Abstract ASON technologies is the development of optical transport network a key breakthrough, the paper discusses the positive aspects of ASON networks as properly as the partnership between SDH and OTN, ASON is discussed in detail the transmission plane, manage plane, and network management characteristics and progress of the plane, and finally for the optical transport network evolution technique to the ASON may be analyzed.
Search phrases automatic switched optical network user network interface synchronous digital sequence good quality of service
2000 years later, the optical transport network technologies there are new developments, mainly automatic switched optical network (AutomaticallySwitched OpticalNetwork, ASON) the emergence of its most prominent function is the introduction of an independent transmission network intelligence handle plane, control plane to full the routing employing automatic discovery, get in touch with connection management, protection and restoration, so as to implement the dynamic get in touch with connection to the network management. ASON draws heavily on the exchange and information technology, to exchange, transfer and data in 3 areas has added a new intersection. Numerous makers and operators of the technologies have been offered due interest. This will be the essential technology and its progress ASON discussed in detail and based on current national transmission network operators, the characteristics of the technical evolution of the system could be discussed.
1 ASON technical qualities 1.1 ASON positive aspects ASON is a service request initiated by the customers, automatic routing, signaling manage achieved by the connection establishment / removal, financial exchange and transfer as a single of the subsequent-generation optical network. Combined with the domestic transmission network operator status, ASON technology can resolve the transmission network into 3 main technical challenges faced:
(1) the concern speedily to provide circuit
ASON most important feature is to swiftly give the circuit, utilizing a distributed control can offer orders of magnitude in the second end of the circuit, the price for 155Mbit / s, two.5Gbit / s and so on. Companies reduce the time assist operators gain more buyers and profit.
(two) transmission circuit QoS troubles Transmission circuit existing level of basic services can not be created in accordance with the proper tariff policy, resulting in waste of resources, and ASON on the circuit can easily divide the priority to provide a service level agreement (SLA) of transmission circuits.
(three) can give quick protection and restoration
Largely rely on existing transmission network SDH rings to be protected, but the circuit efficiency is low, only 50%, whilst on the cross-ring circuit can not be properly protected. The ASON can effectively resolve the circuit protection and restoration can be completed in the second magnitude, and the price of spare circuit significantly less resources, common sources for the operate of the circuit for 30% to 60%, nicely beneath the SDH ring network.
1.two ASON and SDH, OTN relationship
Automatically switched optical network is divided into transmission plane, handle plane and management plane in three parts. Transmission plane which includes the exchange of entities from the transmission network composed of network components, is the realization of the connection establishment / removal, exchange and transfer of the physical plane. The introduction of ASON handle plane is different from the standard transport network is a fundamental point, which consists of a series of actual-time signaling and protocol system to understand the connection establishment, release control and monitoring, maintenance and other functions, the signaling manage plane network assistance. Management plane is the control plane and transmission of the management plane.
ASON handle plane is suited to the OTN (optical transport network), also applies to SDH, the transmission network as a unified handle plane. SDH, OTN and ASON in the relationship can be expressed in Figure 1.
Can be seen from Figure 1, a separate SDH / OTN and does not constitute ASON, to constitute the ASON should SDH / OTN + plane + subsequent-generation network management handle plane (management and control can also plane and the transmission plane), 3 are indispensable. SDH, OTN transmission plane only ASON technologies, ASON and SDH, OTN and does not include relations.
two ASON Technical Improvement 2.1 Technologies transfer plane As the current line price
reached 1.6Tbit / s, line capacity issue has been resolved. Transmission plane sent the most prominent problem is the node that the transmission network in the optical / electrical cross-machine, optical / electrical cross-machine is the core of transmission plane, the size of its processing capacity related to the ASON throughput and processing energy, particle size .
Wavelength cross-present to achieve high capacity in three methods: The 1st is the all-optical switching, the second is the use of O / E / O (optical / electrical / optical) processing to accomplish, the third is the photoelectric hybrid method. All-optical strategies due to its stability and fault detection and place difficulties, is nonetheless in the experimental stage, commercialization will take some time. The opto-electronic hybrid approach the challenges facing the exact same way with all-optical. Now it seems the use of optical / electrical / optical method is the mainstream solution, specially in SDH-based optical / electrical / optical cross-machine (can be cross-VC-4 level). With the advent of huge-capacity cross-chip (presently single cross-chip can reach 160Gbit / s and above), the core cross-cutting capacity of Tbit / s is not really difficult. To the market has been industrial-oriented 1.28Tbit / s merchandise as an instance, assume that input and output ports of the processing price of 10Gbit / s, the cross-matrix of size 128 × 128 ought to be a lot more than the capacity of its external service access 1.28Tbit / s. This rate of capacity is suitable for the present network, although route on the backbone WDM System is 32 × 10Gbit / s, but the actual with the wavelength is generally 4 to eight, assuming that every single line has eight wavelengths need to have to be processed, the matrix can be cross-path of the end of the 16 WDM line. Even for such a core transmission node Beijing, currently meet the specifications. Employing optical / electrical / optical mode is a characteristic of other low-level VC can cross to achieve a low price of integration and aggregation, network a lot more easily.
Optical / electrical / optical approaches can assistance high-capacity cross-Machine VC-four and VC-four-Xc level crossing. In the external interface is usually 2.5 Gbit / s, 10Gbit / s, can be G.707 SDH interface or G.709 OTN interfaces. SDH interface supports 2 fiber, four fiber MS-Spring multiplex section protection ring. As the connection status monitoring by the sending side have to initiate the connection point and end point detection signal good quality for SDH, OTN, you can use SDH, OTN overhead for performance monitoring and fault management, such as SDH monitoring bytes B1, J0 , manage surfaces require