On Distributed Communications Series

XI. Summary Overview


Progress in synthesizing the Distributed Adaptive Message Block Network is reviewed in this Memorandum, and conclusions are drawn with respect to its anticipated characteristics. The advantages and disadvantages of the proposed system are listed in a comparison with traditional approaches to communication networks.

An outline of critical key tasks required for further development of these concepts is given.

Summarizing the last few years' work in this field:

  1. It appears theoretically possible to build large networks able to withstand heavy damage whether caused by unreliability of components or by enemy attack.
  2. Highly reliable and error-free digital communication systems using noisy links and unreliable components can be built without exceeding the present-day state-of-the-art of electronic components--provided we use digital modulation.
  3. We are beginning to understand, or at least to appreciate, the cause of time delays and overloading phenomena in communication systems handling competing users with different levels of importance. There is a basis for hope that one day we may be able to automate highly sophisticated priority systems. Such systems may even be so effective as to provide the operational equivalent of exercised judgment.
  4. it appears that a proper direction in which to move in attacking the secrecy problem in large military and commercial communication systems, is to design the cryptographic provisions as an integral part of the digital switching system.
  5. Digital communication systems able to serve highly automated sources can be more readily designed from the viewpoint of bit-transportation systems rather than the conventional approach of a tandem connection of real-time links.
  6. One day in the future (and we are not foolhardy enough to predict an exact date), for economic reasons alone in the military environment it may be necessary to break away from existing analog signal communication network concepts in favor of all-digital networks.
  7. It is appropriate to redesign user input-output instruments, such as telephones and teletypewriters, for the described system in order to gain the full benefit that accrues to an all-digital conirnunications network.