A couple of weeks ago in January 2020 I spotted the first 5G antenna at the cell site that serves my home in Cologne on my way home. My first reaction: ‘Hm, that wasn’t there this morning…’. It wasn’t switched-on straight away. but when I came back from vacation early in February, I was greeted with a 5G logo after arriving at home. And even without ‘holding the phone the right way’ I immediately got well over 660 Mbit/s out of the downlink channel.
5G RRC Protocol And How It Compares to 4G RRC
Recently I’ve been looking a bit at the 5G NR Radio Resource Control (RRC) protocol in 3GPP TS 38.311 to get an idea how it is structured and how it compares to the LTE RRC protocol specified in 3GPP TS 36.331. As Ralf points out in the comments below (thanks very much!) some parts of it are already used today to embed 5G configuration information in 4G RRC messages for EN-DC, while other parts will become relevant with 5G NR Standalone, i.e. once a 5G core network is available and devices and the gNBs have implemented standalone operation.
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5G TDD Inter-Operator Network Synchronization
Already back in 2018 I wrote a post that one new thing about 5G in TDD band n78 will be that network operators need to agree on a common uplink/downlink pattern and in addition synchronize their networks. Recently I was asked to what level of accuracy the networks need to be synchronized so I did a bit of research to find out.
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Interesting Insights from the EU’s Roaming Report
A couple of weeks ago, Heise had a post on the newly published EU roaming report. Via this page you can get to the actual document that indeed has many interesting insights into pricing, cost and use of roaming in the EU before and after roaming charges became a thing of the past in June 2017. The document has 98 pages full of insights and here are the points that I found particularly interesting.
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Congested Peering and Transit
While I was investigating potential congestion issues in the roaming backhaul link of mobile networks I noticed again once more that this is by far not the only place where network operators are not providing enough capacity during busy hours in the evening. Another unfortunate example are fixed line access networks. Here are two examples over which I trip frequently.
Roaming Interface Congestion?
When I was recently in Austria I noticed that in the evening hours, the superb network speed I got over the LTE network in a town in the mountains at the place I was staying went from 40-50 MBit/s during the daytime to just 2-3 Mbit/s in the evening. Typical dissapointing busy hour overload at the LTE cell site due to underdimensioning I thought at first. But then I noticed that this was not quite the case.
IPv6 While Roaming
In the previous post I had a closer look at the ipv6-only APN of my mobile network operator of choice and how that brings me a step closer to the future of the Internet as it should be. By configuring and activating an additional APN profile, a device can instruct the network to only assign an IPv6 address and to perform DNS64 to reach IPv4 only hosts on the Internet. It works great while I’m in my home country but a bit of care needs to be taken to configure the APN profile properly for roaming.
IPv6-Only in Mobile Networks
For many years, I’ve been using IPv4v6 dualstack on my mobile devices to communicate over IPv6 with servers that also support it. Now T-Mobile Germany (Deutsche Telekom) has taken the next step and offers IPv6-only connectivity over which IPv4 hosts can still be reached.
Linux BIOS Updates Even Update My Mouse – Part 3
All right, I am impressed because the Linux Firmware Updater (fwupd) does not only update embedded Firmware in my notebooks as described in the previous post, but can actually also update the firmware of USB devices!
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Linux BIOS Updates Made (Even) Easier – Part 2
In the first part I’ve taken a look at how to update the BIOS of my Lenovo notebooks that run Linux without burning that ‘other-OS’ installer to a CD-ROM. As I use somewhat older Lenovo notebooks, mostly X250’s, X230’s and T430’s, the best option was to convert the CD-ROM ISO images and write them to a USB Flash stick. For newer Lenovo and other manufacturer’s devices, however, there’s an even better way to do this. Continue reading Linux BIOS Updates Made (Even) Easier – Part 2