RPI: Demo of First Sprint and Sending SMS from 4G Router

In my summer house setup, I have a 4G/Wifi router. The data plan I have allows for some SMS messages to be sent. 

To be able to send SMS messages automatically, I copied a script that I found on a French blog. The code and repo is designed for Jeedom, but it worked on Raspberry PI, too. 

Demo of the First Sprint

With almost all targets met for this sprint, I am able to show a demo of what I've done in my pet project over the very limited spare time I have:

The 4G connection in the summer house is quite slow - 6 Mbit/s. Transmitting a picture of 4 MB will take some 7 seconds, and buffering the video stream will take some time too. When I tried with a better connection, it was a bit quicker.

The Code

I had to create a separate shell script for the stream and SMS setup

NAT Forwarding

The IP number that the 4G router gets is a NAT-ed IP number in the 24 bit block (starting with 10). This makes it hard to access the network from the external internet.

From forum discussions, it seems that I either need to buy a router from the current Internet Service Provider (ISP), or change ISP. Another option would be VPN, but I'll investigate that later in the future.

Next Step

I'll move the remaining task "RPI12: RPI server available from cellular" to the backlog. In the second sprint I'll explore face recognition for openCV. Depending on the output, I'll add more tasks to the sprint later.

IOT: Bringing Up a LTE Based Wi-Fi

As a Christmas gift, I purchased a TP-Link Archer MR600 LTE/4G router to a close relative to use at his vacation home. 

The radio conditions there are a bit challenging, with a concrete house on the northern side of a ridge, 1.3 km from a base station. The metal reinforcement bars in the concrete act as interferers, cancelling out 4G signals.

The router supports several LTE bands, including the coverage bands (8 and 20) and the capacity bands (3 and 7). The former bands have lower frequencies, which gives bigger coverage but lower performance and are suitable for rural areas. The latter bands have higher frequencies which gives smaller coverage but higher performance and are suitable for urban areas.

I tested the modem in my house in Åkarp with satisfactory results (RSRP: -100 dBm for Band 3 and 7). In the summer house, the signal was barely detectable.

I found a discussion on TP Link's forum where another user had the same issue. The support told that there was a firmware version that supported band selection, and I installed that on the router. After that, I was able to register to band 8.

A 4G router that doesn't allow the user to select band is a quite lousy router. Fortunately, it was possible to overcome that with another firmware, but that shouldn't be necessary.

Some of my projects

For the last six months, I've been focusing on other projects than trafficControl.

In my genealogy project, I've reached the 16th century, an achievement I'm proud of. My ancestors were mainly farmers, fishermen, ship pilots and smiths from the western parts of Sweden. The church records dates back to the 17th century, but there are recordings about a poor farm on Brännö, outside Gothenburg. That island had a very dramatic history, I'll write more about that in future blog posts.

At work, I'm in a very interesting development project on the road to 5G. With that project, I get good experience from software development.

On a personal level, I and my girlfriend are in another project that will be very challenging and very rewarding. In a way, it is related to the genealogy project. 

I'll continue with the trafficControl project but on a sporadic pace. 

Telecom: The Generations of Mobile Systems

As I work in the telecommunication business, I sometimes get the question about 5G. Strictly, as of today, 5G isn't formally specified even if some actors write about 5G. I've also seen companies marketing "3.9G" and even 3.5G services as "4G", so I'll try to clarify the different generations and the chronology

Talking about different generations is a way to distinguish the radio network technologies from each other. The collaboration forum 3GPP is using release versions to describe the evolution of the networks. 

Year	3GPP release	Name	Generation	Generation in marketing	Features
1981	None	NMT	1G	1G	Pure voice calls
1992	Phase 1/2	GSM	2G	2G	Voice calls
1997	Release 96	GSM	2G	2.5G	Support for data calls (14.4kbps)
1998	Release 97	GPRS	2G	2.5G	Increased speed for data calls
1999	Release 98	EDGE	2G	2.75G	Further increases in speed for data calls
2000	Release 99	UMTS	3G	3G	Much higher data speed
2001	Release 4	UMTS	3G	3G	Changes in the core network
2002	Release 5	HSDPA	3G	3.5G	High Speed Downlink Package Access
2004	Release 6	HSPA	3G	3.75G	High Speed Downlink/Uplink Package Access
2007	Release 7	HSPA+	3G	3.75G	Improvements on HSPDA/HSUPA
2008	Release 8	LTE	3G	3.9G or 4G	New Radio Network Release, SAE
2009	Release 9	LTE	3G	3.9G/4G	Improvements on HSPDA/HSUPA
2011	Release 10	LTE-Advanced	4G	4G	New Radio Network Release, SAE
2012	Release 11	LTE-Advanced	4G	?	Adapting to heterogenous networks
2014?	Release 12	LTE-Advanced			TBD
2016?	Release 13	TBD			TBD

Commercial operators have been eager to market their services as "4G", rather than the correct term "LTE" or "3.9G". If all other operators use the term "4G", it would be fatal for an honest operator to market the same services as "3.9G". I will elaborate more on both telecommunications and game theory in later blog posts. More information about telecom standards can be found at. Zahir Ghadialy's blog offers interesting posts about what is going on in the telecom business.