Blog

Changes in a control system's outputs are driven based on changes in the input data.  The function of the input stage of the control system is to compare and filter input data.  Allowable output state may be constrained by the environment or limitations of the system. Feedback mechanisms compare the output with desired levels. Control loops must be carefully designed to respond quickly and accurately to changing conditions, while maintaining stability.  

All businesses are constrained by something. Profitability and growth are objectives of all businesses, and we all know how difficult it is to grow and to be profitable. It's constraints that explain why.

We all stand on the shoulders of giants. Today's technology subsumes technologies that were developed earlier. The result is compounding of capacity and functionality which results in exponential improvements with each new wave of products.

The Internet bootstrapped itself first on the shoulders of the old voice+PDH network, and then on the shoulders of the SONET and SDH transport network. The Web stands on the shoulders of the Internet. Mobile Apps are enabled by mobile, the Global Positioning System and the web.

Transport networks are different than IP and other service networks.  I think of transport in terms of a simple equation:

Transport = Transmission + Switching

Transmission

Transmission is the component of Transport systems that is associated with distance, and operates at the physical layer.

Transport networks have the following functional requirements:

G.709 Amendment 3 was approved by the ITU in April of 2009. Amendment 3 will have important implications for network operators all over the world. It defines new multiplexing capabilities that support both higher and lower speed interfaces. Cyan’s range of packet optical transport network platforms are designed to provide network operators solutions that support every advantage of G.709 based networking.

Ethernet has matured from an interface, to a service, to a transport-network. Cost and revenue considerations will inevitably drive network expansion that is biased toward Ethernet in all three of these dimensions.