Digital television terrestrial broadcasting broadcasts video, audio, and auxiliary data services through the VHF and UHF frequency bands. It is a broadband digital transmission system that provides multimedia services from one point to multiple points. The net payload that each channel can transmit is between 19-25Mbit/s. Terrestrial digital television broadcasting is a fundamental and important means of providing public broadcasting and television services. It collaborates with satellite digital television broadcasting systems and cable digital television broadcasting systems to provide comprehensive broadcasting and television coverage
Three types of standards
Satellite broadcasting standard DVB-S
Satellite broadcasting has the advantages of large coverage and no regional influence. However, for ordinary users, the receiving end requires antenna dishes, satellite receivers, etc., which is difficult to accept at a price, so its development is limited to some extent; On the other hand, receiving satellite programs directly requires the support of relevant national policies, making it difficult to promote them in the short term
Cable TV Broadcasting Standard DVB-C
Cable TV broadcasting focuses on solving the problem of "information to the home", especially in densely populated areas such as cities and towns. However, the construction cost of the "last mile" is very high, and for vast areas, watching cable TV cannot be achieved in the short term
Ground Broadcasting Standard DVB-T (European Standard)
Function of testing report:
1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report
2. Online e-commerce platform entry: Quality inspection report recognized by major e-commerce platforms 3. Used as a sales report: issuing legally effective testing reports to make consumers more confident 4. Papers and research: Provide professional personalized testing needs 5. Judicial services: providing scientific, fair, and accurate testing data 6. Industrial problem diagnosis: Verify the troubleshooting and correction of industrial production problemsBaijian and testing process:
1. Telephone communication and confirmation of requirements
2. Recommend solutions and confirm quotations 3. Mail samples and arrange testing 4. Progress tracking and result feedback 5. Provide reports and after-sales service 6. If urgent or priority processing is requiredTesting and testing characteristics:
1. The testing industry is fully covered, meeting different testing needs
2. Fully cover the laboratory and allocate localized testing nearby3. Engineers provide one-on-one services to make testing more accurate
4. Free initial testing, with no testing fees charged
5. Self service order delivery for free on-site sampling
6. Short cycle, low cost, and attentive service 7. Possess authoritative qualifications such as CMA, CNAS, CAL, etc 8. The testing report is authoritative and effective, and is generally used in China