T-Mobile has been in the process of upgrading its LTE network. However, it is not following the path of AT&T and Verizon. It is not looking to increase the speed of its LTE connections, instead it is looking to resolve the issue of inconsistent signals and speed fluctuations that are normally experienced as you move from through a mobile network.
This is something that I experience in my own apartment. If I am in the front of the building I get at least 4 out of 5 bars, however if I walk to the back of the building I’m lucky to have two bars, usually I have just one bar. This has resulted in a call being dropped and I have to move back to the front to reconnect the call.
So, how is T-Mobile doing this? Antennas! More antennas seem to be the key to consistency. According to GigaOM, John Legere’s company has begun installing antenna arrays that use 4-by-2 multiple-input, multiple-output (4x2 MIMO) technology. Supposedly this method has the potential of making a huge difference to T-Mobile’s LTE end users.
In radio, multiple-input and multiple-output, or MIMO is the use of multiple antennas at both the transmitter and receiver ends to improve communication performance. It is one of several forms of what is referred to as smart antenna technology. MIMO technology has attracted attention in wireless communications due to the fact that it offers significant increases in data throughput, as well as link range.
What makes it useful, is that it does this without additional bandwidth or increased transmit power. This goal is achieved by spreading the same total transmit power over the antennas resulting in an array gain that improves the spectral efficiency by providing more bits per second per hertz of bandwidth, it can also achieve a diversity gain that improves the link reliability which reduces fading.
As GigaOM points out, just about every LTE system that is currently in use today uses 2x2 MIMO, which of course, means that two antennas on the cell tower are used to send two simultaneous streams to two antennas on your mobile device. However, with 4x2 MIMO, T-Mobile is doubling up on the number of tower antennas for a total of four. That means that four antennas will be sending the signal to the two in your mobile device.
This method will not increase the top end speeds, however it should provide you with a much more consistent connection. The goal is that as you move throughout the network and approach the fringe, you should consistently have five bars and not fluctuate as you walk around. As GigaOM describes it, “There will be a lot more signals flying at your T-Mobile 4G phone, tablet or mobile hotspot, ensuring you can get a better downlink connection even if you’re at the fringes of the network or their obstacles between you and the tower.”
Mark McDiarmid, who is vice president of technology at T-Mobile, said “We do see the benefits 4×2 MIMO offers and will be deploying this in many cities in 2014 as part of our Wideband LTE rollout. All of T-Mobile’s available devices currently support 4×2 MIMO and we’ll ensure that new devices will as well. We believe this will be one of the first deployments by a top carrier network in the US.”
According to Petri Hautakangas, who is head of technology for North America for Nokia Networks, if you are at the cell edge of the network where your connection usually suffers the most, then you could possibly see a 50 to 60 percent boost in download speeds and as much as 100 percent increase in upload speeds.
Is this the direction to move in? It seems to be as Sprint is currently running its own tests of a similar technology called 8T8R. This creates, as you might be able to guess, eight transmit and receive paths, doubling T-Mobile’s double of the existing 2x2 MIMO. Sprint intends to incorporate 8T8R when it upgrades its tri-band Spark network.
While there has been no official announcement from T-Mobile as to where this new technology will be used, it appears that there is evidence that these antennas have been seen in Chicago, Dallas and San Antonio.
We know that next year the FCC will be conducting a spectrum auction which involves buying airwaves back from broadcasters and then selling new licenses for those airwaves to spectrum hungry wireless companies who are looking to expand their networks. Does that mean that the expansion will go the way of more and more antennas? I guess that we will just have to wait and see if any other carriers follow suit.
Edited by
Maurice Nagle
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