OTN switching & P-OTN effectively reduces network cost by 100 GB (2)

OTN switching & P-OTN effectively reduces network cost by 100 GB (2)

Globally, the growth rate of mobile and Internet traffic is unprecedented. The reasons for this phenomenon include the growth of cloud services, mobile broadband, and Internet-based on-demand video streaming services. Cisco predicts that from 2012 to 2017, Internet IP traffic will triple to 120 bytes per month, and mobile data traffic will increase 13 times, more than 11 bytes [I] each month. Bell lab predicts that traffic in the metro and backbone networks will increase by 560% and 360% [II] respectively in the same time segment. This high-speed Bandwidth growth puts unimaginable pressure on the optical transport network that is the cornerstone of the current IP network. Due to the high cost of deploying new optical fibers, network operators need a new way to greatly increase the network capacity.

In recent years, the optical transmission technology has made great strides, especially coherent optical detection, to help upgrade the 10g bandwidth of the common DWDM transmission network to 100g, there is no need for loss of optical distances, costly Optical Fiber replacement, or addition of dispersion compensation equipment. This is undoubtedly a great benefit for network operators. They can use the existing optical fiber facilities to achieve a 10-fold growth in the optical fiber capacity, reaching 8 TB/s or even higher. However, to make such a technology economically feasible, the network must be able to effectively utilize the new optical fiber capacity generated, which is not achieved overnight.

From the operator's perspective, the adoption of OTN switching in a G network brings the following significant benefits:

1. Improved CAPEX Efficiency
2. Reduced OPEX and faster service speed
3. Improved network Elasticity
4. Flexible "pay-as-you-go" Service

Improve CAPEX Efficiency

To deploy a new 30G service, you can simply add 30g user ports on this node. These user traffic can be combined with the traffic of existing clients to bring together an appropriate 100 Gbit/s WDM uplink card to maximize the use of existing optical fiber resources. Client signals in the shared wavelength do not need to be directed to a public node-as long as the signal can be forwarded to another node through a certain channel. As a result, The capex overhead on the infrastructure and equipment can be more than 35% lower than the network architecture based on muxponder multiplexing forwarder [III]. The conclusion of large-scale network modeling studies shows that using OTN exchange to process and converge sub-wavelength traffic can increase the wavelength utilization by 250% [IV].

Especially in man, more investment in transmission networks is required to reduce the cost per bit. As the price of 10G optical devices keeps falling, the cost of using G bandwidth with low efficiency cannot be higher than that of 10G optical devices. By greatly improving the utilization rate of Gbit/s wavelength, OTN switching is the key to deploying a large scale of Gbit/s in the Metropolitan Area Network.

Reducing OPEX & improving service speed

From the operational point of view, OTN greatly simplifies business deployment and management, and can dynamically allocate client services to any available g wavelength, this means that the addition, deletion, and redistribution of services do not require manual intervention on the intermediate node. On the contrary, the remote implementation can be achieved through OTN switching configuration. The results not only greatly save OPEX costs, but also allow network operators to quickly make profits for high-value differentiated businesses.

Improved network Elasticity

The sub-wavelength processing and the ability to dynamically allocate clients to WDM uplink ports also allow network operators to adopt a mesh network architecture with higher connectivity. Compared with ROADM-based networks, this architecture provides faster fault recovery capabilities. In an OTN switching network, monitoring and protection are implemented at the business layer, instead of the optical layer. Therefore, all-optical protection mechanisms are indispensable and are faulty, the time-consuming and complex optical path calculation and modulation processes are no longer required, which shortens the fault repair time by 10 times or more. This achieves a robust and reliable carrier-level network and significantly improves QoS. [V]

Business flexibility of "pay-as-you-go"

Last, compared with the fixed point-to-point WDM architecture, the OTN switch can split the client port from the WDM line port and upgrade it separately, so that network operators can reduce capital expenditures related to new client services.

To give a simple example, a network operator has a new requirement to support high-value services from a new data center customer. The customer needs 16 GB Fiber Channel client services. In a muxponder-based network, if the existing multiplexing repeater device does not support 16g Fiber Channel client services, the network operator not only needs to purchase new G devices, this includes spending on clients and G coherent optical devices. A new G wavelength must be deployed to support this service. In contrast, in an OTN-based network, network operators can "pay-as-you-go" by deploying a new client line card that supports the 16g Fiber Channel. The new client service can also be added to any line port-as long as the port capacity is sufficient, it can also be moved to any different line port at any time. For network operators, this means the maximum business flexibility. Flexibility is particularly important in the initial phase of the transfer of network services to data centers and the cloud market, because the On-Demand dynamic bandwidth is crucial.

Global network operators recognize these advantages and have fully deployed OTN exchange platforms in China, Europe and North America. In fact, a recent infonetics survey shows that 86% of network operators in the interview are either already or are preparing to deploy OTN switching [VI] in their man and core transmission networks.

 

[I] "Cisco visual networking index: Forecast and methodology, 2012-2017.", ciscosystems inc., May 2013

[II] "Cisco visual networking index: Forecast and methodology, 2012-2017.", ciscosystems inc., May 2013

[III] M. Bertolini et al., "benefits of OTN switching introduction in 100 Gb/s opticaltransport networks.", OFC/nfoec technical digest, paper nm2f. 2, 2012

[IV] a. deore et al., "total cost of ownership of WDM and switching ubunturesfor next-generation 100 Gb/s networks.", IEEE communications magazine, november2012

[V] "cd roadm-Fact or fiction", Fujitsu network communications, 2013

[VI] "OTN, MPLS, and control plane strategies: global service provider survey," infonetics research, May 2013