There are two types of battery-powered radio frequency identification (RFID) tags: battery-assisted passive (BAP) tags and active tags, which are used to collect and communicate asset-level information. BAP tags, which were standardized in 2010 in ISO/IEC 18000-6C:2010 Class 3, use a battery for operating the internal circuitry that facilitates the collection, processing and storage of ancillary information. The additional energy may also be used to boost the communication process in difficult usage scenarios, such as personnel tags. Active (Generation 2 Class 4) tags use batteries to power all functions of the tag—the receiving and transmitting of a signal, as well as the power for the processing and memory chips. Both solutions differ from passive-only tags, where there is no battery for communication, additional processing or storage. Although active and BAP tags can technically be implemented at all frequencies in which RFID is used, they are most common at 433 MHz, 900 MHz and 2.4 GHz.