What are the communication methods now?

Question 1: What is our communication mode now? What are the characteristics of mobile phone calls, landline calls, text messages, network communication, such as QQ, WeChat, network analog calls and, of course, letter writing?

Question 2: What are the communication methods? 1, ADSL, asymmetric subscriber digital line, this networking mode mainly uses telephone lines as physical connections, and completes computer surfing through modulation and demodulation of analog signals. The maximum downlink of the network can reach 8Mbps= 1Mbit. Because of network asymmetry, the maximum uplink is only 4Mbps= 1Mbit. Generally, it is used at home.

2. ISDN, an integrated service data network, uses a cable TV line as a physical connection line, which transmits both TV signals and computer signals, and of course can also transmit other signals, such as videophone and conference TV. ISDN can be divided into STM synchronous transmission and ATM asynchronous transmission. If ATM transmission mode is adopted, the network speed can reach 100M or even 1000M, and ISDN is mainly for enterprises and * * *.

3. Optical fiber. In view of the speed limitation of ASDL, many network operators now use optical fiber as a new data transmission method. Now the light has been sent to the corridor through optical fiber, and then directly connected to the user's computer through network cable, without intermediate equipment. Now this is a popular way for home users to surf the Internet. Of course, many big customers also choose this method.

4. Wireless Internet access. There are two ways to surf the Internet, one is the self-built wireless network, and the other is the wireless network of network operators. Nowadays, Tianyi broadband wireless network (3G is also a wireless Internet access mode) is more popular. The biggest advantage of this kind of network is that there is no restriction on physical connection, but the disadvantage is that it is too expensive.

Question 3: What are the common communication methods, such as mobile phone, QQ and email? ...

Question 4: What are the communication methods? ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Wechat qq SMS phone

Question 5: What are the common communication methods people use now? 15 years ago, then I will say 200 1 year ago by default. At that time, ordinary migrant workers mostly used BP machines, while some rich people used mobile phones. At that time Nokia, Siemens, Motorola and Ericsson produced mobile phones.

Question 6: What communication methods are available for industrial communication mainly depends on the specific situation: generally speaking, there are RS485 bus, CAN bus, industrial Ethernet, optical fiber and other communication methods, depending on how you choose. 485 bus is simple in wiring, simple in system and fast in response, but if the wiring of the system is not standardized and the external electromagnetic environment is complex, it will be easily disturbed. CAN bus wiring, the system is more complex than 485, and can support multi-master working mode. Industrial Ethernet is popular now, but relatively speaking, Ethernet always has time delay, and its real-time performance needs to be strengthened. The biggest disadvantage of optical fiber communication is that wiring is troublesome and needs on-site welding, but its anti-interference ability and real-time performance are the best.

Question 7: What are the characteristics of our present communication mode? There are too many ways, mobile phones, computers, writing letters! QQ, Momo, WeChat, a lot. These communications are convenient and fast.

Question 8: What is our communication mode now? What are the characteristics? Telephone, mobile phone, internet.

Question 9: What is our communication mode now? What are the characteristics? There are too many ways, such as mobile phones, computers and letters! QQ, Momo, WeChat, a lot. These communications are convenient and fast.