6.4. Communications and connectivity
The importance of maintaining communications with infrastructure and solutions for where this is problematic
A mobile signal or internet connection is necessary for any chargepoint using a back-office platform to take payment for charging. It is therefore a key factor to consider when siting public chargepoints.
The image below (produced by the Highlands and Islands Transport Partnership, HITRANS) shows the relationship between the stakeholders involved in operating the public charging network and the communication protocols that support the network. The diagram shows the various communication linkages between the stakeholders. It also details the open protocols that allow the different components of the network to communicate with each other (ie they “speak the same language”).
Using these open protocols provides certain benefits. As an example, procuring chargepoints compatible with the latest open chargepoint protocol (OCPP) means that the back-office software supplier can be changed in the future, meaning it adds additional management flexibility to the network.
In some cases, the chargepoint operator (CPO) and the e-mobility service provider (eMSP) are the same organisation, as is the case with chargeplace Scotland. It is important that organisations looking to install public charging infrastructure understand the various components of the network and how they communicate with each other.
Solutions to communications and connectivity issues
Challenges in establishing and maintaining a mobile connection will affect the suitability of some sites considered for public charging infrastructure. There are however solutions available to tackle communication challenges. Some of these are outlined below.
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The chargepoint operator Swarco advised that in some remote parts of Scotland, satellite connections have been used to provide communications to chargepoint units. This is generally a stop-gap solution to support an area until the mobile network coverage is improved. Once the local mobile network has been upgraded, the satellite connection can then be replaced with a standard mobile connection, as this offers a more cost-effective solution.
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It should be the default position to install SIM cards in chargepoints that can roam between multiple network providers. In instances where the primary network signal is weak, the chargepoint can then simply reconfigure to the strongest alternative network signal to maintain communication with the back-office.
Roaming SIMs are also useful on OCPP enabled chargepoints to allow smooth migration to a new back-office provider in the future, as it removes the need to replace the SIMs in each device.
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We recommend you ensure that chargepoints experiencing temporary back-office communication issues are still able to charge vehicles. This can be achieved by storing the charging session data locally, so that users can be billed when connectivity returns. This is known as a whitelisted cached vend. In situations where this isn’t possible, defaulting to free vend may be necessary.
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It is also possible to install chargepoints that have no communications software built into them. These are often referred to as ‘dumb’ chargers. As these units are unable to process payment for the charge, they must be free of charge. This is not a recommended solution. It’s unlikely that ‘dumb’ chargers will be used on the public network going forward as chargepoints need to generate revenue to cover operating costs and to provide a return on investment.
