Author: Martin

For many years it has been an open secret in the industry that enhancing coverage inside buildings can’t be done well from the outside via the cellular layer but as to be done from the inside. One way this has been attempted by some network operators, especially for homes and small businesses were Femto cells. In this context I define femto cells as small ‘plastic’ routers with 3G functionality inside for home and small office use. But the concept hasn’t really caught on, at least not in Europe anyway, and one big network operator is now phasing out its old 3G femto cells without a replacement offer.

Continue reading Femto Cells On The Retreat – Long Live Small Cells?

There have been many attempts over the past two decades to compete with fixed line copper, coax and fiber installations with Wireless Broadband Fixed Access. Pretty much all of them have failed on a larger scale as technology over copper has evolved and fiber has been deployed in many places. But Verizon thinks Fixed Wireless access can compete with the latest wireless technology and pushes ahead with its mmWave system it has forked from 3GPP specifications last year.

Continue reading Verizon Pushes Forward with mmWave Broadband Fixed Access

A big display with a high screen resolution can only be replaced by a bigger display with an even higher screen resolution! In the past few years display resolutions have steadily increased and there are now affordable ultra-wide curved displays with an aspect ratio of 21:9 and a display resolution of 3440 x 1440 available that are great for programming or working on several documents simultaneously side by side. But do such displays work well (or at all) with my somewhat dated 2012 Lenovo X230 notebook?

Continue reading A Thinkpad X230 And 3440 x 1440 pixels

Going significantly beyond the capacity and geographic reach of current cellular LTE coverage in cities requires to bring the cells to where the people are: Inside buildings. From a technical point of view small cells could do the job, they are now small enough to be installed just about anywhere. From a practical point of view, however, there are a number of major problems with that.

Continue reading Eduroam as a Model for Future Public Wifi Deployments

Last year I reviewed ‘Dealers of Lightning‘, a great book about Xerox PARC in the 1970 where pretty much all of the technology was invented we are still using today on our graphical user interface based PCs today. Over the past year a number of very interesting videos have appeared that are a great complement to the overall story and impressively show just how many things were invented there.

Continue reading ‘Dealers of Lightning’ Revisited – Xerox Alto Videos

A few years ago a number of clever guys figured out how to access the layer 1 functionality of a certain type of modem chip built into entry level GSM phones and implement the GSM stack on a PC. I had a lot of fun getting that to work in a virtual machine and I learnt a lot in the process. Now a few guys have come up with something at least equally impressive: An open source implementation of an LTE eNB base station and an LTE UE.

Continue reading Open Source LTE eNB and UE Implementation

Software updates are great because they keep installations secure and add new functionality. Moving from one Debian version to the next, however, is sometimes a bit painful for projects that modify system configuration files. My VPN-Wifi-Pi project that uses a Raspberry Pi as a Wifi Access Point and an OpenVPN tunnel to a VPN server for secure Wifi access in hotels and other places is unfortunately no exception.

Continue reading VPN-Wifi-Pi Updated to Raspbian Stretch

Wi-Fi is the Internet access technology of choice just about anywhere indoors these days. But just how many people can you connect with Wi-Fi in a small space and still get acceptable (my definition: > 10 Mbit/s) datarates?

Continue reading Wi-Fi For 750 Hackathon Participants

5G is many things to different people. For most, 5G is about more network capacity and faster speeds for Internet access. The main challenge for this goal is that there is little spectrum still available below 6 GHz, a frequency that is generally seen as the limit for the current air interface technologies around. So 5G below 6 GHz brings only few benefits for the broadband Internet use case, it could easily be done with LTE as well. Ultimately, to get to higher speeds and more network capacity, higher frequency bands have to be tapped. The problem here is that with conventional technologies, communication range is severely limited.

Continue reading The 28 GHz 5G Frontier

Setting up Eduroam on a PC securely including certificate checking during authentication to prevent password theft is quite a bit of a challenge but not impossible. On Android, things are even more difficult and it’s a bit strange that many universities are showing how to configure Eduroam manually on their help pages rather than linking to the Eduroam Configuration Assistant Tool (eduroamCAT) web page that makes things a lot easier.

Continue reading Eduroam Configuration App for Android