In phonetics, upstep is a phonemic or phonetic upward shift of tone between the syllables or words of a tonal language. Upstep is much rarer as a phoneme than its opposite, downstep.

Upstep and Embedded Register Levels
Upstep on edge tones and on nuclear accents
Tonal Upstep in Krachi: Evidence for a Register Tier
Upstep, downstep, and phonological weight in Daegu Korean: A preliminary report
Upstep on edge tones and on nuclear accents : Experimental Studies in Word and Sentence Prosody
Abstract 3000: Upstep: A Randomized Study of BNP Guided Management of Systolic Heart Failure in Elderly Patients
A Formative, Descriptive Evaluation of the Iowa-UPSTEP Model. Technical Report No. 17.
Downstep, regressive upstep, H raising, or what?—Sorting out the phonetic mechanisms of a set of ‘‘phonological’’ phenomena
Linear Chain and Network Polymerization during Pressure Upstep and Downstep by Real-Time Dielectrometry
Detecting intonation phrase boundaries in German laboratory speech by means of H tone upstep