7 key features of 5G mobile phones

1. Support high-power terminals

Compared with base stations, mobile phones have much lower transmission power, so the coverage shortcoming of 5G base stations is in the uplink. The 5G frequency band is higher, and the higher the frequency band, the shorter the coverage distance of the wireless signal, which in turn leads to a longer and longer uplink coverage shortcoming.

In order to make up for this shortcoming, the industry has proposed using high power terminals (HPUE, High Power User Equipment) to supplement uplink coverage.

The transmission power of traditional terminals is 23dBm, and the transmission power of high-power terminals can reach 26dBm, which can increase the uplink coverage radius by 3dB.

2. Support dual antenna transmission

Mainstream 5G commercial terminals all use 2T4R, that is, two antennas for transmission and four antennas for reception. Based on dual-antenna transmission, transmit diversity can improve uplink coverage by 1-2dB, and dual-stream MIMO can double the uplink peak rate.

However, dual-antenna transmission only supports SA (standalone networking) mode. In SA networking, both antennas are connected to NR. In NSA (non-standalone networking), one antenna is connected to NR and the other is connected to LTE, and can only transmit in LTE and NR respectively.

As mentioned above, since the terminal dual-antenna transmission can double the uplink peak rate through dual-stream MIMO, the terminal uplink rate under SA networking is nearly twice as high as that of NSA.

3. Support multi-mode and multi-band

Simply put, it means 5G full network access.

Since 2G/3G/4G/5G will coexist for a long time in the future, 5G terminals will add support for new 5G NR frequency bands on the basis of meeting the existing 2G/3G/4G multi-mode and multi-frequency requirements.

The main supported standards and frequency bands are as follows:

The so-called support for multi-mode and multi-band means that the baseband chip, RF chip, RF front-end and antenna inside the terminal must all support multi-mode and multi-band, which brings unprecedented challenges to 5G terminal design.

Taking the RF front-end as an example, its components include filters, duplexers, power amplifiers, RF switches, antenna tuning modules, etc. The increase in frequency bands means an increase in the number of these devices, which brings new challenges to terminal cost, volume and performance.

4. Support NSA and SA

There are two 5G networking modes: NSA and SA. NSA is a transitional solution for 5G networks, and SA is the ultimate goal of 5G networks. Some operators choose to adopt NSA networking first and then evolve to SA, while some operators choose to directly adopt SA mode. Therefore, it is generally recommended that 5G mobile phones should support both NSA and SA modes from the beginning.

5. Support voice solutions

There are three main voice solutions in the 5G era: VoLTE, EPS Fallback and VoNR.

For NSA non-independent networking, the VoLTE solution is adopted.

In NSA networking, the terminal control plane is anchored to 4G and resides on 4G, and voice services are also carried on 4G, that is, voice services are provided directly through 4G VoLTE.

For independent networking (SA), EPS Fallback and VoNR are used as options.

EPS Fallback is similar to CSFB in the early stage of 4G. 5G NR does not provide voice services. When the terminal makes a call on 5G, switching is triggered. At this time, the 5G base station initiates an inter-RAT switching request to the EPC and falls back to the LTE network. Voice services are provided by VoLTE.

VoNR refers to voice services provided directly by 5G NR.

The wireless access technology of 4G is LTE, and voice over LTE is called VoLTE; the wireless access technology of 5G is NR, and voice over NR is called VoNR. Vo5G inherits the advantages of VoLTE, not only with shorter call delays, but also with the ability to enjoy high-speed 5G Internet access while making high-definition calls.

Generally, in the early stage of 5G deployment, if NSA networking is adopted, VoLTE is used, and if SA networking is adopted, EPS Fallback is usually used. As 5G network coverage continues to expand, VoNR will be gradually launched.

6. Support dual SIM cards

Currently, most 4G mobile phones are dual-SIM. There are two main types of dual-SIM solutions for 4G mobile phones: dual-SIM dual standby single pass and dual-SIM dual standby dual pass.

Dual standby means that the two SIM cards can monitor the paging of the two SIM card network systems at the same time when in standby mode. Dual pass means that the two SIM cards can talk at the same time. When one SIM card is making a voice call, the other SIM card can receive voice paging at the same time. Single pass means that the two SIM cards cannot talk at the same time.

If a 5G mobile phone promotes dual-SIM cards, it is recommended to support dual-SIM dual-standby single-pass solutions, one card supports VoNR and EPS Fallback voice solutions, and one card supports VoLTE or GSM.

7. Support high-speed mobile scenarios

4G supports a maximum mobile speed of 350 km/h, while 5G can support a mobile speed of up to 500 km/h to meet the continuous upgrading of the operating speed of transportation vehicles such as EMUs, high-speed trains, and maglev trains.

Therefore, the demodulation capability of 5G terminals is required to support the maximum Doppler frequency deviation at a mobile speed of 500 km/h and support multipath channel demodulation with opposite Doppler frequency deviations.