Fullscreen HTML5Med Res (??MB)HTML4

The latest 5G mobile data and voice communications technology promises to provide much higher data speeds and greater bandwidth than the existing 3G or 4G. But what exactly is new, what benefits can you expect from it and how does it work? Dr David Maddison explains: 5G Mobile Communications 5G band connections at home (in Australia, this would com(fifth generation) mobile technology has been pete with the NBN; see comments in this month’s editorial available in some parts of Australia since late about Australia’s “broadband tax” and the panel below). 2019. 5G is a package of technologies, not just Different carriers might focus on various aspects of the one, including smart antenna design, many more base stations than the typical mobile towers we are used to, a much technology. For example, one might concentrate on offerbroader frequency range (eventually) plus much higher fre- ing fixed internet at home via 5G, another might focus on mobile phone service, and others might focus on the Interquencies (millimetre waves, around 26GHz and up). The vision of 5G is that it will allow much greater connec- net of Things or the Internet of Everything. Or they might tivity between all manner of things (see Fig.1). Apart from become involved in all aspects of 5G. its obvious application in telephony, 5G will: • allow dramatically improved video streaming, for watch- The 5G radio access network (RAN) The RAN is that part of a telecommunications system that ing videos and videoconferencing; • enable communications with vehicles such as driverless connects devices to other parts of the network via radio. For cars and other machinery, and pilotless aircraft such as 5G, it consists of traditional base-station towers, small cells delivery drones in the city, connections to utility meters, to provide additional coverage, wireless systems in builda surgeon connected to a robotic surgical device hundreds ings and homes, and potentially large numbers of mmWave of kilometres away and innumerable other uses, many of (millimetre wave or EHF, 30-300GHz) antennas in suburban areas, on street lights or power poles. which have not yet even been conceived; Like its predecessors, 5G is a cellular system whereby • wirelessly connect “Internet of Things” (IoT) devices, specifically via wireless “machine-to-machine communica- each 5G device operates in a small geographic area called tion” or M2M. This will evolve into “massive Machine a “cell” at any given time. Cells are typically a few kilomeType Communication” (mMTC), where information will tres across in a suburban area and contain one or more fixed be generated, exchanged and acted upon by machines transceiver stations, on dedicated towers or a structure on with little or no intervention from humans. mMTC ap- top of a tall building or hill. Adjacent cells use different frequencies or other nonplications are being developed for healthcare, transport, interfering modulation schemes. These multiple cells and utilities, energy, agriculture and industrial monitoring; transceivers allow for many • achieve all of the above more mobile devices, as the due to high-speed, low- Crazy conspiracy theories frequencies can be reused in latency (delay) data comThere are innumerable conspiracy theories and claims of physiother non-adjacent cells. munications, while sup- cal and mental harm from 5G being promoted online and elsewhere. This scheme also reduces porting a much larger We consider these to be too ridiculous even to bother refuting them. the required transmit and renumber of connections The amount of power radiated from a 5G (or 4G) phone is in most ceiver power, allowing much than existing systems; cases so low that it is of no concern. smaller devices with less bat• and allow wireless broad12 Silicon Chip Australia’s electronics magazine siliconchip.com.au Fig.1: a vision of the near future, with 5G connecting everything we use together. Source: ITU (International Telecommunications Union). tery drain. The cell scheme can also be extended virtually without limits, to cover an entire city or country as required. A key feature and requirement for cellular systems is the ability to reuse the limited number of available frequencies. This is because there might be millions of devices in a city and there simply is not sufficient radio spectrum to have a different frequency assigned to every single device, particularly with modern high-bandwidth service requirements such as streaming video. Frequencies can be reused by other cells as long as they are sufficiently far away to avoid interference. The reuse distance is the minimum spacing between towers before a frequency can be used again, avoiding so-called co-channel interference. Modulation schemes also exist which allow multiple users to share a single frequency. Since there is a limit to the number of available frequencies, as the number of users has grown, the cell size has shrunk. The smaller the cell size, the greater number of total users that are possible and the greater the number of antennas. This leads to a concept of variable cell sizes, which have been given names like macrocells, microcells, picocells and femtocells (Figs.2-6). A full-size (macro) cell usually has a tower at the centre, or antennas mounted on a building. They are generally Indoor: 10-100mW Outdoor: 0.2-1W Coverage radius: 10s of metres Indoor: 10-100mW Outdoor: 1-5W Coverage radius: 10s of metres Outdoor: 5-10W Coverage radius: 100s of metres Outdoor: >10W Coverage radius: kilometre(s) Fig.2: a description of various mobile cell sizes. Small cells allow an increase in the number of users in a particular geographic area. Smaller cells also allow for more frequency reuse than macrocells. “Backhaul” is how the cells connect to the core network, either by an existing wired or optical fibre connection or wireless connections. siliconchip.com.au Fig.3: a 4G microcell mounted on a tram power pole outside Melbourne’s Flinders St Station. These boost capacity in busy locations or improve reception in certain areas. Many more similar small cells will be needed for 5G. Source: Telstra. Australia’s electronics magazine September 2020  13 Before 1G, a Telecom Australia (later Telstra) “007” mobile phone. This is only half the story: there was also a large box mounted in the boot! Fig.4: a cellular pattern from US Patent 4,144,411, granted 1979. Each number represents a frequency. Notice how certain frequencies are used multiple times. Each tower radiates one of its three 120° beams into an adjacent cell, so each cell is served by three beams, one each from three towers. The shape of real cells depends on geography and the availability of antenna sites. directional, often having a radiation pattern covering 120 degrees from each array. So a typical tower has the antennas mounted in a triangular array. This enables more users to be simultaneously connected compared to having just one omnidirectional antenna. It is also possible to electronically ‘steer’ beams to a particular user, which we will discuss later. In all cellular communications, as a mobile user moves to the edge of a cell and signal strength diminishes, they are automatically and seamlessly connected to the next available cell. This is a core functionality in cellular systems. To do this, the base stations have to communicate with each other and the handset. The phone needs to find a station with available channels and sufficient signal strength. If the next nearest cell (the logical one to use) is at capacity, the handover might be to another base station that is further away but has available capacity. Previous mobile telephony (1G to 4G) Before discussing how 5G works, let’s go over the previous generations of mobile telephony. Before 1G, various mobile phone systems were in use in Fig.5: user-captured data of the location of Telstra 4G LTE base stations around the Melbourne CBD. They are placed in convenient locations and don’t necessarily conform to the idealised layout shown in Fig.4. This map was generated at www. cellmapper.net – you can use this website to show cellular base stations in any area or country. 14 Silicon Chip Australia’s electronics magazine siliconchip.com.au Fig.6: the Telstra 5G coverage map around the greater Melbourne area at the time of publication. It is not nearly as complete at this stage as 4G. Australia and elsewhere. In 1950, the PMG (the predecessor of Telecom and then Telstra) introduced a manually-connected mobile telephone service using equipment manufactured by AWA. It only supported hundreds of connections, and there was a long waiting list for service. In 1981, Telecom launched the Public Automatic Mobile Telephone System or PAMTS (“007 service”). It operated at 500MHz in the mainland capitals until 1993, and could support up to 14,000 services on 80 base stations. It was very expensive for equipment and to use. For a US video about an early mobile telephone service see the video titled “1940s BELL EARLY CELL PHONE / MOBILE TELEPHONE SYSTEM 90884” at https://youtu.be/ xDy2tHCPdk8 1G was an analog system. AMPS (Advanced Mobile Phone System), or 1G as it is now also known, was developed throughout the 1970s and 1980s and was introduced into Australia in 1987, starting with just 14 base stations in Sydney and Melbourne. The maximum data throughput on 1G was 2.4kbps. AMPS was fully closed by 2000. 2G, the replacement for 1G, was a digital system, launched in 1993 in Australia. It was implemented by two different technologies depending on who the carrier was; either CDMA (Code Division Multiple Access) or GSM (formerly Groupe Spécial Mobile, now Global System for Mobile Communications). Australian authorities significantly delayed the introduction of these services as they wanted exchanges modified to make interception of the encrypted calls made possible (see siliconchip.com.au/link/ab3d). By 2018, all Australian carriers had shut down 2G service except on Christmas Island and Norfolk Island. 2G introduced many current features such as SMS (short message service) and MMS (multimedia message service), multiple users on a single radio channel via multiplexing, conference calls and roaming. The maximum data rate was 9.6kbps in the initial standard, with enhancements giving 40kbps for GSM GPRS (General Packet Radio Service) and 1Mbps for GSM EDGE. There were interim standards of 2.5G and 2.75G before 3G. Phones that used 2G were not typically in the format of the large touchscreen devices we have today, although an early example of a smartphone was the LG Prada from 2007, followed by the LG Prada II in 2008 that supported 3G. The Prada was announced before the iPhone, and the head of the LG Mobile Handset R&D Center claimed Apple took the idea of the iPhone from that device. 3G introduced better internet connectivity for web browsing, video streaming, email and video conferencing. These features were available on early popular smartphones such as the original iPhone launched in 2007, the LG Prada II from 2008 running on Flash UI and the first Android smartphone, the HTC Dream from 2008. The CPU power of these phones plus the available data bandwidth finally allowed them to upload photos and video to the internet. 3G is based on UMTS or Universal Mobile Telecommunications System, which itself is based on the IMT-2000 standard by the International Telecommunications Union. It combines some elements of 2G with other enhancements for better voice compression and faster data. It uses spreadspectrum technology, whereby the signal is spread across a range of frequencies. The minimum data rate for 3G is 200kbps, but the standard calls for stationary speeds of 2Mbps and mobile speeds Frequency domain Frequency domain The broadband tax Time domain Time domain Fig.7: the difference between two multiplexing methods, ODFM (left) and ODFMA (right). Source: GTA. siliconchip.com.au Unbeknown to many, Parliament introduced a “broadband tax” for users on fixed-line networks other than NBN, to make the NBN seem more competitive by artificially raising the prices of alternatives (see siliconchip.com.au/link/ab3e). Products such as Optus’ 5G Home product are not currently included in this tax, but that could change in the future. It is possible that 5G could become the preferred method of home broadband connections, so this tax could stifle the new technology. Do we need to explain why politicians shouldn’t be making engineering decisions? Australia’s electronics magazine September 2020  15 Fig.8: beamforming, beam tracking and MIMO using a smart antenna array. A beam can be steered by adjusting the phase and amplitude of multiple antennas. Multiple propagation paths due to reflections can be utilised to send one data stream via numerous different paths. Multiple data streams can also be sent on the same path using different signal polarisations. The signal of an interfering user on the same frequency can also be nulled out using this technique. Source: Ericsson of 384kbps. The maximum theoretical speed for the latest implementation of 3G, HSPA+ (evolved High-Speed Packet Access) is said to be 168Mbps download and 22Mbps upload. 3G was introduced in Australia in 2003. Later implementations of 3G were known as 3.5G, 3.75G, 3.9G and 3.95G. 3G LTE (Long Term Evolution) is similar to 4G, and sometimes called by that name, but it is really a “sub-4G” technology and is sometimes referred to as 3.95G. 4G is based on Internet Protocol communications (IP telephony) for voice, unlike previous generations which used traditional circuit-switched telephony (where a dedicated end-to-end communications channel is established for each call). It also allows conventional internet services such as multimedia, web browsing, email, gaming, video conferencing etc with high speed and security. Unlike 3G, it does not use spread spectrum. Instead, it uses the key technology of OFDMA (Orthogonal FrequencyDivision Multiple Access) on the downlink, which allows multiple users to share a single frequency. It also uses MIMO (Multiple Input Multiple Output), whereby multiple antennas in a ‘smart’ array communicate with multiple users via a single radio link by exploiting multipath signal propagation. ODFMA allows fast data communications despite multipath signal propagation. The relevant standard specifies peak data rates of 100Mbps for low-speed users and 1Gbps for high-speed users. Later versions of 4G include 4.5G and 4.9G. 4G LTE was introduced into Australia in 2011, although as mentioned above, LTE is really sub-4G or 3.95G. However, the ITU (International Telecommunications Union) has ruled that LTE can be called 4G while real 4G is called “True 4G” [as if it wasn’t confusing enough already! – Editor]. 5G frequencies If no 5G service is available, a 5G phone will fall back to an available 4G service. In Australia, current 4G networks use frequencies in certain bands from 700MHz to 2.6GHz. Due to government policy, the first phase of 5G is in the 3.6GHz frequency band, from 3575MHz to 3700MHz. Most modern WiFi routers operate at both 2.4GHz and Fig.9: beamforming and beam steering with multiple antennas in a line. They are indicated by blue dots, and all transmit the same signal; the more antennas, the more directional the beam. The beam can be steered by altering the phase and amplitude of each antenna, causing constructive or destructive interference and changing the lobe position. Beamsteering in three dimensions requires a two-dimensional antenna array. Source: siliconchip.com.au/link/ab3f 16 Silicon Chip MIMO Fig.10: multipath propagation of signals as used in WiFi, 4G and 5G. MIMO utilises multiple antennas and transmitters to send signals along numerous pathways to one or more receivers. Each receiver can receive multiple signals from various pathways. Source: Wikimedia user Claudeb. Australia’s electronics magazine siliconchip.com.au Fig.11: approximate existing and new spectrum allocation for 5G worldwide. 5G can use the existing mobile spectrum plus the mmWave spectrum of 26-86GHz. The higher the frequency, the higher the data rate, the smaller the cell size and the greater the number of users in a given geographical area. In Australia, only the 26GHz band is currently allocated for mmWave 5G. 5GHz. If you have one at home, you may have noticed that the 2.4GHz signal reaches more areas of the house, but it has a lower data rate than the 5GHz signal. The initial 5G frequency is almost exactly in the middle of those two frequencies. The very high speeds achievable with 5G require mmWave (~25-300GHz) frequencies to be used which are not yet commissioned. The Australian government will auction part of the 26GHz band for 5G use, 25.1-27.5GHz, in 2021. It is not clear what 5G frequency ranges Australia might use in future, apart from the two mentioned above. Naturally, the network operators will use a combination of frequencies, not just one. Overseas, some 5G operators use low-band frequencies 600-700MHz, mid-band of 2.5-3.7GHz and highband of 25-39GHz, with the possibility of higher frequencies in the future. It is likely that in the future, the spectra of legacy services such as 3G and 4G will be released for use by 5G, as well as mmWave frequencies up to 86GHz. Consider that if you are buying a new 5G phone, you may wish to make sure it supports both mmWave frequencies as well as the 3.6GHz band. It’s not clear what will happen in Australia, but in the USA, a Samsung Note 10+ was offered by two different carriers with each having their own version. Low frequency cells 700MHz Large scale events Thousands of users One version supported 5G on sub-6GHz only, and the other supported mmWave only. Key 5G technologies Apart from the use of certain technologies and features from earlier generations of mobile telephony, 5G introduces or enhances several techniques including but not limited to: 1) Multiple users on a single radio channel. ODFMA was mentioned above concerning the downlink for 4G LTE, and is used for both data uplink and downlink on 5G. To understand ODFMA, we first look at OFDM (Orthogonal Frequency Division Multiplexing) – see Fig.7. The bandwidth is divided into multiple subcarriers with a fixed spacing and transmitted in parallel. Each subcarrier can be individually modulated. In ODFM, users are allocated a specific timeslot in which they can use the entire range of frequencies. In ODFMA, users are allocated a timeslot and a frequency domain, and the subcarrier spacing can be variable and is flexible. So a channel could be given to a single user, or many. In ODFMA, multiple users can use a single channel by assigning subsets of subcarriers to particular users. 2) Smart antennas are antenna arrays that use a combination of hardware (antenna and radio system) and software, High frequency cells 3.2-3.8GHz Vehicle communications Transport Infrastructure Environmental monitoring & smart cities Millimetre wave cells 26GHz Transport & Infrastructure Improved residential connections, smart energy Fig.12: approximate frequency ranges for different cells sizes and possible applications. The smaller the cell size, the higher the frequency and the greater the number of users and data rate, but the shorter the range. The lower frequency cells cover the largest areas and provide the longest range but also the lowest data rate (purple shading). The medium size cells are indicated by blue shading and the smallest cells by the green beam pattern. siliconchip.com.au Australia’s electronics magazine September 2020  17 Peak data rate (Gbit/s) Enhanced Mobile Broadband User experienced data rate (Mbit/s) Area traffic capacity (Mbit/s/m2) Massive Machine-Type Communications Spectrum efficiency Ultra Reliable & Low Latency Fig.13: the original 5G vision. These are new or improved features over previous generations, on top of all existing 4G functions. Source: Samsung. including smart signal processing algorithms, to identify the direction of a received signal from a user. They then calculate the required transmission pattern to form a directional beam aimed at a mobile receiver, and track it as the receiver moves. They are also used to generate multiple beams on multiple independent pathways to one or multiple users. Smart antenna arrays are used for both beamforming and tracking, and simultaneously for MIMO or massive MIMO (see #4). 3) Beam-forming and beam tracking (see Figs.8 & 9). At 3.6GHz, building penetration is not as good as lower frequencies. These two technologies help to improve that. Instead of a base station transmitting a beam in a 120° radiation pattern, wasting transmission power and connection slots, the 5G antenna array tracks the user, and both directs (tracks) and focuses (forms) a pencil-like beam toward them. This results in much better building/foliage penetration than would otherwise be the case. Tests have shown that at 3.5GHz, 5G can get penetration as good as a unidirectional 1.8GHz beam as used by 4G. Due to poor building penetration at mmWave frequencies, 26GHz and above, it is particularly important to use Mobility (km/h) Network energy efficiency Connection density (devices/km2) Latency (ms) Fig.14: a spiderweb chart comparing 4G and 5G. The peak data rate goes from 1Gbps to 20Gbps. “User experienced data rate” refers to the minimum achievable data rate in a real-world environment and goes from 10Mbps to 100Mbps. Latency (delay time for a data packet) is improved from 10ms to 1ms. IMT-advanced is the International Mobile Telecommunications advanced standard for 4.5G, and IMT2020 is the standard for 5G. Source: ETSI. beamforming and tracking at these frequencies. When the base station is receiving from a specific user, the beamforming antenna works in reverse, to capture the signal from a particular user. 4) Massive MIMO (see Fig.10). Multiple-input multipleoutput is a method to increase the capacity of a radio link by exploiting multipath propagation to send and receive more than one data link over the same radio channel. Both 4G and Fig.15: an illustration showing the diverse nature of 5G communications. At the centre is an antenna with massive MIMO (multiple-input multiple-output), allowing radio beams to be directed toward particular users. D2D stands for “device to device” communications. Small cell transceiver 18 Silicon Chip User equipment (UE) Australia’s electronics magazine siliconchip.com.au 4G ANTENNA 5G ANTENNA Fig.16: the directional nature of massive MIMO antennas on 5G makes it possible to direct radio energy to a specific user rather than in all directions as with, say omnidirectional antennas (left). This helps, to some extent, to overcome the more limited building penetration possible for radio signals at higher frequencies. WiFi use this. Standard MIMO uses either two or four antennas, while massive MIMO uses many more. 5) 5G can perform full-duplex data transmissions, that is, data can be sent and received at the same time on the same frequencies, not on separate frequencies as was previously required. This saves radio spectrum. 6) mmWave for higher data rates and more users due to greater frequency availability, and shorter ranges mean a higher cell density is possible too. 7) 5G client communications are designed to minimise power to increase battery life. For example, better focused RF beams mean that less power is required to communicate over the same range. 8) The 5G network is based on virtualisation, using software rather than purpose-built network infrastructure. Functions like network routing, packet processing, security, and many others are performed in software rather than hardware. It is somewhat akin to the concept of a software-defined radio (SDR). 9) The 5G carrier network routes calls and data through the shortest paths, unlike 4G, where calls had to go through the core network. There is interoperability with other networks and connections such as 3G, 4G, WiFi and Bluetooth. Multiple protocols can be used simultaneously. 10) Device-to-device (D2D) communications. 5G devices can communicate directly with other 5G devices without using a carrier network. Usage examples include vehicleto-vehicle and vehicle-to-roadside device communications. 11) “Network slicing”, to create service-specific sub-networks for specific applications or customers. An example might be a network dedicated specifically to the Internet of Everything (see the video titled “what is internet of everything” at https://youtu.be/6Mm8pN6lSSQ), with a large number of low-data-rate devices, or another network dedicated to reading utility meters. Each network slice has specific characteristics optimised for an individual customer’s business requirements. This also relates to “multi-tenancy”, to created logical networks for independent service providers. Complicating the changeover to 5G Moving from 1G to 2G to 3G to 4G allowed essentially the same towers and other base stations to be used, with only the antennas and equipment needing to be changed. But because of the lesser range and penetration of 5G radio beams, many more base stations have to be built than now exist for 4G, especially to utilise the mmWave frequencies siliconchip.com.au when they become available. Bonding 4G and 5G As it will take some time to roll out 5G services fully, a 5G phone can fall back to a 4G service, or it is also possible to utilise 4G and 5G services simultaneously (if both are available) to get higher data throughput and network capacity. This also ensures that a connection is maintained to the greatest possible extent. This dual connectivity technology is also known as EUTRAN New Radio Dual Connectivity (EN-DC) or just Dual Connectivity EN-DC. E-UTRAN is another name for 4G LTE, and New Radio is 5G NR. This is a distinct approach from 2G, 3G or 4G when devices were connected only to one technology at a time, having to switch modes to fall back to an earlier one. Mobile phone cell sizes The ultimate objective is to cover an entire country with cellular coverage. This is easily achievable in smaller countries with a high population density, but it is very difficult and expensive with a low population density such as in Australia. In remote areas, a satellite phone is the preferred communications method (see our article in November 2017 at siliconchip.com.au/Article/10863). Nevertheless, the vast majority of Australians are rarely out of mobile phone connectivity. With current technology, cells can vary in overall size. Originally, cells were “macro” sized. Their size was and still is dictated by usage density and signal strength. The A world first for Australia During the Commonwealth Games in Brisbane in 2018, Telstra provided the world’s first 5G-powered WiFi hotspots. These were free WiFi hotspots with a 10GB download limit per day that people could connect to with the WiFi on their normal mobile phones. But the connection between the Telstra network and the Telstra WiFi hotspot was via 5G (see Fig.22). Connection speeds between the Telstra network and the WiFi hotspot (the “backhaul speed”) of 3Gbps could be obtained. Since 5G phones were not then available, it was a way of demonstrating some benefits of 5G. A speed of 3Gbps would allow 1000 HD-quality movies to be streamed simultaneously. At the same time, Telstra revealed its 5G-enabled “Connected Car” on the road using the Intel 5G Automotive Trial Platform, with a connection speed of 1Gbps and its own WiFi hotspot. Australia’s electronics magazine September 2020  19 more users, the smaller the cell was made due to capacity limitations. The maximum size is limited by the send and receive capability of a mobile handset, which depend on reception sensitivity, transmitter strength and antenna type. Apart from reducing cell size to cope with more users, with certain 5G frequencies, the cell size needs to be reduced to compensate for reduced range. 5G can utilise a variety of frequencies from just under 1GHz up to 86GHz. Frequencies above 30GHz are known as millimetre-wave as the wavelength at 30GHz is about 10mm, dropping to around 1mm at 300GHz. In 5G terminology, frequencies above 26GHz are referred to as millimetre wave or mmWave. As mentioned above, the ACMA (Australian Communications and Media Authority) will auction the mmWave spectrum to prospective telcos in the first quarter of 2021 (see Figs.11 & 12). While higher frequency signals can provide higher data speeds, they have less range and are more affected by fac- tors like fog, rain and tree foliage. Unlike the 4G signals we are used to which can propagate many kilometres, the maximum range of mmWaves in 5G is of the order of just 500m or so, assuming line of sight and no rain or tree foliage. However, 5G can achieve the same range as 4G when lower frequencies are used. Due to the lower range of mmWave signals, there needs to be many more base stations compared with 1-4G. It is anticipated that they will only be installed in high usage areas such as the CBDs of cities, train stations, sports stadiums, high-density urban areas and so on. Small 5G base stations similar in size to WiFi routers could also be installed in the suburbs, at locations such as on power poles, on apartment buildings or other existing structures. Optus is already using 5G to deliver wireless internet to home customers as a substitute for NBN. Future developments using mmWave 5G for home broadband could delivFig.17a (left): This tower in Melbourne, ACMA SITE ID 570447 is shared by Telstra (25m height), Optus (20m height) and Vodafone (19m height) and supports Telstra 3G, 4G & 5G, Optus 3G & 4G and Vodafone 2G, 3G & 4G. All of these services have 2x2 or 4x4 MIMO. Note the triangular pattern of antenna placement to give 120° per array. With MIMO, transmission environments with a large number of good scatterers such as buildings allow a higher data rate due to the multiple signal paths. Weak scatterers such as vegetation do not result in improved data rates. Fig.17b (below): The upper portion of the tower shown at left, which has the Telstra 3G, 4G and 5G antennas. At the moment no active mmWave antennas are installed on that tower, just 5G at 3605MHz with 2x2 MIMO. The small rectangular antenna is probably the one for 5G. 20 Silicon Chip Australia’s electronics magazine siliconchip.com.au 4G/Sub-6-GHz 5G Antenna mmWave 5G Antenna 1 3G/4G/ GPS/WiFi Antenna 3G/4G Antenna mmWave 5G Antenna 2 4G/Sub-6-GHz 5G Antenna Fig.18: this concept drawing shows how multiple antennas can be integrated into a mobile handset. These include 3G, 4G, 5G (both sub 6GHz and mmWave), GPS and WiFi. Note that there are multiple antennas for each of 3G, 4G and 5G. Source: Wonbin Hong via Semantic Scholar. er wireless broadband using an outdoor antenna at speeds ten times faster than a fibre NBN connection. How is 5G different from previous standards? Distinguishing new features for 5G as compared to previous generations include the three main aims of developers, in addition to all previous functionality from 4G (see Figs.13 & 14), which were: 1) Enhanced mobile broadband. This attempts to achieve significantly improved download speeds from 100Mbps siliconchip.com.au Fig.19: the Qualcomm Snapdragon X50 modem-RF system for use in mobile devices or to replace fibre-to-the-home (FTTH) installations with wireless 5G connections. The modem chip (X50, bottom left) can support up to four QTM052 mmWave antenna modules (top) and up to 5Gbps download speeds. It supports beamforming, beam steering and beam tracking and both the sub-6GHz band and mmWave band. It can be combined with a Snapdragon processor with an integrated 4G LTE modem to give 4G/5G dual connectivity. The Australian 5c coin for comparison is 19.4mm in diameter. (minimum) to 20Gbps per user for uses such as high definition (HD) video, virtual reality and augmented reality. Downloading a 15GB HD video takes 120 seconds at 1Gbps on 4G, but could be done in six seconds at 20Gbps on 5G under ideal conditions. Even with weak reception conditions such as at a cell edge, the aim is to achieve 100Mbps. All users in crowded areas such as sports stadiums and airports are expected to have full HD streaming capability. 2) Ultra-reliable and low-latency communications. Low Australia’s electronics magazine September 2020  21 A very interesting app Fig.20: a Taoglas Aurora CMM.100.A 5-6GHz C-Band Massive MIMO Phased Array antenna for a 5G base station. It employs massive MIMO and beamforming and has 64 individual antenna elements, each with two polarisations to give an effective 128 antenna elements. Multiple panels can be clicked together to make an even larger array. While writing this article, we came across an Android app called “Aus Phone Towers”. This plots mobile base stations on a map along with the frequencies, operator and technology used and also tells you which one you are connected to and the signal distribution. It uses the ACMA database for transmitter locations. You may be surprised just how many mobile base stations there are near you. Other apps to look at are OpenSignal and Network Cell Info. latency means short delays, while reliable communication is critical for tasks such as robot remote control; for example, a surgical robot or autonomous vehicle. It’s even more essential for couch potatoes who are “pwning n00bs” in Call of Duty or Fortnite. Err, we are referring to online gaming, of course. 4G latency is typically in the tens of milliseconds, but with 5G the aim is less than 1ms. Consider an autonomous vehicle remotely controlled via the mobile network. With the 10ms delay on 4G, a vehicle travelling at 70km/h (20m/s) will have travelled about 20cm (1/5 of a metre) before a command is received, but will have only travelled 2cm or 20mm after 1ms. Real-world latency for 4G can be much higher than 10ms according to some reports, so the difference will be even more stark. If the mobile network is also being used for sensor feedback from the vehicle, the delay (and thus travel distances) will be doubled due to the data ‘round trip’. Short delays are also crucial for online automated stock trading (so much so that stock trading companies move closer to stock exchange computers to minimise latency due to the speed of light, giving a competitive edge). In the future, these transactions might be made over 5G instead of a wired connection. 3) Massive machine-type communications. This refers to the Internet of Things (IoT) with numerous devices connected to the internet such as washing machines, refrigerators, agricultural machinery and irrigation systems, cars and autonomous vehicles and nearly anything else you can (or cannot yet) imagine. One million devices being connected in one square kilometre is an aim. That’s one device every square metre. Apart from this original vision, many other features have since been added to 5G. 5G or 5G NR? You may hear the term 5G NR (New Radio) instead of 5G. 5G is the overall technology, but 5G NR refers to the early first release of the standard. It is not “pure” 5G just as LTE is not pure 4G. The standard is written and maintained by the 3G Partnership Project or 3GPP (www.3gpp.org). It was named during the development of 3G, but the organisation has not changed its name despite also developing 5G. Mobile phone range In the days of analog mobile phones (AMPS or 1G), the distance between the phone and the cell tower was restricted only by signal strength and line-of-sight considerations. There is an online report of someone placing a call between the Telstra Black Mountain tower in Canberra and the tower in Cooma, 107km away. In the case of 2G or GSM, there was a definite distance limitation of 35km due to signal timing considerations. With 3G, there is no intrinsic distance limitation, and 100km is achievable with the correct antenna (with Tel- Fig.21: a 5G mmWave phased array base station antenna module from Gapwaves for integration into complete antenna systems. The assembly ready for integration is at left with its component parts shown on the right. 22 Silicon Chip Australia’s electronics magazine siliconchip.com.au Fig.22: a Telstra 5G-connected WiFi hotspot as used in the Brisbane Commonwealth Games in 2018. stra and possibly other carriers there was an earlier 80km limit imposed by software). As reported in 2007, Telstra had several special 200kmrange towers in its Next G (3G) network (see www.zdnet. com/article/telstra-boosts-next-g-reach/). 4G also has no intrinsic distance limitation. There are reports that Telstra tested connections at 75km. Extreme distances are not likely to be achieved with a phone’s internal antenna; an appropriate external antenna such as a Yagi is required. As stated earlier, 5G can achieve similar ranges compared to 4G using the lower frequencies, but the higher frequencies required to achieve the lofty bandwidth goals have a much shorter range. It has been estimated that to provided 100Mbps download speeds to 72% of the US population and 1Gbps to 55% would require 13 million utility-polemounted 28GHz base stations at a cost of US$400 billion. Therefore, for maximum range and utility 5G, will need to continue to use lower frequencies when range is more important than speed. 5G antennas As 5G antennas must be capable of operating in the sub6GHz band, they are not dissimilar to 4G antennas. Separate mmWave antennas may be used for the mmWave frequencies 26GHz and up (see Figs.15-21). SC AUSTRALIA’S OWN MICROMITE TOUCHSCREEN Since its introduction in February 2016, Geoff Graham’s mighty Micromite BackPack has proved to be one of the most versatile, most economical and easiest-to-use systems available – not only here in Australia but around the world! Now there’s the V3 BackPack – it can be plugged straight into a computer USB for easy programming or re-programming – YES, you can use the Micromite over and over again, for published projects, or for you to develop your own masterpiece! The Micromite’s BackPack colour touchscreen can be programmed for any of the following SILICON CHIP projects: BACKPACK Many of the HARD-TO-GET PARTS for these projects are available from the SILICON CHIP Online Shop (siliconchip. com.au/shop) Poor Air Quality Monitor (Feb20 – siliconchip.com.au/Article/12337) GPS-Synched Frequency Reference (Oct18 – siliconchip.com.au/Series/326) FREE Tariff Super Clock (Jul18 – siliconchip.com.au/Article11137) P R O G R Altimeter & Weather Station (Dec17 – siliconchip.com.au/Article/10898) Buy either AMMING tell us whichV2 or V3 BackPack, Radio IF Alignment (Sep17– siliconchip.com.au/Article/10799) for and we’ll project you want it Deluxe eFuse (Jul17 – siliconchip.com.au/Series/315) program it fo r you, FREE OF C DDS Signal Generator (Apr17 – siliconchip.com.au/Article/10616) HARGE! Voltage/Current Reference (Oct16 – siliconchip.com.au/Series/305) Energy Meter (Aug16 – siliconchip.com.au/Series/302) Micromite Super Clock (Jul16 – siliconchip.com.au/Article/9887) Boat Computer (Apr16 – siliconchip.com.au/Article/9977) V3 BackPack: Ultrasonic Parking Assistant (Mar16 – siliconchip.com.au/Article/9848) $ 00* JUST 75 See August 2019 (Article 11764) P&P: Flat $10 PER ORDER (within Australia) *Price is for the Micromite BackPack only; not for the projects listed. siliconchip.com.au Australia’s electronics magazine September 2020  23