LTE outperforms 42M bps HSPA+ on streets of Stockholm

IDG News Service - TeliaSonera's 4G network comes out on top when pitched against Three's new HSPA+ (High-Speed Packet Access) network in central Stockholm, with average download speeds at 57.1M bps (bits per second) and 13.7M bps.

The speeds that mobile broadband technologies can offer users depend on a number of factors, starting with the amount of spectrum regulators have allowed the operators to buy and what frequency is used.

TeliaSonera's LTE (Long Term Evolution) network uses two times 20MHz -- one channel for download traffic and one for upload traffic. The network also uses MIMO (Multiple-Input Multiple-Output), a technology that increases download speeds by sending data using multiple antennas.

Three's HSPA+ network uses two times 5MHz when downloading data, made possible thanks to a technology called dual channel or dual carrier, which sends traffic over two channels at the same time. The total amount of spectrum is the same used by Verizon Wireless' U.S. LTE network.

With that in mind it shouldn't come as a surprise that LTE came out on top.

To conduct my test, I traced my steps from last year, when I tested TeliaSonera's LTE network for the first time. Once again, using broadband-measuring site Bredbandskollen (The Broadband Check), I measured download and upload speeds at more than a dozen places.

This time, the laptop was a Lenovo T420, instead of a Sony Vaio Z. TeliaSonera still uses Samsung's GT-B3730 modem and Three uses ZTE's MF680 modem.

LTE's performance was even more impressive than last year. The average speed then was 33.4M bps and this year it had increased to 57.1M bps. The highest recorded download speed increased from 59.1M bps to 84.5M bps. TeliaSonera has continually worked to optimize network performance, according to Tommy Ljunggren, vice president of system development at TeliaSonera.

When compared to HSPA+, LTE also offers shorter latency, between 11 milliseconds and 26 milliseconds, compared to 45 milliseconds and 55 milliseconds.

However, one thing that hasn't improved is the network's inability to reach two indoor locations: an underground subway station and a mall. Here the modem again connected using 3G, which uses a lower frequency, and since Samsung's modem only supports HSPA at a theoretical 17.6M bps, Three's modem and network won both times: offering 10.4M bps and 17.6M bps, instead of 3.7M bps and 6.9M bps.

When those low points are added to the total, the average download speed for TeliaSonera dropped to 49.1M bps.

That shows the importance of having a fast network to fall back on, especially when, like Teliasonera, operators roll out LTE on 2.6GHz.

Next month, TeliaSonera is scheduled to start shipping the ZTE's MF820D modem, which combines LTE on several spectrum bands and HSPA+ at 42M bps. On the other hand, Three will also join the other Swedish mobile operators and launch LTE during the third quarter.