TrafficControl: Overall Structure of the Program

The program is co-ordinating trains with track segments and stations in order to simulate a train network.

For example, a train is currently at a station. That train asks a track segment if it is allowed to use that segment and leaves the station. After some time on that track, the train slows down and asks for permission to enter the target station.

The program will be designed to simulate any (reasonable) complex track network, for example the TGV network in France or the local trains in Skåne county in Sweden.

I have some objects representing all trains, stations and tracks. They will communicate with each other using a signal-and-slots mechanism in QT (similar to the events in other framesets). Don't worry if you are not familiar with those concepts, I will describe it in more detail later.

To be able to handle several trains, tracks and stations, I have three lists, that contain all objects: trainList, stationList and trackList.

All stations, tracks and trains will have a unique ID number that corresponds to their position in the lists (the first train will have the index zero. This will give a quite easy way of addressing each object.

An object, trafficControl will co-ordinate the objects.

The information will be displayed with the model-view framework. This means that, instead of writing a number to a table directly, that number will be written to a datamodel. When that is done, the view will get the data from the model. This slightly more complicated approach will hopefully make the program easier to adapt in the future.

I will describe the frameworks in more detail in future blog posts, so don't worry if it feels to advanced. Meanwhile, I can recommend the video tutorials that I wrote about in The Qt Part of the Blog.

Boulders Beach, ZA: African Penguins (day 6)

Boulder's Beach is a part of Table Mountain National Park, south of Cape Town. That beach is a protected area for thousands of African Penguins. The population of penguins has risen dramatically since the 1980's, when there were only two spotted penguins in the area. It is listed in the IUCN Red List over endangered species.

The diet of African Penguins is normally sardines, anchovies. As you can see in the movie below, that species is monogamous.

If they are not eaten by sharks, seals, mongooses or cats(!), they can live for ten up to twenty-five years.

I think that the language spoken in the background is Afrikaans. If I'm wrong, you're welcome to comment.

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.

Southern Africa: Monkey Business

Wild animals are hard to spot, as they generally leave the area as soon as they hear humans. This is not the case of wild animals that got used to humans.

At Cape Point, a baboon saw a tourist bus stopping and people leaving the bus. After one minute or two, that baboon approached the bus and tried to open the handles, as you can see in the picture. "Whatever humans can do, baboons can do it better."

The operation was successful and very funny. It was not quite as funny (or yes, later we laughed at it) when another baboon raided our bus with some people inside it. The people inside left the bus quickly and the baboon stole some food and left some "remainings" on the seats.

I've compiled a video of some baboons behaving as monkeys. My first Youtube video ever. I got the audio track from https://www.youtube.com/audiolibrary, that is providing free music for Youtube videos

In a earlier trip in the Philippines, we saw some aggressive monkeys too (Puerto Princesa):

Stellenbosch, ZA: Wine Tasting (day 4)

Some photos from Alto, Tokara and Ernie Els wine estates near Stellenbosh, a South African university town.