Partner feature: Apple’s latest eye-catching iPhone models are hitting the market and many users are expected to be attracted to the superior performance of these models. Indeed, the more mature 4.5G solution is implemented on the latest iPhone models. Flagship models iPhone XS and iPhone XS MAX are equipped with 4×4 MIMO antennas to improve the 4.5G experience. Apple is following in the footsteps of Samsung, Huawei, Sony, and LG, equipping their latest iPhone models with four antennas. All mainstream, high-end smartphones now support four antennas, especially for LTE high frequency bands. This is a defining moment, a moment illustrating the maturity of the 4×4 MIMO industry chain.

Multiple-Input Multiple-Output (MIMO) is a technology that uses multiple transmit and receive antennas to transmit and receive radio signals simultaneously. This improves communication quality. MIMO takes full advantages of spatial resources to multiply channel capacity and deliver the best possible user experience without adding spectrum or increasing transmit power. MIMO demonstrates substantial advantages over traditional antenna technologies. It has become a crucial 4.5G mobile communications technology. Apple’s flagship models, the iPhone XS and the iPhone XS MAX have four built-in antennas. More antennas support more concurrent streams and improve user experience.

4T4R is a transmit and receive mode for base stations with four transmit and four receive antennas. 4×4 MIMO is a mode for communications between base stations and mobile phones. 4×4 MIMO requires mobile phones that support four antennas and 4T4R base stations. A 4T4R base station can use four transmit and four receive antennas to transmit and receive signals simultaneously. Traditional 2T2R base stations and LTE 2-antenna mobile phones support 2×2 MIMO.4T4R base stations and 4.5G 4-antenna mobile phones support 4×4 MIMO. In 4×4 MIMO scenarios, four data streams are transmitted concurrently from the four transmit antennas of a base station to the four receive antennas of a mobile phone. This doubles the rate of traditional 2×2 MIMO, enhances uplink coverage, and improves cell-edge experience.

Mobile phone manufacturers are embracing 4T4R in response to dramatic traffic growth

Network evolution from LTE to 5G is entering a critical stage. Massive videos, mobile games, and online shopping generate a huge amount of smartphone traffic. Traditional 2×2 MIMO cannot ensure user experience during busy hours, especially at cell edges, resulting in many user complaints. The emergence of 4×4 MIMO not only improves cell capacity, but also significantly enhances user experience at the cell edge and near the cell center, thereby improving user satisfaction. China’s mobile phone traffic usage in 2017 reached 23.5 billion GB, an increase of 166% over 2016; the average monthly traffic usage of users has increased from 778 MB in 2016 to 1775 MB, an increase of 128%, and user experience has been improving. Currently, the average amount of internet traffic per user per month has reached 1.3 GB, which is more than six times that of 2014. Explosive traffic growth requires smartphones to have powerful capabilities.

Supporting 4×4 MIMO 4-antenna reception significantly increases the speed of mobile phones, which has become one of the major references for consumers to buy mobile phones. Mainstream terminal chip vendors around the world have launched chips that support 4×4 MIMO. Recently, Qualcomm’s medium-end smartphone chips have started to support 4R. Xiaomi and Smartisan have launched medium-end 4R phones costing less than CNY 3000, such as the Xiaomi 8 and the Nut R1. Smartphones supporting 4-antenna reception are rapidly entering the general mass market. GSA statistics show that up to 33 mobile phone models and 60 CPE models support 4×4 MIMO 4-antenna reception. It is expected that there will be more than 50 models of 4×4 MIMO smartphones on the market by the end of 2018.

Operators build 4T4R networks to increase capacity and data rates and enhance user experience

Operators are accelerating commercial deployment of LTE networks. The latest GSA statistics show that over 680 commercial networks have been deployed in more than 200 countries and regions as of August 2018. Among them, there are 261 LTE-Advanced/LTE-Advanced Pro (4.5G) networks, and 2/3 of the LTE terminals support LTE-Advanced. On these 4.5G networks, many operators choose carrier aggregation (CA), 4T4R, and 256QAM to expand network capacity and achieve xGbps peak rates. Since 2016, telecommunications equipment vendors have been promoting deployment of 4T4R networks worldwide, and more than 200 4T4R networks have been deployed around the world so far. In March 2016, a leading telecom operator in South Korea completed commercial testing of the 4T4R network and put it into commercial use. In July 2016, a leading mobile network operator in Thailand deployed the world’s largest 4T4R commercial network. This 4T4R network provides an excellent mobile broadband (MBB) experience and helps the operator usher in a new exciting era of 4.5G. As the 4T4R terminal industry is constantly progressing, operators in Mexico, Canada, Singapore, Hong Kong, South Africa, Kuwait, China, Turkey, Norway, Germany, the UK, Spain and other countries are proactively deploying 4T4R networks.

Higher network speeds are critical for user experience, and the ever-increasing traffic has been putting pressure on terminals and networks to evolve. As 4T4R network deployment grows and the chip industry matures, multiple terminal vendors are investing in 4×4 MIMO-capable commercial mobile phone R&D, 4×4 MIMO-capable terminals will gradually become more popular, and 4×4 MIMO will soon become a standard smartphone configuration.