The Wonders of 5G Beamforming
Imagine you’re thrown overboard on an ocean cruise in the middle of the night. The alarm is raised but the only way to find you is to flood the entire ocean around the ship with powerful lights: fore and aft, port and starboard, in the hope that your florescent jacket reflects enough light to identify where you are. The bright lights draw consistent power from the ship’s generator and your reflection grows weaker and weaker as you drift helplessly away into the darkening slipstream.
Now imagine your jacket is a new design and has incorporated a small transceiver that the ship’s searchlight locks onto and automatically tracks you with a focused beam as you bob around in the ebb and flow of the ocean’s currents. The beam expertly follows you while you drift comfortably around safe in the knowledge the rescue boat will be there soon.
Put simply, this is the difference between 2G/3G/4G mobile antennas and the type of antenna used for 5G. In the olden days, mobile antennas projected their signal in a fixed arc with as much power as the country’s regulator would allow and your chances of picking up a good signal depended on numerous factors, not least of which was your distance from the antenna. The new type of antenna being deployed for 5G networks employ a technology that we call beamforming that instead creates a radio beam like our ship’s searchlight that connects your phone directly to the antenna, tracks it if you are on the move, and intelligently adjusts the power so the beam is just strong enough to reach you.
So let’s dive deeper and take a look at the benefits beamforming will bring us.
5G Benefits Come from a Combination of Technology Upgrades
First, it’s important to remind ourselves that the two principle benefits of 5G (massive increases in bandwidth and speed of data through the network) are achieved by a combination of upgraded technologies including the 5G algorithm itself, the frequency of the radio waves, and the antennas on both the phone and the large units we see on the top of buildings. It’s these antennas we will look at today. Baked into the specification of 5G is the concept of Multiple In, Multiple Out (MIMO) antennas, which increase bandwidth by combining multiple concurrent transmitters and receivers.
The smallest 5G antennas, which we call LampSites, are placed throughout high-density buildings like airports, shopping malls, or sports stadiums, and they incorporate four transmitters and four receivers. But the big ones, the beasts, go up to 64 transmitters and 64 receivers in a single MIMO unit. This results in massive capacity, so we call them Massive MIMO antennas.
The reason we can develop and build Massive MIMO antennas for 5G in a relatively small unit weighing 25 kg is that the radio frequencies being allocated to 5G are much higher than previous generations of mobile technologies. The higher the frequency, the shorter the antenna – if you opened up your 64T64R 5G Massive MIMO antenna, you would see a matrix of adjacent antennas each around one cm in length. (As an aside, you could in theory build a Massive MIMO antenna for mobile signals in the much lower 800 MHz frequency but with each individual antenna measuring a couple of meters long the resulting Massive MIMO antenna would need a football pitch to hold it and its weight would crush the roof of any building brave enough to try supporting it.)
The Physics of Radio Waves
Now we get to the clever physics. By adjusting the power to adjacent tiny antennas in the Massive MIMO unit we can twist the radio waves into beams and direct those beams to the receiving mobile phones just like the beam of our ship’s searchlight. This is beamforming.
The computations involved in this are highly complex, so we use AI in the back of the antenna to manage all of this. The AI directs beams specifically to the receiving devices with the exact amount of power to reach each device and also maximise the signal quality. Beamforming technology has some unexpected benefits too. It allows radio waves to bounce off buildings bringing a reliable signal to areas that are not necessarily in direct Line of Sight (LoS) of the Massive MIMO antennas.
Benefits for the Customer
Beamforming from Massive MIMO antennas immediately brings a number of advantages to the telco operator and to the consumer using their mobile device. First, consumers will no longer have to go waving their phone around in the air to manually search for the strongest signal. The antenna does this for you with beamforming.
Second, beamforming is enabling new uses for mobile networks including the ability to connect and control vehicles (V2X) and homes (B2H) with reliable, strong signals that have guaranteed quality of service and the characteristic of the fibre without digging up the road.
Third, there is the security aspect. Your packets of data travel in the beam itself and not in the entire arc of the antenna unit meaning there’s less possibility to intercept your data, or for interference to affect your mobile signal. Combine this with the higher 256-bit encryption of your mobile identity, location, and data that’s built into the 5G specification and your mobile communications have never been more secure.
Benefits for the Operator
For the operator, beamforming plays a major role in managing the network’s power requirements by only drawing enough power to reach your phone or other terminal device, which is both good for the operator’s finances and good for the environment. In fact, we can show that 5G antennas using beamforming require approximately one-tenth the power to transmit a bit of data compared to legacy 4G antennas, which is a win-win for the spreadsheets and the forests. In addition, the ability to manage and guarantee the characteristics of the broadband’s quality of service using 5G beamforming means new vertical markets such as fibre-like residential broadband or business leased lines where there’s no fibre in the ground, are opening up for telcos, releasing new revenue streams to justify building out the 5G network in the first place.
Beamforming with Massive MIMO antennas is just one way that 5G will help drive transformation in how and what we connect, bringing benefits to consumers, businesses, and telcos alike.
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Disclaimer: Any views and/or opinions expressed in this post by individual authors or contributors are their personal views and/or opinions and do not necessarily reflect the views and/or opinions of Huawei Technologies.