Terms and definitions in messaging

Multichannel messaging service is based on a variety of telecommunication and Internet technologies. In the description of services, we often use abbreviations that may not always be known to you. Here we have compiled a glossary of terms and definitions used in the industry.
By the way, you can create account and send SMS to your customers via Dashboard, plugin or API integration.

Home Location Register (HLR)

The ‘Home Location Register’ or HLR is a central database containing details of each mobile phone subscriber authorized to use the GSM core network.

Each mobile network has one HLR, although there may be many HLR servers creating a single virtual HLR. More precisely, the HLR stores details of every SIM card issued by the mobile phone operator. Each SIM has a unique identifier called an IMSI which is one of the primary keys to each HLR record.

An HLR also stores the following data about a mobile subscriber:

  • Current servicing MSC
  • Status of the subscriber
  • Temporary handset error code if applicable
    • Status – Valid/Invalid
    • If the subscriber is available to receive SMS
    • If there is an error code preventing SMS delivery
    • If the number has been ported to another mobile network