Wednesday 30 May 2012

LTE battery life

In the grand scheme of things LTE is at its infancy, but it is interesting to look at how battery life will be impacted by LTE. Information sources on the subject are rare, but I did come across the following figures on the Samsung website for the Galaxy SII LTE.

As you can see LTE talk time is not mentioned as the current voice solution of LTE is fallback to 3G or 2G. More on this subject can be found on a previous post here.

LTE standby time is mentioned and as you can see it is worse than 2G and 3G by a considerable margin. The actual figures are pretty irrelevant as manufacturers measure these assuming the largest idle mode DRX cycle possible which you will never find in a real network.

The relative difference however, almost 30% reduction in battery life, indicates that the idle mode tasks (listening to the paging channel, measure serving cell and neighbour cells, etc) of the LTE part of the baseband and RF chain require a lot more power that the 2G/3G ones. I expect this will improve over time, but at least in the near term early adopters of LTE smartphones/tablets should have a charger handy.

The full specifications of the Samsung Galaxy SII LTE, including the extract above can be found here.

Sunday 27 May 2012

Nokia Lumia 900 Dual Cell smartphone and much more!


Nokia's recently announced Lumia 900 got good reviews in terms of its design, ease of use, Windows OS etc, but for me this phone represents a truly feature packed device from a radio point of view.

Having a look at its specifications we can see it supports the 3GPP release 8 HSPA+ Dual Carrier/Cell feature with a theoretical DL speed of 42Mbps. Even though there have been a few DC smartphones out already, these have been launched in the US and to my knowledge this is the first European DC smartphone.

Furthermore the Nokia Lumia 900 also has Rx diversity meaning that it has two receive antennas and can combine the energy received from both of them resulting in a much better Eb/N0. This will mean that the gap between the theoretical and real performance of HSPA will be smaller than a traditional single antenna device.

Naturally the Lumia 900 also supports HSPA+ 64QAM single carrier with a theoretical top speed of 21Mbps.

In addition to all of the above the Lumia 900 also supports DTM (Dual Transfer Mode) which allows the simultaneous data transfer of speech and data in 2G, HSUPA category 6, WB-AMR (a.k.a. HD Voice) and all this is powered by Qualcomm's MDM9200 baseband processor.

A truly radio feature packed phone which makes the iPhone4S and even the more recent Samsung Galaxy SIII look poor in comparison.