Uncoordinated frequency hopping has been considered as an important technique for anti-jamming communications. In uncoordinated frequency hopping systems, nodes randomly switch over multiple frequencies without pre-shared keys. Upon rendezvous on the same frequency, they can communicate with each other. Existing algorithms, however, require role (sender/receiver) pre-assignment before frequency hopping. Such approaches only support the communication between sender-receiver pairs (i.e., the communication between a node pair whose receiver play a sender role is not guaranteed). In this paper, we propose a low computation cost and symmetric-role frequency hopping algorithm (i.e., no role pre-assignment requirement). Our proposed algorithm has bounded maximal time to rendezvous under asynchronous scenarios.