A CMS range accrual swap is similar to a range accrual swap (see Range Accrual Swap). The main difference is that for a CMS range accrual swap the observation rate is based on a swap rate, and for a range accrual swap it is based on an index, usually LIBOR.
Pricing a CMS Range Accrual Swap
For more information on pricing a CMS range accrual swap see Pricing a Range Accrual Swap in SDX Interest Rates.