Development Background
In recent years, the fifth generation of mobile communication systems, 5G, has become a hot topic for discussion in the communications industry and academia. The development of 5G has two main driving forces. On the one hand, the fourth-generation mobile communication system, 4G, represented by long-term evolution technology, has been fully commercialized, and the discussion of next-generation technology has been put on the agenda. On the other hand, the demand for mobile data has exploded, and existing mobile communication systems are difficult to meet the future Demand, there is an urgent need to develop a new generation of 5G systems.
The development of 5G also comes from the growing demand for mobile data. With the development of the mobile Internet, more and more devices are connected to the mobile network, and new services and applications are emerging. Global mobile broadband users are expected to reach 9 billion in 2018. By 2020, it is expected that the capacity of mobile communication networks will need 1000 times increase in current network capacity. The surge in mobile data traffic will pose severe challenges to the network. First, if the current mobile communication network is developed, the capacity cannot support the growth of thousands of times of traffic, and the network energy consumption and bit cost are unbearable. Second, the traffic growth will inevitably bring further demand for spectrum, and the mobile communication spectrum is scarce, and the available spectrum is Large-span, fragmented distribution makes it difficult to achieve efficient use of spectrum. In addition, to increase network capacity, intelligent and efficient use of network resources must be made, such as intelligent optimization for business and user personality, but this capability is insufficient; finally, future networks It must be a heterogeneous mobile network with multiple networks coexisting. To increase network capacity, it is necessary to solve the problems of efficiently managing each network, simplifying interoperability, and enhancing user experience. In order to solve the above challenges and meet the growing demand for mobile traffic, it is urgent to develop a new generation of 5G mobile communication networks.
basic concepts
Like earlier 2G, 3G, and 4G mobile networks, 5G networks are digital cellular networks in which the service area covered by a provider is divided into many small geographic areas called cellular. Analog signals representing sound and images are digitized in mobile phones, converted by analog-to-digital converters and transmitted as bit streams. All 5G wireless devices in the cell communicate via radio waves with the local antenna array and low-power automatic transceivers (transmitters and receivers) in the cell. The transceiver allocates channels from a common frequency pool, which can be reused in geographically separated cells. The local antenna is connected to the telephone network and the Internet via a high-bandwidth fiber optic or wireless backhaul connection. As with existing phones, when users traverse from one cell to another, their mobile device will automatically "switch" to the antenna in the new cell.
The main advantage of 5G networks is that the data transmission rate is much higher than the previous cellular network, up to 10Gbit / s, faster than the current wired Internet, and 100 times faster than the previous 4GLTE cellular network. Another advantage is lower network latency (faster response time), less than 1 millisecond, and 4G is 30-70 milliseconds. Due to faster data transmission, 5G networks will not only provide services only for mobile phones, but will also become general home and office network providers, competing with cable network providers. Previous cellular networks provided low-data-rate Internet access for cell phones, but a cell phone tower could not economically provide enough bandwidth as a general Internet provider for home computers.
Network characteristics
1. The peak rate needs to reach the Gbit / s standard to meet the high-data-rate transmission of high-definition video, virtual reality, etc.
2. The air interface delay level needs to be around 1ms to meet real-time applications such as autonomous driving and remote medical treatment.
3. Super large network capacity, providing the connection capability of 100 billion devices to meet the Internet of Things communication.
4. Spectrum efficiency is improved by more than 10 times than LTE.
5. With continuous wide area coverage and high mobility, the user experience rate reaches 100Mbit / s.
6. The traffic density and connection density have been greatly improved.
7. The system is collaborative and the intelligence level is improved. It is manifested in the multi-user, multi-point, multi-antenna, multi-ingestion collaborative networking and flexible automatic adjustment between networks.
The above is the key difference between 5G and previous generations of mobile communication, which is the result of the gradual shift from mobile technology to user-centric mobile communication.
