A kind of digital dispatching communication system
Technical field
The present invention relates to a kind of digital dispatching communication system, the digital dispatching communication system of especially a kind of exchange and the shared time slot of extension set.
Background technology
In the special-purpose digital communication system of scheduling, generally include several dispatching communication subsystems, these dispatching communication subsystems generally adopt the Star Network structure, in this network configuration by one as the exchange of central node with form by several extension sets that the Digital Transmission passage is connected radially with this exchange.According to this networking plan, the conversation of dispatching telephone control board and each scheduling extensions all will take a time slot of Digital Transmission passage, and what scheduling extensions are arranged, and must take what time slots, and these time slots superpose with conferencing at the dispatching telephone control board place again.The subject matter of such scheme is: 1. to take the time slot of data transmission channel many in system communication, the waste resource, and cost is big.2. system safety cost height.For making system communication safety, must consider the time slot backup, otherwise the disconnection of place's Digital Transmission passage will cause whole dispatching patcher paralysis.And the number of time slots of backup should equate with the number of time slots of using, take under the more situation of time slot this, field condition will be difficult to guarantee that the backup time slot has circuitous path, promptly enable to guarantee backup, the data channel of single kind is also very limited to the contribution of the communication security of system, if adopt the transmission channel of other kind, as microwave or satellite channel, the inevitable system cost that increases greatly.3. be unfavorable for carrying out respectively of time slot management and transfer management.
Summary of the invention
At the problems referred to above, the purpose of this invention is to provide and a kind ofly help system safety, take the digital dispatching communication system that the transmission channel resource is few, cost is low.
For achieving the above object, the technical solution used in the present invention is: a kind of digital dispatching communication system, comprise several communication subsystems, each communication subsystem by an exchange with form by several extension sets that the Digital Transmission passage is connected with this exchange, in each communication subsystem, exchange and each extension set all comprise a digital adder separately, exchange and the extension set that is connected with this exchange are connected in series in proper order by digital adder separately, by backup path time slot makeup ring l network, the shared time slot of exchange and extension set.
Described Digital Transmission passage and backup path are the Digital Microwave transmission channels, also can be satellite digital transmission channel, optical cable Digital Transmission passage, copper cable Digital Transmission passage.
Because the scheme that the present invention adopts is in each communication subsystem of digital dispatching communication system, exchange and the extension set that is connected with this exchange digital adder by separately is connected in series in proper order, by backup path time slot makeup ring l network, the shared time slot of exchange and extension set, it is few to take time slot, can save the transmission system resource greatly.When standby time slot,, therefore can in Digital Transmission passages such as microwave, satellite, optical fiber or copper cable, select a kind of better suited passage, and can not increase the cost of system too much in order to the backup time slot owing to need the time slot of backup few.For example, when the normal talking time slot provides from the optical cable transmission, back up the speech time slot and from microwave channel, provide.The scheme that the present invention simultaneously adopts also is convenient to the time slot management of system and the division of labor of transfer management, gives system development, safeguards and brought convenience.
Description of drawings
Fig. 1 is the digital dispatching communication system structural representation of the digital conllinear of employing of the present invention;
Fig. 2 is the digital dispatching system configuration schematic diagram of the employing Star Network structure of prior art;
Fig. 3 is the embodiments of the invention structural representations.
Embodiment
The present invention is further illustrated below in conjunction with drawings and Examples.
At first with reference to figure 2.Dispatching host machine adopts hub-and-spoke configuration with being connected of each scheduling extensions, and dispatching host machine takies the different time slot of Digital Transmission passage respectively with each scheduling extensions, and it is more to take time slot.The scheduling interval of supposing a railway dispatching communication system has 50 stations, there are 10 dispatching servicess, then each dispatching services need constitute a subsystem, the channel slot number that takies is 500, if adopt the E1 digital interface to communicate, because each E1 interface bandwidth is 30 time slots, then approximately needs 17 E1 interfaces.If consider the time slot backup, the timeslot number that takies will double.The Time Slot Occupancy of so many transmission channel is difficult to guarantee that the backup time slot has circuitous path, and adopts the Digital Transmission passage of other kinds, as satellite, microwave channel, will increase the cost of system greatly, is not easy to the communication of system and separating of transfer management simultaneously.
Specifically implement digital dispatching communication system if adopt the solution of the present invention, with reference to figure 1, several communication subsystems that comprise for system, in each communication subsystem, exchange and the extension set that is connected with this exchange digital adder by separately is connected in series in proper order, by backup path time slot makeup ring l network, the shared time slot of exchange and extension set, such connectivity scenario can be saved the time slot of a large amount of transmission channels.For the above-mentioned situation that 50 stations is arranged, have the railway dispatching interval of 10 dispatching servicess, shared time slot only is 10, only needs an E1 interface.When time slot backs up, adopt the Digital Transmission passage of other kinds, as satellite, microwave channel, can not increase too many cost yet, and make system safety more reliable to system.Therefore, the Digital Transmission passage and the backup path of system's employing can be selected Digital Microwave transmission channel, satellite digital transmission channel, optical cable Digital Transmission passage or copper cable Digital Transmission passage according to actual needs.
Fig. 3 is a specific embodiment that is applied to the railway system of the present invention.In this example, system comprises a dispatching communication subsystem, this subsystem by a telephone exchange system with form by several subsystems that the optical fiber and digital transmission channel is connected with this telephone exchange system, this telephone exchange system is connected in series by the digital adder in each system in proper order with the subsystem that is connected with this telephone exchange system, by microwave backup path time slot makeup ring l network.During concrete the connection, the E1 interface of telephone exchange system is connected to an E1 interface of subsystem 1 by optical-fibre channel, another E1 interface of subsystem 1 is connected on the E1 interface of subsystem 2 through optical-fibre channel equally, and another E1 interface of the latter is connected on the E1 interface of subsystem 3 through optical-fibre channel equally.So analogize, subsystem n is connected with a last subsystem E1 interface through optical-fibre channel, and its another E1 interface is directly connected on the E1 interface of telephone exchange system through microwave channel simultaneously.Like this, n subsystem connected with telephone exchange system and constituted a digital channel loop.Certainly, backup path also can be selected satellite digital transmission channel or optical fiber, copper cable Digital Transmission passage for use in this example, and the shared number of time slots of telephone exchange system and subordinate machine system can be determined according to actual needs.
In a word; the digital adder that is exchange and extension set by separately recited above is connected in series in proper order; by backup path time slot makeup ring l network; the digital dispatching communication system of the shared time slot of exchange and extension set, the distortion of any scheme on this basis are all within protection range of the present invention.