Shielding effect of mobile phone jammer is dependent on room size

Shielding effect of mobile phone jammer is dependent on room size.
World of world-renowned IT companies are selected based on the 2005 Fortune 500 ranking (of course some are not) representative of the IT companies, we can look at: where there are many well-known companies, like Intel, AMD, NOKIA and so on, there are many we are not familiar with. Look at the world's top IT companies, IT companies to identify our country with their gap. I hope the company of our country can catch up and exceed them. USA: International Business Machines (IBM) - was founded in 1911, changed to its current name in 1924. The company's actual business, IBM is in U.S. corporate history, one of the top ten celebrity Thomas? Watson (Old Watson).
At present, there are four main business units of AT & T Communications Services Group (mainly to provide a global communications business services), Network System Group (mainly to provide communication network software, hardware and management technology), the AT & T-Global Information Services Group (mainly to provide information technology and services) and multimedia products and services Group ( the main provider of communications, computing, information and entertainment, a combination of multiple multi-dimensional product). Sector technology development and product updates the source from AT & T Bell Labs. The AT & T-Bell Laboratory is the world's leading scientific research institutions, both engaged in a wide range of the basis of research, but also committed to cutting-edge technology and the popularity of the product's development, and AT & T's various business Group design development of new processes, new systems and new business. Vodafone Group currently has over 100,000 employees. Newbury (Newbury), headquartered in Berkshire County, England and Dusseldorf, Germany. Is currently one of the world's largest mobile telecommunications network company, have investments in 27 countries around the world. Do co-operate with the local mobile phone operators in 14 countries, the mobile phone network of associates. As of December 31, 2004, Vodafone has about 151.8 million users worldwide. Vodafone Vodafone Group as the name listed on the London Stock Exchange (code VOD.L) and the NYSE (symbol VOD). Is currently one of the world's largest mobile telecommunications network company, have investments in 27 countries around the world. Do co-operate with the local mobile phone operators in 14 countries, the mobile phone network of associates. As of December 31, 2004, Vodafone has about 151.8 million users in the world. Vodafone Vodafone Group as the name listed on the London Stock Exchange (code VOD.L) and the NYSE (symbol VOD). mobile phone jammer can be installed in the ceiling in the hall.