Category Archives: Cell Phones

OpenWRT Quality-of-Service module caveat: speed limit

As I still have “issues” with my DSL line being extremely slow during certain times (especially between 18:30 and 23:00), I wanted to use USB tethering from my OpenWRT router to my Android LTE phone to enjoy the massive speed I have in our area (up to 90 MBit/s downlink and 70 MBit/s uplink, according to the Ookla Speedtest.Net).

So I configured the router according to the OpenWRT wiki. The internet connection did not come up immediately, and I couldn’t find out why, so as a last resort I rebooted the router. After I switched on USB tethering again on my mobile phone (which seems to be required each time you reboot the router since the mobile phone then loses the USB tethering connection), I suddenly had a working Internet connection.

However, for some reason the Internet speeds I was seeing in Ookla’s web browser-based speed test (which is a Flash applet) were very disappointing, around the same speeds I’m used to with my DSL line (14 MBit/s downlink, about 0.8 MBit/s uplink). I thought it might be an issue with USB tethering not working well in my build of OpenWRT (still r39582), so I tried USB tethering with my Mac (using HoRNDIS). I got the full speed I expected. So back to OpenWRT…

Then suddenly I suspected what might be going on: Since I had more or less exactly the same speed as my DSL connection (with the uplink of less 1 MBit/s being dramatically slower than what I should get via LTE) I thought about what could possibly limit the speed. And then I remembered that in the “Quality of Service” (QoS) module I configured the speeds of my DSL line (at the top of the page, in the Download speed (kbit/s) and Upload speed (kbit/s) fields). Could it be that these settings actually limit your speed to these values?!

I disabled QoS, and immediately thereafter I got the full LTE speed I expected.

So, another thing learnt.

I hope this helps people who might be in a similar situation…

iPhone 4 Battery Repair

If you follow my blog you know that my old iPhone 4 suffered from the well-known issue of a swollen battery. I didn’t want to throw it away before checking the actual extent of the damage — maybe it could be repaired with little effort?!

So I spent 15 EUR and ordered a Pentalobe screwdriver and plastic opening tools from iFixIt Europe. Only a few days later I received the tools, and using the instructions they have on their website how to open the iPhone 4 and replace the battery it took me only 5 minutes to find out that there was no damage whatsoever to the inner of the iPhone: It was only the battery itself that was damaged (swollen), and the glass back cover that was glued into a plastic frame had become loose.

Here’s a picture of the old battery:


You can clearly see that the battery was not “flat”, but strongly swollen.

Therefore I decided to order a new battery. This time I ordered from eBay since a new battery could be had from there for only 12 EUR, while iFixIt would have charged me 30 EUR (both incl. shipping).

The actual repair was extremely easy: Just unplug the damaged one (after removing a tiny Philips screw that secured the battery plug), and then insert the new one into the iPhone, plugging in the battery cord into its socket, and secure it with the tiny Philips screw.

I also “repaired” the back cover by firmly pressing the glass plate onto the plastic frame. Luckily the glue was still strong enough to firmly hold the glass.

I then assembled the iPhone again, and plugged the charger in. After a couple of seconds, it started booting, and the charging process started, so the new battery seemed to at least not be D. O. A. 🙂

Since I had read comments on Amazon that obviously some people had received used batteries as replacement parts (some had already around 200 charge cycles!), I decided that I wanted to check my battery stats. There’s a tool in Cydia Store called BatteryInfoLite that will display extensive information about your iPhone’s battery, so I decided to jailbreak my phone (that still had iOS 5.0.1 installed) to get Cydia. I used redsn0w 0.9.13dev4, and within only a couple of minutes my device was jailbroken, and Cydia was installed.

Here’s a screenshot of what BatteryInfoLite displayed about my battery:


 The serial number that was displayed by the tool was identical to the one printed on the battery, which I regard as another indication of reasonable quality. The last 4 digits are obviously an indication of the battery’s design capacity.

I felt happy when the phone was working again. I will now use it as an MP3 player (which it essentially is, after all… ;-))

Don’t neglect your iPhone, or else… :-(

I did not use my iPhone4 for a while (since I have a Samsung Galaxy S4 now, which I like much more), and when I wanted to “revive” it recently as a music player I found that it had burst (no, I didn’t drop it, it was just lying around on my desk):


20130927T100257-IMG_0107Obviously the battery had swollen…

I immediately called the Apple dealer closest to my home and told them about it. They said it’s normal for a battery to burst if the device hasn’t been used for a while. They said I could buy a new iPhone 4 for a “mere” 190 EUR… 🙁

If you Google for this issue you will notice that it’s pretty common, still Apple cares a sh*t about it… I’ve never seen such major battery issues on any mobile phone I’ve owned before — and I had many!!!

Thanks, Apple. This is what you get when you buy from a “premium” manufacturer…

Needless to say that I will never buy an iPhone again…

“Call Forwarding” setup on iPhone – what a stupid user interface design…

I’m using call forwarding a lot on my iPhone — every day after I left the office I forward calls to my voice mail, and next morning I cancel this forwarding. Also, in periods where I’m on-call I forward calls to my fixed line as soon as I arrive home, and I cancel this forwarding when I leave home so that I can be reached on my cell phone again…

Ok, here’s the thing I’m complaining about: When you want to enable call forwarding, you need to move the Call Forwarding switch from OFF to ON. This immediately enables call forwarding without giving you the chance to enter the number you want calls to be forwarded to. So if you’re frequently changing call forwarding destinations a lot as I do you will often end up setting a wrong destination for a short while until you have clicked the Forward to field and updated the destination phone number.

And, what’s really lame, you still cannot select a number from your phonebook as the destination, you have to manually key in the destination number — I already complained about that two years ago, and Apple still hasn’t fixed this in iOS 6.1.3. Unbelievable for the self-proclaimed leader in usability, Apple! My first cell phone 15 years ago could do that already…