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.

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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.

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The Amazing Datarate of a 5G NR Control Channel

I was recently thinking a bit about the 5G NR Control Channel inside the CORESET and wondered what its datarate would be. This seems to be a bit of a theoretical exercise at first. On the other hand, the Control Channel is a significant portion of the channel overhead which is lost for user data. In LTE, the PDCCH spans the complete channel bandwidth and at least one symbol. Perhaps reasonable for a maximum channel bandwidth of 20 MHz. However, I expected that on an 80, 90 or 100 MHz 5G NR carrier, the control channel would not span the complete channel bandwidth. I was quite surprised however, when I had a closer look.

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Linux BIOS Updates Made (Even) Easier – Part 2

Image: Firmware update in a Linux shellIn 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

Linux BIOS Updates Made Easier – Part 1

Image: Flashing in progressTriggered by a survey on Mastodon on how often people upgrade the UEFI BIOS in their PC or notebook I thought it would be a good time to have a go at it again with some of my machines at home. The thing with UEFI BIOS updates of my Lenovo notebooks is that update utilities are only offered for Mac and Windows. For Linux and other operating systems, they offer bootable CD-ROM ISO images. Srsly? I have to admit that’s a bit too much hassle unless it is really urgent. But then I noticed that there are actually two methods to get around burning a CD-ROM to update the BIOS.

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5G NR Resource Assignment

After the previous post on what is inside a 5G NR CORSET and DCI messages, let’s have a look at how downlink assignments and uplink transmit opportunities for a device are signaled in a DCI. As you might remember from the previous post, the DCI contains, among other information, information on the frequency domain resource assignment and time domain resource assignment.

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