Samsung 700G7C - Bluetooth vs Wi-Fi tethering speeds

Hi all

I'm using a Samsung 700G7C-S01UK laptop, and have been testing internet speeds when I tether the laptop to my phone, which is a Nexus 4 (stock Android 4.2.2), over Bluetooth and wi-fi.

As some of you will know, the Bluetooth card in the laptop is an Intel Centrino 6235, which is Bluetooth 4.0-capable. The latest drivers from Intel are installed.

Today I was running both laptop and Nexus on battery, and was in an area where Speedtest on the Nexus reported ~15Mbps download.

When I tethered the laptop to the Nexus over wi-fi, Speedtest on the laptop reported about the same download speed.

However, when I tethered the laptop to the Nexus over Bluetooth (moments later), Speedtest on the laptop reported speeds of ~1.5Mbps.

Obviously this is a huge difference, and I repeated the tests a few times, getting similar results.

I wondered if the Bluetooth card in the laptop was in power-saving mode, due to running on battery - but then the same card provides the wireless connection, so I don't understand why the two connection methods would produce such widely different speeds.

Any ideas? TIA.

(This is a cross-post from the Android Central forum, because I'm not sure if the issue is specific to the laptop, or to the phone.)

 

Hi iain_m,

Interesting observation, thanks for posting. There is a Bluetooth AMP setting on the Advanced tab of the 6235 adapter settings (at least for my 6230). I usually keep that disabled because I never use BT and think I found slightly better WiFi without it. It's worth checking that your AMP setting is enabled -- though it probably is by default

I don't know what the max throughput is for Bluetooth 4.0, but I would assume it is lower than WiFi, given its applications (peripherals and audio devices). I checked Bluetooth vs WiFi on Wikipedia and found the following quote:

I guess the lower power consumption of Bluetooth would make it a good candidate for tethering from a smartphone -- with the slower speed being the downside.

Gosh, I am just speculating here, I don't really know what I am talking about

Update: I made it down to Bluetooth 4.0 on Wikipedia and I can appreciate the appeal of what you are trying to do even better. It would seem your phone or PC may be stuck in Bluetooth low energy mode when you probably want Bluetooth high speed mode in order to natch WiFi speeds.

You probably already knew about these two; but I didn't -- and maybe others don't either...

 

Hi and thanks for the reply.

First up I can confirm that Bluetooth AMP is ON in the device manager settings panel for the Intel 6235 card.

I also had a look at the Wikipedia information about Bluetooth, and it would seem that I'm getting only Bluetooth 2.0-equivalent speeds.

It could well be because both laptop and phone were running on battery - unfortunately for me, I don't currently have access to anywhere with good enough mobile signal where I can run them off mains power!

Would be interested to hear how other users are managing the 'low energy' bluetooth mode in scenarios where they need faster speeds - is there a way to disable it?

 

I've always looked on Bluetooth as a slower, shorter range technology. Reading further on that Wikipedia page it says:

If the WiFi is turned off then the data rate would be the normal Bluetooth speed with a nominal maximum of 3Mb/s (and, in reality, less).

Is this the explanation?

BTW, a new driver for the 6235 has been released this week. It might be worth check what it does for you. Some of us have seen improved WiFi performance.

John

 

@John: That's gotta be it.

So max throughput with Bluetooth is 24 Mbps -- ASSUMING we can use WiFi for the actual transfer. Sounds like the marketing guys thought long and hard about this one

1.5 Mbps (as reported by iain_m) is still not bad for simple browsing and other mundane tasks. If power consumption is significantly less than WiFi, I still think that's a feasible alternative when tethering far away from a power outlet.

I learned something here!

 

We need a volunteer to do comparative testing over, say, an hour, checking the battery drain on the device at each end of the link.

Several (>5) years ago I found that BT was a power guzzler due to the increased CPU activity that it caused when running, but maybe drivers and the hardware have improved since then.

John

 

That has been my understanding as well - and one reason why I always just disable BT on my PC and never look back. My only BT use has been to connect my phone to my car.

But maybe 4.0 and this low energy mode make a difference.

It could also mean that my standard advice to skip installation of Bluetooth drivers (beyond the standard Windows ones which are fine for BT mice and keyboards) is outdated - at least for some users.

 

Hi both,

Sorry for not replying sooner. Thanks for your posts.

The information about the maximum practical Bluetooth speed does seem to explain my experience. I have to confess that I don't quite understand how a 'collocated 802.11 link' would work - wouldn't it just be a wi-fi connection, then?!

In any case, I agree that for normal browsing the trade-off of speed vs power consumption is acceptable. I guess my main concern was just to check that the speed I was experiencing is normal, and that there isn't something wrong with the phone and/or laptop.

I haven't tested it scientifically but I can tell you that tethering my Nexus 4 over Bluetooth for light browsing and email resulted in very, very little battery drain after several hours. With wireless, the phone gets hotter and of course the power drain is greater. (I haven't yet tried using it as a USB modem, because I don't have a free port.)

I wasn't keeping a close eye on CPU use on the laptop while running the Bluetooth connection, but I would say that performance is in some ways better than wireless, insofar as I don't get the DPC latency spikes that always accompany wireless internet connections.

If I get a chance to test all this more thoroughly, I'll report back.

Thanks again!

 

That's good information, iain_m. Thank you for testing and reporting this.

I am thinking of getting a Nexus 4 myself, and although I will not be tethering it regularly, I do hope to be able to use it as an emergency fallback if I critically needs to get online during a cable outage (as happens in Florida). I'll probably just stick to Wi-Fi tethering, though, which is what I've been doing with my old phone in these situations.

As for the latency spikes during WiFi use, you may find some help in the latencies thread (that was a link).

In particular, it will help if you get rid of the Intel PROset junk for both WiFi and Bluetooth, and install just the Driver Only WiFi package. Also, getting rid of as much Samsung software as you can. The old Easy Software Manager gave bad latency spikes, and I would think so does SW Update (though I haven't measured it). I actually DO keep SW Update installed nowadays, but have disabled the Scheduled Tasks to load sAgent. I load it manually (Start Menu shortcut) before opening SW Update.

OK, that was off thread topic. This subject gets me going

Update: Wait, I remember now, we already discussed this in the latencies thread some time ago; so you're already on top of that. Well, at least it's there now for others to see.

 

Haha, yes - I was just trying to find that conversation, but you beat me to it.

Some DPC latency when using wireless is normal with all wireless adapters, as far as I know (though some drivers are worse than others). So usually when doing audio work I just switch off wireless from Windows Mobility Centre (no need to disable it in device manager, at least for this model of laptop).

The heinous Samsung sAgent is another story - I found that it remains on the computer even after uninstalling SW Update!