LTE Field Performance

Ericsson has published an interesting article in their Ericsson review (3/2008) on their latest LTE development state. Both lab and outdoor trials were done and the article together with the many graphs and pictures is an interesting read. Highly recommended! While you read, however, you should keep the following things in mind:

  • Unlike the setup recently used by T-Mobile and Nortel in Germany, only a single base station site was used, i.e. their measurement results do not reflect a typical network deployment, were neighboring cell interference will have an impact on the throughput.
  • When looking at the graphs, it should be kept in mind that according to this article by Agilent's Moray Rumney, 90% of the users will not experience a signal to noise ration (SNR) of more than 15 dB. 50% of the users will be below 5 dB. So make sure you have a look at the graphs at those locations.
  • Figure 8 shows nicely, that 64QAM modulation only makes sense at an SNR of more than 15 dB. In other words 90% of the users will not benefit from such high order modulation. However, if you can place your LTE receiver (e.g. your dongle dock) near the window in the direction of the next base station for stationary use the system will be able to server you a lot better than indoors.
  • 4×4 MIMO is nice but I doubt that we will see this implemented in base stations or real mobile devices anytime soon.

Despite these things, however, the graphs and experiences made by Ericsson should make for a nice experience in practice once LTE gets deployed and mobile devices are available.