It depends on which approach you follow for realizing localization and which devices are you trying to localize. In general, both RSSI-based and Time-based technique needs few pkts/secs to be effective, but the need to have accurate radio increases the required number of packets.

"Bhatti S, Xu J. Survey of target tracking protocols using wireless sensor network.

Fifth International Conference on Wireless and Mobile Communications, ICWMC’09, IEEE. 2009. " demonstrates the broad-spectrum process of target tracking to save energy in wireless sensor networks.

Link for your reference:

http://www.indjst.org/index.php/indjst/article/viewFile/70102/66983

Thanks to All