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.
At the start of 2013, Three Days Grace announced that lead singer Gontier was resigning from the band because of a non-life-threatening health issue. Gontier was replaced by My Darkest Days frontman, Matt Walst (the brother of bassist Brad Walst).