Notebooks are generally networked in schools in the following ways:
1, install fixed broadband in the dormitory, you can install it yourself or install it with your classmates and then install a router. A little monthly, unlimited time, unlimited traffic. However, the Internet can only be used within the WIFI signal range of dormitory or router.
2. Use 3G or 4G network cards, or directly use the mobile phone network as the hotspot of the notebook. These two methods are the same, the advantage is that they can be used anywhere; The disadvantage is that you need to use a similar mobile phone number to pay in the business hall. Every time I surf the Internet, it takes up a lot of traffic, which is not suitable for downloading things or watching movies.
3. Use the campus-specific WIFI network. Generally, there is a campus network WIIFI covering the whole school. You only need to apply for an account. There is little money every month. It can be used anywhere as long as it is in school, regardless of traffic and time, and regardless of mobile phones or notebooks. For example, Wuhan University of Technology spent a month in 20 yuan.
4. Use public ***WIFI. If you can search for the WIFI of telecom, mobile and Unicom in many places with Internet access, you can buy an account on Taobao for about a few cents a day, and then you can use this account to surf the Internet.
principle
The traditional telephone line system uses the low frequency part of copper wire (frequency band below 4kHz). ADSL adopts DMT (Discrete Multi-tone) technology, which divides the frequency band from 0 khz to 1. 1MHz of the original telephone line into 256 subbands with a bandwidth of 4.3khz.
Among them, people in the frequency band below 4khz are used to transmit POTS (traditional telephone service), the frequency band from 20KhZ to 138KhZ is used to transmit uplink signals, and the frequency band from 138KhZ to 1. 1MHZ is used to transmit downlink signals.
DMT technology can adjust the number of bits modulated on each channel according to the situation of the line, thus making full use of the line. Generally speaking, the greater the signal-to-noise ratio of subchannels, the more bits are modulated on the channel. If the signal-to-noise ratio of a subchannel is poor, it will be discarded. ADSL can reach the data transmission rate of 640kbps upstream and 8Mbps downstream.