Networking plays an important role in our life. It brings people closer even though they r physically miles apart. The traditional networks are wired (optical) networks and wireless networks. The future of networking lies on the amount of traffic which is increasing day by day. Current optical networks are providing a transmission capacity of 100Gbits/sec per Ethernet (100GbE). Assuming the network traffic is going to double every two years we require transmission capacity atleast 100Tbits/sec in 2020. Assuming high network traffic in future due to growing population and business activities it is essential to make ultra high speed networks to support traffic and system reliability. These networks must also should make use of low power so as to consider the global warming. A huge bandwidth service is defined as circuit switched, highly reliable, low latency and dynamic end to end paths. Examples of these networks include, remote conferencing, e-commerce based on virtual face to face systems, remote diagnosis, remote teaching etc.
The networks requiring ultra high capacity, low power, high reliability and extremely low latency will require combination of following points. 1) Much higher speeds than OF comm. and wireless comm. 2)Efficient operation of the network. From the viewpoint of the environment we can’t increase the consumption of resources to increase capacity. And also developments in transfer and optical transmission technologies need to cope up with physical limits of optical fibers (OF).
The first physical limit is OF bandwidth. Core networks which transmit signals to long distances must make use of low loss wavelengths in the range 1450-1650nm. This 200nm bandwidth corresponds to the frequency band of 25THz. New technologies can help to increase frequency efficiency range from 0.4bits/s/Hz to tenfold so that entire low loss bandwidth range is utilized then we can able to get transmission capacity up to 100 THz. The second physical limit is optical power at the input. The current transmission power per unit of transmission bit is of the order of several tens of mill watts per terabit per second. If we increase transmission capacity to 100 THz, the power required at the input will be in the range of several watts. This exceeds threshold of fiber (about 1.5 to 2 watts) and fiber core melts which is known as fiber fuse phenomenon. Therefore to support growth of the traffic, we must not only utilize the potential of optical fiber by developing innovative technologies but also provide network resource utilization efficiency through fundamental network architecture.
To build ultrahigh speed networks the following points are considered to be essential for the architecture of the network. 1) Simplification of networks that use potential optical technology, such as introducing high capacity routers which avoid usage of intermediate optical-electrical-optical (OEO) regeneration. 2) Adaptive access, so that wireless and optical networks can be customized depending on bandwidth requirements.3) Efficient usage of network resources, such as allocation and adjustment of servers, routers etc.
The technologies which support this network architecture to achieve ultra high speed networks are, 1) Optical core network technology : This includes advanced optical transmission technology (multilevel modulation, OFDM etc), optical transparent network and elastic path(line capacity increases with increase in traffic). 2) Access network technology: This includes optical access network (has FTTH- Fiber to the home), terabit lan (providing multiwavelength interface) and ultrahigh speed wireless access technologies. 3) Device technology : This includes developing devices which provide high capacity, high sensitivity with low power consumption by using planar light wave circuit (PLC) and MEMS techniques in photonic crystal fibers.
The amount of information is growing erroneously, which can’t be handled by human by usage of current networking models. These networks will change the way how information is to be shared throughout the world. Thus the future networks will be ultra high speed networks, which contain high capacity and also low power so as to reduce the usage of resources and helping environment.
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