The HERE SDK is built around comprehensive map data that includes not only rendering information but also details on embedded points of interest (POIs), road curvature, elevation data, speed limits, road signs, and much more. This section explains the map data format, catalogs, data availability, configuring regional maps like Japan, and backend services.

Map data format

The HERE SDK stores all kind of data in map tiles. This can include data needed for rendering purposes in the map view, but it is not limited to this. For example, map tiles also contain data about places or road attributes that are not visualized on the map view, but are needed for other purposes such as turn-by-turn navigation.

The information that is stored in a map tile is categorized into several layers that hold the information for such distinct topics as traffic or landmarks.

• Under the hood, the Navigate Edition uses the Optimized Client Map (OCM) catalog format which provides a compact, fast and flexible map. The OCM catalog is compiled from HERE Map Content (HMC). The access to the HERE Optimized Client Map - Developer Guide is restricted. If you cannot access this document, contact you HERE Account executive for assistance.
• Internally, the Explore Edition uses a slightly different map format (OMV) which is not supporting the offline use case.

The OCM format allows to store all used data permanently in the device storage or temporary in the map cache. This way, an application can access the same features - regardless if the device is online or not.

OCM is using a default configuration covering the whole world. For selected areas, this includes only a base map - such as for Japan. Extended map data for Japan with a higher level of details is available through a dedicated configuration on request.

Catalogs

All map data is part of downloadable regions that are referenced from a catalog. Therefore, the catalog itself does not contain map data, but only links to the data. Each catalog is identified through a HRN. A HRN is a unique HERE Resource Name identifying catalogs or other HERE resources.

Usually, there are only two HRN values used by the HERE SDK to identify the following two catalogs:

• Optimized Client Map (Base). A catalog containing references to all available regions, world-wide. HRN: "hrn:here:data::olp-here:ocm": https://platform.here.com/data/hrn:here:data::olp-here:ocm/overview
• Optimized Client Map for Japan. A catalog containing additional references to detailed map data for Japan. This is not enabled, by default. If enabled, it will enhance the base map for Japan with rich details. If your company has an agreement with HERE to use a detailed Japan map, then in this case you can use this second catalog. HRN: "hrn:here:data::olp-here:ocm-japan": https://platform.here.com/data/hrn:here:data::olp-here:ocm-japan/overview

Keep in mind, that a catalog only contains references to the available regions. The map data for a region may differ based on the catalog that is used or on the version that is downloaded and installed. Practically, you do not update a catalog itself, but only the data that is linked to an existing catalog.

Availability of map data

By default, a few regions in the world including Japan, China and Korea, contain limited map data. To get access to the full map data for Japan and South Korea, please get in contact with your HERE representative.

Configure a Japan map

You do not need to take any actions to configure a Japan map catalog. Once your credentials are enabled by the HERE team, you can see the enriched Japan map. Internally, our Decision API will control if you are granted with access.

If your credentials are not enabled for access, the map falls back to the Japan base map and you will see less details on the map view for Japan. On top, certain features that require map data, like navigation, may not work as expected.

Get in touch with the HERE team to get access to the enriched Japan map data.

Backend services

For the features that do not work offline, the HERE SDK will request content internally from various backend services. All backend services are requested from the following domains:

• here.com
• hereapi.com

Note that sub domains like for example, search.hereapi.com, are not listed here. We use a multitude of URLs, which are all under the here.com and hereapi.com domains. Each and every of these hostnames resolve to multiple sets of IP addresses, partially depending on the geography you’re in - detected via GeoIP. Also, the IP addresses are subject to change. If needed, it is recommended to enable / whitelist only the domains and use a wildcard to do the same for all possible sub domains.