Home Subscriber Server

The Home Subscriber Server (HSS ), the central subscriber database in the LTE mobile networks. The HSS of the function corresponds to the function of the home location register ( HLR, engl. ) In GSM or UMTS mobile networks.


HSS in all information about the user are stored, the required

  • To identify a subscriber and to allow him access to the wireless network
  • To determine the location of the subscriber, and to determine which mobile network components are responsible for it.
  • To manage the allowed for a subscriber services

For this data is stored on their phone access in HSS as

  • The number of the subscriber
  • The mobile identifier of the subscriber ( IMSI)
  • Key required for authentication of the subscriber.
  • Mobile networks with which the participant may call.

This HSS data on the position of the subscriber are stored in the mobile radio network in such

  • The group of mobile cells, in which the participant is currently located (Location Area )
  • The mobile core network elements that just manage the subscriber ( for example, the MME or IMS system, in whose area the participants happen to be

For this purpose, information is stored on the services, which may use a participant, and which rate is applicable for each of the participants.

Behavior of the HSS

HSS systems are used in LTE mobile networks and services that run on IMS systems. Turns participants use their mobile device within a corresponding network or he enters a corresponding network, the mobile phone network in the HSS system searches for the data of the participant. The participant is not in its own network, the home network of the subscriber is determined based on the IMSI and the participant data will be requested in the home network of the subscriber on the HSS.

If it emerges from the inquired authentication data that the subscriber is allowed to use the wireless network, he will be booked into the mobile network. To this end, the competent core network elements call to the subscriber record from the HSS and save it locally between. Using the local copy of the subscriber data of the subscriber is managed in the mobile network.

Moves the user in the mobile network, it is determined which area is collected by mobile stations the participants. This information is given in each case to the HSS on. Using the information about the whereabouts of the mobile network determines what network components are responsible for the participants and provides them with the necessary from the HSS subscriber data.

Gets to a subscriber or he requests data over the wireless network (eg, downloads) then on the basis of the requested data from the HSS determines whether it is allowed to use these services and what features are allowed for the participants ( eg maximum data rate for downloads).


The HSS is connected via a Diameter interface. The network elements that require HSS data must have corresponding Diameter interfaces.

In addition to the scope and format of the stored data, the use of the Diameter interfaces by the HSS is the essential difference from the HLR system, which is used in GSM or UMTS networks to manage subscriber data., The HLR is connected through SS7 interface to the telephone network.