450 MHz networks provide cost-effective broadband coverage across wide areas of countryside. 450 MHz networks offer the most benefits to organizations that need a reliable network for critical communications or smart grids and especially meter reading. They are also used to provide rural broadband services, such as connecting remote schools and clinics. So far, more than 70 different countries have allocated 450 MHz spectrum for new uses, and there are already active networks in 20 of those.
450 MHz supports LTE in the Third Generation Partnership Project’s (3GPP) band 31. This brings the advantage of a much higher bandwidth and a standard that all manufacturers support. Known as LTE 450, it will provide narrowband IoT (NB-IoT), CAT-M1 and LTE-M communications on the 450 MHz frequencies. The LTE bands available in the 380 MHz to 512 MHz spectrum are band 31 450 MHz, band 72 450 MHz, band 73 450 MHz, band 87 410 MHz and band 88 410 MHz
450 MHz Users The earliest adapters of 450 MHz are in Europe, where a number of utilities and public authorities in the Netherlands, Austria, Poland and Lithuania are already using 450 MHz for smart utility applications and critical communications. German recently allocated 450 MHz spectrum and utilities there will follow shortly.
Scandinavia already has several active 450 MHz networks. In Norway, ICE uses band 31 for consumer broadband, where it provides internet services to second homes in the countryside. Teracom uses 450 MHz for a similar rural broadband network in Sweden. These utilities and businesses use this network as well, and the Danish police service holds the license for band 87 in Denmark. In Poland, the national energy provider, PGE, is using 450 MHz networks to connect millions of smart meters and thousands of SCADA systems that control its wind turbines and other equipment. The technical advantage of 450 MHz.
There are a number of reasons why 450 MHz networks are so attractive for mission-critical communications. First, the relatively low operating frequency sets the 450 MHz networks apart from the networks using higher frequencies, such as 900 MHz. At this low frequency, the radio waves are longer so the propagation of the radio signal is better. 450 MHz is therefore ideal for communications across large areas of rugged countryside and difficult terrain.
The low frequency also means that the radio signals have good propagation within buildings and underground. Utilities can therefore use it to connect equipment installed in basements to a network. These are the two key reasons why 450 MHz fits so well with applications for smart grids. Electricity and water meters are installed in exactly those places, where there is no other cellular coverage.
With a 450 MHz network, each single base station can cover a much larger range than is possible with higher frequencies and can potentially support a very large number of devices. This adds up to an important commercial advantage because the infrastructure is less expensive to build and a service provider can roll out new services faster.
Business Considerations These technical characteristics of the network translate into a compelling business case for the 450 MHz networks, and the overall investment required to build the network infrastructure is lower than for any other cellular network. Besides this, some countries already have some infrastructure in place because it was previously used for cellular communications.
All these factors add up to make 450 MHz extremely attractive for smart grids, transport and public-safety networks. Yet, there is another important reason why organizations will choose 450 MHz. Public authorities and utilities can have a private LTE 450 network, which remains completely separate to other network traffic and consumer services, and 450 MHz gives them secure, reliable communications without any interference.
Where LTE 450 is available, it supports voice, data and remote monitoring, so operators can use it to connect rugged routers and smartphones used in critical communications and public safety. In fact, any application that operates across wide areas of countryside such as the energy supply networks could potentially use and benefit from 450 MHz networks.
Energy utilities can use 450 MHz to build smart grids, and we expect to see new devices emerging to manage these. Companies are moving to smart meters and designing innovative devices to monitor substations, distribution networks and remote controlled lighting. The smart devices running on 450 MHz will be data loggers, smart meters and IoT devices with sensors.
Smart meters are rolling out to help consumers use energy more efficiently. The technology is ready to use and there is a strong business case for 450 MHz networks. Accordingly, 2021 saw most of the cellular module suppliers move to introduce modules for the 450 MHz frequency groups.
New antennas are also arriving in the market to build these devices, and the designer will need to integrate the antenna into the design with care. The antennas are interesting, because the low frequency dictates that the antenna component needs to be relatively large, compared to an antenna for the higher cellular frequencies supporting LTE. This creates a challenge for the engineer designing the device because a smaller antenna is easier to integrate into a board design and optimize to provide resilient RF coverage. If space on the printed circuit board (PCB) is limited, the designer may prefer to use a flexible printed circuit flexible printed circuit (FPC) antenna, which can be curved or folded and inserted into the design.
Where next for 450 MHz? 450 MHz provides the infrastructure for smart grids, smart metering and all kinds of remote-controlled infrastructure, and other public services. A number of authorities are already obtaining spectrum licenses, usually for private LTE networks.
In the Netherlands, Utility Connect holds the band 31 license for smart meters and smart grid connectivity. In Germany, 450 Connect holds the band 72 license, which will enable critical infrastructure, emergency voice communications, smart meters and smart grids. Telefonica will use band 31 to build a public-safety network in Spain.
Similar networks are at the early stages of planning in Africa, Asia and South America. In North America, utility companies are evaluating 450 MHz spectrum in 410 MHz and 380 MHz. Outside the U.S., similar networks are already live in Suriname and Argentina. The rollout of smart metering and smart grids using 450 LTE is sure to gather pace globally in the next two years.
Michael Castle is product marketing manager at Antenova, a manufacturer of embedded antennas for M2M and IoT applications.