Traffic routing and automatic network management system for telecommunication networks

Claim 2

A computer based, adaptive traffic routing and automatic network managing system for multi-service telecommunications networks, said system comprising: a plurality of nodes; a plurality of transmission trunks connecting the nodes; means for determining a tariff, in communication with the nodes, for each communication between said nodes, said tariff being determined depending on distance between said nodes and on other parameters including type of service provided; and means dependent on said tariffs for providing the nodes with instructions for routing connections within the network of nodes such that revenues of handled communications are maximized and such that trunks and nodes which are not available for service are automatically bypassed.

Claim 3

The system defined in claim 1 wherein the means for determining a tariff and the means for providing the nodes with instructions for routing connections comprise a computer having a data base, the tariff information being stored in the data base wherein a plurality of the nodes are Stored Program Control (SPC) nodes and wherein information is stored in the data base relating to overall network status in terms of actual traffic offered in each SPC node to each other node and actual availability for service of each trunk group and node.

Claim 4

The system defined in claim 2 wherein for calls originating in each SPC node i to each other destination node j, the direct trunks between the nodes will be indicated to be used as a first choice and two other alternative paths I and II will be indicated, one of them comprising a two-link path over a tandem node t to be used as a second choice and the other comprising a three-link path over tandem nodes t and u respectively to be used as a third choice.

Claim 5

The system defined in claim 3 wherein the indicators for paths in terms of direct trunks and/or identities of tandem nodes t and u respectively, for calls originating in the SPC node i to any destination node j are determined according to the following algorithm: (a) calls of service type k with the related tariff c ij (k), where: c.sub.ij (1)>c.sub.ij (2)> - - - >c.sub.ij (K); will be indicated to use direct trunks between nodes i and j as a first choice, if the destination node j is available for service, R jx =1) and the trunk group between node i and j has at least one trunk available for service, (N ij -P ij >0) and the actual traffic and occupancy status for the trunk group between nodes i and j is such that the expected revenue from a connection of service k is greater than the estimated loss of revenue due to this connection, from services of higher tariffs, which mathematically can be expressed as: ##EQU22## (b) node t as a feasible tandem for a two-link path is determined, if the destination node j is available for service, (R jx =1) and such, for which the tandem node t is available for service, (R tx =1) and trunk groups between nodes i and t as well as between nodes t and j, each have at least one trunk available for service, (N it -P it >0 and N tj -P tj >0) and the expected revenue from the service k tandem connection is greater than the estimated loss of revenues, due to this connection from traffic that could be handled over direct trunks in the two trunk groups i-t and t-j, which mathematically can be expressed as: ##EQU23## (c) nodes t and u as feasible tandems for a three-link tandem path are determined, if the destination node j is available for service, (R jx =1) and such, for which the tandem nodes t and u are available for service, (R tx =1 and R ux =1) and the trunk groups between nodes i and t, between nodes t and u and between nodes u and j each have at least one trunk available for service, (N.sub.it -P.sub.it >0, N.sub.tu -P.sub.tu >0 and N.sub.uj -P.sub.uj >0) and the expected revenue from the service k tandem connection is greater than the estimated loss of revenues, due to the tandem connection from traffic that could be handled over direct trunks in the three trunk group i-t, t-u and u-j, which can be expressed mathematically as: ##EQU24## where: i=number of an originating node; i=1, 2, - - - m; j=number of a terminating node; j=1, 2, - - - m; j≠i; m=total number of Stored Program Control nodes in the network, which can be used as tandems; k=number of a service type; k=1, 2, - - - K; m=number of another service type; K=total number of services; c jk (k)=tariff per time unit of communication between nodes i and j for service type k; R jx =availability indicator for node j; R jx =1, indicates that node j is available for service associated with receiver and sender x; N ij =total number of trunks in operation in trunk group between nodes i and j; P ij =the actual number of occupied trunks in trunk group between nodes i and j; A ij (k)=traffic of service type k, offered from node i to node j; A ij (k)=y ij (k).h j (k); y ij (k)=call intensity of service type k, offered in node i to node j; B(N;p)=conditional probability of all N trunks busy, given p trunks have been observed to be occupied at the moment of network scanning; can be approximately calculated from ##EQU25## A=total traffic offered to N trunks; t=identify (number) of tandem node 1; t=1, 2, - - - m; t≠i, t≠j; u=identity (number) of tandem node 2; u=1, 2, - - - m; u≠i; u≠j; u≠t; and h i (k)=average holding time for service type k, originating in node i.

Claim 6

The system defined in claim 4 wherein the algorithm is applied to only one type of service, e.g.: c.sub.ij (1)>0 and c.sub.ij (2)=c.sub.ij (3)= - - - =c.sub.ij (K)=0; A.sub.ij (1)>0 and A.sub.ij (2)=A.sub.ij (2)= - - - =A.sub.ij (K)=0; in which case the system is directly applicable to present intercity telephone networks.

Claim 7

The system defined in claim 5 wherein the tariff for a communication is equal to unity, e.g.: c.sub.ij (1)=1; in which case the system is directly applicable to flat rate networks, such as present metropolitan telephone networks.

Claim 8

The system defined in claim 4 wherein the two alternative paths I and II, if more than one route is feasible for either or both types of alternative paths, are respectively selected at random for the type or types having more than one feasible path and where the alternative I is used as a principal tandem path and alternative II is used only in case path I is unavailable.

Claim 9

The system defined in claim 7 wherein the routing instructions in terms of tandem node identities are transferred to the SPC nodes over data links provided between the nodes and the system's computer and wherein these data links are serving also for transfer of data from the SPC nodes to the computer in terms of indicators for: (a) node-to-node offered call intensities, y ij (k); (b) trunk group availabilities, P ij , or N ij -P ij ; (c) average holding times, h i (k); (d) node availabilities, R ix ;

Claim 10

The system defined in claim 8 wherein on-demand interventions and man-machine communication are performed by means of a special System Management & Intervention Language SMIL.

Claim 11

The system defined in claim 9 wherein routing instructions stored in the SPC nodes serve as a back-up in case all communication means between the SPC nodes and the system's said computer are out-of-service.