Back in February I noticed that layer 2 Wifi tracing on my Intel Centrino Core Duo based Toshiba notebook from 2009 stopped working after upgrading to Ubuntu 15.10. This had me a bit worried but it looks like it is back with Ubuntu 16.04!
In a previous post on Bluetooth Low Energy, I’ve shown how to do a Wireshark trace on the HCI interface without additional hardware and attached a sample trace. The downside of this approach is that the trace is made on the HCI interface between the PC and the Bluetooth hardware so layer 2 frames are unfortunately not included. It seems to be quite hard to get hold of Bluetooth layer 2 traces, but finally, I’ve come across from which one can gain interesting insights.
I’ve written a number of blog posts in the past on Eduroam, how to set it up in case you have access to the system and how cool it is to use it as secure Internet access at any supporting institution around the world without a login procedure. As I recently found out, Eduroam Wifi networks are not only deployed on University campuses but also train stations and airports!
As I pointed out in previous posts on LTE in Sweden, using several different LTE channels (carriers) is now becoming the norm rather than the exception. Telenor/Tele2, for example, are on-air in 4 different bands at the same time. Good for you if you have a recent product that supports LTE-Advanced Carrier Aggregation. While CA is great for advertising top speeds, it is much more useful in practice for another purpose.
I recently wanted to dive a bit into how Bluetooth Low Energy, also referred to as BLE or Bluetooth Smart, works on the inside. One thing that is really helpful after looking at a lot of documentation and great resources on the web is to have a look at an actual trace. There are quite a number of good tools out there to make Wireshark traces but unfortunately it’s quite difficult to find downloadable BLE pcap files. Time to change this!
TD-LTE is used extensively in China (China Mobile) and Sprint in the US today. In Europe, there are only few deployments so far and I haven’t come across one until recently when I was in Stockholm. And again, there was more deployed than I initially thought!
When it comes to file access over the Internet, Windows Shares (SMB) are a no-go as file transfers are not encrypted and the ports used by the protocol are often blocked by Internet providers. Webdav shares are often also not practical. Therefore I’ve used SCP in the past on the command line to transfer individual files from any place in the remote file system. The problem with this is that for many tasks the command line is way to cumbersome to use. But did you know that the Ubuntu file explorer can use SSH/SCP/SFTP to connect to a remote file system and bind it locally? Continue reading Ubuntu And SSH File Access In the File Explorer
In a previous post I’ve taken a look at the current deployment of LTE in a more rural area of Sweden south of Göteborg. One of the interesting things I found there was that Telenor used 10 MHz in the 900 MHz band for LTE while only the remaining 5 MHz was used for GSM. At the time I expected that perhaps in a more urban area things might be different as there might still be more need for GSM when there are more people. So I had another look in Stockholm.
Ever since I discovered the use of a TV in hotel rooms for streaming videos or its use as a second screen almost a decade ago, I’m always taking a DVI/HDMI cable along when I travel. These days, however, TVs in hotel rooms are getting larger and larger. While this is great news for video streaming from the PC, they become less and less useful as a second screen for work. But recently I’ve found a great alternative: Portable USB screens.
There are a number of devices and network operators out in the wild now which do not only support Voice over LTE (VoLTE) but also Voice over Wifi (VoWifi) and can even hand-over ongoing calls between the two radio access networks. But there is one thing: Which RAN should be preferred if both LTE and Wifi are available? The answer is not as simple as it looks at first.