What is the working principle of Time division Switching ?

Question

In telephony space switching is well understood, but time slot switching, is not all that clear. Any reference to web site is welcome.

Answer 1

www.eecs.berkeley.edu/~messer/PAPERS/IEEE/Jul89-1.pdf

ieeexplore.ieee.org/iel5/8749/27719/01236307.pdf

and an interesting newly awarded patent that I c/p'd from freepatentsonline:

Title:Time slot switching function diagnostic system Document Type and Number:United States Patent 5349578 Link to this page:http://www.freepatentsonline.com/5349578.html Abstract:According to this invention, a time slot switching function diagnostic system includes a first inserting circuit, a data memory, an address controller, a second inserting circuit, and a check circuit. The first inserting circuit inserts path monitoring test pattern data into a specific on-line time slot of a unit frame consisting of N time slots. The data memory writes and reads data input to the time slots. The address control circuit supplies write and read addresses to the data memory. The second inserting circuit feeds back an output from the data memory to an input side to repetitively insert the test pattern data in time slots sequentially following the specific time slot. The check circuit extracts the test pattern data from an output corresponding to an Nth time slot of the data memory to check the test pattern data.

Answer 2

Participants in the network have very excellent clocks connected to their radio (with a clock precision that is finer than the time between messages). Each radio also has an assigned address. When that address has its calculated time to broadcast it sends out the preamble to its message followed by its message and a post-amble. The other radios are listening before transmitting. If another radio was about to broadcast and then hears that message, that other radio will defer its message to avoid interfering with the radio's message. If two radios interfere they will lose their messages and then wait a random time before retransmitting. The result is that each radio ends up with a time slot in which it broadcasts when its time is due. Every other radio is expected to listen while one is transmitting. In addition to the slot that each has, those network participants with a lot of information to share may get multiple time slots.