| Popis: |
This study investigates the antenna performance of some of the most widely used mobile phones in Denmark in 2022. The communication performance varies for each kind of mobile phone, and the antenna performance of a phone is vital for its ability to ensure radio coverage in low signal situations. The study is based on the mobile systems in Denmark and on both voice and data services including both 4G Long Term Evolution (LTE) and 5G New Radio (NR). The selected phone models are the most popular new phones at the time of this study. Although it was not yet available when the main study took place, a limited study of the iPhone 14 is also included in the final report.The radio coverage for a phone depends on the available signal from the antenna mast and on the phone’s ability to collect this signal. This ability is strongly influenced by the antenna in the phone and by the way the user holds the phone close to the head during a voice call [Pel09] or away from the head in browsing mode. If the phone is not handheld but is instead in a hands-free installation or connected to a headset, the phone itself may for example be placed in so-called free-space mode, where no objects are near the phone. In such case the ability to collect a radio signal is typically very different and generally better than for the handheld case.The present study is a follow-up on similar studies conducted in 2012, 2013, 2016 and 2018 on phone models common in the market at that time [Ped12, Ped13, Ped16, Ped18]. The aim of the earlier studies was to establish the field strength calculations for mobile telephony and to set the minimum field strength needed to ensure coverage, see appendix II. Besides, the earlier studies also measure the phones’ ability to transmit (for voice mode) and receive (for data mode) in 4G service and below. The new study described in this report investigates 5G mobile phones in the market, and also considers the position of the phone with respect to the head in voice mode and to the hand in data mode. The phones are measured in the 4G bands LTE700, LTE900, LTE1800, LTE2100 and the 5G NR TD3500 band.In order to ensure a connection between the mobile phone and the base station, a sufficiently strong link is needed both from the phone to the base station (the phone is transmitting and the base station is receiving) and from the base station to the mobile phone (the base station is transmitting and the mobile phone is receiving). The weakest link determines the quality of the connection/service. For voice services, the weakest link is typically the one from the mobile phone to the base station, called “uplink” by mobile network operators, see Figure 1. The mobile phone has less resources than the base station and will be the limiting factor, e.g. in areas relatively far away from the nearest base station. Therefore, the antenna performance is crucial in such areas. For data services, the weakest link is typically the one from the base station to the mobile phone, called “downlink” by mobile network operators. A weak downlink can often be compensated for by the base station sending a stronger signal. However, this is an undesirable solution from the network point of view and ultimately also for the individual user. For the reasons mentioned, the current study focuses on the transmitter performance for voice services and the receiver performance for data services, as these are the crucial links in weak radio signal conditions.The present study is focused on the antenna test, even though the test includes more than the antenna itself. The transmitter and receiver electronics is also involved in the tests, but the electronics must fulfil mandatory limits during manufacturing, e.g., for the transmitted power, as given by e.g. the 4G LTE and 5G NR specifications [ETSI-1]. Therefore, the differences in the design of the antennas are the reason for the significant performance variation among phones.As 5G matures, now is the time for its large-scale deployments and commercialization. The 5G new radio (NR) system is now implemented in so-called non-standalone mode. There are two types of 5G, i.e. non-standalone (NSA) and standalone (SA). The main difference between NSA and SA is that NSA anchors the control signalling of 5G radio networks to the 4G core, while the SA scheme connects the 5G radio directly to the 5G core network, and the control signalling does not depend on the 4G network at all. As the name suggests, the NSA is a 5G service that does not “stand alone” but is built over an existing 4G network. Therefore, an NSA architecture enables the mobile network operators to leverage their existing network investments in transport and mobile core — rather than deploy a completely new end-to-end standalone 5G network. |
