They showed that their algorithm makes readers aware of neighbors low to minimize reader collisions.HiQ [12] utilized Inhibitors,Modulators,Libraries three basic hierarchical tiers in its control structure: readers, R-servers, Inhibitors,Modulators,Libraries and Q-servers. The lowest tier is the RFID readers which they communicate solely when they have been granted a frequency and time slot in communication by a server (R-server) tier. R-servers are allocated frequencies and time slots by the Q-learning servers or Q-servers. Q-learning servers comprise the highest tier in this hierarchical algorithm. Q-servers distribute resources to the servers directly below them in the hierarchy.These two works [11,12] are utilizing the servers which have global knowledge to solve reader collision problem. However, in many cases, using servers to resolve the problem takes Inhibitors,Modulators,Libraries cost and time.

Birari and Lyer [13] suggested a simple Pulse protocol which separates a control channel from Inhibitors,Modulators,Libraries a data channel. A reader, which is communicating with tags, periodically broadcasts beacon messages to an extent greater than its interference range through the control channel. The readers that receive these beacon messages do not prompt for communications with the tags; rather, they wait until they no longer receive beacon messages. In [14], an improved pulse protocol-based reader anti-collision algorithm was proposed for reducing reader collisions via slot occupied probability. They showed that their algorithm improves the reading speed, throughput and system efficiency compared with the conventional anti-collision algorithms.

Another study [15] proposed a cooperative, distributed reader collision avoidance algorithm termed DiCa and insisted that DiCa is suitable for energy-efficient wireless mobile network environments in conjunction with RFID, Carfilzomib as this algorithm is capable of not only avoiding collisions but also changing the power state autonomously through simple interactions between adjacent readers.Recently, a study [16] presented a two phase dynamic modulation (TPDM) technique, which consists of regional scheduling and hidden terminal scheduling phases, aims to efficiently perform communications between readers and tags in high density and mobile RFID networks. They insisted that TPDM is a simple mechanism for coordinating simultaneous transmissions among multiple readers and hidden terminals, and that TPDM can prevent reader collisions by using a distributed self-scheduling scheme.

These algorithms [13�C16] were developed based on the assumption that there are only two channels, a control channel and a data channel. However, assuming a single data channel is no longer realistic as the international selleck chem standards [6,7] suggested multi-channel environments for mobile RFID and, as far as we know, GENTLE is the only work that takes consider multi-channel environments for mobile RFID.