What Are the Cognitive Misunderstandings of mmWave?

1. What is mmWave?

What is mmWave? The mmWave frequency is 30GHz to 300GHz, and the corresponding wavelength is 10mm to 1mm, respectively. In the field of mobile communication, 24GHz-100GHz is usually called 5G mmWave. Both mmWave technology and sub-6GHz are 5G standards specified by 3GPP. The difference between the two is that Sub-6 has a low frequency, so it travels farther, and the construction cost of the base station is low, while the mmWave frequency is high and the speed is faster, but the transmission is close, and the construction cost of the base station is about ten times that of Sub-6.

2. Cognitive misunderstandings of mmWaves

(1) "mmWave coverage is limited and expensive."

This problem can be solved through two measures: first, combine Sub-6GHz and mmWave, and use the low frequency band of Sub-6GHz for nationwide 5G coverage. Use mmWave technology to achieve hotspot coverage in scenarios that require large capacity and high speed; second, deploying mmWave networks in key application scenarios, such as Olympic venues, concert halls, shopping malls, transportation hubs, etc., not only costs relatively much lower, but also achieves better coverage.

(2) "mmWave only supports line-of-sight transmission."

In fact, supporting fast channel switching is a key solution for mmWaves. That is, if a transmission path is blocked by the hand or other parts of the body, a new transmission path can be quickly found by activating another module on the phone. When this conversion is extended from within the base station to between different base stations, the handover of mmWave transmission between different base stations can be quickly realized.

(3) "mmWave is only used in fixed scenarios".

In order to verify the performance of the mmWave technology modem, Qualcomm experimenters either placed the mobile phone in a scene with heavy traffic and crowds, or chose a more extreme test environment, then the mobile phone equipped with the Snapdragon X50 chip is fixed on the drone, and the remote control drone flies around the park. Thanks to advanced beam management algorithms, mobile phones can maintain high-speed network connections even in these challenging environments.

(4) "The mmWave terminal has a large size."

Taking Qualcomm's first commercial millimeter-wave module as an example, the antenna, RF front-end, and transceiver are integrated in a very compact size. A mobile phone can use multiple such millimeter-wave modules, which not only meets the compact and thin design requirements of smartphones, but also meets the power consumption requirements and provides maximized performance.