1. Communication and communication
At present, these two words are used frequently, but how to define the scope of meaning has not been clearly unified.
"Communication" in the traditional sense mainly refers to telephone, telegram and telex. The "message" of communication refers to the message, and the media message is transmitted from one end to the other through the communication network. The contents of media messages are mainly voice, text, pictures and video images. Its network is mainly composed of electronic equipment system and radio system, and the signals transmitted and processed are analog. Therefore, the word "communication" should refer to the process of realizing the above-mentioned media information transmission by means of telegraph, telephone and other media transmission systems.
"Communication" only refers to data communication, that is, end-to-end transmission of data is realized through computer network system and data communication system. The letter of communication refers to information, and the carrier of information is binary data. Data can express information in traditional media forms such as sound, image and animation.
Because the old "communication" system has realized the transformation of digitalization and computer networking, it can be considered that the current data communication system has covered the functions of the old "communication" system. According to this conclusion, at present, the word "communication" should be used more to represent the data transmission between the Internet and LAN, and the word "communication" should be used less or not as much as possible to avoid conceptual misunderstanding.
2. Node to node, interconnection and interconnection
You can often see "network nodes" and "network nodes" in technical articles, and also mention "interconnection" and "interconnection". Is there a clear definition between them? In fact, this is a purely linguistic problem, which has nothing to do with technology. Even if there is a mixture, it will not cause ambiguity, so these words can be used indiscriminately.
3. Protocols and standards
There are different protocols or standards on the Internet. The concepts of "agreement" and "standard" are similar, but different. The agreement is hierarchical, which refers to the agreement that all communication parties abide by in low-level terms; As far as the top layer is concerned, it is an agreement about network application and management. So the essence of the protocol is an agreement, and it is a formal agreement. For example, IP is the third layer protocol of OSI/RM.
The scope of the standard is broader, including not only written agreements, but also all rules that are uniformly implemented on the network. So standards are sometimes called norms or rules. For example, IEEE 802.3u is a fast Ethernet standard formulated by the American Institute of Electrical and Electronics Engineers, and it can also be considered as a large class of protocol sets of 100M Ethernet. Category (CAT3, CAT5) is the line standard of unshielded twisted pair set by EIA/TIA. It can only be called a standard, not an agreement.
Second, the same word has different meanings.
1. Bandwidth
In network technology, bandwidth has different meanings in different applications. One refers to the frequency bandwidth of the network-frequency band width, that is, the difference between the maximum frequency and the minimum frequency of the network signal, in hertz; The other refers to the maximum transmission rate of local area network, which represents the data transmission capacity of local area network, and the unit is bps.
2. Speed
"Communication rate" is usually divided into two types: one is the number of bits transmitted per unit time, also called bit rate, data transmission rate, data rate or simply rate; The other is the number of symbols transmitted per unit time, also known as symbol rate, modulation rate, baud rate or simply baud rate. The bit rate value can be the same as or different from the baud rate value. For example, for a modem, its bit rate value in operation is much greater than the baud rate value.
3. Media
"Media" is a frequently used word, which can be understood as a medium used to connect two or more things. Also called media, media, media, interface, etc. In different applications, its meaning is different.
When "media" is used in the field of public information dissemination, it is called media, such as radio, television, newspapers, magazines and websites. , all belong to the media.
When used in computer information processing technology, "media" is called media information. Usually refers to voice, text, graphic images, animation and other media, that is, multimedia.
When used in network and communication technology, it is called media medium, communication medium and transmission medium. We are familiar with cables, optical cables, radios and microwaves. , belong to this category.
In addition, in the field of software application, the part of media information output to users through the display is called the user interface of software (>: >.
Question 2: What does communication mean? Communication refers to the transmission and exchange of information from one place to another, with the purpose of transmitting information. However, with the development of social productive forces, people's requirements for delivering news are getting higher and higher. Among all kinds of communication modes, the communication mode that uses electricity to transmit information is called remote communication. This kind of communication is fast, accurate and reliable, and it is almost not limited by time, place, space and distance, so it has been developed rapidly and widely used.
Question 3: What does communication protocol mean? Communication protocol refers to the rules and conventions that two entities must follow in order to complete communication or service. Multiple data communication systems in different geographical locations interconnected by communication channels and devices must have the same language, so that they can work together to realize information exchange and resource sharing. What to communicate, how to communicate and when to communicate must follow some rules acceptable to both sides. This rule is the communication protocol.
Communication protocol refers to the rules and conventions that two entities must follow in order to complete communication or service. The protocol defines the format used by the data unit, the information and meaning that the information unit should contain, the connection mode, and the time sequence of sending and receiving information, so as to ensure that the data in the network can be successfully transmitted to a certain place.
In computer communication, communication protocols are used to realize standards between computers and networks. If there is no unified communication protocol in the network, the information transmission between computers cannot be recognized. Communication protocol refers to the communication rules agreed by both parties in advance, which can be simply understood as the same language used by computers to talk to each other. The communication protocol that two computers must use when communicating.
Question 4: What's the difference between communication and communication?
1. Communication and communication
At present, these two words are used frequently, but how to define the scope of meaning has not been clearly unified.
"Communication" in the traditional sense mainly refers to telephone,
、
. The "message" of communication refers to the message that media messages pass through.
The network travels from one end to the other. The contents of media messages are mainly voice, text, pictures and video images. Its network mainly includes
System and
The system structure, transmission and processing signals are all analog. Therefore, the word "communication" should be used concretely.
Telephone and other media transmission systems.
This process.
"Communication" only refers to
, that is, through
and
Data realization
Transmission. The letter of communication refers to information, and the carrier of information is binary data. Data can be used to express.
Formal information, such as sound, image, animation, etc.
Because the old "communication" system has been realized.
Computer network transformation, so it can be considered that the current
It has covered the functions of the past "communication" system. According to this conclusion, the word "communication" should be used more at present.
between ... and ...
The word "communication" should be used as little as possible to avoid conceptual misunderstanding.
2. Nodes and
, interconnection
You can often see ""and ""in technical articles.
Is there a clear definition between "interconnection" and "interconnection"? In fact, this is a purely linguistic problem, which has nothing to do with technology. Even if there is a mixture, it will not happen.
So these words can be used indiscriminately.
3. Protocols and standards
There are different protocols or standards on the Internet. The concepts of "agreement" and "standard" are similar, but different. The agreement is hierarchical, which refers to the agreement that all communication parties abide by in low-level terms; As far as the top level is concerned, it is right.
, management protocol. So the essence of a protocol is a protocol, and it is a formal protocol, such as IP.
Layer 3 protocol.
The scope of the standard is broader, including not only written agreements, but also all rules that are uniformly implemented on the network. So standards are sometimes called norms or rules. For example,
It is electricity.
Formulated by the association
Standard, which can also be considered as1100mm.
A large category
; Categories (CAT3, CAT5) are two organizations of EIA/TIA.
Established line standards can only be called standards, not protocols.
Second, the same word has different meanings.
1. Bandwidth
exist
"Bandwidth" has different meanings in different applications. One refers to the frequency bandwidth of the network-
, that is, the difference between the highest frequency and the lowest frequency of the network signal, in hertz; The other means
maximum
, representing the data transmission capacity of the local area network, in bps.
2. Speed
"Communication rate" is usually divided into two types: one is transmission in unit time.
Also known as bit rate,
、
Or simply rate; The other is transmission in unit time.
Number, also known as
、
Baud rate or abbreviation.
(Baud rate). The bit rate value can be the same as or different from the baud rate value. For example, for modems, the bit rate is much higher.
Special rate value.
3. Media
"Media" is a frequently used word, which can be understood as a medium used to connect two or more things. Also called media, media, media, interface, etc. In different applications, its meaning is different.
When used by the public
In the field, "media" is called media, such as radio, television, newspapers, magazines, websites and so on. , all belong to the media.
When used in a computer
Technically, "media" is called media information. Usually refers to voice, text, graphic images, animation and other media, that is
.
When used in networks and
It is called media media, media,
. As we all know, cables,
、
, microwave, etc. , belong to this category.
In addition, in the field of software application, the part of media information output to users through the display is called software.
(User Interface) ...>& gt
Question 5: What does it mean to be engaged in providing letters? Training objectives: This major trains senior engineering and technical personnel who have knowledge of communication technology, communication system and communication network, can engage in research, design, manufacture and operation in the field of communication, and engage in the development and application of communication technology and equipment in various departments of national economy and national defense industry. Business training requirements: Students in this major mainly study the basic theory, composition principle and design method of communication systems and communication networks. After the training of communication engineering practice, they have the basic ability to engage in the design, development, debugging and engineering application of modern communication systems and networks. Graduates should acquire the following knowledge and abilities: 1. Master the basic theory and knowledge in the field of communication; 2. Master communication technologies such as light wave, wireless and multimedia; 3. Master the analysis and design methods of communication system and communication network; 4. Have the basic ability to design, develop, debug and apply communication systems and communication networks; 5. Understand the basic principles, policies and regulations of communication system and communication network construction; 6. Master the basic methods of literature retrieval and information query, and have certain scientific research and practical work ability. Main courses: main subjects: information and communication engineering, computer science and technology. Main courses: circuit theory and application series, computer technology series, signal and system, electromagnetic field theory, digital system and logic design, digital signal processing, communication principle, etc. Main practical teaching links: including computer training, electronic technology practice, circuit comprehensive experiment, production practice, curriculum design, graduation design, etc. Generally, it is required that the practice teaching link should be no less than 30 weeks. Length of study: four years. Degree awarded: Bachelor of Engineering with similar major: microelectronics automation, electronic information engineering, communication engineering, computer science and technology, electronic science and technology, biomedical engineering, electrical engineering and its automation information engineering, information science and technology software engineering, film and television art technology, network engineering, information display and photoelectric technology integrated circuit design and integration system, photoelectric information engineering, radio and television engineering, electrical information engineering, computer software, electrical engineering and management intelligence. Science and technology digital media art computer science and technology detection guidance and control technology electrical engineering and its automation digital media technology information and communication engineering building electrical and intelligent electromagnetic field and wireless technology.
Question 6: Why does modern communication still exist when there are so many things that communication cannot be realized? For example, it is a pleasure to be familiar with a person's trajectory. Now, for example, a small painting represents the meaning that communication can't achieve. There are also stamps that can be issued as collectibles, which have commemorative significance and collection value, and can be used by countries and places to commemorate great men and events. .....
Question 7: What do you mean by the first author and correspondent? In papers, we often see that besides the first author, the second author and the third author, there are also correspondent authors.
The main difference between the two is that the correspondent is the most important author of the article, and the correspondent is generally responsible for all liaison work in the process of submission, revision and acceptance of the paper.
The correspondent is the person in charge of the project, responsible for project funding, design, article writing and proofreading, and contact with the outside world. If you want to know the difference between them, you can consult 58 Journal Network.
The correspondent is not necessarily the first author, but the first author can be a correspondent. In most cases, the author of the communication and the first author are the same person. Only when the correspondent author and the first author are inconsistent, it is necessary to attach the logo of the correspondent author to the footnote of the article.
Question 8: What does it mean that the main party of communication is called in the same exchange?
Communication in which one or both parties are in motion. Include land, sea and air mobile communication. The adopted frequency bands cover low frequency, intermediate frequency, high frequency, very high frequency and ultra-high frequency. A mobile communication system consists of a mobile station, a base station and a mobile exchange. In order to communicate with the mobile station, the mobile switching office sends a call to the whole network through each base station, and the called station sends a reply signal after receiving it. After receiving the reply, the mobile switching office assigns a channel to the mobile station and sends a signal from this channel to ring it.
Features:
(1) mobility.
Is to keep the communication of objects in a moving state, so it must be wireless communication, or a combination of wireless communication and wired communication.
(2) The propagation conditions of radio waves are complicated.
. Because the moving body may move in various environments, electromagnetic waves will produce reflection, refraction, diffraction, Doppler effect and other phenomena in the propagation process, resulting in multipath interference, signal propagation delay and broadening.
(3) Serious noise and interference.
Automobile spark noise, all kinds of industrial noise, intermodulation interference between mobile users in urban environment, adjacent frequency interference, same frequency interference.
(4) The system and network structure are complex.
It is a multi-user communication system and network, and users must not interfere with each other and work in harmony. In addition, the mobile communication system must be interconnected with local telephone network, satellite communication network and data network, and the whole network structure is very complicated.
(5) Require high frequency band utilization and good equipment performance.
Baidu Encyclopedia has a very detailed explanation, you can have a look!
Question 9: What do you mean by' flow' in communication? The amount of data transmitted by communication, the unit is bit, Kb, Mb, etc. We usually know. And these are generally charged.
Question 10: What does the mailing address mean? Mailing address refers to the effective actual address that can be marked and received on envelopes, mails, e-mails and other mails sent by postal means or the Internet, and generally consists of district name, street name and house number; Generally, large websites can register a free personal email address, and the email address you apply for is your email address.