TSI (Time Slot Interchange)From space switch to T-S-T switchSlide 3Programming the switchlast updated March 8, 04 M. Veeraraghavan 1TSI (Time Slot Interchange)•Let the contents of time slots 1 through 24 be as shown on the incoming line.•The switch configuration requires data in slot 1 to be read into slot 24 and vice versa, and data in slot 2 to be read into slot 23 and vice versa1224abc1224cdadb2323abcd122324writes inorder of arrivalpermutes as per switch configurationand reads outlast updated March 8, 04 M. Veeraraghavan 2From space switch to T-S-T switch•The intermediate stage switch is a single switch of size: n 12....n 12....n 12....k 12....k 12....k 12....k 12....k 12....k 12....n 12....n 12....n 12....TSI 1TSI 2TSI N/nTSI N/nTSI 2TSI 1nNnNnNnNThe intermediate stage switch is reprogrammed for each of the k time slots.Replace each first-stage and every last-stage switch by a TSI. Replace multipleintermediate-stage switch with a single time-shared space switch.last updated March 8, 04 M. Veeraraghavan 3BVIEW WITH ANIMATIONA CDProgram the two sets of TSI stages and the intermediate space stage accordingly A->C, B->A, C->D, D->BThe time to send three slots between 1st stage and 2nd stage is the same as the time to receive two slots into the 1st stage.D1 could have been sent in the first slot on L2 because it could have been sent out on L4 in time slot 1 and then switched around by TSI 4 to the appropriate slot going to D2 x 3(TSI 1)B1 A1Connected to A and BB1 A1L12 x 3(TSI 2)D1 C1Connected to C and DD1 C1L2t=1A1L3L43 x 2(TSI 3)3 x 2(TSI 4)Connected to C and DConnected to A and BA1B1C1C1B1t=2D1D1t=3last updated March 8, 04 M. Veeraraghavan 4Programming the switch•Means setting the operational behavior of all the TSIs and the time-shared space switch•Previous slide example:–TSI1: TS1->TS1; TS2->TS2; blank->TS3–TSI2: blank->TS1; TS1->TS2; TS2->TS3–TSI3: TS1->unmapped; TS2->TS1; TS3->TS2–TSI4: TS1>TS1; TS2->TS2; TS3->unmapped–time-shared switch•at time = 1, cross-over•at time=2, direct•at time=3,