ubuntu-phone team mailing list archive

[sturmflut <sturmflut@xxxxxxxxxxxxxx>]

Hey,

On 22.04.2015 13:35, Michael Zanetti wrote:
> 
> 
> On 22.04.2015 13:15, Wayne Ward wrote:
>> Thats a relief its funny how it used to show 2g 3g on the nexus
>> 5 im probably going to flash it when vivid becomes available
>> instead of using reset phone option as im sure it resets the
>> phone but not the mobile sim stuff ?
> 
> If I understand correctly HSPA is actually better than 3G :) It is
> 3G with some "High Speed" extensions. Similar as EDGE is "Enhanced
> Data rates for GSM Evolution", an upgrade to 2G, also referred to
> as 2.5G.
> 
> Looking at the specs of the devices, it looks like the Nexus 5 has 
> "only" HSDPA, which would only offer the high speed extensions for
> the down link, but not for the uplink while the bq claims to
> support HSPA+, in both directions. That could well be the reason
> why the indicator shows 3G on one, but H on the other.
> 
> That said, I'm not a total expert on this field, so take it with a 
> grain of salt, but at least it would match with those:
> 
> http://www.gsmarena.com/lg_nexus_5-5705.php 
> http://www.bq.com/gb/products/aquaris-e4-5.html
> 
> https://en.wikipedia.org/wiki/2G 
> https://en.wikipedia.org/wiki/Enhanced_Data_Rates_for_GSM_Evolution
>
> 
https://en.wikipedia.org/wiki/3G
> https://en.wikipedia.org/wiki/High_Speed_Packet_Access


I think I can provide some clarification here:

2G ist standard GSM.
2.5G is EDGE, most devices display an "E" for this.
3G is UMTS, most devices display a "3G" for this.
3.5G is HSPA/HSPA+, most devices display an "H" for this.
4G is LTE, most devices display a "4G" for this.


To the confusion surrounding 3.5G, or the "H" displayed by most
devices: It actually consists of two parts, downstream acceleration
(HSDPA) and upstream acceleration (HSUPA). If a device supports HSPA
(which both the Nexus 5 and the bq do), then it has to implement both
HSDPA and HSUPA in at least their minimum specifications of up to 14
MBit/s downstream and 5.76 MBit/s upstream. There is an extension for
HSPA called HSPA+, which increases the maximum bitrates, and there
will likely be even more extensions in the future.

So Michael is absolutely correct, "H" is better than "3G". Usually
much better.


Now back to the original question: The Nexus 5 actually has the better
radio part because it also supports LTE, which the bq doesn't. So if
both devices were tested with the same SIM card in about the same
location, both should have switched to HSPA and displayed the "H"
indicator.

kind regards,
Simon