Jitter

is packets arriving at a non-consistent rate due to a type of distortion caused by the variation of a signal from its reference that can cause data transmission errors, particularly at high speeds.


 * NENA-INF-021, NENA Request for Proposal Considerations Information Document
 * NENA-STA-010, Detailed Functional and Interface Standards for the NENA i3 Solution
 * NENA-INF-016, NENA Emergency Services IP Network Design (ESIND) Information Document

Wikipedia definition