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This is a vehicle control unit supporting gradual development for at least the next 10 years even including video services and camera picture processing!!! The new services also include voice calls with  dispatching via GSM (LTE/UMTS) or with a general device connected by the SIP protocol.

Basic innovations compared to the previous solutions

Basic advantages of the solution of units EPC 4.0Cx:

• old solution conception – the original unit EPC  4.0 from 2009 can be replaced by EPC 4.0Cx without any vehicle modifications, this even includes the same application on the computer (if it is 32 bit and newly also 64 bit). The connection of supply conductors is still the same and internally stable including connection of  driver touchscreen LCD terminal EPT 4.xx (the computer mount needs to be refitted but with the same anchor apertures).
• identical measurements to the previous types EPC 4.0A and EPC 4.0B – just replacing is enough in this case (the same connectors and connector layout are used).
• standard solution of on-board computers without ventilators and without the need of flowing air (some computers require outer ventilators for casing cooling). There are industrial computers that require flowing air especially indoors.
• possibility of using 4 core processors with  up to 10x higher performance compared to the current types EPC 4.0A and EPC 4.0B, fast memory RAM up to 4 GB – type DDR3. This performance in necessary to solve fast data transfers (log transfers, video processing, …)
• sufficient performance for processing more than 10 camera streams including encryption – even video calls with dispatching including encrypted camera recordings are possible. In some solutions, the on-board computer can replace a camera system including meeting the requirements of UOOU (The Office for Personal Data Protection).
• possibility of connecting cameras  – front cameras, camera for backing up or for connecting to trolley wires. Data stream processing speed of up to 25 Mbit/s is required to process picture in real time (picture delay 100-200 ms) which burdens 100 Mbit/s Ethernet vehicle data networks.
• possibility of using an internal SSD drive or MLC chips without having to use significantly slower SD cards (speed up to 250 Mbit/s). SSD drives are a more reliable solution and their communication speed can be about 3 Gbit/s  (given by the on-board computer). The current speed is about 600 Mbit/s (almost 3x faster). This solutions significantly decreases the boot time of on-board computers to 35 seconds while full operation system is preserved. Consequently this brings the advantage of using various SW without the need of changing the OS of the on-board computer.
• new modern interfaces: - 1GB Ethernet  and USB 3.0 (enabling fast emergency reading of data from an on-board computer) – again for fast data transfers.
• unified interface for various types of data stations – analog (e.g. TAIT), digital DMR or TETRA including an integrated transformer 24V/12V. Newly, radio stations commonly used in Czechia including the TETRA radio station interface can be connected to the on-board computer.
• complete readiness for checking at the driver – new interface for  passive validator EPP 5.0 – i.e. a unit for direct checking at the driver including selling tickets (equipped with a printer), a bank and non-bank card reader, QR code reader. The on-board computer contains a ticket sale transaction database.
• 2x video output resolution up to 2560 x 1600, with a high-performance Intel graphic card GEN 7.
• integrated power supply unit – multiple uses: equipped with an intelligent power supply unit, a digital annunciator, a command receiver, GPS, a wake up frequency modem, a radio communicaton adapter and other features known from previous on-board computers.
• possibility of integrating a command receiver for the vision impaired

Types of on-board computers EPC 4.0Cx

As the on-board computer – control unit EPC 4.0Cx supports further development of on-board systems (production of versions 4.0A and 4.0B will be terminated in 2019), the following types are  being produced or are prepared for production:

Explanatory notes:

• x – is included in the unit.
• Waking on request – the on-board computer is equipped with low input power radio communication that sends queries about data freshness to a server in regular intervals (usually in minutes). The term “interval” means that the unit wakes itself at defined times and sends a query about the freshness of its data (usually after a few hours).
• Radio station transformer – the on-board computer is equipped with a transformer 24V/12V for the radio station in the control unit. Max. current is up to 15A.
• LTE modem – the EPC can be equipped with a modem or the modem can be connected via the USB interface (unit EPG 4.x) or via an output to the communication  unit UCU (identical Ethernet, the same output as for WiFi).
• GNSS – receiver of the satellite navigation system GPS, Glonas or Galileo is either integrated (x) or it uses a GNSS (GPS) server of UCU or other.
• EPNEV – a special command receiver EPNEV 1.1x  is integrated to receive commands from the vision impaired as per the general frequency in CR and SR. It can open the doors of public transportation vehicles and provide voice announcements to the vision impaired or the driver.
• WiFi ext. - usually solved by the EPW 54 or UCU 5.0. unit  This is a connection to an independent Ethernet network including PoE to provide power to the WiFi unit.

If lower computing performance is required a similar version can be supplied, however the PC computer will only be equipped with a single-core processor. The expected designation of this solution is EPC 4.0Cx1 (in this case camera signal processing has to be limited or the on-board computer will have difficulties handling voice transmissions via the GSM data service).

Why the new type EPC 4.0C – busbar speed

The new on-board computer EPIS 4.0C is equipped for fast communication 1 Git/s (one Ethernet output has this speed, the other has standard 100 Mbit/s). The reason for this is simple – in depots WiFi as per the IEEE 802.11 ac standard is required which provides communication speeds of 1 Gbit/s and higher via a radio interface. If WiFi communication is supposed to work reasonably and use such speed vehicles have to be equipped with means of distributing this data stream also in vehicles. The previous communication was not able to do that – i.e. Ethernet 1 Gbit/s.

Using cameras that can now be displayed on the driver LCD terminal  is another reason for this. If camera shots are to be displayed to the driver with 100-200 ms delay and in high quality data streams of up to 25 Mbit/s have to be transferred. We have to realize that 100 Mbit/s Ethernet can actually reach 30% of its effective communication speed (i.e. around 30 Mbit/s !!!) and 100 Mbit/s Ethernet can be affected by busbar overloads and communication losses.

The same is valid for LTE which can provide data streams of 40 Mbit/s, e.g. our UCU 4.0 and UCU 5.0  have this ability. Even in this case, the Ethernet busbar could get overloaded. This is eliminated by the arrangement of WiFi units. In this way we can find other reasons for using higher speed busbars.

Pic. no. 1: Reasons for using a fast communication busbar 1 Gbit/s.

We have to realize that based on competitive tendering assignments there will be a lot of data produced by vehicles in the near future and this data will be stored on SSD drives. If data transfers from vehicles are to be effective and not limit e.g. manual operation during updates and data reading USB 3.x has to be available for use in such a way that data reading is at the level of a number of Gbit/s.

Integration of checking into on-board computers

The new type of on-board computer continues the integration of a new type of checking unit. Ethernet busbar can be used to connect independent validators type EVK 5.x. The new integration also includes the possibility of directly controlling passive checking units EPP 5.0. Newly, on-board computers are equipped with an integrated control interface for these units.

We have already integrated a transaction database including on-line communication with backoffice  both in municipal PT and regional PT vehicles.

The new EPC 4.0C concept makes installing checking into vehicles significantly simpler. In this case it is advisable to optimize the control LCD display size based on the number of tariffs – the possible sizes are 8″ (low number) and 10,1″ (full checking). The following picture shows an example of vehicle installation.

Pic. no. 2: Checking layout when EPIS 4.0C is used.

Why PC architecture

There is a competition in the field of high performance processors, the competition is between the PC – x86 architecture and the ARM (Advanced RISC Machines) architecture. From the point of view of utilizing processors to achieve high performance the x86 architecture is ahead and most probably will remain ahead for the next few years. It does not require crosscompilers and it can run the same applications as desktops, the time of use is 10 years and more.

On the other hand, ARM processors can be found in almost all smartphones and tablets. Portable devices  are universal small computers that use applications written for them and they take over more and more tasks of regular computers while their lifespan only counts in years compared to the x86 architecture (both processor and operation system become outdated). ARM processors are not designed to achieve as high computing performance as possible that can be measured and expressed using FLOPS (floating point operations per second). Instead, other parameters such as efficient processor architecture, low power consumption ensuring long battery operation, and minimum heat output (to keep low operation temperature) play an important role just like low production and license cost (see below).

Intel  processors based on the x86 platform belong to the type Compact Instruction Scheduling Computing (CISC) i.e. instructions optimized from the point of view of instruction execution speed and they can have more machine cycles. On the other hand, each RISC command (Reduced Instruction Set Computing) only requires one machine cycle. A minimalist instruction set makes it possible for RISC processors to be designed with a quite simple structure and fewer transistors. Reducing the number of transistors means lower energy consumption. ARM processor command set inserts each instruction into an If-Else condition loop to prevent code jumps and by doing this slows the processor down. The ARM philosophy produces an independent software model in many versions, therefore applications and operation systems have to be compiled specifically for this architecture and ARM type. The disadvantage of reduced RISC command sets is that operations such as calculations and divisions with floating point cannot be executed in one cycle of hours but require a number of such cycles.

Note: ARM type computers are a software model provided in the form of a license (for a fee) to individual processor manufacturers who add their own peripheries to this model. The architecture was created by a British company called ARM Limited, formerly known as Acorn. Although the ARM model has only come into use during the last few years, the architecture itself is already 30 years old.