New Reassembly Buffer Management System in 6LoWPAN Kar Hoey Teo 1,2 *, Azizol Abdullah 1 , Shamala K. Subramaniam 1 , Gopinath Rao Sinniah 2 . 1 Department of Communication Technology and Network, Faculty of Computer Science and Information Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. 2 Wireless Communications Cluster, MIMOS Berhad, Technology Park Malaysia, 57000 Kuala Lumpur, Malaysia. E-Mails: kh.teo@mimos.my, {azizol, shamala}@fsktm.upm.edu.my, gopinath.rao@mimos.my. Abstract: Recently, Internet of Thing (IoT) appears to be a new paradigm for everything to be connected seamlessly to the Internet. One of the standards used to fit the low power devices into IoT is IEEE 802.15.4 wireless sensor network (WSN). To support IPv6 packet transmission over the IEEE 802.15.4 networks, the IPv6 over Low power Wireless Personal Area Network (6LoWPAN) adaptation layer is necessary. The 6LoWPAN adaptation layer divides the packet into a number of fragments before it is transmitted. At the receiver, these fragments will be reassembled to become the original packet. However, the existing reassembly process in the adaptation layer fails to consider the irregular arrival sequence of fragments which can cause the packet that has been reassembled to be corrupted. This serious impediment in reassembly mechanism can cause unacceptable packet lost. In this paper, a new reassembly mechanism namely Multi-Reassemblies Buffer Management System (MR- BMS) is proposed in the context of providing efficient 6LoWPAN packets reassembly. In this proposed mechanism multiple reassembly buffers are created dynamically such that multiple reassembly sessions can be processed simultaneously. Each reassembly session is responsible for a packet reconstruction. The performance of proposed MR-BMS is compared with RFC 4944-based reassembly mechanism and SICSlowPAN implementation. Results show that the proposed mechanism outperforms RFC 4944-based reassembly mechanism and SICSlowPAN implementation with 121.7% and 16.2% higher packet delivery ratio respectively when packet encountered more fragmentation. Moreover, the proposed MR-BMS has a comparable average energy consumption with other mechanisms. Keywords: 6LoWPAN; fragmentation and reassembly; buffer management system. Proceedings of the Asia-Pacific Advanced Network 2013 v. 36, p. 57-64. http://dx.doi.org/10.7125/APAN.36.8 ISSN 2227-3026 57