Communication engineering majors train senior engineers 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. Below, I will sort out the internship summary of communication engineering specialty for you. Welcome to read!
Summary of Cognition Practice of Communication Engineering Specialty I
1 exercise purpose
Through two weeks' professional practice, I will further master and strengthen my understanding of the theoretical knowledge of communication specialty, understand the new communication technology and the actual situation of operators, understand the electronic door network wiring and the operation of school network center equipment, and learn its working principles and fields. Integrate theory with practice to lay a good foundation for practical work.
2. Time and place of internship
Internship time: two weeks
Practice location: on-campus practice: electrical and electronic laboratory, network center, network wiring, high-performance platform, off-campus practice: China Unicom Telecom Company.
3 internship tasks and content
3. 1 internship tasks
1. Take exercise notes. 2. Contact the professional knowledge you have learned, think more and ask more questions. 3. Summarize the knowledge and experience gained in the internship and complete the internship report.
3.2 Practice content
3.2. 1 Visit the Network Wiring Laboratory of Computer College 407 to learn about the network wiring of electronic doors and their functions. Understand the equipment used in the wiring process. Handmade network cable and crystal head, combining theory with practice.
Integrated wiring training room is an important part of integrated wiring course, which creates a good platform for improving students' practical ability. By cultivating students' abilities in topology design, engineering construction, testing and project management of integrated wiring system, they can understand computer network technology, topology structure, planning and construction of computer network engineering, integrated wiring system, transmission media in integrated wiring system and integrated wiring.
Design and construction of line engineering, etc. Analyze the typical network engineering and integrated wiring engineering, and learn the design, construction and management knowledge of network engineering and integrated wiring engineering, so as to lay a theoretical and practical foundation for us to embark on the corresponding jobs.
3.2.2 Visit the High Performance Computing Platform of Security College. The high-performance computing platform of Security College is Shuguang 4000 system, and the theoretical calculation peak value is 2.9 trillion floating-point operations per second. Hardware configuration: infrastructure: rack-mounted high-performance computer cluster, which can be dynamically expanded. There are 35 existing nodes, including 30 computing nodes, 2 fat nodes, 1 management node 1 and 2 I/O nodes. In addition, it also includes: node cabinet, power supply system, wiring system, cooling system, main console, KVM and so on. Computing node: Shuguang Tiankuo i620r-g. CPU: Intel Xeon E5530 quad-core 64-bit processor,
2.4GHz？ Two. Memory: 16G
Hard disk: 146GB 15000RPM hot swap SAS. Network: Dual Gigabit Ethernet. SMP fat node:
Dawn and Sky Width I840R-H. CPU: Intel Xeon 7440 quad-core 64-bit processor, 2.4GHz? Four. Memory: 32G. Hard disk: 300GB? 2 15000RPM hot swap SAS. Network: Dual Gigabit Ethernet. Management node: The management node is competent for NIS server and compilation server, and can withstand long-term and large-scale concurrent access, with the same basic configuration as the computing node. Node hard disk: 15000RPM 10TB, hot-swappable SAS node operating system: Suse Enterprise Server 10.
3.2.3 Visit the campus network center to learn about the functions of servers and switches.
Before 20 10 and before 10, the campus network was divided into two 1000M from the main activity center of the network center. Network backbone exists? Hao San activity center infrastructure teaching building? When the activity center or three teaching equipments fail, the ring redundant network plays an emergency role. After 20 10 and 10, the backbone structure of campus network is changed to dual-core and 10 Gigabit connection. The school is divided into four areas, southwest teaching building, east teaching building, student dormitory, family area, library and service area. In the office area and home area, cancel the three-layer switch in the building and gather the directly connected area to avoid the performance bottleneck of the switch in the building. After the transformation, the campus backbone network is a dual-tree structure, and each part is connected by two 10 Gigabit links, with a bandwidth 20 times larger than before.
3.2.4 Listen to the school card lecture and learn the operation process of the one-card system.
Campus IC card adopts non-contact IC card with mature technology, and successfully combines RFID technology with IC technology to solve the technical problems of no power supply and no contact in the card. It has the advantages of convenient operation, fast running speed, strong anti-interference ability, high reliability, good safety, multi-purpose with one card and so on. With the development of VLAN technology and the strengthening of firewall technology, the campus card system based on campus network has been designed and applied. First of all, the network equipment of campus network is required to support VLAN function. Secondly, the campus network should be divided into VLANs, and the segments of all-in-one card private virtual network should be drawn on VLANs. The routing function between this network and other campus networks should be cancelled, so as to be logically separated from the campus network and ensure the security of the one-card private network. The user query part adopts dynamic Web publishing technology and adopts a three-tier structure of client /Web server/server (see Figure 4). The background is the same database server, the client is a web browser, and the middle layer is an Internet information publishing server. On the one hand, it sends a database request to the database server according to the user's operation and the definition of the script, on the other hand, it receives the feedback information from the database server, converts it into a standard HTML format and sends it to the client.
3.2.5 Visit Unicom's computer room. Understand the operation process of Unicom and the functions and functions of core equipment such as switches and routers.
Visit the computer room of China Unicom Center, network monitoring room and program-controlled exchange room. Contact with the actual equipment in the computer room; Understand the configuration of various devices and the function and composition of the actual communication network; Listen to the engineer's explanation; Familiar with the operation and maintenance content and process of each computer room.
After studying in Unicom, I benefited a lot. Computer majors have learned and become familiar with modern enterprise operation concepts and working methods, as well as many professional knowledge, such as CDMA technology, G network switching, ADSL technology and so on, which are closely related to my major. Students have a deeper understanding of program-controlled switching control, communication principle, optical fiber communication and other disciplines. Through this study, students have a deeper understanding of the division of functions in the actual operation of the communication department and further understand the communication industry.
3.2.6 Unicom senior engineer lecture, explaining the network knowledge and the prospect of communication industry. 3G wireless mobile network has greatly promoted the development of mobile Internet. At present, most 3G operators have upgraded to 3G enhanced technology, and the downlink transmission rate has increased to 21mbit/s. The high bandwidth provided by 3G enhanced technology enables Internet services that occupy more bandwidth and have strong real-time interactivity to be used in 3G networks.
The wide application on the Internet provides more space for operators' business innovation.
Optical transmission is a technology that transmits between the sender and the receiver in the form of optical signals. At present, the commercial system SDH system is 155Mbps, 622Mbps, 2.5Gbps, 10Gbps. DWDM system is 32x 10Gbps and 40x 10Gbps. Optical transmission technologies include SDH (Synchronous Digital Series), Quasi-synchronous digital hierarchy (PDH), wavelength division multiplexing, optical add-drop multiplexing, optical cross-connection and all-optical network. Optical transmission network technology, optical internet technology and broadband integrated optical access technology are the driving forces for the development of optical communication.
EPON (Passive Optical Network) is a new type of optical fiber access network technology, which uses a point-to-multipoint structure to provide a variety of services on Ethernet without optical fiber transmission. It uses PON technology in the physical layer and Ethernet protocol in the link layer, and uses the topology of PON to realize Ethernet access. It combines the advantages of PON technology and Ethernet technology: low cost; Broadband enough; Strong expansibility, flexible and rapid service reorganization; Compatibility with existing Ethernet; Convenient management, etc. Under the condition of no shortage of optical fiber resources, the cost of optical fiber can be saved by using multi-stage optical splitter with different splitting power. Triple play refers to the evolution of telecommunication network, broadcast TV network and Internet to broadband communication network, digital TV network and next generation Internet. Through technical transformation, the technical functions of the three major networks tend to be consistent, the business scope tends to be consistent, the networks are interconnected, and resources are shared, which can provide users with various services such as voice, data, radio and television. Triple play does not refer to the physical integration of the three major networks, but mainly refers to the integration of high-level business applications. Triple play is widely used, covering intelligent transportation, environmental protection, government work, public safety, safe home and other fields. The development of optical communication technology provides the necessary bandwidth and high quality for the comprehensive transmission of various business information, and has become an ideal platform for triple play services. The universal adoption of unified TCP/IP protocol will enable various IP-based services to interoperate on different networks. It has a unified communication protocol that can be accepted by the three major networks, which technically lays the most solid foundation for the integration of the three networks. For end users, triple play provides more choices and richer interactive applications.
3.2.7 Visit the campus base station to master network knowledge. Learn WCDMA network optimization technology,
Master the basic knowledge of network optimization and experience the technical application of cognitive network optimization. Network optimization is an important part of the whole wireless network construction process. Its purpose is to adjust the network reasonably according to the actual performance and performance of the wireless network system, gradually improve the network performance, and achieve the best system performance under the existing configuration conditions. Global optimization is a typical feature of CDMA technology. because
Because the frequencies are the same, network optimization should be carried out simultaneously for all base stations in the system as a whole. The optimization of WCDMA system mainly includes the following aspects:
1 cell layout optimization: including the optimization of site location, topology, whether to use multi-layer multi-frequency network, antenna azimuth, inclination and height.
2 coverage optimization: optimize the relationship between capacity and coverage, and optimize coverage indicators according to business characteristics. 3 Capacity optimization: reasonably control the load, and adjust the resource allocation by combining the blocking rate, dropped call rate and other indicators. Optimization of radio resource management: including optimization of cell parameters, handover parameters, access parameters, power control parameters and various timers.
5. Pilot pollution problem: analysis of pilot pollution problem and its solution.
Neighbor optimization: including neighbor set list optimization, controlling the reasonable number of neighbors and adjusting neighbor parameters according to the actual situation.
3.2.8 Visit the Electrical and Electronic Experiment Center
First, the teacher introduced us to the high-frequency electronic laboratory. The laboratory equipment mainly includes: oscilloscope, DA22B ultra-high frequency millivoltmeter (20KHZ~600KHZ), BT3-B frequency characteristic tester, signal generator, etc. Then give us a single chip microcomputer, which is mainly an understanding exercise of embedded and ARM. Embedded system is a computer system that designs hardware and software with complex functions and closely couples them together. The word embedded reflects that these systems are usually components of a larger system (called embedded system). Embedded systems can store multiple embedded systems. At the same time, we know the technology of PLC, and let us know the advantages and good development prospects of PLC.
4 Internship experience and harvest
College students' professional practice is the most important practical link after completing a certain course in the university study stage. Internship is a necessary experience for every qualified college student, which enables us to enhance our professional awareness and practical awareness in practice. During the two-week internship in beijing beijing Shelley Chaoyue Technology Co., Ltd., we got a deeper understanding of the basic knowledge of communication, broadened our horizons, increased our knowledge, understood the simple principles of some communication equipment, understood the latest development of the current industry, and applied the knowledge in books to practice. Seeing the lack of knowledge, the knowledge accumulated in universities is only the tip of the iceberg in the industry. Moreover, university education is far from the actual situation in real work, which requires me to study harder and learn more relevant knowledge.
Enrich your experience.
Through internship, we have the opportunity to face professionals, listen to their professional explanations and personally see many large-scale communication equipment, which is very helpful for us to understand knowledge and connect with reality, and is very beneficial to our future work. Through practice, I realized the position and role of communication in the development of national economy, deepened my perceptual knowledge of communication engineering in production and life, understood the production and operation rules of these enterprises, learned the organizational management knowledge of these enterprises, consolidated the theory, cultivated the initial practical work ability and professional and technical ability, and enhanced my academic foundation and love for the specialty of communication engineering.
(1) It's not easy to really experience the work.
(2) What used to be empty in books is much clearer now. Do you really feel it? Practice makes true knowledge? The connotation of this sentence, what you practice yourself is unforgettable, which is also the fundamental reason why human beings can live better.
(3) think small, don't be careless, there is no chance to make mistakes, and work hard every day. I personally realized the importance of doing my job well. Before doing something, we should consider all aspects of the work, especially those of us who study science and engineering, and we should have logical thinking and meticulous attitude towards things.
(4) I deeply realized the importance of learning my major and knowledge well, because we are studying communication engineering, and the status of communication engineering is very important, so I want to study in practice and make contributions to the communication cause of the motherland.
(5) Learn to be open-minded, because you can really learn things by asking with an open mind, and you can make rapid progress by asking with an open mind. We should learn from our experienced predecessors and their working attitudes and principles. This will save us a lot of detours
(6) I realize that unity and mutual assistance are crucial.
Generally speaking, I dare not say that I know a little about this internship, but what I know and feel is that I have benefited from a fortune all my life. So I firmly believe that as long as I dig hard, try bravely and consult carefully, I will certainly gain more and be inspired. Only in this way can I accumulate more rich knowledge and valuable experience for my future work and life.
Summary of cognitive practice of communication engineering specialty II
When I was a freshman, I only studied Introduction to Communication for eight weeks. Usually, through magazines, newspapers and the Internet, some teachers and professionals gave lectures for two weeks, and also visited the telephone offices of China Unicom (Daqing Branch) and Daqing Petroleum Institute. Now I sort out and summarize the basic knowledge of communication that I have mastered, so as to make better use of these resources in my future life, study and work.
The teacher
First, optical communication.
1876 After Bell invented the telephone, the research of optical telephone became a new topic for many scientists. The factors affecting the birth of optical telephone are: a meteorological conditions, stable medium for transmitting light, and c finding an ideal light source.
Known as? Father of optical fiber communication? Gao Kun, a British Chinese, has made great contributions to the research of optical telephone. Mary, Kaplan and Keck reduced the noise to 20 dB/km in 1070. What's more exciting is that they invented a semiconductor laser that can generate an ideal light source by solving two fundamental problems in the production of optical telephones.
In 1974, the light impurity noise is reduced to 1 dB/km. 1979 to 0. 2 dB/km. From 65438 to 0977, a commercial optical fiber communication system was built for the first time between Chicago and Santa Monica. Hair-thick fiberglass can open 8000 telephones at the same time.
By 1990, the development of optical fiber communication has made great progress: 1 has changed from multimode fiber to single mode (only one mode is transmitted without dispersion, and the transmission frequency bandwidth is much larger than that of multimode fiber) 2 has changed from short wavelength (0. 85 microns) to longer wavelengths (1. 3 1 micron). In the 1990s, the transmission speed of optical fiber reached 10000 megabits per second. It is equivalent to110, 1000 phones can be opened at the same time in the optical fiber of the hair. Increase optical communication every tens of kilometers? Regenerative repeater? (photoelectric lamp) Increase transmission signal. 1985? Erbium doped fiber amplifier? Born.
Optical communication: the two effects of broadening and narrowing of optical pulses cancel each other out and become constant optical communication.
The development of China optical fiber: 1977, the first wavelength (0. 85 microns) step-type adaptive fiber came out, with a length of 17 m and an attenuation of 300db/km. 1978 is reduced to 5db/km. The laser and pin detector are at 80-8 1. 1984, Wuhan and Tianjin established multimode optical fiber communication. 1986 dynamic single longitudinal mode laser was born.
Second, neural network.
Real-time implementation of optimal filtering 2 points: calculate the weight coefficient of a filter in real time and realize the optimal nonlinear filter in real time.
Digital signal processing system;
X(t)- sampling-quantization-digital signal processor -y (t)
Optimal filtering system of neural network: A: network system B: RBF network system
Their network structure is the same, r (x) = exp (-1x-c1/c * c).
Third, mobile communication.
Features: 1 Complex channel features: path loss.
multipath propagation
2 More and stronger interference: co-frequency interference (co-frequency)
Adjacent channel interference (adjacent channel)
Adjacent channels in a cellular system cannot use the same frequency.
3 Multi-puller effect 4 Flexible networking mode: large area system, small area system.
5 Limited frequency resources 6 High requirements for equipment.
Mobile network structure: base station, mobile station and mobile service switching center.
Gsm network system consists of three subsystems: mobile station, base station subsystem (bts) and network subsystem (including hrl, vrl and mobile service switching center). Regulatory system)
The frequency band in which the mobile station works: the transmission frequency (uplink) is 890 MHz 915 MHz; The receiving frequency (downlink) is 935mhz960mhz.
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