FEC (Future Enterprise Club of Zhejiang University)

Club

Cultural Philosophy

FEC takes membership growth as its core, and its mission is to create future business leaders. It extends six values, namely: sharing and tolerance Sex, entrepreneurship, adherence to ideals and beliefs, equality and VIP. Among them, VIP specifically represents Vision, Initiative and Professional. The cultural composition diagram is as follows:

Department Introduction

HD(HumanDevelopmentDepartment, Human Development Department Development Department)

1. New member recruitment, training, and assessment

2. Member incentives

3. Internal training

4. Member information maintenance

5. Mentor system promotion

6. Family culture construction

MPR(Market&PublicRelationsDepartment, Marketing Public Relations Department)

1. Market research

2. Resource development and maintenance

3. Club image planning and marketing

PM(ProjectManagementDepartment, Project Management Department)

1 .Establishment and promotion of project standardization system

2. Case library construction and case discussion study

3. New project development and incubation

4. Project management study And practice

KM(KnowledgeManagementDepartment, Knowledge Management Department)

1. Management and maintenance of the club’s main information platform

2. The extraction, accumulation and dissemination of effective information such as knowledge strategy

3. The compilation and management of the club’s internal publications

CCEG(CultureConsultingExecutiveGroup,Cultural Consulting Team) p>

CCEG is a permanent consultant structure of FEC, which prompts FEC to always keep a reflective mind and commit to the core of FEC development strategy and cultural continuation

Magazine

" "Speech"

"Speech" is published once a year, which brings together all members’ project summaries. Suggestions and criticisms on the common family of FEC represent the voices from FEC. Many of them are far-sighted and insightful. A club publication that is really worth reading and thinking about.

FEC (Future Enterprise Club of Zhejiang University)

Forward Error Correction

FEC: ForwardErrorCorrection, forward error correction.

It is a data encoding technology. Error detection during transmission is verified by the receiver. In FEC mode, the receiver can not only find the error, but also determine the location of the binary symbol error, so as to correct it. . The FEC method must use error correction codes. It is not necessary to notify the sender to resend if an error is found. Different from ARQ method.

In digital communication systems, forward error correction technology FEC (Forward ErrorCorrection) has been widely used. The generation and development of this technology stems from the needs of the communication system itself. In engineering practice, there is no ideal digital channel. The signal will always produce distortion and non-equal time delay in the transmission process of various media. To say it means that bit errors and jitter are generated, and the final effect of jitter is also reflected in the bit error of the system. FEC encoding and decoding can be implemented by hardware or software, and the use of FEC technology can better improve the error performance.

Forward error correction means that the signal is processed in a certain format before being transmitted, and the receiving end is decoded according to the specified algorithm to achieve the purpose of finding out and correcting the wrong code. Modern error-correcting code technology has been developed in the past 50 years by mathematicians who are interested in communication systems and engineers who have a solid foundation in mathematics. In 1948, the French mathematician Shannon published a foundational article "The Mathematical Theory of Communication Systems" on modern information theory. In 1949, Hamming proposed a Hamming code that can correct a single random error. Prange proposed the concept of cyclic codes in 1957. Subsequently, Hoopueghem, Bose and Chaudhum discovered BCH codes in 1960. Later, Reed and Solomon proposed ReedSolomon (RS). Encoding, this is actually an improved BCH code. Various new technologies used in modern communications, such as MMDS multipoint-to-multipoint distribution service, LMDS local multipoint distribution service, Bluetooth technology, high-speed DH, etc. require channel coding correction Error ability is more efficient, higher computing speed, and faster, which has led to the emergence of various dynamic coding schemes and is widely used in engineering. Information theory is still one of the most active research fields at present.

Forwarding Equivalence

FEC: ForwardingEquivalenceClass, forwarding equivalence class.

Forward Equivalence Class (FEC) is a term used in Multi-Protocol Label Switching (MPLS), which is used to describe a series of packets with similar or identical features, which may be transported in the same way That is, it may be tied to the same MPLS label. Packets of the same forwarding equivalence class will get exactly the same processing in the MPLS network

From the perspective of forwarding behavior, they all have the same forwarding attributes. One type of FEC is a group of monocular broadcast packets, the destination addresses of which all match an IP address prefix. Another type of FEC is a group of packets whose source and destination addresses are the same.

The division method of forwarding equivalence class is very flexible, and it can be any combination of source address, destination address, source port, destination port, protocol type, VPN, etc. For example, in traditional IP forwarding using the longest matching algorithm, all packets to the same destination address are a forwarding equivalence class.

Federal Election

FEC: FederalElectionCommission Federal Election Commission

An independent agency under the US government. It implements and enforces the Federal Election Campaign Act and the Revenue Act (RevenueAct) passed in 1971. These laws provide for (1) the public financing mechanism for presidential elections; (2) public disclosure of campaign fundraising activities by political committees that support candidates’ acquisition of federal government positions; and (3) enforcement restrictions and prohibitions to encourage candidates to obtain federal government Contributions and expenditures for the position.

FEC was established in 1971. It is composed of six commissioners appointed by the president and two non-voting members-the secretary of the Senate and the secretary of the House of Representatives.

Classification

In fact, FEC is divided into in-band FEC and out-of-band FEC. The so-called out-of-band FEC refers to the addition of an additional FEC layer below the SDH layer, dedicated to FEC processing. In this way, the code rate needs to be adjusted to increase the line code rate, thereby increasing the cost and complexity of the system; in-band coding refers to mapping the supervision symbols to the overhead bytes used in the SDH frame structure, that is, using The unused overhead byte transmits the FEC check bit. Obviously, this method avoids code rate adjustment, and the cost of the system is not much increased. However, the decoding delay of this method is slightly larger than that of out-of-band coding, and it occupies part of the overhead. At the same time, due to the limited bandwidth available for the check bit, its error correction performance is affected to a certain extent.

The ITU-TG.975/G.709 standard supports out-of-band FEC. G.975 uses RS (255, 239) format encoding, inserts redundant codes at the end of the frame, and the encoding redundancy is 7%. The G.709 standard stipulates the use of RS (255,238) coding, which has greater coding redundancy. Out-of-band FEC coding has large redundancy, strong error correction ability, and high coding gain, generally reaching 5-6dB, and can easily insert FEC redundant codes without being restricted by the SDH frame format, and has strong flexibility sex.

The in-band FEC supported by the ITU-TG.707 standard uses part of the overhead bytes in the SDH frame to load the redundant code of the FEC code. Its advantage is that it does not change the data transmission rate, but due to the limited number of bytes and frame length available in the frame overhead, the coding gain is small, generally only 3-4dB. It is often encoded in BCH3 format.

According to reports, the third-generation FEC is used in submarine optical communication systems and has achieved good error correction capabilities. Some scholars are studying the combination of third-generation FEC and Raman amplifiers and high-quality high-power optical transmitters to achieve long-distance and even ultra-long-distance non-relay high-speed optical fiber communication, and good performance has been achieved. It can be expected that the third-generation FEC will bring huge benefits to high-speed optical fiber communication systems.

FEC,ForwardingEquivalenceClass: Forwarding Equivalence Class

In the MPLS multi-protocol label switching network, the packets with the same forwarding processing method are grouped into one group, which is called forwarding equivalence class .

The packets of the same forwarding equivalence class will get exactly the same treatment in the MPLS network.

FEC, the DOD team of conquerors from the East.

FEC: FastEthernetChannel Fast Ethernet Channel.

FEC: Forward error coding.

FEC (Future Enterprise Club of Zhejiang University)

Club

Cultural Philosophy

Department Introduction

Magazine

Forward Error Correction

Forwarding Equivalence

Federal Election

Classification

Related content

Character description

Physical parameters

Use