Leonard Kleinrock – 112 Lindner
by Saurabh Gupta
Lecturer – Leonard Kleinrock
Venue – 112 Lindner / College of Business, University of Cincinnati
I, in my own excursion, had been catching upon Threat to Internet, Tim Berners Lee’s first WWW, Ted Nelson’s idea of this. I had this lecture as upcoming since last year spring. I liked it all coming together yesterday (05/05/2011). The community of people who were bent to foster a new language through a new medium. The were bent to bend the world.
So what did Leonard Kleinrock talk about? I tweeted –
Leonard klienrock. Nikola tesla. Idea since?ARPA1958.1969.Queuing.NCP.BBN.EMAIL.hawai.robert morris.al gore.grokster.future.nomadic.embeddedtech.ubiquitouscomp.softagents.
so that I can come back to it later ..
twt prt#1 About Leonard Kleinrock
He picked up his PhD. dissertation on following topic – “Information Flow in Large Communication Net”. His problem was many fold. The best resource allocation mechanism for incoming messages for a node, establish design guidelines for node capacity, routing, topology, determine channel capacity between two nodes, what can jam a large network of nodes.
twt prt#2 So what did Nikola Tesla say
“It is intended to give practical demonstrations of these principles with the plant illustrated. As soon as completed, it will be possible for a business man in New York to dictate instructions, and have them instantly appear in type at his office in London or elsewhere. He will be able to call up, from his desk, and talk to any telephone subscriber on the globe, without any change whatever in the existing equipment. An inexpensive instrument, not bigger than a watch, will enable its bearer to hear anywhere, on sea or land, music or song, the speech of a political leader, the address of an eminent man of science, or the sermon of an eloquent clergyman, delivered in some other place, however distant. In the same manner any picture, character, drawing, or print can be transferred from one to another place. Millions of such instruments can be operated from but one plant of this kind. More important than all of this, however, will be the transmission of power, without wires, which will be shown on a scale large enough to carry conviction. These few indications will be sufficient to show that the wireless art offers greater possibilities than any invention or discovery heretofore made, and if the conditions are favorable, we can expect with certitude that in the next few years wonders will be wrought by its application.”
wow! did he really say that in 1908?!.. An idea, how much ever crazy it might be, always develops a meta physical form for an invention which is itching to take shape. This is how Mr. Kleinrock introduced us to the brief history of such a wild idea
twt prt#6 Understanding Queuing for a system of unsteady flow through network of channels
In such a flow system, the demand for resources is unsteady. The response time for a node in network is also indeterministic. Thus, as he explains, the transmission time for the packet was indeterministic. However, he put up interesting assumption on response time of each node – i.e. that it follows simple rule of being independently random. Therefore, our exponential distribution can be easily used to determine this. Now for the demand on resources. This, how much ever random it is, follows a rule of being so large that “total demand is equal to the sum of average demands of each member”.
Lets consider a network of nodes which are interlinked to one another. Now each node is connected to one or more number of other nodes, and this number is termed as resources available to transmit a message across the network. So the next thought he explains is optimum number of such resources needed to serve incoming messages at this node. This optimum number would mean most throughput against least average response time across the system of interlinked nodes. This, as part of his dissertation, is where he lays down a deduction which lead to development of Internet as we see it today. The optimum number of resources needed to serve a queue, which is being filled at random and which can be only served at random length of time, is ONE. This means every node should be only connected one another node which will be further connected one another node and so on.
So as he explained, our complicated system is reduced to M/G/1 type Queuing problem which has a formula
This kind of network of nodes is called “point to point” topology served by switches – in our case Packet Switching. Introduced by Leonard Klienrock for first time as “Message Switching”.