Earlier in October I spent a weekend in Berlin again to be part of the Vintage Computing Festival Berlin. This year, I did not bring along an exhibit or give a talk but rather decided to help a bit with organizing the event. A most gratifying experience and of course there was enough time to talk to a lot of people and learn new things. Here are some impressions.
When I recently flew from Frankfurt to Hong Kong with Cathay Pacific, I flew on two different planes with two different Internet providers. On the outbound leg, I was on a Boeing 777 that was equipped with a system operated by Gogo wireless, well known for providing in-flight Internet access for many airlines in the US. On the return trip I was on an Airbus A350 and Internet access there was provided with a Panasonic system. The experiences could not have been more different.
Ever since I can remember, my wireless mice came with a USB dongle. They shrunk in size over the years so this straight forward approach has served me well. But the number of USB ports on notebooks is on a steep decline. Put recent security vulnerabilities on top that have been found in proprietary protocols and the manufacturer’s inability to deliver a fix that addresses them all made me look for a wireless mouse that uses Bluetooth and thus no longer requires an extra USB dongle. Obviously it has to work with Ubuntu Linux.
When I was recently on a long-haul flight I accidentally didn’t activate flight mode on my smartphone and to my surprise the device registered to an on-board 3G network of AeroMobile once we were at cruising altitude. I was really glad my home network operator of choice has a landing page to block mobile data outside the EU until I confirm because as I already discussed here, 2G/3G/LTE mobile network use on planes and ships is still super expensive. Calling a price of close to one Euro per 50 kb of data ‘modern piracy’ is probably an understatement.
First Wifi products are now coming to the market that support WPA-3 personal mode authentication and ciphering key exchange so I thought it would be a good idea to have a closer look at how it works and why an update was necessary.
To answer the last question first: WPA-2 PSK (Pre-Shared Key) uses the Wifi password as basis for all authentication and encryption exchanges between Wifi access point and clients. Many networks only use short and thus very weak passwords, and brute forcing them offline without interaction with the network has become quite feasible with current generation computing hardware. WPA-3 tries to address this issue with a new authentication scheme referred to as ‘Simultaneous Authentication of Equals’ (SAE). It is based on Diffie Hellman Elliptic Curve Public/Private keypair generation algorithms that are also used for generating ciphering keys for secure HTTPS connections today.
The mathematical details of the process can be found in RFC 7664 and a good higher level description can be found here. Still, it took me quite a few hours to understand the principles, so I though I’d assemble a less mathematically focused description on the basics of WPA-3 SAE and how it is used in practice:
Over the past weeks I’ve noticed a few articles, posts and videos on the net that were looking at first 5G deployments in the wild and were commenting on the seemingly limited range of the 3.5 GHz band that is used for 5G NR. Some people noted that only 200m from the base station they could no longer use 5G and fell back to LTE. Therefore, they concluded, the range of the n78 frequency band must be very limited. But is this really so?
When it comes to mobile network speeds, most people only talk about the downlink direction. Few think about the uplink and what it’s capabilities are today. Relatively little has happened there since LTE was launched around a decade ago until recently.
I am probably one of the few people on the planet who uses ordinary conference calling quite a lot. When in a call with someone it is sometimes helpful to add a third person to the conversation. This is done by putting the other party on hold while the call is established to the third person. Once the third person picks up you have to explain that you have someone on the other line and would like to make a conference that person in. In most cases that explanation takes many additional seconds during which the other side is still on hold. In other words, this solution is far from ideal in practice.
The spectrum situation for mobile services in the US has always been different from much of the rest of the world. More often than not, US network operators have to cobble together 5 and 10 MHz chunks of spectrum for their customers while in the rest of the world, aggregating 20 MHz channels is the norm rather than the exception. For 5G, the US again took a different path with mixed results so far. However, it now seems to be partly changed to match the rest of the world.
Back in February I wrote a post on how to download and install apps from the Google Play store to an Android device without a Google account. At the time I was using ‘Yalp’, which is ‘Play’ spelled backwards. Unfortunately, the app became a bit unreliable over the months so I was very happy when I found an incredibly good replacement recently after reading about ‘Google alternatives’ on Kuketz-Blog (in German).