Introduction
Ethernet technology has evolved to meet new bandwidth and market requirements. In addition to computers, Ethernet is now used to interconnect appliances and other personal devices. It is used in industrial applications and is quickly replacing legacy data transmission systems in the world’s telecommunications networks.
In this research, we shall discuss interface options for Ethernet and the optical transport network (OTN) beyond 100G. 100G Ethernet technologies give carriers the flexibility to phase in the implementation of these higher-speed rates to better align capacity increases with their specific growth and budget strategies. As we will see, 100G single wavelength channel is capable of significant cost reduction for the required component. Also we will have a look into HECTO project.
Because of the increasing Ethernet traffic in networks, in this paper you will find some Ethernet services should be scaled by Ethernet infrastructure which will protects the traffic.
100G Ethernet
With the reality of 100G ethernet, the community has recently started to increase its ambitions to look into technology beyond 100G. Nowadays, ethernet is keeping up with the plethora of data services that drive exponential network traffic growth between 40 and 90 percent per year.
IEEE 802.3 has 10x bit rate scaling by incorporating 40G ethernet into the 100G standard. This way shows us the increasing technology gap between desired ethernet rates and cutting-edge serial transmission bit rate in 100 LAN technologies.
For the 100G WAN technologies, they need to accommodate exponentional rising traffic demands increasing per-fiber WDM capacities.
In the future, there might be 400G LAN technology. It will likely continue the parallel transmission approach by 100G Ethernet, but the degree of 400G Ethernet is higher comparing to the 100G Ethernet standard.
For 400G WAN technology options it must be higher spectral efficiencies to allow increase WDM system capacities.
Nowadays,1 Tb/s interface rates differ. 1 T Ethernet and OTN will almost certainly need significantly parallel transport interface in the LAN and in the WAN.
High-speed components for 100G Ethernet transmission in one wave length only
To transmit 100G b/s on multiple wave length is almost impossible because of the partitioning of the signal and the different speed at which the lower-rate signals propagate through the fiber. So, the transmission of signal at 100 G b/s data rate on one wave length seems to be simple and straight forward by using on-off-keying (OOK). There is also a way to make this transmission works. We can use quadrature phase shift keying with polarization multiplexing and coherent detection. This phase carries the information of 4bits instead of 1bit, but the transmission is very expensive because of the complexity of it.
The utilization of four wave length and 25 G b/s for each sub signal is the result of comparing a low number of wave lengths and the low bit rate of the sub signal.
HECTO
“HECTO” is the name of a project done by European commission which is the short-term of: (High-speed Electro-optical Components for Integrated Transmitter and Receiver in optical Communications).
The idea of this project is to develop the circuits for a rate of 112G b/s with error-free operation. The goal of HECTO is to make 100 Gb/s Ethernet cost efficient components for electrical to optical as well as optical to electrical conversion. These converters should be developed as integrated devices to achieve high-performance devices and cost-efficient technologies. Also the project tries to develop both components in tight cooperation. Dedicated system experiment were planned to investigate the proper interaction between the transmitter component ant the receiver component. The transmitter and the receiver for fiber optical communications should be able to be manufactured as products after completion of the project based on serial 100 GbE signals requiring about 100G b/s.
The result achieved by the HECTO consortium would strongly impact the telecommunications industry and overall network-user community.
Ethernet aggregation and transport infrastructure OAM
Ethernet is now expanding to inter-metro virtual private network (VPN) services as a layer 2 alternative to multiprotocol label switching (MPLS) VPN services. It is poised to become the dominant backhand interface for mobile services with the deployment of fourth generation technology.
Service provider Ethernet architectures have evolved because of the increasing volume of Ethernet traffic and broad ended of application for Ethernet. By using platforms that utilized Ethernet ports effectively and provide significant Ethernet aggregation back toward the service edge.
Ethernet support OAM tools that enable providers to capitalize the simplicity and flexibility of Ethernet OAM protocol comprise four components: configuration and service provisioning, fault indication, diagnostic functions, and performance monitoring. These protocols operate at different layers within the Ethernet stack:

Discovery layer: that discover attributes of physical links on network elements
Transport layer: which is the physical or link layer. It is a link monitoring and remote failure indication.
Network layer: deals with the forwarding of Ethernet frames based on tunnel identifiers within the frame. It is used as the aggregation component for the services layer.
Service layer: deals with individual service instances. This layer uses 3 protocols: IFFF 802.1ag , MEF 16 E-LMI ( Ethernet- local Management interface), and 1TU-T Y.1731. it helps operators turn up services and support measurements of performance parameters at the service instance granularity.

Ethernet aggregation and transport network must have protection. There are 2 ethernet forwarding mechanisms that provide Ethernet aggregation and transport infrastructure

First: Ethernet aggregation and transport over point-to-point VLAN(s),
Second: Ethernet-based packet aggregation and transport over IEEE 802.1 Qay(PBB-TE).

These mechanisms meet all the functional and availability requirements for Ethernet-based packet aggregation and transport layer and create point-to-point Ethernet networks with no MAC learning and flooding functions enable.
Conclusions
100G Ethernet and OTN are employing the highest serial bit rates. For 400G it seems to be available in both LAN and WAN.
And for the components developed in HECTO potentially have set the stage for cheaper 100GBE by transmitting on one wave length only with one transceiver instead of using 4 wave lengths.
Key Ethernet OAM and protection switching protocols are essential enhancement to evolve Ethernet beyond a simple switch metro enterprise service.
References
From IEEE magazines:
– COMG_20100701_Jul_2010
– COMG_20090201_Feb_2009