3

For my master thesis I am writing a reference implementation in Java. It uses HERE Api to obtain traffic incident information. The XML received contains a TPEGOpenLRBase64 code. TomTom provides an open standard with which a OpenLRBase64 code can be decoded and the location can be transferred to the routing database (https://github.com/tomtom-international/openlr) (https://www.openlr-association.com/method.html). However, this decoder does not work for the OpenLR code provided by HERE. According to their own statements, they use TPEG OLR / OpenLR for encoding and decoding. Do any of you know a reference implementation or a GitHub project that uses this decoder? Unfortunately I have not found anything online.

Perhaps someone could also explain to me why there seem to be two open standards. According to the OpenLR Association, TomTom works with TISA (https://www.openlr-association.com/openlr-association.html). HERE informed me that they were using a TISA based TPEG OLR encoder to encode the location. Isn't the TomTom OpenLR standard the official TISA standard?

Nimantha
  • 6,405
  • 6
  • 28
  • 69
erddasem
  • 31
  • 2
  • thanks for the query, can you please help to share the API that you are consuming for traffic incident data –  May 20 '20 at 07:09

1 Answers1

2

The difference between TISA OLR and TomTom OpenLR relates to the history of the specification: TomTom submitted the OpenLR specification to TISA. It was adopted in a slightly modified form by TISA as part 22 of the TISA SP14006 (TPEG2) standard series. The TISA standard was later in turn adopted without modifications as ISO 21219-22:2017.

In the TISA standard the abbreviation OLR (OpenLR Location Referencing) is used to describe this location referencing method.

As part of the adoption by TISA the standard was modified to be in line with the conventions and rules used in the TPEG2 series of standards. The concepts and the information in the references are the same, but the TISA version uses some different field names and the binary and XML representations are slightly different from those found in the TomTom OpenLR version. This means there are now two versions of the standard that are not interoperable at the binary or XML level.

The implementation in the Location Library follows the TISA OLR (and thus also ISO 21219-22:2017) specification for marshalling and unmarshalling of OLR References. Whenever we use the terms OLR or OpenLR we refer to the TISA OLR version of the standard.

  • 1
    Thanks for the answer. The execution of the ISO standard is not suitable for programming on the basis of it. However, I found the following page by accident: [link] (https://developer.here.com/documentation/location-library/dev_guide/docs/location-referencing-olr.html) The location library contains a package for decoding the OpenLR Base64 code provided by HERE. Since I had contact to the @HEREDeveloperSupport it would be nice if someone would have told me about the library. Furthermore there should be a link in the Traffic API Guide. – erddasem Jul 22 '20 at 10:04