Heise news reports today about an LTE field trial T-Mobile is performing right now in Innsbruck, Austria and lists some interesting details about it:
- Base stations: The outdoor test network consists of 20 base stations with three sectors each, supplied by Huawei.
Note: That's a good network setup to test the impact of neighbor cell interference, a major factor that limits throughput in live networks. If the network vendor has implemented a test mode in the base stations, it might even be possible to simulate neighbor cell interference as there are probably not enough mobiles yet to generate meaningful load in all cells of the setup.
- Backhaul: Fiber backhaul (200 MBit/s) is used. Looks like Innsbruck has good network infrastructure in place!
- Frequency band: The 2.6 GHz frequency band is used.
- Throughput: Downlink up to 35 MBit/s, uplink up to 31 MBit/s with a 20 MHz carrier.
Note1: That sounds quite realistic as there's probably not much interference from neighboring cells yet due to the limited number of mobile devices used in the trial.
Note 2: Broken down to a 5 MHz carrier for easy comparison with HSPA, the speed would have been 8.75 MBit/s (disregarding statistical multiplexing gains of a broader channel). I wonder what the speed would be today with HSPA+, 64QAM (no MIMO) and suitable devices. I suppose it would not be much less. Happy to hear your thoughts on this!
- Round trip delay times: 21 ms. Very nice, current HSPA technology in live networks have a round trip time of around 100-110 ms.
- Mobile device used: No names given but the picture in the original post is interesting!
Note: Looks like the devices they used are still early proof of concepts. Side note: The LG dongle sized LTE mobile I've seen at the Mobile World Congress in Barcelona this year was already a lot smaller.
When looking at those giant test terminals with an apparently enormous power consumption, I wonder how much more computing power LTE terminals need compared to UMTS ones?
And how much more computing power does UMTS require compared to GSM?
Will there be a significant impact on standby-endurance of LTE handsets like we saw on first-generation UMTS devices, which worked for less than 2 days?
Hi Christian,
All good questions!
LG has LTE mobiles the size of 3G dongles these days as shortly mentioned in the post. So form size wise, we seem to be quite close to the first generation now. Looking back, UMTS and GSM mobile devices looked quite similar during advanced trials in their days.
In terms of processing speed required for LTE I think it is significantly more than pure GSM, which is, compared to UMTS or LTE really child’s play for current technology. How much more than UMTS, I can’t say except that UTMS and HSPA on top are no simple critters either and require significant processing power 🙂
Cheers,
Martin