Bar-code reader
Description/objectives
Barcode reading devices can be fixed or handheld which allows for flexible usage in multiple operational types. Barcode based tickets sent via MMS or GPRS or printed from internet bookings are decoded into a valid ticket ID using a laser scanner for one-dimensional barcodes, or a camera based digital imager for two-dimensional barcodes. Barcode validation can occur locally or via continuous wireless connection to a remote server. The barcode received by the customer contains encrypted data which the reader can interpret locally to provide validation. The units have an in-built processor to perform validation and an internal memory unit to record data for download to a central computer system which can be done wirelessly or via removable memory device. Local validation and wireless information transfer are far more favourable methods which speed up the validation process avoiding potential signal problems, and remove the need for staff to manually transfer data. Wireless data transfer for accounting purposes can occur via LAN or GPRS.
In-vehicle readers can be stand-alone with embedded wireless devices, or they can be integrated with vehicle radio or wireless LAN systems via the on-board computer. Fixed units in stations are typically connected to a central computer system via wireless LAN or Ethernet connection. These units can also provide local validation and data storage through an embedded processor and memory unit, or validation can occur via wireless connection to the central computer system.
Applications
- Fare collection/ticket validation
Benefits and cautions
Both scanner categories can be fixed or handheld, however laser scanners have moving part to perform the scanning function, whereas camera based digital image scanners do not. So in situation where there is a lot of movement and the potential for knocks or drops, such as on moving vehicles, camera based digital image scanners may be a better option. The susceptibility to damage though, can largely depend on the design of the individual unit and may not be a major issue. In addition, laser scanners are also less expensive which further minimises the cost of such a system. This considered, 2D barcodes do provide a number of other advantages though which may mean that they would be a better option. They can contain a far greater amount of information than linear barcodes, approximately 2,000 characters as opposed to around 30 for linier barcodes, they can read images from multiple directions, and can also be used to read 1D barcodes as well as various other image types.
Relevant Case Studies
Not observed in the Case Studies
Relevant examples in London (Heathrow Express), UK; Japanese cities
References
http://www.barcoding.com/information/barcode-scanner-technology-comparison.shtml
http://www.socketmobile.com/pdf/techbrief/techbrief_2d-bar-code.pdf