Efficient, Real-Time Short Address Allocations for USN Devices Using LAA (Last Address Assigned) Algorithm

In this paper, we proposed an efficient way of allocating short addresses in real-time for the USN (ubiquitous sensor network) devices. By the "efficient" we mean that the 16-bit address space is never wasted. The proposed addressing mechanism is based upon the information of the last address assigned (LAA) that is delivered over the beacon every time it is transmitted. In contrast to the ZigBee hierarchical block addressing based on C_skip address blocks, the proposed scheme is not a systematic way of allocating short addresses and thus tree-routing is not available. However, it has great advantages when real applications for U-City services are considered. Moreover, the proposed mechanism can provide mobility of the USN devices, expandability of the wireless network, and fast device discovery.