Open source implementations of pretty much all GSM network and UE components have been available for quite some time now and there are people that do use the software for private and commercial purposes. For many years now, for example, the Chaos Communication Congress has a dedicated private GSM network and, in recent years, a UMTS setup was added. And now, and I am very happy about this, the first successful attempt to also set-up a private LTE network has taken place at this years cccamp#19.
‘Because We Can’ is the motto when it comes to technology and Chaos events so when cccamp19 came around there were no less than three backup microwave links available to the land based temporary fiber cable to the next POP that rodents find quite attractive. In the first post on the topic I’ve described the first two that bridged a distance over 10 km and offered a bandwidth of 10 Gbit/s. For this post I’ve collected some technical details about the microwave link they had all the way to Berlin which was 57 km away!
Unfortunately I could not come to cccamp#19 so I missed a lot of fun. Fortunately, people shared a lot of technical details online so I was able to pull together a number of interesting details about the different microwave backhaul links that were put in place for the event as a backup to the cross country fiber that was somewhat unreliable at the previous camp due to the rodent population.
The last time I had a closer look in 2012, a wireless backhaul link speed of around 500 Mbit/s was state of the art. Things have progressed nicely in the last 5 years, we are now at 10 Gbit/s, symmetrical, of course.
I like ‘Conversations’, my XMPP based messenger app on my smartphone and the list of people I interact with has grown steadily over the years. In some cases I would prefer, however, to use a messenger on my notebook with the same account as on my mobile. So far, I didn’t have a solution that I liked. There is of course Gajim, but unfortunately the current version doesn’t like the old libraries still used in Ubuntu 16.04. Updating to a newer OS version just for Gaijim was out of the question, however. But now I’ve found ‘Converse.js‘ a great web browser based solution that exactly fits my needs.
When I was in the US recently, I noticed that AT&T now broadcasts 2 Mobile Country Codes / Mobile Network codes from their LTE base stations in the places in Illinois and Ohio I checked. One is their own, MCC/MNC 310/410, and the other is MCC/MNC 313/100. A quick search revealed that this is the code assigned to Firstnet, a network for emergency services and first responders such as police, fire departments, ambulances and other public functions that require high priority access in congestion situations. Wikipedia has an article about Firstnet here. Up to now I always thought that the US wanted to establish a separate network but it looks like I was either wrong or that they have changed their mind over the years.
For various reasons that you can probably imagine, I usually don’t like to connect Android devices to Google accounts. Unfortunately, Google requires a login for the Play store. In most cases that is not a problem because I use the F-Droid store for most of my apps. However, some apps I (unfortunately) need on some devices are not available there because they are closed source. One way around this is to install ‘Yalp’ from the F-Droid store which can access the Play store without an account. Unfortunately this approach is a bit slow and unreliable so I had to look for an alternative.
As indicated in the previous part on this topic I wanted to take a look at a second LTE network north of Chicago to see how networks are deployed and operated on this side of the Atlantic. I found this network to be a bit faster for me with data rates between 15 and 20 Mbit/s. Still comparatively slow but I’m hampered by the same issue as in the other network, i.e., my top of the line European smartphone does not indicate a single carrier aggregation combination for US bands. I really have to follow this up, as the spectrum landscape is so fractured in the US and networks are loaded quite a bit, so carrier aggregation is no longer only a ‘nice thing to have’.
A few weeks ago, two US network operators have launched 5G in the Chicago area, just when I happened to be there for a week. While I don’t have a 5G device that supports US deployments yet, I expected that, perhaps as a side effect, there would also be a significant LTE deployment. However, I was rather underwhelmed about the data rates I got. While I staid in Evanston, about 15 km North of Chicago, I could only get 5-15 Mbit/s from one network operator in most places I measured while I could at least get 10-25 Mbit/s from another network operator in that city. As that is very little compared to data rates I get when I travel to other parts of the world I started to investigate a bit.
There’s quite a bit of a gap between this and the previous book review mainly due to the 50th anniversary of Apollo 11 in July that has kept me busy with re-reading a number of books I’ve had for many years and spending many hours with ApolloInRealtime. Anyway, the book review today, is a follow-up to this activity. Neil Armstrong certainly was an interesting and deeply inspiring person, so after watching the move ‘First Man’ on a plane to Chicago, I decided to pick up the book of the same title by James R. Hanson on which the movie was based.
Sprint has recently deployed 5G in the Chicago area and has put an impressive coverage map online. Needless to say that I had to go to a Sprint store to see if I could get a demo of their 5G network. My expectations where high because they did advertise 5G in their windows.