Enhanced ZigBee tree addressing for flexible network topologies Since, IEEE 802.15.4 complaint devices are resource constrained, traditional heavyweight routing algorithms are not suitable. Although, ZigBee provided an addressing scheme and a table-free Tree routing algorithm for such devices, it has several limitations. In this paper, we have proposed an extended version of ZigBee addressing scheme. The proposed scheme has all the properties of original addressing scheme and hence the same table-free routing algorithm can be applied. In addition, it supports asymmetric tree networks which original scheme cannot cope up with. It does not also use the parameter, maximum network depth (Lm), which is often very difficult to choose before forming the network. Simulation shows that proposed addressing scheme works seamlessly with existing ZigBeetree routing.