What are the disadvantages of traditional communication networks?

Due to the limitation of small communication capacity and low degree of automation, the communication established by traditional methods has been difficult to meet the needs of modern warfare.

Armed with modern science and technology, the networking mode of "one place, one network" is easy to realize.

There are four reasons for the high timeliness of "one area, one network" communication:

(1) adopts multiplex transmission channel, so the communication blocking probability is low. Multiplexing channels can increase transmission capacity, so more users are allowed to communicate at the same time, and communication is not easily blocked, just as the wider the road, the greater the traffic volume, and the less the traffic volume.

(2) The network structure is adopted, and there are many communication routes. Communication network has the characteristics of multi-route transmission, and there can be multiple routes from the beginning of communication to the communication terminal. From the mesh network introduced earlier, we already know that when there are four nodes interconnected in a mesh, there are five routes from the communication starting point to the communication ending point; When five nodes are interconnected, there are 16 routes from the communication start point to the communication end point. When six nodes are interconnected, there are 65 routes from the beginning of communication to the communication terminal. The regional communication network is a grid structure. Although the number of routes from communication starting point to communication terminal is not as much as that of mesh network, it is much more than that of tree network and mesh network. Obviously, due to many routes, when the transmission in a certain direction is crowded, the idle channel can be automatically connected first to realize non-blocking handover; In addition, the regional communication network has the function of high-speed automatic exchange, and the information usually passes through a switching node in less than half a second; When passing through 20 switching nodes, it does not exceed 10 second at most, which can meet the needs of transmitting and exchanging a large amount of information in a limited time.

(3) Digital channel transmission with high transmission rate. In the section from analog transmission to digital transmission, we mentioned that communication can be divided into analog communication and digital communication according to the characteristics of signal transmission. The former transmits continuously changing electrical signals in the channel, while the latter transmits discrete current/no current (or positive current/negative current) pulse signals in the channel. The transmission rate of digital pulses can reach 56 kilobits per second on ordinary telephone lines and 65,438+0 gigabits per second on twisted-pair super-category 5 lines, which is equivalent to transmitting 5.665,438+004 and 65,438+009 current pulses in a moment. If special coaxial cable and optical cable are used for transmission, the speed will be higher.

(4) Users can be found automatically. The local communication network adopts switching equipment controlled by program memory, which can automatically search according to the pre-programmed stored program. When searching, according to the calling number issued by the user, various technical measures are taken to automatically find the user. The calling user does not need to know the current location of the called user, but only needs to dial the communication number of the other party to automatically search the whole network; Even if the user often changes the location or communication number, it can still be found according to the original number, and the time from calling the user to finding the called user is very short.