The HSS (Home Subscriber Server) is the concatenation of the HLR (Home Location Register) and the AuC (Authentication Center) â two functions being already present in pre-IMS 2G/GSM and 3G/UMTS networks.
Three Days Grace's music has been described as post-grunge, hard rock, alternative rock, alternative metal and nu metal. Their self-titled album mostly uses the sounds of alternative metal and post-grunge. However, on their second album One-X, the band had more guitar solos and a more melodic sound.
The band also holds the record for the most weeks for a hard rock album at #1 on the Billboard 200 with Slippery When Wet, as well as the most Top 10 singles from a hard rock album, with New Jersey, which charted five such singles.