Harness classification

According to different structures, it is divided into full utilization harness, partial utilization harness and link system; according to different service methods, it is divided into loss system harness and waiting system harness (see random service system); according to the number of service load sources Different, divided into infinite load source wire harness and limited load source wire harness.

In the telecommunications system, the equipment directly used for communication between users is mostly an infinite load source loss system full utilization link system, while the equipment used to control the connection process of communication equipment is mostly an infinite load source waiting system full utilization system. . When the number of load sources is not very large relative to the capacity of the wire harness, a full utilization system or a partial utilization system with limited load sources is generally used.

According to the call behavior of the load source, that is, whether to make a new call attempt after the user's call fails, the wiring harness can be divided into a repeating call system and a non-repeating call system. The actual communication system has repeated calls, and the non-repeated call system is an approximation of the repeated call system.

1) Full utilization harness. If any service equipment (trunk or machine key) in the harness can be used by any load source in the load source group it serves, such a harness is called a full utilization harness.

Figure 2 shows the full utilization of 100 first preselectors (load source groups) of the step-by-step switch, and 10 outgoing lines of its arcs are correspondingly multiplexed to 10 first group selectors (the service device is the machine key) harness. Any service device (the first group selector) in the circle can be used by any load source (the first preselector) in the load source group (100 first preselectors) it serves.

2) Partial utilization of the harness. If any load source in the load source group can only use part of the service equipment in the wire harness, such a wire harness is called a partial utilization wire harness. The partial utilization harness divides the load source group into several sub-groups, and performs sub-product reconnection between the outlet wires of the load group. This structure can be described by the example shown in the figure below.

The traffic load capacity of the partial utilization harness is lower than that of the full utilization harness under the same harness capacity. Its traffic load capacity or call loss rate is related to the utilization and the multiplexing method of the product. Under the conditions of the same wire harness capacity and call loss rate, a good split-product composite structure can improve the load capacity of the wire harness. The greater the utilization, the closer the efficiency of the harness is to the full utilization of the harness.