Chris Anderson, Vice President of Engineering
The universal goals of 5G are to decrease latency, provide at least a 10 times speed increase over LTE, and service up to a million Internet of Things (IoT) devices per square kilometer. To meet these goals, 5G networks will look a lot different than any existing 3G or 4G network. Deploying technology solutions in the millimeter wave spectrum has completely different requirements and challenges from anything currently commercially deployed.
What isnt immediately obvious from those goals is that from an IoT standpoint, the network actually doesn’t look a lot different. Many IoT devices typically involve small data throughput needs, little to no latency concerns and an overall need for very low cost and power consumption. That means millimeter wave is unlikely to be part of a general IoT deployment.
There are several key technologies such as massive MIMO and beam forming that add the ability to service more IoT devices, and provide higher service to some of those that need it. Of particular interest is how these new technologies can be used to service an IoT device dynamically, based on the IoT devices needs. These technologies, however, are concentrated on the base station or small cell side of the radio link. They will also have to be implemented so that they are backwards compatible with existing devices.
After the announcement by major US carriers that they intended to sunset GSM and 1xRTT 2G networks, a lot of device manufacturers who have had the ability to do so have been waiting for low-cost, LTE-only radio solutions before redesigning their hardware. Of course, there are a lot of companies that could not wait and had to do either 3G or LTE Cat 3- or 4-based product implementations, but there are some business cases that only work when the hardware cost is below a certain threshold. The LTE category M1 and NB1 User Equipment radio modules hitting the streets now re-enable these business cases and pave the way for new ones given the higher bandwidths, lower power consumption and levels of integration these new radios have over 2G radios.
So going from 3G to 4G, IoT device makers waited a long time for new low-cost UE radios. Going from 4G to 5G, the UE radio devices are unlikely to change much, if at all. 5G is mostly a network side, infrastructure upgrade and, as such, there’s no need to wait for next thing as there was with 4G. From an IoT standpoint, its full speed ahead on the device side.
So How Will 5G Affect the Antennas?
Some IoT devices use unlicensed spectrum. Many of these devices rely on the 868 MHz, 915 MHz, 2.4 GHz and 5.8 GHz ISM bands. One aspect of 5G is the drive to integrate the use of unlicensed spectrum with cellular products. This is one of the 5G points still under discussion, but any use of unlicensed spectrum will almost certainly require adding these bands to the cellular antenna. Current converged devices use separate radios for cellular and unlicensed spectrum access, for instance, Bluetooth, Wi-Fi and Ant+, would all show up in a typical smartphone.
IoT devices are seldom converged they normally use a specific unlicensed band or cellular, but not both at the same time. Thus, in the IoT sense, the antennas sold today for IoT applications will remain perfectly suitable for IoT.
Once the discussion is settled over unlicensed spectrum use, certain converged devices may need antennas that support both cellular and unlicensed spectrum, similar to many modern smartphones. There are already IoT-focused antenna products that cover this need on the market, but its common for such converged devices to need customized antenna solutions to meet design and size requirements.
Many IoT products will continue to use the same licensed cellular bands used today, simply based on the coverage availability. The US carriers will continue to enforce basic device performance requirements and most likely add new spectrum bands here and there, as required. While the addition of these new bands will require radio and antenna makers to update their products, Cat M1 and NB1 radios and antennas can expect network compatibility and support equal to or longer than what we saw with 2G. For the antenna, this all boils down to the need for the same level of performance, and thus, implementation volume as well as the need for that antenna to provide as good performance on multiple bands.
Right now, this means radio and antenna solutions for M1 and NB1 are ready to go today off the shelf. There are even products available that support cellular, GPS and unlicensed spectrum on the same antenna.
Which brings us to what will change on the UE side of things. Millimeter wave radio systems are very short range, have line of sight only, but have very high bandwidth. The antennas have to be very directional, and hence they need to be pointed at a base station or small cell to work. These factors would initially appear to all work against using such a radio for IoT. There are likely to be special cases, however, where this sort of system could be leveraged to good use. An example mobile application would be the download of surveillance camera video and other data from buses and other mass transit vehicles. Putting access points at the maintenance garage or where the vehicles change drivers allows for very high-speed download of this data. This can be done much faster with mm wave than with Wi-Fi, for instance. New antenna and radio solutions are needed for mm wave products and this is the subject of a lot of new development.
Where the real changes are happening is on the bases station and infrastructure antennas. Large numbers of independent elements supporting massive MIMO, beam forming and full duplex technologies promise to dramatically increase the available bandwidth within a given cell coverage area. The higher top-end speeds will come from having dedicated data streams via multi-user MIMO as well as carrier aggregation across bands. There are other changes in the signaling that could add improvements as well, but these things are still being sorted out.
The other major part of the base station story is small cells. While the above improvements create more bandwidth in a given cellular coverage sector, small cells create the ability to create entire new sectors, taking advantage of geographic frequency reuse. Some small cells will only have low order MIMO, but others could well include the same features as full-size base stations.
While 5G promises improvements in capacity, speed and latency, since those improvements are largely on the network side, IoT products finally have a clear road ahead and a long future to look forward to.
For more information please visit www.taoglas.com
Chris Anderson is the VP of Engineering at Taoglas; he joined the team in 2013 and has more than 15 years experience in the industry. Chris is responsible for managing and coordinating global engineering resources to ensure Taoglas continued growth and efficiency. He is an expert in his field, having executed and overseen hundreds of successful RF/cellular product developments for many Fortune 100 organizations and other household company names.
Throughout his career, Chris has held positions at Grayhill, NextNet, Motorola, Spectrum Design and Digi International, to name but a few. He has been responsible for all aspects of radio product development including chip level cellular, GPS & WiFi solutions, antennas, software, production test systems, agency and carrier certifications, as well as manufacturing deployment.