When I recently wanted to find out which network operators have which and how much spectrum assigned in a country I found an incredibly cool website that has up to date information on this topic. Have a look over at spectrummonitoring.com! Not included in the charts is the US, probably because in this part of the world spectrum assignments vary quite significantly even between cities. But for Europe, Asia and the Americas a huge number of countries are present on the site.
VoLTE – Some Thoughts On Emergency Calls
Even if you have a VoLTE capable phone and use it in a VoLTE capable home network, chances are that when push comes to shove and you have to make an emergency call, it’s not done over VoLTE. Instead, CS-Fallback is used to establish the emergency call in GSM or UMTS. But at some point, network operators will likely retrofit their VoLTE installations to be also able to handle emergency calls. I recently wanted to have a closer look and found an interesting resource on the web that saved me a lot of time.
USB-2 Is Not Fast Enough for LTE 3-CA
Ten years ago, Bluetooth tethering was a big thing and the only option to wirelessly tether a notebook via a phone to the Internet. How things have changed since then…
VoLTE and Quality of Service – The Ultimate Test
If your uplink bandwidth at home is limited and you use Skype or other Internet based voice services you’ve probably experienced more than once that when someone else in your household starts uploading cat videos, your Skype call goes south. That’s because the voice packets are treated like all other packets and start queuing up behind those fat IP packets with parts of the cat video inside. This is not a theoretical scenario, it happens in practice. So how does VoLTE on LTE cope with this?
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LTE Bearers Are Like Virtual Network Interfaces
In LTE, data is transferred over the air interface over ‘Default Bearers’ and ‘Dedicated Bearers’. The terms are a bit confusing but actually the concepts behind them can easily be explained: Virtual Network Interfaces and Traffic Shaping Rules.
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Ubuntu 16.04 Leaks DNS Requests With OpenVPN Tunnels and IPv6
Recently I noticed, much to my dismay, that when using OpenVPN over network interfaces for which IPv4 and IPv6 is configured, Ubuntu 16.04 doesn’t configure DNS lookups correctly. As a result, DNS requests that should only be sent inside the OpenVPN tunnel are sent on the outside network interface thus massively compromising security and privacy. Read on for the details and a temporary fix.
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The Specs Behind LTE-Advanced Pro’s Mission Critical Communication
One reason for referring to 3GPP Release 13 as ‘LTE-Advanced Pro” is that this version of the specification finally has everything in place for Mission Critical Communication, the LTE based successor to 2G TETRA networks designed in the 1990’s and used by public safety organizations in many countries today. One of the first countries that will use LTE-Advanced Pro’s Mission Critical Communication is the UK and a contract has already been awarded to Everything Everywhere. Time to have a look at the specs for Mission Critical Push to Talk (MCPTT), the central feature for public safety organizations.
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I Don’t Even Bother With Hotel Wifi Anymore (in Europe)
I like going on vacation to Austria. One of the reasons is that I have a SIM card from local operator “Drei” (Hutchison Three) that gives me unlimited Internet access over 3G (sadly not LTE) for 18 Euros per month. In other countries, I had to be bit more careful with my daily data usage while traveling. But at least for Europe things have changed to the better in the past months once again.
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Book Review – 30 Years of Mobile Phones in the UK
While I got my first mobile phone at the end of the 1990’s, mobile devices and networks have been around for a bit longer than that. In their book ‘30 Years of Mobile Phones in the UK‘, Nigel Linge and Andy Sutton take a look at the developments over the past 30 years. An interesting title and I obviously couldn’t resist to pick up a copy.
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New Train Windows Against Moving Coverage Holes
Most trains these days come with specially coated windows to keep the heat out. Unfortunately these windows also block the RF waves of wireless networks. While most high speed trains in Germany these days compensate for the loss with RF repeaters many regional and inter-city trains don’t come with the luxury. Thus, without really strong network coverage outside, passengers are pretty much sitting in a moving coverage hole. But there seems to be a fix for this now.
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