LTE Feature Group Indicators Decoder

Feature Group Indictor (FGI) is a bitmap field within UE-EUTRA-Capability IE of UE Capability Information uplink message. FGI is a BIT STRING of size 32 bits, where each bit represents a functionality/feature.

FGI information is important for the eNB or MME before setting up any procedure or enabling a specification functionality.

The UE shall set a specific indicator (bit) to one (1) only if all functionalities for a feature group have been implemented and tested. If any one of the functionalities in a feature group have not been implemented or tested, the UE shall set the indicator as zero (0).

The UE shall set all indicators that correspond to RATs not supported by the UE as zero (0)

3GPP TS 36.331 specifies featureGroupIndicators and featureGroupIndRel9Add in Annex B.1 for release-8 and release-9 capabilities respectively. For release-10 and later, featureGroupIndRel10 is specified in Annex C.

The UE shall include the fields featureGroupIndicators in the IE UE-EUTRA-Capability, featureGroupIndRel9Add  in the IE UE-EUTRA-Capability-v9a0 and featureGroupIndRel10 in the IE UE-EUTRA-Capabilityv1020-IEs.

The FGI field is optional and the UE shall not include FGI bitmap field if the UE supports (implemented and tested) all the functionalities associated with that indicator.

There is not much information to share on this topic. The main intention behind this post is to implement a decoding tool for FGI as there have been several requests.

Reference: 3GPP TS 36.331

FGI Decoding Tool

The following tool has two functionalities.

• Decode the bit or hex string to present the support (‘Supported’ or ‘Not Supported’) for each feature group.
• Display 3GPP definitions table for all 3 FGI releases individually or all at once.

Example bit string: 11111110 00101101 11011000 10000000

Example hex string:  FE0DD880

Note: Spaces are allowed…

Seems like my HTML code has some issues with Internet Explorer, so please use either Google Chrome or Firefox which are tested OK.

Feature Group Indicator                           data               
featureGroupIndicators featureGroupIndRel9Add featureGroupIndRel10 featureGroupAll