tube. Use a beam tube vertical strip knife to strip the beam tube 85 ~ After 110cm, the cables are also removed. Then, the cables are added with a strong core, and the two stripping ends of the original cables are respectively shelved.

3) after the fiber bundle tube of the original optical cable is vertically peeled off, the first and second optical fiber cables are picked out to ensure that the site is not interrupted into the optical fiber receiving disc of the receiving box. Then, the new intervention optical fiber cable is mounted from another exit of the Connection Box. After splicing, the No. 3 and No. 4 optical fiber cables of the original optical fiber cable are cut off, and the new intervention optical fiber cable is bridging. The optical fiber color sequence of the new intervention optical fiber and the original optical fiber cable is: 1, 2 blue and orange fiber of the new intervention optical fiber) the core is connected to the 3, 4 Green, and 4 Green cores introduced by the original Optical Cable respectively. The core is 3, 4 Green, and 4 Green) the core is connected to the 3, 4 Green, and local fiber cores of the original optical cable.

4) after the optical cable cutover is completed, call any contact number on the 1 or 2-Core Optical Fiber. You can call the number to confirm that the optical cable cutover has been completed successfully.

5) This optical cable cutover scheme can also be applied to customers who are newly involved in the future. However, it is worth noting that although the scheme does not interrupt fiber links that do not need to be opened, it will open the physical connection to the fiber links that need to be opened, in this way, the communication between devices that need to be enabled in the optical fiber link must be manually blocked. The disconnection time is closely related to the technical level of the connection personnel.

5 conclusion

At present, to maximize the development and utilization of optical fiber resources in the man, the solution is to rationally configure the optical fiber resources in the network. Although the focus of the solution varies with the transport layers of the entire man, the solution relies on different solutions, the purpose is to build a large-capacity, multi-service, scalable, and open high-reliability man transmission platform to provide a good material foundation for new businesses in the future. Compared with the upgrade of transmission technology, it is cheaper and safer to reasonably configure optical fiber resources.

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