IEEE 802.16 protocols for metropolitanbroadband wireless access systems have been standardizedrecently. According to the standard, a subscriber station candeliver bandwidth request messages to a base station bynumerous methods. This paper provides both the simulation andanalytical models for the investigation of specified random accessmethod, which is compared with centralized polling and stationgroupingmechanisms. Based on the assumptions of Bernoullirequest arrival process and ideal channel conditions, the meandelay of a request transmission is evaluated for varying numberof transmission opportunities and different arrival rates.