8Yen L, Tsai W. The room shortage problem of tree-based Zig- Bee/IEEE 802.15.4 wireless networks[J]. Computer Communications, 2010, 33(4): 454-462.
9Longkang W, Baisheng N, Ruming Z, et al. Zigbee-based positioning system for coal miners[J]. Procedia Engineering, 2011(26) : 2406-2414.
10Kim W H, Lee S, Hwang J. Real-time energy monitoring and controlling system based on Zigbee sensor networks[J]. Proce- dia Computer Science, 2011(5): 794-797.
