How is 5G different from 4G?
5G is a hot word in the field of mobile communications in 2018. From ZTE’s chip card neck incident, Lenovo’s 5G voting turmoil to Huawei’s frequent threats. These events have aroused everyone’s attention to 5G, so what exactly is 5G, and what is the difference between it and 4G? Today, let’s take a brief look at their relationship and difference.
From 1G to 5G
Before talking about 5G and 4G, let’s first understand what has changed from 1G-5G?
1G: This refers to the first generation of wireless telephony technology, ie mobile communications. It uses an analog signal with speeds up to 2.4kbps. At that time, the big brother did not have a screen and could only make a phone call.
2G (GPRS): This refers to the second generation of mobile technology. Use digital telecommunications standards. The data rate is between 56-114kbps. 2G has realized the digitalization of voice communication, and the function phone has a small screen to send text messages.
3G (WCDMA/CDMA 2000/TD-SCDMA): Refers to the third generation of mobile phone technology. It offers a data rate of 384kbps, so it’s easy to browse websites and stream music.
4G refers to the fourth generation of mobile technology, known as LTE (Long Term Evolution). Compared with 1G-3G, it is the best among them, and it is as stable and fast as Wi-Fi at home or office.
5G is the 5th generation of mobile communication technology and an extension of the 4G system. On June 13, 2018, US time, the 3GPP meeting in San Diego set the first international 5G standard. Compared with the former, the 5G network has three main characteristics, extremely high speed (eMBB), extremely large capacity (mMTC), and extremely low latency (URLLC). Let’s talk about the difference with 4G through its three major features.
5G VS 4G
We all know that communication relies on electromagnetic waves, and the frequency resources of electromagnetic waves are very limited. Different frequencies have different speeds. Frequency resources are like carriages. The higher the frequency, the more carriages, and the more information can be loaded in the same time. So the higher the frequency, the greater the bandwidth and the faster the speed.
At present, our 4G uses low-frequency bands. Its advantages lie in its good performance and wide coverage, which can effectively reduce operators’ investment in base stations and save money. But the disadvantage is that if there are many users, the “road” for data transmission will be congested. Although the existing technology has been optimized, the rate provided is still limited. However, 5G uses high-frequency bands. The use of high-frequency bands can not only alleviate the tension of low-frequency resources, but also make the “road” wider and increase the bandwidth rate because there is no congestion phenomenon. However, limited by the high-frequency propagation performance, many high-frequency frequency resources are not used for transmission, which are resources that 5G can make good use of.
But how to solve the propagation problem of high-frequency communication?
This requires relying on massive MIMO. MIMO is “Multiple-Input Multiple-Output”. Multiple antennas transmit and multiple antennas receive. Allow me to find a schematic diagram (probably like this):
The frequency of high-frequency resources is very high, and the wavelength is very short. When designing the antenna, the distance between the antenna element and them can be small, and the antenna array can be integrated within a small range. The increase in the number of antenna elements can bring additional gain, combined with beamforming and beam tracking technology to compensate for the limited propagation of high-frequency communications.
With these characteristics, 5G offers peak data download rates of up to 10Gbps. The peak rate of 4G is about 100Mbps, which is 100 times faster. Ideally, users would be able to download a 1G HD video in seconds. 4K video requires a minimum download speed of 25Mbps, which 4G falls short of. Therefore, 4K video live broadcast becomes possible in the 5G environment. In addition, VR/AR has a huge demand for bandwidth, and 5G makes virtualization such as VR possible. Just like the first picture in the text, 2G can read Cang’s novels, 3G can read Cang’s pictures, 4G can watch Cang’s videos, and 5G can interact with Cang in VR.
High-frequency millimeter waves can increase the transmission rate, but it is difficult for high-frequency signals to pass through solids. As the transmission distance increases, the transmission rate will drop faster than the low frequency band of 4G. In order to ensure an efficient and stable transmission rate, more base stations are needed for a stable signal transmission effect. 5G technology introduces micro base stations with small size and low energy consumption. This kind of base station can be installed anywhere in the city, and can be installed in street lights, signal lights, shopping malls, houses, etc. Each base station can receive signals from other base stations and transmit data to users anywhere. The signal reception is even and the carrying capacity is large, forming a ubiquitous network, which solves the shortcoming of poor long-distance transmission in high-frequency bands.
This also makes the Internet of Things a possibility. In the 5G network, in addition to common 3C products such as smartphones and PCs. More terminal devices can also be incorporated into the network, such as smart furniture products that can be controlled through the network, such as smart sockets, smart air conditioners, smart refrigerators, and smart wearable devices. In the field of Internet of Things, different application scenarios. Networks have different needs. Some terminal devices need a large amount of real-time data to process feedback quickly, while some terminal devices only need a small amount of data or a few bits of data transmission. It does not have high requirements for the speed of transmission, and may even update a small amount of data in a month or two. For example, the usage information of water meters and electricity meters is displayed. Therefore, in the 5G network, it is necessary to automatically identify the network requirements of the device terminal and use different network bandwidths respectively. When a small amount of data is transmitted, 5G intelligent identification uses a narrowband network with less energy consumption to transmit data, thereby effectively reducing energy consumption and use, and ensuring the usability of low-consumption and long-term operation of terminal equipment. Realize the real Internet of Everything.
Compared with 4G, 5G has been greatly optimized and adjusted on the existing technical architecture. In order to achieve ultra-low latency, 5G starts from all aspects of the access network, bearer network, core network, and backbone network.
While greatly reducing the transmission delay of the air interface, the number of forwarding nodes is reduced as much as possible, and the distance between nodes is shortened. The network slicing technology is introduced to divide the physical network slicing into N logical networks to adapt to different application scenarios. Lower the control function of the core network and deploy it to the edge of the access network, approaching the user, reducing the transmission distance and delay.
The 4G network application server is concentrated in the central computer room, far away from the terminal, and needs to pass through multiple transmission nodes in the middle . 5G will deeply integrate the access network and Internet services through edge computing technology, deploy cloud computing equipment with computing, processing and storage functions at the edge of the access network, build a mobile convenient cloud, and provide an information technology service environment and cloud computing capabilities. It can reduce the forwarding and processing time during data transmission and reduce the end-to-end delay.
Low latency makes unmanned driving possible. A car is at a speed of 60Km/h. The braking distance of 50ms is 1m, that of 10ms is 17cm, and that of 1ms is 17mm. In 4G network delay is about 50ms. The approximate braking distance is 1m in 50ms. This may be the difference between life and death, and the 5G network delay as low as 1ms makes it possible for autonomous driving to ensure driving safety on the road. Everyone knows the time when the Chongqing Wanzhou bus fell into the river. If the bus was using 5G technology at that time, equipped with intelligent monitoring and intelligent system management, when it was found that the vehicle deviated from the normal track and was about to rush out of the bridge embankment, the emergency system would pass the low-latency Features, braking within 1ms may not cause tragedy.
4G has greatly increased the data rate, entered the era of mobile broadband, made the Internet, and changed people’s way of life. Whether ordering food, takeaway, payment, etc. are changed by the mobile terminal, white-collar workers order food every day, sleep in on weekends, are you hungry, Meituan, etc., order food with one button on the mobile app, fast delivery to the door, and online payment is fast and cheap , Life has been changed by takeaway, and there are fewer going out; the convenience of online shopping, less going to physical stores and supermarkets, and direct online shopping. Then the live broadcast service Douyu, the rise of the Panda platform, and the popularity of short video Kuaishou and Douyin have also changed our entertainment methods.
4G changed life, and 5G will change the whole society. From VR/AR and other virtual items, virtual characters, enhanced situational information and other ways to give people a new media experience. It will also enter the era of the Internet of Things and penetrate into all walks of life. Internet of vehicles, smart manufacturing, global logistics tracking system, smart agriculture, municipal meter reading, etc. When 5G arrives, it will also be a time of social disruption. So as to move towards a digital and informationized intelligent world.