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What is RFID?

Image via Touch ‘n Go


What is RFID?

RFID tags, once used only as a means for tracking cattle, are now being used all over the world to track all sorts of things--retail merchandise, vehicles, airline passengers, Alzheimer’s patients, even your pet dog.

RFID is an acronym for “Radio Frequency Identification”, which encodes digital data in stickers known as RFID tags. The data is then transmitted and captured by a reader via radio waves. Adapted by Touch ‘n Go locally, the RFID tags are embedded with a radio frequency chip unique to each vehicle, and attached to one of the headlights or windscreen of the vehicle. The sticker contains a tiny chip and an antenna, which  is linked to the user’s Touch ‘n Go eWallet. As the driver passes a toll booth, an overhead scanner detects the radio frequency signals from the RFID sticker (up to a distance of 2 metres compared to Smart Tag’s 1.5 metres) and the toll fare is automatically deducted from the eWallet.

Since these stickers are tied to a particular vehicle, if you own multiple cars, they will each need its own RFID sticker. It claims to have a 5-year average lifespan, and is designed to be resistant to various weather conditions, while being tamper-proof to deter robbery so removing it after it has been affixed will render it useless. 

Image via New Straits Times

Passive vs Active Tags

There are two general categories of RFID tags--passive and active. 

Passive RFID tags are smaller and less costly than active tags, but have shorter read ranges. Radio frequency signals transmitted from RFID readers or antennas power the tag and reflect the energy back to the reader. The cost-effectiveness of passive RFID tags makes this widely used. Ultra high frequency passive tags are regularly used for the tracking of pharmaceuticals or consumer goods.

Active RFID tags are larger and pricier, but can offer longer read ranges that reach up to 100m. However, active tags have a shorter lifespan in comparison to passive tags. There are two types of active RFID tags: Beacons and Transponders. Beacons emit a signal at preset intervals, while transponders only activate when they receive a radio signal from an RFID reader. Active tags are usually battery operated and have their own transmitter. They are often used to support sensors that measure and transmit weather conditions like temperature, light and humidity, or are used to track larger assets like vehicles or cargo containers.

How Does This Compare with Singapore’s ERP System?

There have been issues with our Touch ‘n Go RFID stickers on tinted windows, and the tag cannot be located near metal, which means the sticker can’t be placed on the top or side of the windscreen. Window or headlamp tinting also hinders the performance of the sticker.

Many have questioned the company’s decision to opt for a passive RFID system instead of an active tag that utilises a powered transponder to boost the signal, which would allow for higher reading speeds and better transmission, as is used in Singapore’s Electronic Road Pricing (ERP) system.

Touch ‘n Go CEO, Syahrunizam Samsudin said the decision was due to cost, as active RFID systems are approximately five times the cost of passive systems. It was also more convenient to do away with batteries or an external power source using a passive system.

Watch this youtube link to see what Touch ‘n Go’s RFID system is all about!