Implementation of the IEEE 802.15.4 module with CFP in NS-2

摘要

The IEEE 802.15.4 standard, widely used in sensor networks, specifies the CAP (Contention Access Period) and the CFP (Contention Free Period). The devices contend for access to transmission media using the CSMA/CA mechanism in the CAP, while, in the CFP, the devices are allocated the GTS (Guaranteed Time Slot) to access media without contention. Therefore, the CFP is useful for the safe and fast delivery of data packets. In spite of such usefulness and need, the CFP is not implemented in widely used NS-2. This paper presents the issues of the modification and extension for the implementation of the CFP module in NS-2. The simulation is used to validate the implemented module.