Using Broadband Technology for Mission Critical Train Radio Communications

If you live in or around a big city like Sydney or Melbourne, you will have traveled by train at some point in time. Most people would understand the basic concepts, like the signal is at green, the train arrives turning the signal red for a short period of time until the first train has moved a safe distance away, allowing the signal to turn green again. There are signals located in every sector, where trains travel through and they are very reliable; should the signalling system fail, then all the trains stop and you have a right side failure. When the signalling system is no longer operating correctly or if it has received conflicting data from track circuits, all the signals display a red signal and the driver needs to be authorized by the signaller to pass.

The driver after waiting for a short period of time, contacts the signaller using a train radio for permission to pass a signal at red. The train radio is used for mission critical communications, because passing a signal at red can cause an accident, such as one train crashing into the back of another or head on collision if at a siding entering a main line.

The origins of modern train radio go back 40 years to 1977 when a paper written by Clive Kessell on “The Development of Radio Communications between the Signal man and the Driver” was presented at an Institute of Railways Signalling Engineers meeting to promote interest in developing radio communication between train and the signal box. Radio communications was the best way to stop a train or move one that had stopped; it is safer to keep the driver in the train rather than walking the track looking for a signal post phone to contact the signaller.

A communication standard was developed at the time called UIC751-3 created a 4 channel UHF analogue train radio network that was deployed around London’s Kings Cross and St Pancreas station; it was also rolled out in parts of Europe, especially in West German where much of the initial development occurred.

The analogue train radio Metronet was rolled out in Sydney in 1994 at the same time a very similar radio system called “Cab Secure Radio” was deployed in the UK and other parts of the world. In early 2000 a newer radio network was developed based in Europe on the popular GSM standard, moving away from an analogues network to digital voice improved the voice quality, reducing the unwanted static that analogue communication was famous for. This digital train radio system (DTRS) was commissioned in 2017 in Sydney to replace the analogue Metronet and improve rail communications.

However the pace of change by mobile phone utilities occurred quickly, GSM (a second generation technology) which DTRS is based on is now almost obsolete; we have all come to love the benefits of advanced 4th generation mobile phone technology. In the railway sector, there is considerable interest in what technology will be used to replace DTRS, how it will be developed and when it will be implemented.

My research looks at these issues to identify how a modem broadband 4th generation mobile technology can be developed to provide all the mission critical communication needed to operate trains along with the benefits that high speed broadband data can deliver like real time CCTV. The risk adverse nature of railways consider any change as an increase in risk, so they have become change adverse in the process. However by keeping old technology, risk increases because the safety benefits associated with newer ways to communicate are not realized; there is also the technical challenges in keeping equipment that is not supported operational when replacement hardware components cannot be found.

Running a modern railways such as the one in Sydney, where you have a million passenger journeys a day really requires a modern communication system so safety is not compromised. The signalling system is reported to have a wrong side failure once in thousands of years but yet they happen for reasons no one every considered.

The train radio allows corrective action to happen immediately by the driver a

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Ham and CB Radio Communication – A Basic Primer to Two-Way Radio

Radio communications have come a long way from the original concept derived by Marconi’s discovery of electro-magnetic radiation (radio waves). Marconi conceived that an electro-magnetic pulse, sent through the air, would create an electron flow (flux) when it passes through a non-ferrous metal source. Such an electron flow can then be amplified to create sound if the pulses are emitted a certain way. This is the simplest representation of what Marconi discovered, and by its revelation many things have become clear. Many possibilities have derived from such thought, and clearly all mans inventions come from such seemingly small realizations.

At its base, radio communication is fairly simple. During this modern age there are many forms, so many in fact that their discussion will be outside the scope of this article. Basically, we have two forms of Radio Communication in the hobby realm. Citizen’s Band and Short Wave are the two that most of us are familiar with. Though short wave offers many optional communication modes, we are going to look at ‘full duplex’ and ‘half- duplex’ modes involving AM (amplitude modulation) communications.

Modes of Communication

1). In full-duplex mode a radio is capable of transmitting and receiving date or voice over two channels at the same time. This is important for transmitting visual and voice date as in television. Ham radios are capable of such transmission, but we will not delve that far into it here. Microwave communication is another form of full-duplex transmission. Cell phones have this capability and ham radio operators can definitely tune their radio and hear your telephone conversations.

2). In half-duplex we have the ability to transmit and receive on one channel, but not at the same time. The radios we normally use, CB’s or Walkie Talkie, operate in half-duplex mode. Ham radio communications are common done in this mode too. As a consequence, we must make our own breaks during transmission so the people we are talking to can respond. Because of this, a protocol has been developed to assure proper etiquette during conversation. Words such as, ‘Roger’ and ‘Ten Four’ are used to indicate a transmission was received, or ask for confirmation it was received. In addition there are 10-Codes and Q-Codes that have developed in the United States. The ones listed below should be memorized as the most commonly used.

Most Common 10- Codes

* 10-1 Receiving Poorly

* 10-4 Ok, Message Received

* 10-7 Out of Service, Leaving Air (you’re going off the air)

* 10-8 In Service, subject to call (you’re back on the air)

* 10-9 Repeat Message

* 10-10 Transmission Completed, Standing By (you’ll be listening)

* 10-20 What’s your location? or “My location is… Commonly asked as What’s your 20?

Most Common Q-Codes

* QRM Man made noise, adjacent channel interference

* QRN Static noise

* QRO Increase power

* QRP Reduce power

* QRT Shut down, clear

* QSL Confirmation, often refers to confirmation cards exchanged by hams

* QSO Conversation

* QSX Standing by on the side

* QSY Move to another frequency

* QTH Address, location

For a beginner, the codes listed above are standard. Either the 10 Code or Q Code can be used interchangeably on the Citizens Band or Ham Radio arena. Ham operators have to be licensed in this country. This assures that an operator knows the rules of the road, and will not be unknowingly interfering with other communication bandwidth areas. It is possible to transmit into television frequencies and bandwidth, as well as interfere with cell telephone conversations and transmissions. In fact, short wave ham radio operators have the whole spectrum of frequencies available to them and inappropriate use can cause serious civil problems.

Fire and Police bands can be disrupted during emergencies; pilots can be misled and so on. This is way it is tightly regulated. However, it is much easier to get a license now, than in the past. You do not have to be an electronic technician anymore. Simply learning the rules of the road and proper use of the equipment can get you a basic ham radio license. As a beginner, you should buy a receiver and antenna system first. Enjoy listening to the different ham and citizen band conversations, as well as marine and private pilots. You’ll be able to listen to people from all around the world. I am sure it will amaze you and ‘pick’ your interest.

A good ham receiver can be bought for as little as $450.00, with an antenna and mast. Wiring can be included at around $250.00. You might even consider buying second-hand equipment for an even better deal, as many radio enthusiast’s upgrade looking for a way to save on their new purchase. Citizen band radios can be had for as low as $95.00, with 40 channels available. An antenna system for a CB home base would run about $180.00, while again you could find something cheaper second-hand. These are ballpark figures, but accurate enough. Citizen band radios do not require a license to operate. The units are transceivers, meaning they are capable of half-duplex mode transmitting and receiving. Power on these units is usually limited to 5-10 Watts. Your average ham has capabilities depending on license, to transmit at 1.5 KW (1500 watts), and are very powerful.

Whatever you decide, I hope you try the hobby of radio communication. It can be a great hobby you can share with family and friends. The real value is in the sharing and learning that you and your children will enjoy. It can spark interest in the electronics field, leading both you and the kids wanting to know more about the science and physics related to radios and how they work. All of this would be valuable and enduring, a guarantee of many memories that will last forever.

Good luck should you become involved. Have lots of fun and enjoy!

The Author is a native of California and a conservative family oriented person. Through his articles and website promotions, Larry intends to promote Quality Time Hobbies that have the potential to create strong family bonding, and quality friendships. Not all hobbies have potential to bring people togeher in the same way. In promotion, it is the intent of this author to present and educate on hobbies that are especially rewarding because of group involvement. Physical interaction and exchange of information and learning are key to the creation of lasting memories, and the bonds created by them.

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