VoLTE and VoWifi – Wireless Telephony Has Truly Become Network Independent

When GSM was designed, the network and the voice service running over it were inseparable. That’s because the GSM network was designed in the 1980s as a mobile voice network. Fast forward 20 years and the picture had changed significantly with LTE having been designed as a wireless network that only transports IP packets. Agreed, it took another 10 years before Voice over LTE (VoLTE) was ready to replace the CS-fallback (to GSM and UMTS) mechanism for voice telephony. Now Voice over Wifi that is deployed by first network operators shows that VoLTE really is network independent. Continue reading VoLTE and VoWifi – Wireless Telephony Has Truly Become Network Independent

Global Mobile Spectrum Assignments

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.

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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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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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