NACC Network Assisted Cell Change
NACC was introduced to reduce the service outage period which is experienced by a mobile during a packet data session, as it cell reselects from one cell to another. With NACC, the serving BTS supplies the MS with system information for the new cell, before it reselects to that new cell. Utilizing this technique, the delay associated with acquiring the SI from the new cell is mitigated, hence service outage time is reduced. In 4G LTE, NACC can be used in support of CSFB (Circuit Switched Fallback), in order to make the fallback to 2G procedure a quicker process.
