With the advent of cloud computing,
over-the-top on-demand video (Netflix, YouTube, Hulu etc.), high definition TV
there has been immense rise in the IP traffic with most aggressive rise seen in
financial sector thus demanding huge scalability and availability of the data
centers. The standardization of 100G has been a massive success for optical
industry and with the collaboration of ITU-T and IEEE, has led to the
commercial availability of products featuring 100G in the market. But the strive for
improving the bandwidth need and network capacity has required to look what’s
ahead 100G. As 40G and 100G are already standardized, the next Ethernet rate
with OTN is supposed to be 400G or 1T.
The Task Force that has been appointed
for 400G are going through many architectures based on advanced modulation
formats including 16 channels x 25Gb/s NRZ, 8 channels × 50 Gb/s duo binary and
PAM-4, 4 channels × 100 Gb/s PAM4, hybrid CAP-16/QAM- 16, and QAM-16-OFDM. Among
these, all except 16 channels x 25 Gb/s NRZ shows greater power efficiency
improvement while 16 channels x 25 Gb/s NRZ provides best optical power budget
margin. In order to make 400G commercially feasible, there is a need for denser
photonic integration as the optical parallelization will increase compared to
the standards set by 100G Ethernet. The issues with high lane rates can be addressed
using advance format of modulation with photonic integration.
Looking at 1T Ethernet
and OTN, it requires great extent of parallel transport in LAN and moderate
spectral efficiencies in WAN. There have been experiments with results of 1.2Tb/s
optical super channels, but solutions to such results needs substantial optical
parallelization. Under WAN, a move from 8bit/s/Hz (which is for 400G) to a
higher value is extremely difficult, but nevertheless not impossible. Results
like this makes 400G much more achievable as the next target for LAN and WAN.
The growing needs of
operators and end users requires network change in terms of addition of
stations/ improved reliability and cost-efficiency. Ethernet requires to cope
up with situations, thus adapting and evolving to all the levels of network changes.
Ethernet has its widespread use in transport, data centers, data connectivity
services which asks for new improved standards to address market demands. We
have seen Ethernet evolving from shared CSMA/CD to switched point-to-point Ethernet
and then bringing multi-lane technology over shared media of passive optical
networks. Now Ethernet has undertaken new brand by providing common transport platform
for control and multimedia applications.
The introduction of 40Gb
and 100Gb Ethernet standards for the very first time, saw the Ethernet network
at 40G and 100G. This was called High-Speed Optical Point-to Point Links. Keeping
into account the huge demand of customers and the network providers, the
optical standards for 40G and 100G aims at reducing the cost and complex nature
of broad deployment of 100G Ethernet. Then we had EPON which provided low cost
deployment of optical access lines from carrier’s central office to customer
site. Even though EPON was hugely successful, there were issues in addressing
problems such as deployment of EPON architecture in rural areas in cost
effective manner, how to decrease the cost of connection per subscriber,
serving more people at longer distance. To address all these issues came
Extended EPON Taskforce.
Next there was a shift from MPEG-2
to MPEG-4 video distribution over IP Ethernet. This aimed at mixing EPON and EPoC
while reusing existing coaxial distribution infrastructure along with
fiber-deep access technologies. Metro Ethernet Forum (MEF) service performance
and competitive service level agreements (SLAs), are all being managed by Data
over Cable Service Interface Specification (DOCSIS) Provisioning of EPON technology,
which is jointly developed by operators, vendors, and CableLabs. This was how
EPON Protocol was tied together to work with coaxial.
Ethernet continues to evolve by
providing support to new media types, addressing new application space. It has
now entered in the new market of Automotive Industry as it has variety of
solutions for optical media and electrical backplanes. The modern cars have
infotainment, auto braking, collision avoidance, GPS which creates huge traffic
for in car network, all of which was not managed in the previous automotive networks.
Having new standards for 40G and 100G already in the market, Ethernet now has
broader market for products that are more cost effective, decreases complexity
and power consumption.
Carrier Grade Ethernet- Since Ethernet
is extremely simple to operate and is inexpensive, it has highly gained
popularity in transport network operator. Since transport network have huge
number of attached devices, scalability is very important. For corporate
customers, to meet the requirements of QoS, SLAs are defined which includes
bandwidth, availability, delay and jitters.
Ethernet in the first Mile- uses existing
copper pairs to provide fixed connection speed, symmetric bandwidth up to 35 Mb/s
within an Ethernet enabled exchange. With this one can extend network reach by providing
cost-effective and flexible alternative to fiber. This helps small and
medium-sized enterprises (SMEs) to move to hosted cloud environment.
Avionics Ethernet- ARINC 429 data bus has
been used by civil avionics applications, but the data bus has its limit of
100Kb/s which is not sufficient owing to the increased complexity of avionics
systems. In order to reduce the development costs, Avionics full duplex switched
Ethernet was introduced(AFDX). Its integration in Airbus 380 was great success
in civil avionics and because of this it has become attractive for adoption in
military avionics as well.
Audio and Video Bridging Ethernet- With rise
in home multimedia, customers are attracted towards the technology of accessing
content and resources from anywhere in the house using their own devices.
Ethernet finds its use in such applications as well. The changes of MAC and
802.1D bridges would enhance the old Ethernet technology allowing it to provide
low latency service for streaming applications.
Among many fields of application, Automotive
Ethernet interests me majorly. We did not see the Ethernet being used in
automobiles even though it existed way before, since it could not bring down
the latency levels to microsecond range, it could not control bandwidth and synchronize
time between devices. The demand for advanced infotainment features and better driver’s
assistance is on rise now, hence great demand in automotive Ethernet use. The
most used in-vehicle network technologies are LIN, CAN and MOST, all of which
are automotive specific, but they are reaching their capacity limits. Ethernet
is low cost network technology which also fulfills the in-vehicle network requirements.
When it comes to infotainment, we need interactive
and streaming applications. Ethernet has variable frame which means that it has
full control over the flow of the data, transmitting few bytes at high
frequency and transmits frames of large size. Also, customers have the tendency
to connect their personal devices to the in-vehicle network which creates
additional traffic. Because of this the critical domains need to be separated
from such traffics, for this VLANs are used which isolates the broadcast
domains thus not affecting any domains.
The number of smart cars have risen after
BMW, Volkswagen and Jaguar have launched their respective smart cars that are
equipped with WiFi hotspots, music docks, smartphone chargers etc. Apart from
this, the Automotive Ethernet cables also reduces the labor cost by nearly 50%.
Because of all these features Ethernet is considered as potential backbone technology
which can also carry CAN and other bus system traffics. Ethernet has shown its
adaptability in picking up new technology towards wired and wireless
communication thus choosing to stay in automotive industry.