Potts, D. T. 2014. Nomadism in Iran: From antiquity to the modern era. Oxford: Oxford University Press.
For details, see here. Abstract:
A completely new approach to nomadism in Iran, one which rejects the identification of nomads in the archaeological record of the Neolithic and Bronze Age (c. 8000-1200 BC). Emphasizes the fundamental changes brought about by major influxes of nomads from outside the region, beginning in the 11th century.