TX- 1 Faculty ALTTC, Ghaziabad Concept of a Speech in Point to Point link RXTX TX RX
TX- 1 Faculty ALTTC, Ghaziabad SDH Rings 1 SDH is normally configured in a ring architect. 2 This is done to create loop diversity for uninterrupted service protection purposes in case of link failures. 3.The SDH rings are commonly called self healing rings, Because traffic flowing in a certain path can be switched automatically to an alternate path. 4.Self healing rings works on two different type of chemistry. A- Unidirectional Self healing rings. B- Bi-directional Self healing rings. 5. The concept of traffic in both type ring is different.
TX- 1 Faculty ALTTC, Ghaziabad Features of SDH Rings 1.There can be either two or four fibers running between the nodes on a ring. 2. The operating signals can travel either clockwise or counter clock only (USHR). 3. The operating signals can travel in both directions around The ring (BSHR). 4.Protection switching can be performed either via a line switched Or a path switching scheme. 5.In BSNL only two fiber ring mechanism is being adopted.
TX- 1 Faculty ALTTC, Ghaziabad Concept of Speech in SDH Ring A – in Uni Directional Self Healing Ring RX TX TX RX RX TX TX RX RX TX ADM A ADM B ADM C ADM D
TX- 1 Faculty ALTTC, Ghaziabad Continued Features of USHR 1.The chemistry of USHR is less informative. 2.But it protect traffic positively. 3.It offers cost effective solution for low level of capacity network.
TX- 1 Faculty ALTTC, Ghaziabad In USHR, two type of protection scheme are applicable 1- Path protection 2- line switched protection
TX- 1 Faculty ALTTC, Ghaziabad USHR – Path Protection Node E Node D Node C Node A Node B
TX- 1 Faculty ALTTC, Ghaziabad Actually in our system path protection is not there Q. Why Ans. In our systems we are keeping on auto laser set and auto laser restart functions on always. So if one fiber is going to be faulty both ends lasers switched off and it simulate the condition of complete section faulty condition.
TX- 1 Faculty ALTTC, Ghaziabad In our systems actually line switch protections is available It satisfied three condition –Traffic is always in Ring –And traffic always in one direction –Traffic is in ring of one fiber. Concept of Line Switched Protection
TX- 1 Faculty ALTTC, Ghaziabad Concept of Line Switched Protection A – in Uni Directional Self Healing Ring RX TX TX RX RX TX TX RX RX TX ADM A ADM B ADM C ADM D
TX- 1 Faculty ALTTC, Ghaziabad Feature of BSHR The chemistry of BSHR is more informative. The scheme requires a APS protocol to make operative. The traffic flows from node 1 to node 3 in clockwise Direction along links 1p and 2 p. But in return path the traffic flows in counter clockwise From node 3 to node1 along links 7p and 8p. Thus the information exchange between nodes 1and3 does not tie up any of the primary channel bandwidth in the other Half of the ring.
TX- 1 Faculty ALTTC, Ghaziabad Concept of Speech in SDH Ring A – in Bio Directional Self Healing Ring RX TX TX RX RX TX Node 1 Node 2 Node 3 Node 4 RX TX TX RX RX TX 1p 2p 3p 4p 5p 6p 7p 8p
TX- 1 Faculty ALTTC, Ghaziabad Concept of BSHR – Protection Mechanism To understand the concept of BSHR – it is very essential to understand the concept of traffic. Traffic is Theoretically of two type – Centralized Traffic – Distributed Traffic But practically traffic is having mixed concept
TX- 1 Faculty ALTTC, Ghaziabad Node A Node D Node B Node C Two-fibre STM-16 ring 2 AU-4s 8 AU-4s 6 AU-4s 16 AU-4s total Spare between Nodes A & B and Nodes A & D are at capacity Centralized Traffic Pattern 8 AU-4s 6 AU-4s 2 AU-4s Two fiber STM-16 ring
TX- 1 Faculty ALTTC, Ghaziabad Since all the traffic is designated for node A, and the span Between Node A and node B is full. Traffic from node C routes through node D, Leaving the span between Node B And node C vacant.
TX- 1 Faculty ALTTC, Ghaziabad Node A Node D Node B Node C Two-fibre STM-16 ring 8 AU-4s 32 AU-4s total All spare are at capacity Purely Distributed Traffic Pattern 8 AU- 4s
TX- 1 Faculty ALTTC, Ghaziabad Node A Node DNode C Two-fibre STM-16 ring 4 AU-4s 2 AU-4s 8 AU-4s 5 AU-4s 22 AU-4s total All spare are at capacity Node B 4 AU-4s 3 AU-4s T1516760-94d11 Mixed Traffic Pattern 3 AU_4s 3 AU-4s 2 AU-4s 1 AU-4s 4 AU-4s
TX- 1 Faculty ALTTC, Ghaziabad MS shared protection rings MS shared protection rings scheme is supported by only BSHR.The ring protocol is essential for both two fiber ring or four Fiber ring. In BSNL only two fiber rings are deployed. MS shared protection rings are characterized by dividing the total payload per multiplex section equally into working and protection capacity. For a two fiber STM_N ring, N/2 administrative unit Groups (AUGs) available for working and N/2 (AUGs) for protection. The protection capacity is shared between multiple Multiplex sections
TX- 1 Faculty ALTTC, Ghaziabad The sharing of protection capacity may allow a multiplex section shared protection ring to carry more traffic under Normal conditions than other ring types. The sum of the tributaries that transverse a span cannot exceed the maximum capacity of the particular span. In MS shared protection the service can be routed in either one of the two directions,the long way around the ring or the short way. For normal working shortest path is preferable. For failure condition,the alternate path in used.
TX- 1 Faculty ALTTC, Ghaziabad Node A Circuit Q Node B Node C Node FNode E Node D Working Protection Circuit Transporting Service Normal Traffic In MS-Spring Node a Node b Node c Node d Node e Node f working protection Ckt transporting service Normal state
TX- 1 Faculty ALTTC, Ghaziabad ` Node A Circuit Q Node B Node C Node FNode E Node D Working Protection Circuit Transporting Service Protected Traffic In MS-Spring working protection Ckt transporting service Node a Node b Node c Node d Node e Node f Failed state
TX- 1 Faculty ALTTC, Ghaziabad Procedure of loading MS- spring. Prepare physical map of ring of different nodes. assign individual node ID to each node either in clockwise direction or in counter clockwise direction. Zero node ID be offered to master node. Maximum station may not be more than 16 excluding regenerator.