The battle of the 5G technology route, is the battle of frequency band essentially. Currently, 5G networks are deployed in two different frequency bands around the world. The frequency band between 30-300ghz is called millimeter wave. The other type, concentrated in the 3GHz-4ghz band, is called sub-6.
Constrained by the physical characteristics of radio waves, the short-wavelength and narrow beam characteristics of millimeter-wave enhance signal resolution, transmission safety and transmission speed, but greatly reduce the transmission distance, which is also why cellular amplifier antenna is user-friendly.
According to Google's 5G coverage tests on the same range and the same number of base stations, the MMW deployed 5G network can cover 11.6% of the population at 100Mbps rate and 3.9% of the population at 1Gbps rate. However, 5G networks with the sub-6 band used by cellular antenna manufacturers can cover 57.4% of the population with a 100Mbps rate and 21.2% of the population with a 1Gbps rate.
It can be seen that 5G network coverage under Sub-6 is more than 5 times that of MMW. And it would cost $400 billion to build an MMW base station, which would require about 13m poles to be installed, to achieve coverage of 72% at 100 Mbps per second in the 28GHz band and about 55% at 1Gbps per second.Sub-6 only needs to install a 5G base station on the original 4G base station, which greatly saves the deployment cost and is benefitic to combo antenna manufacturing.
In the commercial range from coverage to cost, SUB-6 is superior to MMW in the short term.
But the reason is rich spectrum resources, carrier bandwidth up to 400MHz/800MHz, wireless transmission rate up to 10Gbps; Second, the millimeter-wave beam is narrow, the direction is good, has the extremely high spatial resolution ability; Third, millimeter wave components are small in size and easier to be miniaturized compared with sub-6ghz devices; Fourth, the subcarrier interval is large, the single SLOT period (120KHz) is 1/4 of the low-frequency sub-6ghz (30KHz), and the open SLOT delay is reduced. In private network applications, the millimeter-wave advantage is almost rolling sub-6.
At present, the vehicle-to-ground communication private network implemented by millimeter-wave communication in the rail transit industry has been able to realize the transmission rate of 2.5Gbps under high-speed dynamic condition, and the transmission delay is up to 0.2ms, which has a very high promotion value for the private network.
For private networks, such as rail transit, public security monitoring and other scenarios can give full play to the technical advantages of millimeter-wave to achieve the real 5G speed.